C_HOSTS_Che_Cod – Blackman & Eastop's Aphids on the World's Plants

*Cheilanthes*	Adiantaceae
*Cheilanthes albomarginata*	Micromyzodium filicium
*Ch. argentea*	Micromyzus judenkoi
Ch. compositor (?)	Micromyzus judenkoi
*Ch. farinosa*	Macromyzella polypodicola; Micromyzus niger
Ch. varies (?)	Macromyzus manoji, woodwardiae; [Macrosiphum rosae]
Cheilanthes spp.	Amphorophora ampullata ssp. bengalensis;
	Micromyzodium dasi, filicium

Use key to fern-feeding aphids under Polypodium.

Cheilocostus see Costus

Costaceae

Cheiranthus see Erysimum

Brassicaceae

*Cheirolophus*	Asteraceae
*Cheirolophus sempervirens*	Brachycaudus helichrysi; Uroleucon jaceae

(Use key to apterae on Centaurea.)

*Chelidonium*	Papaveraceae
Chelidonium asiaticum	Acyrthosiphon chelidonii; Aulacorthum solani
Ch. majus	Acyrthosiphon chelidonii; Aphis fabae; Aulacorthum solani;
	Macrosiphum euphorbiae; Myzus persicae;
	Rhopalosiphoninus latysiphon
Ch. sinense	Acyrthosiphon chelidonii

Key to apterae on Chelidonium:-

–	Head smooth, pale, with rather low, divergent ANT tubercles. ANT III never with rhinaria. SIPH pale with darker apices, without polygonal reticulation, 1.7-2.3 × cauda which bears 7-14 hairs. R IV+V 0.8-0.9 × HT II, and ANT PT/BASE 2.7-3.3	…..Acyrthosiphon chelidonii
–	Without this combination of characters	…..go to key to polyphagous aphids

*Chelone*	Plantaginaceae
Chelone glabra	Pseudosiphonaphis corni

*Chenopodium*	Amaranthaceae
Chenopodium acuminatum	Aphis craccivora
Ch. album	Abstrusomyzus phloxae; Acyrthosiphon malvae;
(incl. var. centrorubrum)	Aphis asclepiadis, craccivora, fabae, gossypii,
	nasturtii, sambuci, solanella, spiraecola;
	Aulacorthum solani; [Cryptosiphum atriplicivorum];
	[Dysaphis microsiphon];
	Hayhurstia atriplicis, atriplicis ssp. chenopodii;
	Landisaphis davisi;
	Macrosiphum [cholodkovskyi], euphorbiae;
	Myzus antirrhinii, ascalonicus, ornatus, persicae;
	Pemphigus betae, fuscicornis, populivenae;
	Protaphis middletonii; [Rhopalosiphum rufiabdominale];
	Smynthurodes betae
Ch. amaranticolor	Myzus persicae
Ch. ambrosioides	Aphis citricidus, craccivora, fabae, gossypii, spiraecola;
(incl. anthelminticum)	Hayhurstia atriplicis; Macrosiphum euphorbiae;
	Myzus persicae; Pemphigus fuscicornis
Ch. aristatum = Dysphania aristata
Ch. bonus-henricus	Aphis fabae, gossypii; Hayhurstia atriplicis;
	Macrosiphum euphorbiae; Myzus persicae
Ch. botrys	Aphis fabae; Myzus persicae
Ch. capitatum = Blitum capitatum
Ch. ficifolium	Hayhurstia atriplicis
Ch. foliosum	Aphis fabae, gossypii; Myzus persicae
Ch. fremontii	Pemphigus betae
Ch. gigantum	Myzus persicae
Ch. glaucum	Aphis fabae, solanella; Hayhurstia atriplicis
Ch. hybridum	Aphis craccivora, fabae;
	Hayhurstia atriplicis, atriplicis ssp. chenopodii;
	Myzus persicae
Ch. murale	Aphis craccivora, fabae; [Brevicoryne brassicae];
	Aulacorthum solani; Hayhurstia atriplicis;
	Macrosiphum [creelii], euphorbiae; Myzus persicae
Ch. opulifolium	Aphis fabae, gossypii; Hayhurstia atriplicis;
	Macrosiphum euphorbiae; Myzus persicae;
	Smynthurodes betae
Ch. polyspermum	Aphis fabae, nasturtii, sambuci; Hayhurstia atriplicis;
	Macrosiphum euphorbiae
Ch. pumilio	Aphis fabae
Ch. quinoa	Aphis craccivora, fabae, nasturtii; Aulacorthum solani;
	Hayhurstia atriplicis; Macrosiphum euphorbiae;
	Smynthurodes betae
Ch. rafaelense	Aphis craccivora, fabae
Ch. rubrum	Aphis fabae; Hayhurstia atriplicis; Macrosiphum euphorbiae
Ch. sooanum	Brachyunguis bahamondesi
Ch. suecicum	Hayhurstia atriplicis; Brachyunguis bahamondesi
Ch. urbicum	Aphis fabae; Hayhurstia atriplicis
Ch. virgatum	Aphis fabae
Ch. viride	Hayhurstia atriplicis; Myzus persicae
Ch. vulvaria	Hayhurstia atriplicis; Pemphigus fuscicornis
Chenopodium spp.	Aphis sp. (Eritrea, BMNH collection);
	Brachycaudus helichrysi; Brachyunguis tetrapteralis;
	[Hyalomyzus raoi]; Neomyzus circumflexus;
	Rhopalosiphoninus staphyleae ssp. tulipaellus;
	[Semiaphis dauci]; [Thecabius affinis]
† Records of	Lipaphis and Hyalopterus, and of Hyadaphis coriandri, on Ch. album in India and Africa respectively, are assumed to be all referable to Hayhurstia atriplicis.)

Key to apterae on Chenopodium:-

1	SIPH as short as or shorter than (0.55-1.04 ×) cauda, which bears 5-8 hairs	…..2
–	SIPH (if present) either longer than cauda or, if shorter, then cauda bears more than 10 hairs	…..5

2	ANT PT/BASE 0.50-0.73. SIPH pale	…..Brachyunguis tetrapteralis
–	ANT PT/BASE 0.97-2.50. SIPH pale or dark	…..3
3	ANT PT/BASE 1.4-2.5. SIPH slightly swollen on distal half, and 0.6-0.8 × cauda (plate 14b). Clypeus not abnormally swollen	…..Hayhurstia atriplicis
–	ANT PT/BASE 0.97-1.36. SIPH tapering or cylindrical, 0.7-1.04 × cauda. Clypeus swollen	…..4
4	R IV+V 0.8-0.9 × HT II. Cauda finger-shaped, with a slight midway constriction. Clypeus greatly swollen, filling space between antennal bases	…..Brachyunguis blanchardi
–	R IV+V 1.1-1.25 × HT II. Cauda triangular, tapering without a constriction. Clypeus not so swollen, occupying about 0.75-0.8 of space between antennal bases	…..Brachyunguis bahamondesi
5	Dorsal abdominal hairs spatulate and/or flabellate (expanded and flattened from bases). SIPH pale or dusky and distinctly clavate	…..Landisaphis davisi
–	Dorsal abdominal hairs pointed, blunt or slightly expanded at apices. SIPH clavate, cylindrical, tapering or absent	…..6
6	SIPH thick, black, tapering, only 2.6-3.1 × their diameter at midlength and c.1.5 × the black cauda which bears 6-7 hairs. ANT PT/BASE 1.95-2.35. R IV+V 1.05-1.25 × HT II	….. Aphis sp. (Eritrea, BMNH collection)
–	Without that combination of characters	…..7
7	SIPH black, tapering/cylindrical and 2.1-3.5 × cauda which bears 10-20 hairs. ABD TERG 2-4 consistently with well-developed flat marginal tubercles (MTu)	…..Aphis sambuci
–	Without that combination of characters	….go to key to polyphagous aphids

*Chiliadenus*	Asteraceae
*Chiliadenus bocconei*	Capitophorus sp. near similis

*Chilopsis*	Bignoniaceae
*Chilopsis linearis*	Aphis chilopsidi
Ch. saligna = Ch. linearis

*Chiliotrichum*	Asteraceae
Chiliotrichum diffusum	Brachycaudus helichrysi; Uroleucon chiliotrichi

*Chimonanthus*	Calycanthaceae
*Chimonanthus fragrans* = Ch. praecox
Ch. praecox	Macrosiphum euphorbiae

*Chimonobambusa*	Poaceae
*Chimonobambusa jaunsarensis* = Yushania anceps
*Ch. quadrangularis*	Cerataphis bambusifoliae; Takecallis taiwanus

Or use key to bamboo-feeding aphids under Bambusa.

*Chiococca*	Rubiaceae
*Chiococca alba*	Aphis aurantii, spiraecola

Use key to polyphagous aphids.

*Chionachne*	Poaceae
*Chionachne semiteres*	Tetraneura fusiformis

Use key to apterae of grass-feeding aphids under Digitaria.

*Chionochloa*	Poaceae
Chionochloa conspicua	Sitobion miscanthi

Use key to apterae of grass-feeding aphids under Digitaria.

*Chionodoxa*	Asparagaceae
*Chionodoxa* sp.	Dysaphis tulipae

*Chloraea*	Orchidaceae
*Chloraea crispa*	Sitobion indicum
*Ch. grandiflora*	Aphis ?solanella (Chile, BMNH collection)
Ch. gravilu	Sitobion indicum

Use key to aphids on orchids under Cymbidium.

*Chloris*	Poaceae
*Chloris barbata*	Ceratovacuna perglandulosa; Hysteroneura setariae;
	Sitobion graminis, lambersi, miscanthi
Ch. gayana	Hysteroneura setariae; Rhopalosiphum maidis;
	Schizaphis hypersiphonata; Sitobion graminis;
	Tetraneura fusiformis
Ch. inflata = C. barbata
Ch. petraea =Eustachys petraea
Ch. pilosa	Aphis gossypii; Hysteroneura setariae
Ch. pycnothrix	Sitobion lambersi
Ch. radiata	Hysteroneura setariae
Ch. truncata	Rhopalosiphum maidis
Ch. verticillata	Schizaphis graminum
Ch. virgata	Ceratovacuna nekoashi; Hysteroneura setariae;
	Paracletus cimiciformis; Rhopalosiphum maidis
Chloris spp.	Geoica lucifuga; Sipha flava;
	Tetraneura nigriabdominalis

Use key to apterae of grass-feeding aphids under Digitaria.

Chlorocodon see Mondia

Apocynaceae

*Chlorophytum*	Asparagaceae
Chlorophytum blepharophyllum Aphis craccivora
Ch. comosum	Aphis craccivora, fabae; Myzus ascalonicus, persicae;
	Neomyzus circumflexus
Chlorophytum spp.	Aulacorthum solani

Use key to polyphagous aphids.

*Choisya*	Rutaceae
*Choisya ternata*	Aphis (Toxoptera) aurantii
*Choisya* sp.	Aphis (Toxoptera) citricidus

*Chondrilla*	Asteraceae
Chondrila acantholepis	Chondrillobium blattnyi
Ch. brevirostris	Brachyunguis [tausaghyz], transaralensis
Ch. canescens	Chondrillobium blattnyi; Uroleucon chondrillae
Ch. chondrilloides	Uroleucon chondrillae
Ch. japonica	= Youngia japonica
Ch. juncea	Aphis craccivora, fabae, gossypii;
	Chondrillobium blattnyi;
	Hyperomyzus lactucae; Myzus persicae;
	Rectinasus buxtoni; Uroleucon chondrillae, sonchi
Ch. laticoronata	Uroleucon chondrillae
Ch. latifolia	Uroleucon chondrillae
Ch. pauciflora	Uroleucon chondrillae
Chondrilla spp.	Aulacorthum solani
	Chomaphis chondrillae Mordvilko 1932 – nomen nudum];
	Protaphis chondrillae; Titanosiphon chondrillae

Key to apterae on Chondrilla:-

1	ANT 5-segmented, with ANT V BASE very long and PT very short, peg-like. R IV+V extremely long, similar in length to hind femur, and bearing numerous hairs. Body and appendages densely clothed in fine hairs. SIPH absent	…..Rectinasus buxtoni
–	ANT 6-segmented, with PT not peg-like. R IV+V much shorter and less hairy. Body and appendages not densely hairy. SIPH evident, tubular	…..2
2	ANT PT/BASE 0.55-0.80. SIPH very short and thick, less than 0.7 × cauda	…..3
–	ANT PT/BASE more than 1. SIPH if very short then thin, otherwise more than 0.7 × cauda	…..4

3	SIPH dark. Cauda with 17-20 hairs	…..Protaphis chondrillae*
–	SIPH pale. Cauda with 6-10 hairs	…..Brachyunguis transaralensis*
4	SIPH pale, thin and very short, only 0.4-0.5 × cauda. R IV+V only about as long as basal width	…..Chondrillobium blattnyi
–	SIPH pale or dark, more than 0.7 × cauda. R IV+V clearly longer than its basal width	…..5
5	SIPH dark, with polygonal reticulation on distal 0.16-0.28 of length. Cauda long, pale, finger-like	…..6
–	SIPH pale or dark, if dark then without polygonal reticulation, and cauda also dark	…..7
6	ANT III with 40-74 rhinaria. Crescent-shaped antesiphuncular sclerites usually present. Cauda with 11-21 hairs	…..Uroleucon chondrillae
–	ANT III with 9-35 rhinaria. Antesiphuncular sclerites vestigeal or absent. Cauda with 23-30 hairs	…..Uroleucon sonchi
7	SIPH very long, 3.1-3.5 × cauda and 0.4-0.5 × BL	…..Titanosiphon chondrillae
–	SIPH much shorter	…..8
8	SIPH markedly swollen (clavate). ANT tubercles smooth and rounded. ANT III with 5-29 secondary rhinaria	…..Hyperomyzus lactucae
–	SIPH tapering/cylindrical or slightly clavate. ANT tubercles if well-developed then scabrous or spiculose, with inner faces apically convergent or almost parallel. ANT III with 0-3 rhinaria	…..go to key to polyphagous aphids

Chorisia see Ceiba

*Chorispora*	Brassicaceae
*Chorispora sibirica*	Lipaphis erysimi
C. *tenella*	Brevicoryne brassicae

Use key to apterae on Brassica.

Chosenia see Salix

Salicaceae

*Christella*	Thelypteridaceae
*Christella dentata*	Idiopterus nephrelepidis; Macromyzella polypodicola;
	Macromyzus maculatus, woodwardiae

Use key to fern-feeding aphids under Polypodium.

*Chromolaena*	Asteraceae
*Chromolaena heteroclinia*	Aphis gossypii
Ch. laevigata	Aphis fabae
*Ch. odorata*	Aphis aurantii, [citricidus], craccivora, eugeniae, fabae,
	gossypii, nasturtii, spiraecola;
	Brachycaudus helichrysi; [Macrosiphoniella kikungshana];
	Micromyzodium levipes;
	Myzus ornatus, persicae, siegesbeckicola;
	Neomyzus circumflexus; [Pentalonia nigronervosa];
	Uroleucon ambrosiae

Use key to apterae on Eupatorium.

*Chrysalidocarpus* see Dypsis	Arecaceae
*Ch. lutescens* = Dypsis lutescens
Ch. madagascariensis = Dypsis madagascariensis

*Chrysanthellum*	Asteraceae
*Chrysantellum americanum*	Aphis gossypii
(incl. procumbens)

*Chrysanthemoides*	Asteraceae
*Chrysanthemoides monilifera*	Aphis gossypii; Aulacorthum solani; Myzus persicae

Use key to polyphagous aphids.

Chrysanthemum

Asteraceae

[Note: many species formerly placed in Chrysanthemum are now assigned to other genera, e.g. Argyranthemum, Coleostephus, Dendranthema, Leucanthemopsis, Tanacetum. “Florist’s chrysanthemum” was however restored to the genus Chrysanthemum in 1999.]

*Chrysanthemum anethifolium* Wlld. (L. Buch) = Argyranthemum foeniculum
Ch. annuum = Tanacetum annuum
Ch. arcticum = Arctanthemum arcticum
Ch. argenteum = Tanacetum argenteum
Ch. balsamita = Tanacetum balsamita
Ch. boreale Makino	Aphis fabae;
	Macrosiphoniella abrotani ssp. chosoni, antennata,
	atra ssp. latysiphon, [borealis], [tanacetaria ssp. divia],
	[yomenae];
	Uroleucon [cephalonopli], simile
Ch.× *burbankii*	Pseudomegoura magnoliae
Ch. carinatum = Ismelia carinata
Ch. caucasicum = Matricaria breviradiata
Ch. cinerariifolium = Tanacetum cinerariifolium
Ch. coccineum = Tanacetum coccineum
Ch. coronarium (incl.	Aphis fabae, gossypii, spiraecola; Aulacorthum solani;
concolor, spatiosum)	Brachycaudus cardui, helichrysi, lateralis;
	Coloradoa rufomaculata; [Lipaphis pseudobrassicae];
	Macrosiphoniella pseudoartemisiae, sanborni, taspukae,
	yomogifoliae;
	Macrosiphum euphorbiae; Myzus persicae;
	Uroleucon gobonis, [nigrotuberculatum]
*Ch. corymbosum* = Tanacetum corymbosum
Ch. flaveolum = Leucanthemopsis flaveola
Ch. frutescens = Argyranthemum frutescens
Ch. fruticulosum = Brachanthemum fruticulosum
Ch. hortorum = Ch. morifolium
Ch. indicum (incl. morifolium)	Acyrthosiphon malvae:
	Aphis craccivora, fabae, gossypii, nastutii, parvus,
“Florists’ chrysanthemum”	spiraecola;
	Aulacorthum solani;
	Brachycaudus cardui, helichrysi, lateralis;
	Capitophorus formosartemisiae;
	[Chaitophorus chrysanthemi];
	Coloradoa rufomaculata, tanacetina;
	Macrosiphoniella oblonga, sanborni, [subterranea],
	tanacetaria, [yomenae], yomogicola;
	Macrosiphum centranthi, euphorbiae;
	Myzus ascalonicus, ornatus, persicae;
	Neomyzus circumflexus;
	Pleotrichophorus chrysanthemi, [glandulosus];
	[Sitobion miscanthi (as Uroleucon yiliense)];
	Rhopalosiphoninus latysiphon;
	Smynthurodes betae; Tuberocephalus misakurae;
	Uroleucon ambrosiae group, [giganteum], tanaceti
Ch. japonense = Dendranthema occidentali-japonense
Ch. lacustre = Leucanthemum lacustre
Ch. lavandulifolium = Dendranthema lavandulifolium
Ch. leucanthemum = Leucanthemum vulgare
Ch. lineare	Uroleucon erigeronense
Ch. maximum (DC.) Ramond = Leucanthemum maximum
Ch. morifolium see indicum
Ch. multifidum	Brachycaudus helichrysi;
	Macrosiphoniella tanacetaria, tapuskae;
	Uroleucon tanaceti
*Ch. myconis* = Coleostephus myconis
Ch. nipponicum = Nipponanthemum nipponicum
Ch. nivellei = Nivellea nivellei
Ch. ornatum = Dendranthema ornatum
Ch. pallens = Leucanthemum pallens
Ch. parthenifolium = Pyrethrum parthenifolium
Ch. parthenium = Tanacetum parthenium
Ch. procumbens	Aphis gossypii
Ch. roseum = Tanacetum coccineum (Note: Persian insect powder = Pyrethrum roseum)
*Ch. rotundifolum* = Leucanthemum rotundifolium
Ch. × rubellum	Brachycaudus helichrysi
Ch. segetum	Aphis fabae, nasturtii;
	Brachycaudus helichrysi, lateralis;
	Macrosiphoniella [millefolii], sanborni;
	Macrosiphum euphorbiae; Myzus ornatus, persicae;
	Protaphis terricola; Uroleucon sonchi
Ch. shahrudense = Tanacetum canescens
Ch. sinense = Ch. morifolium
Ch. sylvaticum = Leucanthemum sylvaticum
Ch. uliginosum = Leucanthemella serotina
Ch. vulgare = Tanacetum vulgare
Ch. yezoense = Dendranthema zawadskii
Ch. zawadskii = Dendranthema zawadskii
*“Chrysanthemum” spp.*	Aphis craccivora, [kurosawai], [malvae], [solitaria];
	Aulacorthum solani; Brachycaudus cardui, lateralis;
	[Capitophorus formosanus (= Pleotrichophorus
	chrysanthemi?)];
	Coloradoa tanacetina;
	Macrosiphoniella absinthii, [kikungshana],
	oblonga, tanacetaria, yomogifoliae;
	Macrosiphum centranthi, pachysiphon, rosae;
	[Metopeurum capillatum]; Myzus ascalonicus, ornatus;
	Neomyzus circumflexus; Pleotrichophorus chrysanthemi;
	Sinomegoura citricola;
	[Tetraneura basui, nigriabdominalis];
	Uroleucon compositae, formosanum ssp. crepidis,
	pseudotanaceti, [rudbeckiae], tanaceti

Key to apterae on Chrysanthemum and Dendranthema:-

(For an illustrated key to the aphids most commonly found on florist’s chrysanthemums see Blackman & Eastop, 2000)

1	ANT PT/BASE much less than 1. Body and appendages very hairy	…..2
–	ANT PT/BASE much more than 1. Body and appendages not usually very hairy	…..3
2	HT II very elongate, more than 0.5 × length of hind tibia. SIPH present as pores on pigmented shallow cones	…..Protrama flavescens
–	HT of normal length, much less than 0.5 × hind tibia. SIPH absent	…..Smynthurodes betae
3	Cauda very short, helmet-shaped, not longer than its basal width in dorsal view. Spiracular apertures large and rounded	…..4
–	Cauda tongue- or finger-shaped, longer than its basal width. Spiracular apertures reniform	…..6
4	Dorsum without dark markings. Mesosternum without mammariform processes. R IV+V 1.2-1.3 × HT II. SIPH pale, smooth, 0.8-2.0 × cauda	…..Brachycaudus helichrysi
–	Dorsum with an extensive black shield. Mesosternum with a pair of dark mammariform processes. R IV+V 1.4-2.0 × HT II. SIPH dark, imbricated, 1.7-3.4 × cauda	…..5
5	Hairs on ABD TERG 8 are 30-61 µm long. Longest hairs on hind femur 10-25µm long	…..Brachycaudus lateralis

–	Hairs on ABD TERG 8 are at least 70µm long. Longest hairs on hind femur more than 25µm long	…..Brachycaudus cardui
6	SIPH with a distal zone of polygonal reticulation, occupying 0.08-0.8 of length. SIPH tapering/cylindrical	…..7
–	SIPH without any polygonal reticulation, or if with then SIPH markedly swollen	…..24
7	SIPH with at least basal part pale, although often darker distally	…..8
–	SIPH wholly dark, or dark at base as well as apex	…..12
8	SIPH 1.0-1.3 × cauda, with polygonal reticulation on distal 0.45-0.6 of length	…..Macrosiphoniella oblonga
–	SIPH more than 1.5 × cauda, with polygonal reticulation on distal 0.12-0.25 of length	…..9
9	SIPH mainly dark, pale only on basal third, with polygonal reticulation over distal 0.3-0.4 of length. Cauda tapering almost to a point	…..Uroleucon erigeronense
–	SIPH mainly pale, only dark towards apices, with reticulation of distal 0.12-0.25 of length. Cauda finger-like, almost parallel-sided for part of length	…..10
10	SIPH flared at apex and completely lacking any flange, the zone of polygonal reticulation ending abruptly at apex (Fig.5i). Dorsal hairs long (those on ABD TERG 3 more than 50 μm long). ANT III with 6-26 rhinaria	…..Macrosiphoniella tapuskae
–	SIPH with zone of polygonal reticulation ending in some transversely elongate cells and a small but distinct flange. Dorsal body hairs shorter (those on ABD TERG 3 not more than 50 μm long). ANT III with 1-10 rhinaria	…..11
11	Apices of femora and SIPH dark. ANT 1.3-1.6 × BL. Longest hairs on ABD TERG 3 are 33-50 mm long. Cauda with 11-19 hairs	…..Macrosiphum centranthi
–	Apices of femora and SIPH pale/dusky. ANT 0.9-1.4 × BL. Longest hairs on ABD TERG 3 are 20-37 mm long. Cauda with 8-12 hairs	…..Macrosiphum euphorbiae
12	SIPH 1.7-3.2 × longer than the short, pale cauda, which bears 5-10 hairs	…..13
–	SIPH 0.6-2.3 × cauda, but if more than 1.7 × then cauda is long and finger-like and bears more than 10 hairs	…..14
13	SIPH with polygonal reticulation on distal 0.17-0.25 of length, and usually with a paler middle section. R IV+V 1.0-1.2 × HT II	…..Uroleucon tanaceti
–	SIPH wholly dark, with polygonal reticulation on distal 0.25-0.38 of length. R IV+V 1.2-1.4 × HT II	…..Uroleucon pseudotanaceti
14	SIPH 0.6-1.2 × cauda, which is dark. First tarsal segments with 3 hairs	…..15
–	SIPH 1.1-2.3 × cauda, but if less than 1.2 × then cauda is pale. First tarsal segments with 5 hairs	…..21
15	ANT III with 29-55 rhinaria. R IV+V 1.0-1.2 × HT II	…..Macrosiphoniella absinthii
–	ANT III with 4-32 rhinaria, but if with more than 25 then R IV+V is 0.7-0.9 × HT II	…..16
16	SIPH 0.95-1.2 × cauda, with reticulation on distal 0.26-0.4 of length	…..Macrosiphoniella subterranea
–	SIPH 0.6-0.95 × cauda, with reticulation on distal 0.4-0.8 of length	…..17
17	ANT III with secondary rhinaria usually distributed over almost its entire length. SIPH with reticulation on distal 0.6-0.8 of length	…..Macrosiphoniella sanborni
–	ANT III with secondary rhinaria restricted to basal 0.6 or less. SIPH with reticulation over distal 0.4-0.7 of length	…..18
18	ANT III mainly pale, with 2-9 rhinaria. Tibiae with an extensive paler middle sections. Cauda with 10-14 hairs	…..Macrosiphoniella pseudoartemisiae
–	ANT III mainly or wholly dark, with 1-32 rhinaria. Tibiae wholly dark. Cauda with 16-44 hairs	…..19
19	Dorsal body hairs long, fine and numerous, not in rows, the spinal and pleural hairs usually placed on dark tranverse sclerotic cross-bands (sometimes these are reduced). Hairs on ANT III long and fine	…..Macrosiphoniella yomogicola
–	Dorsal body hairs much fewer and arranged in single somewhat irregular rows across each tergite. Abdomen without dark dorsal cross-bands. hairs on ANT III not long and fine	…..20
20	R IV+V 0.7-0.9 × HT II. ANT PT/BASE 2.9-3.5. SIPH with polygonal reticulation extending over distal 0.4-0.55	..…Macrosiphoniella tanacetaria
–	R IV+V 1.0-1.4 × HT II. ANT PT/BASE 2.3-2.9. SIPH with polygonal reticulation extending over distal 0.48-0.7	….. Macrosiphoniella yomogifoliae
21	Cauda dark, like SIPH	…..Uroleucon compositae (or gobonis)
–	Cauda pale, or much paler than SIPH	…..22
22	ANT III very long, 1.5-2.1 × ANT IV+V together, and bearing very numerous (96-135) strongly protruberant rhinaria distributed over its entire length	…..Uroleucon formosanum
–	ANT III shorter than or about equal in length to ANT IV+V together, and with 8-38 rhinaria extending over 0.35-0.65 of length	…..23
23	Coxae black. SIPH 1.4-1.9 × cauda. Dorsal hairs mostly without dark basal sclerites	…..Uroleucon sonchi
–	Coxae pale. SIPH 1.1-1.5 × cauda. Many of dorsal hairs arising from dark scleroites	…..Uroleucon ambrosiae
24	Dorsal hairs long, with knobbed or funnel-shaped apices	…..Pleotrichophorus chrysanthemi
–	Dorsal hairs short and blunt, or club- or fan-shaped, or if long then pointed	…..25
25	Triommatidium merged with compound eye, so that there is no distinct ocular tubercle. Dorsal hairs small, fan- or club-shaped, or at least with somewhat expanded apices. Front of head weakly convex in dorsal view, ANT tubercles undeveloped. ANT PT/BASE 1.4-2.0. SIPH cylindrical for most of length, slightly swollen subapically. R IV+V with slightly concave sides. Cauda less than 1.5 × its basal width, with 4-5 hairs	…..26
–	Triommatidum forming a distinct ocular tubercle at posterior margin of eye, dorsal hairs with blunt or pointed apices, and other characters not in above combination	…..27
26	Dorsal hairs fan-shaped (Fig.52c). RIV+V more than 1.1 × HT II. SIPH 0.17-0.2 × BL, with basal part almost smooth (Fig.12o)	…..Coloradoa rufomaculata
–	Dorsal hairs very small and weakly club-shaped, or with only slightly expanded apices (Fig.52d). R IV+V less than 1.1 × HT II. SIPH 0.13-0.18 × BL, with basal part coarsely imbricated like distal part (Fig.52e)	…..Coloradoa tanacetina
27	ANT 5- or 6-segmented, with penultimate segment less than 1.2 × length of base of last segment. SIPH short and tapering, scabrous or coarsely imbricated, ending in a large flange. Head spiculose	…..Tuberocephalus misakurae
–	ANT 6-segmented, rarely 5-segmented, with penultimate segment more than 1.2 × length of base of last segment. SIPH various, and head smooth or spiculose	…..go to key to polyphagous aphids

Chrysobactron see Bulbinella

Xanthorrhoeaceae

*Chrysobalanus*	Chrysobalanaceae
*Chrysobalanus oblongifolius* = Licania michauxii

Chrysobotrya see Ribes

Grossulariaceae

*Chrysophyllum*	Sapotaceae
*Chrysophyllum oliviforme*	Aphis (Toxoptera) aurantii

*Chrysopogon* (including Pollinia)	Poaceae
*Chrysopogon aciculatus*	Hysteroneura setariae; Tetraneura fusiformis
Ch. arnottianus = Ch. nodulibarbis
Ch. aucheri	Sitobion graminis
Ch. elongatus	Diuraphis noxia
Ch. gryllus	Sipha elegans, maydis; Sitobion avenae
Ch. nodulibarbis	Sitobion fragariae, graminis, miscanthi
Ch. serrulatus	Asiphonella dactylonii
Ch. zeylanicus = Ch. nodulibarbis
*Ch. zizanioides*	Hysteroneura setariae
Chrysopogon sp.	Kaochiaoja arthraxonis (? – as Macrosiphum pollinae
	Shinji)

Use key to apterae of grass-feeding aphids under Digitaria.

*Chrysopsis*	Asteraceae
*Chrysopsis graminifolia*	Uroleucon chrysopsidicola
Ch. mariana	Uroleucon chrysopsidicola
Ch. villosa = Heterotheca villosa

*Chrysosplenium*	Saxifragaceae
*Chrysosplenium flagelliferum*	Taiwanomyzus chrysosplenii
Ch. oppositifolium	[Jacksonia papillata]

*Chrysothamnus*	Asteraceae
*Chrysothamnus frigidus* = Ericameria nauseosa
Ch. graveolens = Ericameria nauseosa var. graveolens
Ch. greenei	Pleotrichophorus oestlundii
Ch. lanceolatus = Ch. viscidiflorens ssp. lanceolatus
Ch. nauseosus = Ericameria nauseosa
Ch. parryi	Aphis gregalis, infrequens, zonassa; [Forda marginata];
	Pleotrichophorus elongatus, oestlundi, palmerae, packi,
	xerozoous
Ch. plattensis = Ericameria nauseosa
Ch. viscidiflorus	Aphis chrysothamni, gregalis; Durocapillata utahensis;
(incl. sssp. lanceolatus)	[Macrosiphoniella glabra];
	Pleotrichophorus elongatus, gregarius, magnautensus,
	oestlundi, palmerae, pycnorhysus, stroudi, utensis;
	Uroleucon erigeronense, [zerogutierrezis]
Chrysothamnus spp.	[Artemisaphis artemisicola]; [Aspidaphis adjuvans]
	Protaphis middletonii

Key to apterae on Chrysothamnus and Ericameria (also Gutierreza):-

1	Many or all dorsal hairs expanded from base, fan- or funnel-shaped, or with fan- or funnel-shaped apices, or (in one species) minute with club-shaped apices. SIPH thin, at midlength less than half thickness of cauda, without any polygonal reticulation	…..2
–	Dorsal hairs never fan-or funnel-shaped; tapering from base, with pointed, blunt or capitate apices. SIPH either thicker or with subapical polygonal reticulation	…..13
2	R IV+V short and blunt, with the pair of accessory hairs on basal half shorter than or similar in length to the longest pair of primary (subapical) hairs (e.g. Fig.21a)	…..3
–	R IV+V acutely pointed or with extended, tubular apex, with the pair of accessory hairs on the basal half usually longer than the longest subapical pair (Fig.21b)	.….6
3	SIPH distinctly clavate, with maximum diameter of distal half about 1.4 × minimum diameter on basal half	…..Pleotrichophorus lagacei
–	SIPH not distinctly clavate, if at all swollen on distal half then maximum diameter no more than 1.25 × minimum diameter on basal half	…..4
4	SIPH 1.80-3.13 × cauda, and mainly pale, only darker distally	…..Pleotrichophorus pycnorhysus
–	SIPH 0.78-1.63 × cauda, and mainly dark	…..5
5	Dorsal body hairs minute (less than 10 μm long), club-shaped (Fig.21c). Ventral side of ANT I with 15 or more hairs. SIPH 0.78-1.03 × cauda	…..Pleotrichophorus magnautensus
–	Dorsal body hairs larger, fan-or funnel-shaped (Fig.21d). Ventral side of ANT I with less then 10 hairs. SIPH 1.06-1.63 × cauda	…..Pleotrichophorus utensis
6	Dorsal abdomen with cuticle raised into paired longitudinal rows of spinal (and often also smaller, pleural) tubercles, largest on ABD TERG 5-7, bearing groups of spinal and pleural fan- and funnel-shaped hairs (e.g. Fig.21e)	…..7
–	Dorsal abdomen without tubercles	…..8
7	R IV+V 0.6-0.7 × HT II. SIPH mainly pale, only dark at apices. Cauda usually with 3 pairs of lateral hairs, plus 0-3 dorsal hairs	…..Pleotrichophorus xerozoous
–	R IV+V 0.7-1.0 × HT II. SIPH dark at least on distal half of length. Cauda usually with 4 pairs of lateral hairs plus 0-6 dorsal ones	…..Pleotrichophorus gregarius
8	SIPH long and thin, 0.22-0.39 × BL	…..9
–	SIPH 0.11-0.21 × BL	…..12
9	SIPH pale, sometimes dusky towards apices. Cauda with 5-6 hairs (only 2 lateral pairs). Dorsal cephalic hairs all short and fan- or funnel-shaped (Fig.21f)	…..Pleotrchophorus elongatus
–	SIPH dark over at least distal half of length. Cauda with 5-21 hairs (usually 3-5 lateral pairs). Dorsal cephalic hairs varying in form; all fan- or funnel-shaped, or with some longer hairs with flattened, blunt or pointed apices	…..10
10	All dorsal cephalic hairs expanded from base; fan- or funnel-shaped, or with flattened, fan- or funnel-shaped apices. Accessory hairs on R IV+V not or hardly longer than longest subapical hairs	…..Pleotrichophorus stroudi*
–	Frontal dorsal cephalic hairs long, with blunt, slightly expanded or pointed apices (e.g. Fig.21g). Accessory hairs on R IV+V distinctly longer than longest of subapical hairs	…..11
11	SIPH 0.32-0.39 × BL and 2.04-3.02 × cauda; dark except for pale basal 0.15-0.2 of length. Cauda tapering, with 5-13 hairs (usually 3-5 lateral pairs). Posterior dorsal cephalic hairs expanded from base, with spatulate apices (Fig.21g)	…..Pleotrichophorus packi
–	SIPH 0.27-0.33 × BL and 1.58-2.11 × cauda, with pale basal part 0.35-0.6 of length. Posterior dorsal cephalic hairs variable, sometimes with flattened or spatulate apices, or with blunt or pointed apices, but not expanded from base. Cauda rather thick, with 10-21 hairs (usually 5-8 lateral pairs)	…..Pleotrichophorus sporadicus complex (sporadicus, neosporadicus, packi ssp. brevis)
12.	Dorsal cuticle rather sclerotic with blunt spicules irregularly distributed among the fan-shaped hairs (Fig.21h). Cauda with 3 pairs of lateral hairs and 4-10 dorsal hairs that are usually spatulate or have funnel-shaped apices	…..Pleotrichophorus oestlundi
–	Dorsal cuticle without any generally distributed large spicules. Cauda with 2 pairs of lateral hairs and a single dorsal hair which has a blunt or pointed apex	…..Pleotrichophorus wasatchii
13	SIPH with subapical polygonal reticulation. ANT tubercles well developed, their inner faces smooth and divergent. Cauda long and finger-like	…..14
–	SIPH without any polygonal reticulation. ANT tubercles absent or weakly developed. Cauda short, triangular or helmet-shaped	…..17
14	SIPH wholly dark, 1.0-1.5 × cauda, which bears 12-27 hairs	…..Uroleucon ambrosiae group (incl. U. aaroni)
–	SIPH paler at base, 1.7-2.5 × cauda, which bears 5-11 hairs	…..15
15	ANT IV of alata with 9-12 secondary rhinaria, and ANT IV of aptera sometimes with 1-3 secondary rhinaria	….. Uroleucon zerogutierrezis
–	ANT IV of alata usually without rhinaria, rarely with 1-4, and ANT IV of aptera always without rhinaria	…..16
16	R IV+V 1.2-1.3 × HT II. Caudal hairs all long and strong	…..Uroleucon riojanum
–	R IV+V 0.9-1.1 × HT II. Distal caudal hairs usually short and blunt or capitate	…..Uroleucon erigeronense
17	Most hairs on dorsum and ANT III with distinctly capitate apices. SIPH thick and tapering, almost smooth, with a very marked subapical incision and a large flange (Fig.21i)	…..Durocapillata utahensis
–	Hairs on dorsum and ANT III blunt or pointed. SIPH imbricated, without a subapical incision and with a moderately developed flange	…..18
18	R IV+V stiletto-shaped, with R V extended as a needle-like tip, and R IV with a pair of very finely pointed accessory hairs, as long as or longer than the subapical (primary) hairs (Fig.21j, k)	…..19
–	R IV+V varying in shape but R V is not extended as a needle-like tip, and the accessory hairs are usually shorter than the longest of the subapical pairs	…..21
19	R IV+V (Fig.21j) 0.11-0.18 mm long, 1.1-1.4 × HT II. Dorsal abdomen usually with a dark central sclerite of irregular shape on tergites 1-3 or 1-4	…..Aphis chrysothamni
–	R IV+V 0.21-0.29 mm long, 1.75-2.4 × HT II. Dorsal abdomen without dark markings anterior to SIPH, or with small sclerites not fused between tergites	…..20
20	R IV+V (Fig.21k) 0.21-0.24 mm long, 1.75-2.0 × HT II. ANT III without secondary rhinaria	…..Aphis chrysothamnicola
–	R IV+V 0.24-0.29 mm long, 2.0-2.4 × HT II. ANT III with 0-4 secondary rhinaria	…..Aphis infrequens
21	SIPH 1.6-1.8 × cauda and 1.7-1.9 × R IV+V. Secondary rhinaria distributed ANT III 0-1, IV 4-8, V 0-1	…..Aphis zonassa*
–	SIPH 0.7-1.5 × cauda and 0.6-1.3 × R IV+V. Secondary rhinaria distributed ANT III 0-10, IV 0-3, V 0-2	…..22
22	Cauda rounded at apex, with 10-16 hairs. Hairs on ANT III short, recumbent, with rather blunt apices, the longest of them 0.5-0.8 × BD III	…..Protaphis middletonii group (incl. crypta, gutierrezis)

–	Cauda triangular, bluntly pointed at apex, with 8-12 hairs (e.g. Fig.21l). Longest hairs on ANT III are 1-3 × BD III, with fine-pointed apices	…..23
23	ANT PT/BASE 1.3-2.0	…..Aphis ornata
–	ANT PT/BASE 1.1-1.5	…..Aphis gregalis

*Chusquea*	Poaceae
*Chusquea abietifolia*	Hysteroneura setariae
Ch. tomentosa	Rhopalosiphum chusqueae
Ch. valdiviensis	Rhopalosiphum padi
*Chusquea* sp(p).	Aphis craccivora; Aploneura lentisci; Melanaphis donacis

–	SIPH and cauda both dark, SIPH being distinctly swollen on distal half, and cauda finger-like with a midway constriction and bearing 5 hairs. ANT 6-segmented, with longest hairs on ANT III 55-65 μm long, 1.8-2.6 × basal diameter of segment, and ANT PT/BASE 3.9-4.4	…..Rhopalosiphum chusqueae
–	Without that combination of characters	…..go to key to grass-feeding aphids under Digitaria (or also try keys to aphids on bamboos under Arundinaria and Bambusa)

*Cicca*	Euphorbiaceae
Cicca acida = Phyllanthus acidus

*Cicer*	Fabaceae
*Cicer arietinum*	Acyrthosiphon gossypii, pisum;
	Aphis craccivora, fabae; Macrosiphum euphorbiae;
	[Therioaphis trifolii]
C. songaricum	[Acyrthosiphon hissaricum]; [Paracletus cimiciformis]

Use key to apterae on Pisum (Acyrthosiphon hissaricum could not be keyed on the basis of the available information).

*Cicerbita*	Asteraceae
*Cicerbita alpina*	[Amphorophora gei]; Aphis fabae; Aulacothum solani;
	Macrosiphum alpinum, euphorbiae, polanense;
	Nasonovia ribisnigri; Uroleucon sonchi
C. azurea	Acyrthosiphon ilka
C. cacaliifolia = C. macrophylla
C. macrophylla	Nasonovia ribisnigri;
	Uroleucon cicerbitae, longisetosum, sonchi
C. pancicii = Lactuca pancicii
C. racemosa = Lactuca racemosa
C. reticulata (?)	Aphis craccivora
C. rosea = Mulgedium roseum

Key to apterae on Cicerbita:-

1	SIPH with polygonal reticulation on distal 0.1-0.4 of length. Cauda bearing 12-34 hairs. ANT III with 10 or more rhinaria	…..2
–	SIPH without distal polygonal reticulation (or if with then other characters do not apply)	…..6
2	SIPH mainly pale, tapering/cylindrical, with a rather constricted subapical zone of polygonal reticulation occupying less than 0.2 of total length. Postsiphuncular sclerites absent	…..3
–	SIPH dark, cylindrical, with polygonal reticulation on distal 0.15-0.40 of length, the reticulated section not at all constricted. Large dark postsiphuncular sclerites present	…..4
3	Cauda with 17-21 hairs. ABD TERG 8 with 10-11 hairs, and disc of subgenital plate with 3-4 hairs	.…..Macrosiphum polanense
–	Cauda with 12-15 hairs, ABD TERG 8 with 6-9 hairs, and disc of subgenital plate with 4-12 hairs	…..Macrosiphum alpinum
4	SIPH 1.21-1.25 × cauda, which bears 12-17 hairs. SIPH with reticulation on distal 0.35-0.40	…..Uroleucon longisetosum
–	SIPH 1.4-2.1 × cauda, which bears 23-30 hairs. SIPH with reticulation on distal 0.15-0.30	…..5
5	R IV+V 0.7-0.9 × HT II. SIPH reticulated over distal 0.15-0.25 of length. Hind coxae much darker than trochanters. Dorsal hairs not arising from distinct dark scleroites	…..Uroleucon sonchi
–	R IV+V 1.05-1.15 × HT II. SIPH reticulated over distal 0.25-0.30 of length. Hind coxae pale like trochanters. Dorsal hairs mostly arsing from dark scleroites	…..Uroleucon cicerbitae
6	ANT PT/BASE 8-11. ANT III with 7-28 rhinaria extending over 0.4-0.7 of length. Spiracular apertures on pro-and metathorax much larger than those on abdomen	…..Nasonovia ribisnigri
–	ANT PT/BASE 1.7-7.5. ANT III with 0-3 rhinaria near base. Thoracic spiracular apertures similar in size and form to abdominal ones	…..7
7	SIPH dark (or if pale then either clavate or with subapical polygonal reticulation)	…..go to key to polyphagous aphids
–	SIPH pale or only dark at apices, tapering/cylindrical, without subapical polygonal reticulation	…..8
8	Head spinulose, ANT tubercles with inner faces steep-sided, almost parallel. R IV+V 1.05-1.50 × HT II. ANT BASE VI 1.2-2.0 × HT II	…..Aulacorthum solani
–	Head smooth, ANT tubercles with inner faces divergent. R IV+V 0.75-0.93 × HT II. ANT BASE VI 0.9-1.11 × HT II	…..Acyrthosiphon ilka

*Cichorium*	Asteraceae
*Cichorium divaricatum* (?)	Aphis intybi
C. endivia (incl. ssp. pumilum)	Aphis craccivora, fabae, intybi;
	Aulacorthum solani; Hyperomyzus lactucae;
	Macrosiphum euphorbiae;
	Myzus [certus], ornatus, persicae;
	Nasonovia ribisnigri; Pemphigus bursarius;
	Prociphilus erigeronensis; Protaphis pseudocardui; Protrama flavescens; Rhopalosiphoninus latysiphon;
	Trama caudata, troglodytes;
	Uroleucon ambrosiae, cichorii, murale, picridis, sonchi
C. intybus	Acyrthosiphon [gossypii], ilka;
	Aphis albella, craccivora, fabae, gossypii, intybi,
	[vandergooti];
	Aulacorthum solani; Brachycaudus helichrysi;
	Hyperomyzus lactucae, picridis; Macrosiphum euphorbiae;
	Myzus ornatus, persicae; Nasonovia ribisnigri;
	Pemphigus bursarius, [vesicarius];
	Prociphilus erigeronensis;
	Protaphis anuraphoides, [elatior], middletonii, [Protaphis
	sp. (Mier Durante, 1978; Holman & Pintera, 1981)];
	Protrama flavescens, radicis;
	Trama caudata, maritima, [narzykulovi], pamirica,
	troglodytes;
	Uroleucon altaicum, cichorii, [cirsii], [jaceae], picridis,
	pseudambrosiae, sonchi;
	Xerobion inthybi
C. pumilum = C. endivia ssp. pumilum
C. spinosum	Aphis fabae
Cichorium spp.	[Trama rara]

Key to apterae on Cichorium:-

[For keys to common aphids on C. endiva and C. intybus see Blackman & Eastop (2000).]

1	Hind tarsus II elongate, much longer than other tarsi	…..2
–	Hind tarsus II of normal length	…..6
2	SIPH completely absent. Eyes of 3 facets	…..Trama troglodytes
–	SIPH present as slightly raised pores. Eyes usually with more than 12 facets	…..3
3	ANT VI similar in length to ANT V or a little longer, with PT at least one third as long as BASE VI. Many apterae alatiform with dark tranverse bands on dorsal abdomen	…..4
–	ANT VI a little shorter than ANT V, with PT very short. No dorsal abdominal pigmentation	…..5
4	HT II 0.72-0.87 × length of hind tibia. Hind tibia 5.0-6.4 × ANT IV. R IV with 8-12 accessory (dorsal) hairs	….. Protrama radicis
–	HT II 0.59-0.70 × length of hind tibia. Hind tibia 6.5-9.2 × ANT IV. R IV with 6-8 accessory (dorsal) hairs	…..Protrama flavescens
5	ANT III 2.3-2.9 × ANT IV. HT II 3.3-4.2 × ANT VI (incl. PT)	…..Trama maritima (or pamirica?)

–	ANT III 1.6-2.25 × ANT IV. HT II 2.6-3.5 × ANT VI (incl. PT)	…..Trama caudata
6	ANT PT/BASE less than 0.3. SIPH absent. Eyes with only 3 facets	…..7
–	ANT PT/BASE more than 0.5. SIPH present. Eyes multi-faceted	…..8
7	R IV+V 0.08-0.12 mm long, a little shorter than last ANT segment (incl. PT), and without any accessory hairs. Hairs at apices of tibiae and first tarsal segments short and thick	…..Pemphigus bursarius
–	R IV+V 0.13-0.175 mm long, as long as or longer than last ANT segment and bearing 4-8 accessory hairs. Hairs at apices of hind tibiae and first tarsal segments long and fine	…..Prociphilus erigeronensis
8	ANT tubercles absent or weakly developed	…..9
–	ANT tubercles well developed	…..18
9	Cauda short, helmet-shaped or bluntly triangular, not longer than its basal width in dorsal view	…..10
–	Cauda tongue-shaped, clearly longer than its basal width	…..14
10	ANT PT/BASE c.0.58	…..Xerobion inthybi
–	ANT PT/BASE 0.8-3.2	…..11
11	SIPH pale, smooth-surfaced, with an annular incision below the well-developed flange. ABD TERG 1 and 7 without marginal tubercles (MTu). ANT PT/BASE 2.4-3.2	…..Brachycaudus helichrysi
–	SIPH dark, without a subapical annular incision, and flange small. ABD TERG 1 and 7 with large MTu. ANT PT/BASE 0.8-2.3	…..12
12	ANT PT/BASE 1.5-2.4. Cauda as dark as SIPH	…..Protaphis middletonii
–	ANT PT/BASE 0.8-1.4. Cauda paler than SIPH	…..13
13	ANT III usually without secondary rhinaria (rarely with 1-3). R IV+V 1.28-1.36 × HT II. Longest hairs on ABD TERG 3 are 0.7-1.1 × ANT BD III	…..Protaphis pseudocardui
–	ANT III usually with (1-10) secondary rhinaria. R IV+V 1.45-1.65 × HT II. Longest hairs on ABD TERG 3 are 1.2-1.3 × ANT BD III	…..Protaphis anuraphoides
14	Cauda black like SIPH. Dark dorsal markings present, at least on head, thorax and ABD TERG 7 and 8, and often more extensive	…..15
–	Cauda pale or, if dusky to dark, then paler than SIPH. No dark dorsal markings	…..17
15	Dorsal abdominal dark markings not fused between segments. hairs on ANT III 0.8-3.4 × BD III. Cauda with 11-27 hairs	…..Aphis fabae
–	Dorsal abdomen with dark markings usually fused between segments to form a central patch or shield. Hairs on ANT III 0.25-0.75 × BD III. Cauda with 4-9 hairs	…..16
16	R IV+V 1.25-1.75 × ANT BASE VI (only less than 1.3 × in large specimens (BL 2 mm or more). R IV+V 1.1-1.5 × HT II	…..Aphis intybi
–	R IV+V usually 0.8-1.2 × ANT BASE VI (1.2-1.4 × in hot-weather dwarfs). R IV+V 0.7-1.3 × HT II	…..Aphis craccivora
17	SIPH dark	…..Aphis gossypii
–	SIPH pale	…..Aphis albella
18	Head spiculose, with inner faces of ANT tubercles almost parallel or apically convergent	…..19

–	Head smooth, with inner faces of ANT tubercles divergent	…..22
19	SIPH black and markedly inflated	…..Rhopalosiphoninus latysiphon
–	SIPH pale or only dusky at apices, tapering or only slightly clavate	…..20
20	Dorsal abdomen with a pattern of dark intersegmental markings. ANT PT/BASE 1.7-2.8. SIPH coarsely imbricated, tapering and with a slight S-curve	…..Myzus ornatus
–	Dorsal abdomen without any dark markings. ANT PT/BASE 2.8-5.5. SIPH moderately imbricated, cylindrical and almost straight, or slightly clavate	…..21
21	SIPH slightly clavate. ANT III never with rhinaria	…..Myzus persicae
–	SIPH cylindrical. ANT III usually with 1-2 small rhinaria near base	…..Aulacorthum solani
22	SIPH strongly clavate	…..23
–	SIPH tapering or cylindrical	…..24
23	Dorsum pale. R IV+V 0.88-1.0 × HT II	…..Hyperomyzus lactucae
–	ABD TERG 1-6 with dark pleural flecks. R IV+V 1.45-1.8 × HT II	…..Hyperomyzus picridis
24	SIPH with a subapical zone of polygonal reticulation occupying 0.12-0.43 of total length	…..25
–	SIPH without any subapical polygonal reticulation, or with striae containing a few closed cells but occupying less than 0.1 of total length	…..32
25	SIPH pale at least basally, sometimes rather darker towards apices, with reticulation on distal 0.12-0.20 of length. First tarsal segments with 3 hairs. ANT III with 1-11 rhinaria	…..26
–	SIPH black, with reticulation of numerous rather small polygonal cells on distal 0.16-0.43 of length. First tarsal segments with 5 hairs. ANT III with 8-97 rhinaria	…..27
26	ANT PT/BASE 4.3-6.1. HT II 0.13-0.18 mm. Dorsal hairs never on scleroites, and no postsiphuncular sclerites	….. Macrosiphum euphorbiae
–	ANT PT/BASE 2.9-3.6. HT II 0.175-0.21 mm. At least some of dorsal hairs usually arising from small pigmented scleroites, and large (but sometimes weakly pigmented) postsiphuncular sclerites present	…..Uroleucon altaicum*
27	Dorsal hairs on ABD TERG 1-5 mostly not placed on dark scleroites. R IV+V 0.73-0.88 × HT II	…..Uroleucon sonchi
–	Dorsal hairs on ABD TERG 1-5 all or mostly placed on dark scleroites. R IV+V 0.76-1.84 × HT II	…..28
28	Crescent-shaped black antesiphuncular sclerites present	…..29
–	Antesiphuncular sclerites absent or indistinct	…..30
29	R IV+V 1.45-1.84 × HT II	…..Uroleucon picridis
–	R IV+V 1.17-1.33 × HT II	…..Uroleucon cichorii
30	SIPH long and thin (c.11-17 × longer than diameter at midlength), 1.5-1.9 × cauda. R IV+V 0.75-0.9 (-1.0) × HT II). ANT III with 20-36 rather large rhinaria occupying 0.87-0.98 of length of segment	…..Uroleucon murale
–	SIPH rather thick (c.8-12 × longer than diameter at midlength), 1.1-1.5 × cauda. R IV+V 0.9-1.45	× HT II. ANT III with 8-46 secondary rhinaria on basal 0.5-0.7 of segment …..31
31	HT II rather long and thin, about 6 × its maximum thickness, and 0.9-1.1 × R IV+V	…..Uroleucon pseudambrosiae
–	HT II shorter, less than 5 × its maximum thickness and 0.7-0.95 × R IV+V	…..Uroleucon ambrosiae
32	Dorsal abdomen with paired dark intersegmental markings, closer together on ABD TERG 4 and 5 than on more anterior segments. Spiracular apertures on pro-and metathorax much larger than those on abdomen. SIPH 0.18-0.26 × BL	…..Nasonovia ribisnigri
–	Dorsal abdomen without dark markings. Spiracular apertures on thorax of similar size to those on abdomen. SIPH 0.26-0.34 × BL	…..Acyrthosiphon ilka

Ciclospermum see Cyclospermum

Apiaceae

*Cicuta*	Apiaceae
*Cicuta bulbifera*	Cavariella konoi
C. californica = C. douglasii
C. douglasii	Aphis gossypii
C. maculata (incl. var. angustifolia)	Aphis asclepiadis, saniculae, spiraecola, thaspii;
	Cavariella aegopodii, [hendersoni], konoi, pastinacae,
	theobaldi;
	Hyadaphis foeniculi; [Pemphigus sp. (as lactucae)];
	Rhopalosiphum nymphaeae
C. occidentalis = C. maculata var. angustifolia
C. virosa	Anuraphis subterranea;
	Aphis fabae, grosmannae, nasturtii, [schilderi];
	Cavariella aegopodii, cicutae, cicutisucta, konoi,
	pastinacae;
	Macrosiphum gei; Rhopalosiphum nymphaeae;
	Semiaphis anthrisci;
	[Wahlgreniella nervata (as Amphorophora cicutae Shinji)]
Cicuta spp.	Dysaphis apiifolia

Key to apterae on Cicuta:-

1	ABD TERG 8 with a posteriorly projecting process above cauda; sometimes reduced to a small, warty, knob in the centre of ABD TERG 8, with 2 associated hairs	…..2
–	No supracaudal process, nor are there 2 hairs on ABD TERG 8 close together and associated with a warty knob	…..7
2	ABD TERG 8 with a warty knob. SIPH tapering/cylindrical. R IV+V c 0.22 mm, longer than ANT PT	…..Cavariella cicutisucta
–	ABD TERG 8 with an evident backwardly-pointing process. SIPH clavate. R IV+V 0.08-0.19 mm, usually shorter than ANT PT (except in cicutae)	…..3
3	SIPH tapering, with no trace of swelling	…..Cavariella theobaldi
–	SIPH clavate	…..4
4	ANT PT/BASE 0.6-1.3. R IV+V with 0-2 accessory hairs	…..5
–	ANT PT/BASE 1.4-4.0. R IV+V always with 2 accessory hairs	…..6
5	Supracaudal process large, broad-based, projecting beyond and usually covering cauda. SIPH thick, less than 5 × longer than their maximum width	…..Cavariella cicutae
–	Supracaudal process finger-like and not projecting beyond tip of cauda. SIPH more than 5 × longer than their maximum width	…..Cavariella aegopodii
6	ANT PT/BASE 1.4-2.0	…..Cavariella konoi
–	ANT PT/BASE 2.6-4.0	…..Cavariella pastinacae
7	ANT tubercles well developed. SIPH cylindrical with a distal zone of polygonal reticulation. Longest hairs on dorsal abdomen 66-106 μm. Anterior half of subgenital plate with 2-11 (usually 4-8) hairs	…..Macrosiphum gei
–	ANT tubercles weakly developed or absent. SIPH without polygonal reticulation. Dorsal abdominal hairs shorter and/or fewer hairs on anterior part of subgenital plate	…..8
8	SIPH very small and flangeless, only about 0.5 × cauda, with aperture slanted towards midline of body	…..Semiaphis anthrisci
–	SIPH more than 0.75 × cauda	…..9
9	SIPH clavate	…..10
–	SIPH tapering or cylindrical	…..11
10	SIPH more than 2 × cauda. Dorsal cuticle with a reticulate pattern of small round bead-like spinules arranged in polygons. R IV+V 1.0-1.5 × HT II	…..Rhopalosiphum nymphaeae
–	SIPH 0.9-1.4 × cauda. Dorsal cuticle without spinules arranged in polygons. R IV+V 0.7-0.8 × HT II	…..Hyadaphis foeniculi
11	Cauda helmet-shaped, not longer than its basal width in dorsal view. Head and ABD TERG 8 or 7-8 usually with spinal tubercles (STu)	…..12
–	Cauda tongue-shaped, longer than its basal width. Head without, and ABD TERG 7-8 usually without, STu	….13
12	SIPH with close-set rows of fine spinules. Cauda with 11-12 hairs	…..Anuraphis subterranea
–	SIPH with normal imbrication. Cauda with 5 hairs	….. Dysaphis apiifolia
13	ABD TERG 1-7 or 1-5 and 7 with well-developed marginal tubercles (MTu)	…..Aphis grosmannae
–	MTu only regularly present on ABD TERG 1 and 7, with occasionally small ones on other segments	…..14
14	Hind femora with many long fine hairs, most of them as long as or longer than width of trochantro-femoral suture. Cauda 1.6-2.5 × ANT BASE VI	…..15
–	Hind femora with most or all hairs shorter than width of trochantro-femoral suture. Cauda 1.2-1.9 × ANT BASE VI	…..16
15	SIPH 0.75-1.1 × ANT III and 1.8-2.7 × ANT BASE VI. Cauda hardly constricted near midlength and bearing 11-24 hairs. ABD TERG 7 and 8 with dark bands and dark dorsal markings also anterior to SIPH. (Al. with 10-23 rhinaria on ANT III)	…..Aphis fabae
–	SIPH 1.1-1.45 × ANT III and 2.8-3.4 × ANT BASE VI. Cauda usually clearly constricted near midlength and bearing 6-15 (usually 9-11) hairs. Abdomen without any dark markings. (Al. with 4-12 rhinaria on ANT III)	…..Aphis spiraecola
16	ANT III-V (of apt.) usually with sec. rhin. (III 0-14, IV 0-12, V 0-8)	…..Aphis saniculae
–	ANT III-V (of apt.) without sec. rhin. (except in alatiform specimens)	…..17
17	SIPH mainly pale or dusky, only dark towards apices	…..Aphis nasturtii
–	SIPH uniformly dark	…..18
18	SIPH much darker than cauda, which bears 4-7 (-8) hairs	…..Aphis gossypii
–	SIPH and cauda similarly pigmented. Cauda with 8-12 hairs	…..19
19	HT I with 3 hairs. Longest hairs on ANT III 16-35 μm, 0.6-1.2 × BD III. (Al. with sec. rhin. III 14-40, IV 0-2, V 0)	…..Aphis asclepiadis
–	HT I with 2 hairs. Longest hairs on ANT III 10-15 μm, 0.3-0.5 × BD III. (Al. with sec.rhin. III 28-56, IV 5-11, V 0-6)	…..Aphis thaspii

*Cienfuegosia*	Malvaceae
*Cienfuegosia gossypioides* = C. sturtianum
*C. sturtianum*	Myzus persicae

*Cimicifuga* see Actaea	Ranunculaceae
*Cimicifuga dahurica* = Actaea dahurica
C. foetida = Actaea cimicifuga
C. heracleifolia = Actaea heracleifolia
*C. simplex* = Actaea simplex
Cimicifuga sp. (= Actaea sp.?)	Aphis fabae; Aulacorthum solani

Use key to apterae under Actaea.

*Cinchona*	Rubiaceae
*Cinchona ledgeriana*	Aphis aurantii, gossypii, odinae, spiraecola

(Use key to polyphagous aphids.)

*Cineraria*	Asteraceae
*Cineraria cruenta*	Acyrthosiphon malvae; Aphis fabae, gossypii;
(= Pericallis cruenta)	Aulacorthum solani;
	Brachycaudus cardui, helichrysi, lateralis;
	Eriosoma patchiae; Macrosiphum euphorbiae;
	Myzus ascalonicus, ornatus, persicae;
	Neomyzus circumflexus
C. hybrida see C. cruenta
C. renifolia = Dolichorrhiza renifolia
C. saxifraga	Aphis gossypii; Macrosiphum euphorbiae; Myzus persicae
C. stellata see C. cruenta
Cineraria spp.	Aphis craccivora, [umbrella]; Myzus ascalonicus;
	Sitobion miscanthi

Key to apterae on Cineraria:-

1	SIPH as large pores with partially sclerotised rims, ringed with hairs. ANT PT/BASE less than 0.8. Dorsal body with wax glands on all segments, each normally comprising a ring of facets around a central pore	…..Eriosoma patchiae
–	SIPH conical or tubular. ANT PT/BASE more than 1. No discrete wax glands	…..2
2	Cauda tongue-shaped, clearly longer than its basal width. Spiracular apertures reniform	…..go to key to polyphagous aphids
–	Cauda helmet-shaped, short, not longer than its basal width in dorsal view. Spiracular apertures large and rounded	…..3
3	Dorsum without dark markings. Mesosternum without mammariform processes. R IV+V 0.10-0.15 mm, 1.2-1.3 × HT II. SIPH pale, smooth, 0.8-2.0 × cauda	…..Brachycaudus helichrysi
–	Dorsum with an extensive black shield. Mesosternum with a pair of dark mammariform processes. R IV+V 0.17-0.24 mm, 1.4-2.0 × HT II. SIPH dark, imbricated, 1.7-3.4 × cauda	…..4
4	Hairs on ABD TERG 8 are 30-61 µm long. Longest hairs on hind femur 10-25µm long	…..Brachycaudus lateralis
–	Hairs on ABD TERG 8 are at least 70µm long. Longest hairs on hind femur more than 25µm long	…..Brachycaudus cardui

*Cinna*	Poaceae
*Cinna latifolia*	Rhopalosiphum padi; Sitobion fragariae

Use key to apterae of grass-feeding aphids under Digitaria.

Cinnamomum

Cinnamons Lauraceae

Aphids recorded from camphor (C. camphora) and cinnamon (C. zeylandicum) are included in Blackman & Eastop (2000). The key following the host list includes all aphids recorded from members of the genus Cinnamomum.

*Cinnamomum brevifolium*	Euthoracaphis umbellulariae
*C. burmanni*	Aphis (Toxoptera) aurantii; Euthoracaphis heterotricha;
	Sinomegoura citricola;
*C. camphora*	Camphor Tree
	Aiceona actinodaphnis, japonica;
	Aphis (Toxoptera) aurantii, citricidus
	Euthoracaphis umbellulariae; Machilus machili;
	Sinomegoura citricola
*C. iners*	Euthoracaphis heterotricha
*C. japonicum*	Euthoracaphis umbellulariae; Machilaphis pseudomachili;
	Sinomegoura citricola; Thoracaphis sp.
*C. loureirii*	Sinomegoura citricola
*C. pedunculatum*	Euthoracaphis umbellulariae
*C. tamala*	[Myzus persicae]
*C. zeylanicum*	Cinnamon Tree
	Euthoracaphis heterotricha;
	[Micromyzus nigrum van de Goot 1918];
	Sinomegoura citricola

Key to aphids on Cinnamomum:-

1	SIPH longer than basal width	…..2
–	SIPH either inconspicuous pores or broad cones, shorter than basal width	…..4
2	Body spindle-shaped. Cauda very large with pointed apex. SIPH dark apically, pale on basal half. No stridulatory apparatus	…..Sinomegoura citricola
–	Body broadly oval. Cauda rounded at apex. SIPH wholly dark. Stridulatory apparatus present	…..3
3	Cauda with usually more than 25 hairs. Longest hairs on ANT III longer than basal diameter of segment. BL often 2 mm or more	….. Aphis (Toxoptera) citricidus
–	Cauda with usually less than 20 hairs. Longest hairs on ANT III shorter than basal diameter of segment. BL less than 2 mm	….. Aphis (Toxoptera) aurantii
4	Body of aptera aleyrodiform; subcircular, sclerotized, with much reduced legs and antennae	…..5
–	Body of aptera of normal aphid type with well-developed legs and antennae	…..7
5	Dorsal area of prosoma entire	…..Thoracaphis sp.
–	Dorsal area of prosoma with distinct sutures dividing it into a large quadrate central area, plus an anterior and two dorsolateral areas (fig. 39A)	…..6
6	Prosoma with two longitudinal spinal rows of long thick hairs (80-125 µm long) in addition to many long and short fine hairs (fig.39B )	…..Euthoracaphis heterotricha
–	Prosoma with all hairs fine, the longest of them 40-80 µm long (fig. 39C)	…..Euthoracaphis umbellulariae
7	SIPH in form of small sclerotized rings. Wax glands evident. Hairs rather sparse and mainly short	…..8
–	SIPH in form of broad hairy cones. Wax glands not evident. Hairs long and numerous	…..9
8	Wax pore plates on posterior abdomen mostly with circles of minute wax pores like small pearl necklaces, supplemented with fields of similar-sized ring-shaped elements; wax pore plate on ABD TERG 8 has entirely such circles of minute pores except for a narrow median zone with a few ring-shaped elements. R IV+V with 4-8 accessory hairs. Alata with 0-4 secondary rhinaria on ANT III	…..Machilaphis machili
–	Wax pore plates on posterior abdomen including that on ABD TERG 8 consisting entirely of ring-shaped elements. R IV+V with 3-4 accessory hairs. Alata with 7-11 secondary rhinaria on ANT III	…..Machilaphis pseudomachili
9	R IV+V shorter than HT II	…..Aiceona japonica
–	R IV+V longer than HT II	…..Aiceona actinodaphne

*Circaea*	Onagraceae
*Circaea alpina*	Ericaphis ?wakibae see aphidtrek.org
*Circaea* sp.	Aphis fabae

*Cirriphyllum*	Brachythecaceae
*Cirriphyllum piliferum*	Muscaphis escherichi

*Cirsium*	Asteraceae
*Cirsium achantarense* (?)	Aulacorthum cirsicola
C. acarna = Picnomon acarna
*C. acaule*	Aulacorthum solani; Protrama radicis; Trama troglodytes
C. afrum = Ptilostemon afer
*C. alatum*	Aphis fabae, janischi, solanella; Dysaphis radicivorans
C. altissimum	Aphis asclepiadis, fabae; Capitophorus elaeagni
C. americanum	= C. scariosum var. americanum
C. aomorense	Capitophorus cirsiiphagus, elaeagni
C. argyracanthum	Uroleucon kumaoni
C. arvense	Aphis [acanthoidis], craccivora,
	[euonymi of Bozhko (1976a) = solanella?], fabae,
	fabae ssp. cirsiiacanthoidis, gossypii, janischi, nasturtii,
	solanella
	Aulacorthum solani; Bipersona ochrocentri, torticauda;
	Brachycaudus cardui, cardui ssp. turanica, helichrysi;
	Capitophorus carduinus, elaeagni, gynoxanthus, [horni];
	Chitinosiphum cirsorhizum;
	Dysaphis atina, lappae ssp. cirsii, radicivorans;
	Hyperomyzus lactucae; Macrosiphum euphorbiae;
	Myzus cymbalariae, persicae; [Nasonovia ribisnigri];
	Protaphis ancathiae, anuraphoides, terricola, turanica,
	[Aphis (Protaphis) sp.- Holman and Pintera, 1981)];
	Protrama [flavescens], radicis; Smynthurodes betae
	Trama [mordvilkoi Börner 1940], [caudata], troglodytes;
	Uroleucon aeneum, cephalonopli, cirsicola, cirsii, gobonis,
	jaceae, [ jaceae ssp. henrichi], [nigrotuberculatum],
	pepperi, [rudbeckiae], [sonchi];
	[Xerobion compositae]
*C. brevistylum*	Capitophorus elaeagni; Uroleucon cirsii
C. buergeri	Capitophorus elaeagni
C. candelabrum	Aphis fabae group
*C. canescens*	Bipersona torticauda
C. canum	Aphis cirsiioleracei, fabae; Brachycaudus cardui;
	Uroleucon cirsii
C. caput-medusae	Brachycaudus cardui
C. carniolicum	Aphis fabae ssp. cirsiiacanthoidis
C. caucasicum	Aphis fabae group; Brachycaudus cardui
*C. cephalotes*	Brachycaudus cardui
C. ciliatum	Aphis fabae ssp. cirsiiacanthoidis
C. coloradense = S. scariosum var. coloradense
C. coryletorum	Aphis cirsiphila, fabae group; Uroleucon cephalonopli
C. costaricense	Capitophorus elaeagni
C. creticum	Aphis fabae ssp. cirsiiacanthoidis;
	Brachycaudus helichrysi; Capitophorus bulgaricus;
	Uroleucon aeneum, cirsii
C. desertorum = C. alatum
C. dipsacolepis	[Aphis horii? doubtful record – see Takahashi (1966)]
C. discolor	Aphis fabae group; Brachycaudus cardui;
	Capitophorus elaeagni
C. dissectum	Aphis fabae group; Uroleucon cirsii, jaceae
C. ducellieri	Capitophorus elaeagni
C. eatonii var. *eriocephalum*	Aphis asclepiadis; Capitophorus elaeagni
C. echinus	Brachycaudus cardui
C. edule	Brachycaudus cardui; Capitophorus elaeagni
C. elodes (or alatum?)	[Aphis viridescens Bozhko = cirsiioleracei?];
	Protaphis anuraphoides; Uroleucon jaceae
C. engelmannii	Bipersona torticauda; Uroleucon longirostre
C. eriophorum	Aphis fabae ssp. cirsiiacanthoidis; Brachycaudus cardui;
	Dysaphis lappae ssp. cirsii
C. erisithales	Aphis fabae, fabae ssp. cirsiiacanthoidis;
	Aulacorthum solani; Brachycaudus cardui;
	Capitophoris elaeagni, [gynoxantha];
	Nasonovia ribisnigri; Uroleucon aeneum, macrosiphon
C. esculentum	Uroleucon cirsii
C. falconeri	[Capitophorus gynoxanthus]
C. filipendulum = C. engelmannii
C. flavispina = C. pyrenaicum
C. flodmanii	Bipersona torticauda; Neomyzus circumflexus
C. foliosum	Aphis fabae
C. furiens	Capitophorus bulgaricus
C. glabrifolium	Brachycaudus cardui ssp. turanica; Capitophorus elaeagni
C. glabrum	Aphissolanella
C. helenioides	Acyrthosiphon malvae;
	Aphis fabae, fabae ssp. cirsiiacanthoidis;
	Aulacorthum solani; Brachycaudus cardui, helichrysi;
	Capitophorus carduinus, elaeagni, [gynoxanthus];
	Dysaphis lappae ssp. cirsii; [Macrosiphum chukotense];
	Uroleucon cirsii, jaceae, [sonchi]
*C. heterophylloides* = helenioides
*C. heterophyllum* = helenioides (?)
C. horridulum (incl. var. vittatum)	Capitophorus elaeagni
C. horridum Fisch. = C. caucasicum
C. incanum = C. arvense
C. italicum	Brachycaudus cardui, helichrysi
C. japonicum	Aulacorthum cirsicola, vandenboschi;
	Capitophorus cirsiiphagus, elaeagni, [evelaeagni],
	montanus;
	[Macrosiphum naazamiae Shinji];
	[Micromyzodium nipponicum];
	Uroleucon cephalonopli, [formosanum], giganteum,
	gobonis, [rudbeckiae]
**C. japonicum var. maackii**	Aphis fabae; Aulacorthum cirsicola;
	Capitophorus cirsiiphagus, elaeagni, montanus;
	Chitinosiphum cirsorhizum;
	Uroleucon cephalonopli, giganteum, gobonis, [lactucicola]
C. japonicum var. ussuriense = C. japonicum var. maackii
C. kamtschaticum	Aphis fabae group; Aulacorthum cirsicola, solani;
	Capitophorus elaeagni; Macrosiphum euphorbiae;
	Uroleucon cephalonopli, giganteum
C. kawakamii	Uroleucon gobonis
C. lanceolatum = C. vulgare
C. laniflorum	Brachycaudus cardui; Uroleucon cirsicola
C. leucanthum = C. maritimum
C. maackii = C. japonicum var. maackii
*C. maritimum*	Uroleucon cephalonopli, gobonis
C. megacephalum see C. undulatum
C. mexicanum	Aphis gossypii, spiraecola;
	Capitophorus carduinus, elaeagni; Myzus ornatus, persicae;
	Uroleucon ambrosiae
C. monspessulanum	Aphis fabae group
C. montanum	Brachycaudus cardui
C. morisianum	Brachycaudus helichrysi; Capitophorus bulgaricus
C. muticum	Aphis fabae; Brachycaudus cardui;
	Macrosiphum euphorbiae; Uroleucon pepperi, jaceae
C. myrianthum	Brachycaudus cardui
C. neomexicanum	Bipersona torticauda
C. nipponicum	Aulacorthum cirsicola; Capitophorus cirsiiphagus
(incl. var. incomtum)
C. nuttallii	Capitophorus elaeagni
C. obvallatum	Aphis fabae group; Brachycaudus cardui
C. occidentalis = Carduus occidentalis
C. ochrocentrum	Bipersona ochrocentri
C. odontolepis	Brachycaudus cardui
C. oleraceum	Aphis cirsiioleracei, fabae ssp. cirsiiacanthoidis, janischi;
	Aulacorthum solani; Brachycaudus cardui;
	Capitophorus horni; Dysaphis lappae ssp. cirsii;
	Pemphigus bursarius; Protrama radicis;
	Uroleucon cirsii, jaceae, [sonchi]
C. palustre	Aphis cirsiioleracei, fabae; Brachycaudus cardui;
	Capitophorus carduinus, horni; Protrama radicis;
	Trama troglodytes; Uroleucon aeneum, cirsii , jaceae
C. pannonicum	Aphis cirsiioleracei, fabae, fabae ssp. cirsiiacanthoidis;
	Brachycaudus cardui; Protrama radicis;
	Uroleucon aeneum, cirsii
C. pauciflorum = C. waldsteini
C. pendulum	Aphis fabae, Aulacorthum cirsicola;
	Chitinosiphum cirsorhizum; Uroleucon cephalonopli
*C. purpuratum*	Capitophorus cirsiiphagus
C. pyrenaicum	Aphis fabae group
C. rhizocephalum	Brachycaudus cardui
C. rivulare	Aphis fabae, fabae ssp. cirsiiacanthiodis;
	Brachycaudus cardui; Uroleucon aeneum
C. scariosum (incl. vars	Aphis fabae group; Bipersona torticauda
americanum, coloradense)
*C. schantarense*	Aulacorthum cirsicola; Capitophorus cirsiiphagus;
	Uroleucon cephalonopli
C. scopulorum = C. eatonii var. eriocephalum
C. segetum = Breea segeta
C. serratuloides	Aphis janischi
C. serrulatum	Protaphis turanica
C. setidens	Uroleucon cephalonopli
*C. setigerum* = C. alatum
C. setosum	Aphis fabae group, gossypii, janischi, solanella;
	Capitophorus elaeagni; Chitinosiphum cirsorhizum;
	Protaphis turanica;
	Uroleucon cephalonopli, gobonis, jaceae ssp. henrichi
C. siculum = Galactites tomentosa
C. sieversii = C. straminispinum
C. smallii = C. horridulum var. vittatum
C. spicatum	Aulacorthum cirsicola
C. spinosissimum	Brachycaudus cardui; Capitophorus horni;
	[Uroleucon sonchi]
*C. straminispinum*	Aphis fabae, janischi, solanella; Brachycaudus cardui;
	Protaphis anuraphoides, turanica; Uroleucon cirsii
*C. subcoreacium*	Myzus ornatus
*C. svaneticum*	Aphis fabae group
C. syriacus	Aphis fabae group; Capitophorus elaeagni;
	[Dysaphis lappae ssp. cynarae]
C. *tanakae* = C. nipponicum var. incomtum
C. tuberosum	Aphis fabae group; Brachycaudus helichrysi
C. turkestanicum	Aphis cirsiioleracei; Brachycaudus cardui ssp. turanica
C. undulatum	Aphis asclepiadis; Bipersona torticauda;
	Brachycaudus cardui; [Protaphis middletonii]
C. verutum	Hyperomyzus lactucae
C. *vlassovianum*	Uroleucon cephalonopli
C. vulgare (incl. lanceolatum)	Aphis asclepiadis, fabae, fabae ssp. cirsiiacanthoidis,
	gossypii, janischi, solanella;
	Aulacorthum solani; [Artemisaphis artemisicola];
	Bipersona ochrocentri;
	Brachycaudus cardui, cardui ssp. turanica, helichrysi;
	Capitophorus bulgaricus, carduinus, elaeagni,
	gynoxanthus, horni;
	Dysaphis lappae ssp. cirsii;
	Myzus ascalonicus, ornatus, persicae;
	Protaphis [carthami?], terricola, turanica;
	Trama troglodytes;
	Uroleucon aeneum, cichorii, cirsicola, cirsii, compositae,
	jaceae
*C. waldsteinii*	Brachycaudus cardui; Hyperomyzus lactucae
(incl. pauciflorum)
C. wallichii	Aphis craccivora, fabae group;
	Brachycaudus cardui, helichrysi;
	Capitophorus carduinus, elaeagni;
	Dysaphis atina, microsiphon
C. weyrichii	Aphis fabae group; Uroleucon cephalonopli, giganteum
Cirsium spp.	Aphis pilosicauda, [Aphis (Protaphis) sp. (Mier Durante 1978)];
	Brachycaudus cardui ssp. turanica, lateralis;
	[Capitophorus similis]; [Cavariella salicicola];
	Eotrama moerickei; [Macrosiphum sp. (Leonard 1964: 96)];
	[Uroleucon riparium, sonchi spp. stepposa]

Key to apterae on Cirsium (also Cnicus):-

1	ANT PT/BASE 0.1-0.7. SIPH absent or as pores on flat cones. Cauda broadly rounded, not evident	…..2
–	ANT PT/BASE 0.8 or more. SIPH conical or tubular, usually longer than basal width. Cauda various, usually evident	……5
2	HT II very elongate, at least 0.5 × length of hind tibia, and fused to HT I	…..3
–	HT II much less than 0.5 × length of hind tibia and separate from HT I	…..4
3	SIPH completely absent. Head and appendages pale or dusky. ANT PT/BASE 0.16-0.24	…..Trama troglodytes
–	SIPH present as pores on flat, pigmented cones. Head and appendages dark. ANT PT/BASE 0.33-0.69	…..Protrama radicis
4	SIPH absent. ANT PT/BASE 0.12-0.32	…..use key to polyphagous aphids, couplets 2 and 3
–	SIPH present as pores. ANT PT/BASE 0.44-0.57	…..Eotrama moerickei
5	Long, thick capitate dorsal hairs present at least on head and posterior abdomen. SIPH slender, about as thick as hind tibiae at midlength	…..6
–	Dorsal hairs not thick and distinctly capitate; if conspicuous, long and slightly expanded apically then SIPH are much thicker than hind tibiae at midlength	…..12
6	Spinal hairs duplicated (e.g. Fig.22a), so that on each of ABD TERG 1-5 there are 4 spinal hairs, 2-4 pleural hairs and 4-6 marginal hairs (the longest similar in length to those on ABD TERG 6-8)	…..7
–	Spinal hairs not duplicated (e.g. Fig.22b); each of ABD TERG 1-5 with at most 2 spinal hairs, 2 pleural hairs and 2-4 marginal hairs (sometimes much shorter than those on ABD TERG 6-8)	…..9
7	R IV+V 1.7-2.3 × HT II. Pleural hairs on ABD TERG 1-3 often duplicated	…..Capitophorus bulgaricus
–	R IV+V 1.1-1.5 × HT II. Pleural hairs on ABD TERG 1-3 not duplicated, except in some large individuals	…..8
8	R IV+V 1.1-1.4 × HT II (mostly 1.1-1.25 X), and 0.8-1.2 × ANT BASE VI. SIPH 1.4-1.9 × ANT III	…..Capitophorus horni
–	R IV+V 1.3-1.5 × HT II, and 1.0-1.45 × ANT BASE VI (mostly 1.2-1.4 X). SIPH 1.6-2.2 × ANT III	…..Capitophorus gynoxanthus
9	R IV+V 1.15-1.7 × ANT BASE VI	…..10
–	R IV+V 0.7-1.1 × ANT BASE VI	…..11
10	Cauda 1.1-1.5 × R IV+V, and bearing 5-8 hairs. ANT PT 3.1-4.4 × R IV+V, and ANT PT/BASE 4.6-6.3. SIPH without dark apices	…..Capitophorus carduinus
–	Cauda 1.4-2.3 × R IV+V, and bearing 7-13 hairs. ANT PT 4.5-6.3 × R IV+V, and ANT PT/BASE 6.0-9.2. SIPH with dark apices	…..Capitophorus elaeagni
11	ANT PT/BASE less than 6. ABD TERG 6 with 1 pair of minute spinal hairs, and ABD TERG 7 with 1 pair of thick capitate spinal hairs (and 0-2 much smaller pleural ones) (Fig. 22c)	…..Capitophorus montanus
–	ANT PT/BASE more than 6.5. ABD TERG 6 with 1-2 pairs of thick capitate hairs, and ABD TERG 7 with 2 pairs of thick capitate spinal hairs (Fig.22d)	…..Capitophorus cirsiiphagus
12	SIPH with a zone of polygonal reticulation occupying subapical 0.15-0.4 of length	…..13
–	SIPH without subapical polygonal reticulation, sometimes with 1-3 rows of closed cells occupying less than 0.1 of length	…..28
13	Cauda broad at base, tapering to a very thin distal section that has a twisted appearance. Anal plate extended below cauda, and ending in a rounded protruberance (Fig.22e)	…..14
–	Cauda tongue- or finger-shaped. Anal plate not extended	…..15
14	Hairs on ANT III and dorsum of head less than 0.5 × BD III	…..Bipersona ochrocentri
–	Hairs on ANT III and dorsum of head more than 0.5 × BD III	…..Bipersona torticauda
15	Cauda dark	…..16
–	Cauda pale or dusky	…..21
16	R IV+V 0.22-0.30 mm long. Cauda with 16-55 hairs (usually more than 20)	…..17
–	R IV+V 0.17-0.22 mm long. Cauda with 10-26 hairs (usually less than 20)	…..19
17	Tibiae wholly dark. Cauda with more than 40 hairs	…..Uroleucon giganteum
–	Tibiae with paler middle section. Cauda with 16-34 hairs	…..18
18	ANT III with rhinaria extending over 0.5-0.8 of length. Hind femur dark on distal 0.65-0.75 of length. SIPH with polygonal reticulation on distal 0.25-0.33. R IV+V 1.4-1.62 × HT II	…..Uroleucon cephalonopli
–	ANT III with rhinaria extending over 0.37-0.52 of length. Hind femur dark on distal 0.4-0.5. SIPH with polygonal reticulation on distal 0.15-0.20. R IV+V 1.20-1.35 × HT II	…..Uroleucon aeneum
19	ANT III with rhinaria extending over 0.68-0.95 of length. Hind femur dark on distal 0.6-0.75 of length	…..Uroleucon gobonis (or compositae)
–	ANT III with rhinaria extending over 0.45-0.7 of length. Hind femur dark on distal 0.4-0.55 of length	…..20
20	R IV+V 0.9-1.1 × HT II, which is more than 0.20 mm long	…..Uroleucon macrosiphon
–	R IV+V 1.2-1.35 × HT II, which is less than 0.19 mm long	…..Uroleucon jaceae
21	Hairs on cauda all pointed and of similar length	…..22
–	Distal hairs on cauda clearly shorter (and often blunter) than more proximal hairs	…..26
22	SIPH 1.1-1.5 × cauda, with polygonal reticulation on distal 0.25-0.45 of length	…..23
–	SIPH 1.6-2.2 × cauda, with polygonal reticulation on less than distal 0.25 of length	…..24
23	R IV+V less than 0.19 mm long. Cauda with 12-27 hairs. SIPH with polygonal reticulation on distal 0.25-0.36 of length	…..Uroleucon ambrosiae
–	R IV+V more than 0.20 mm long. Cauda with 23-39 hairs. SIPH with polygonal reticulation on distal 0.36-0.45 of length	…..Uroleucon pepperi
24	SIPH pale. Cauda with 8-12 hairs	…..Macrosiphum euphorbiae (or chukotense?- see text)
–	SIPH dark. Cauda with more than 20 hairs	…..25
25	Crescent-shaped antesiphuncular sclerites present. SIPH 0.25-0.34 × BL. Cauda with 20-33 hairs	…..Uroleucon cirsii
–	No antesiphuncular sclerites. SIPH 0.32-0.42 × BL. Cauda with 30-45 hairs	…..Uroleucon cirsicola
26	SIPH wholly dark. Dorsal hairs with basal dark scleroites. ANT III with 39-49 rhinaria	…..Uroleucon kumaoni*
–	SIPH pale at least basally. Dorsal hairs not arising from dark scleroites. ANT III with 5-24 rhinaria	…..27
27	R IV+V c.2 × HT II	…..Uroleucon longirostre
–	R IV+V 0.9-1.1 × HT II	…..Uroleucon erigeronense
28	Head spiculose	…..29
–	Head without spicules	…..35
29	ANT tubercles rather low with inner faces divergent. SIPH 2.7-3.6 × cauda. ANT III with 3-16 secondary rhinaria	…..Chitinosiphum cirsorhizum
–	ANT tubercles well developed with steep-sided, almost parallel or apically convergent inner faces. SIPH less than 2.6 × cauda, or if more then clavate. ANT III with or without secondary rhinaria	…..30
30	SIPH slightly to moderately clavate	…..31
–	SIPH cylindrical/tapering	…..33
31	SIPH as long as or longer than ANT III. R IV+V 0.9-1.0 (-1.2) × HT II …..Myzus persicae
–	SIPH much shorter than ANT III. R IV+V 1.3-1.5 × HT II	…..32
32	SIPH with a narrow basal stem, its narrowest part thinner than, or as thin as, hind tibia at mid-length. R IV+V with 7-15 accessory hairs. ANT tubercles with inner faces almost parallel. Tergum not rugose	…..Myzus ascalonicus
–	SIPH thicker on basal half, its narrowest part thicker than hind tibia at midlength. R IV+V with less than 7 accessory hairs. ANT tubercles apically convergent. Tergum very rugose	…..Myzus cymbalariae
33	ANT, SIPH and femora mainly black	…..Aulacorthum vandenboschi
–	ANT segments, SIPH and femora mainly pale, darker at apices	…..34
34	Head uniformly spiculose both dorsally and ventrally. Hind tibiae 0.6-0.8 × BL. SIPH 2.0-2.6 × cauda. ANT III with (0-) 1-3 (-4) rhinaria near base. BL 1.8-3.0 mm	…..Aulacorthum solani
–	Head smooth dorsally and with spiculose areas between ANT tubercles and clypeus ventrally. Hind tibiae 0.9-1.5 × BL. SIPH 1.5-2.0 × cauda. ANT III with 3-12 rhinaria on basal half. BL 3.0-4.1 mm	…..Aulacorthum cirsicola
35	ANT tubercles well developed, with divergent inner faces. ANT III with 1-36 rhinaria	…..36
–	ANT tubercles absent or weakly developed. ANT III usually without rhinaria	…..38
36	SIPH markedly clavate. Dorsum pale. ANT PT/BASE 4.6-8. R IV+V 0.9-1.0 × HT II	…..Hyperomyzus lactucae
–	SIPH tapering/cylindrical. R IV+V 1.0-1.6 × HT II	…..37
37	Dorsum usually with dark intersegmental markings. ANT PT/BASE 8-11. Thoracic spiracles much larger than abdominal spiracles	…..Nasonovia ribisnigri
–	Dorsum usually without dark intersegmental markings. ANT PT/BASE 4.4-7.5. Thoracic and abdominal spiracles similar in size	…..Acyrthosiphon malvae
38	Cauda shorter than its basal width, rounded or helmet-shaped, with 5-8 hairs. Marginal tubercles (MTu) absent from ABD TERG 1 and 7, or only present if there are spinal tubercles (STu) and MTu on other segments	…..39
–	Cauda tongue-shaped or bluntly triangular, shorter or longer than its basal width, but if shorter then it bears more than 10 hairs. MTu always present on ABD TERG 1 and 7, and sometimes on other segments, but STu never present	…..45
39	Paired STu present, at least on head, and often on ABD TERG 8 or 7-8. Spiracular apertures reniform	…..40
–	STu absent from head, and rarely on ABD TERG 8. Spiracular apertures large and rounded	…..43
40	SIPH shorter than cauda. Paired STu only present on head	…..Dysaphis microsiphon
–	SIPH longer than cauda. Paired STu present at least on head and ABD TERG 8	…..41
41	STu usually only on head and ABD TERG 8, with occasionally 1 on ABD TERG 7. MTu on ABD TERG 1-5 rather small, not much larger than spiracular apertures on those segments. Longest hairs on ANT III 1.0-1.2 × BD III	…..Dysaphis atina
–	Paired STu consistently present on head and ABD TERG 7 and 8, and also on several other segments. Large MTu present on ABD TERG 1-5 or 1-7. Longest hairs on ANT III shorter than BD III	…..42
42	Longest hairs on head about equal in length to ANT BD III. Dorsal abdominal hairs 0.5-0.6 × BD III. Cauda with 4 hairs	…..Dysaphis radicivorans*
–	Longest hairs on head and dorsal abdomen shorter than 0.5 × ANT BD III. Cauda with 5-7 hairs	…..Dysaphis lappae sspp. cirsii
43	Dorsum without dark markings. SIPH pale, smooth-surfaced, 0.8-1.5 × cauda. ANT III 0.07-0.25 mm, 0.9-2.2 × HT II	…..Brachycaudus helichrysi
–	Dorsum with an extensive black shield. SIPH dark, imbricated, 1.7-3.4 × cauda. ANT III 0.31-0.47 mm, 2.4-3.4 × HT II	…..44
44	Hairs on ABD TERG 8 are 30-61 µm long. Longest hairs on hind femur 10-25µm long	…..Brachycaudus lateralis
–	Hairs on ABD TERG 8 are at least 70µm long. Longest hairs on hind femur more than 25µm long	…..Brachycaudus cardui (incl. ssp. turanica)
45	ANT PT/BASE 0.8-1.2. SIPH short, 0.7-1.2 × the short blunt triangular cauda	…..46
–	ANT PT/BASE 1.8-4.0. SIPH 0.8-2.5 × cauda, if 0.8-1.2 × then cauda is tongue-shaped, clearly longer than its basal width	…..47
46	Longest hairs on ABD TERG 3 are 1.2-1.3 × ANT BD III. SIPH 0.9-1.2 × cauda, and with a distinct flange. R IV+V 1.45-1.65 × HT II	…..Protaphis anuraphoides
–	Longest hairs on ABD TERG 3 are 0.3-0.9 × ANT BD III. SIPH 0.67-0.92 × cauda, with a weak flange . R IV+V 1.2-1.4 (-1.5) × HT II	……Protaphis terricola group (incl. ancathiae and turanica)

47	Cauda with 4-9 hairs (usually 5-7)	…..48
–	Cauda with 7-27 hairs (usually 8-24)	…..51
48	Dorsal abdomen with an extensive solid black patch	…..Aphis craccivora
–	Dorsal abdomen without extensive dark markings	…..49
49	Semi-globular MTu consistently present on all or most of ABD TERG 2-6 as well as 1 and 7	…..Aphis cirsiphila
–	MTu absent from ABD TERG 2-6, or irregularly present, and then conical or papilliform	…..50
50	ANT 5-segmented (in both apt. and al.). SIPH and cauda both black. ABD TERG 2-4 sporadically with MTu (mean total 1.7)	…..Aphis cirsiioleracei
–	ANT 6-segmented (except in summer dwarf apt.). SIPH distinctly darker than cauda. ABD TERG 2-4 very rarely with any MTu	…..Aphis gossypii
51	Longest hairs on ANT III less than 0.5 × BD III. Cauda short, only about as long as its basal width, with 16-20 long, curved hairs	…..Aphis pilosicauda
–	Longest hairs on ANT III more than 0.5 × BD III. Cauda much longer than its basal width, with 7- 27 hairs	…..52
52	ABD TERG 8 with 6-11 hairs (fewer in hot-weather dwarfs). ANT III (1.6-) 2.0-4.0 (-5.0) × R IV+V. HT I with 3 hairs (sense peg present). Cauda with 7-12 hairs. (Al. with 14-40 rhinaria on ANT III)	…..Aphis asclepiadis
–	ABD TERG 8 with 2-7 hairs. ANT III 1.3-2.6 (-3.0) × R IV+V. HT I with 2 hairs (no sense peg). Cauda with 7-27 hairs. (Al. with 4-23 rhinaria on ANT III)	…..53
53	Dorsal abdomen without any dark markings. Cauda bearing 7-15 (usually 9-11) hairs, and usually with a distinct midway constriction	…..Aphis spiraecola
–	Dorsal abdomen with dark cross-bands on ABD TERG 7 and 8, and some small dark markings anterior to SIPH. Cauda bearing 11-24 hairs, and without a constriction	…..54
54	SIPH more than 6.5 × longer than marginal hairs on ABD TERG 3, which are 12-49 μm long. Longest hairs on ANT III 0.6-1.5 × BD III	…..Aphis solanella
–	SIPH less than 6.5 × longer than marginal hairs on ABD TERG 3, which are 50-85 μm long. Longest hairs on ANT III 1.3-3.5 × BD III	….. Aphis fabae group (incl. A. fabae ssp. cirsiiacanthoidis, A. janischi)

*Cissampelos*	Menispermaceae
*Cissampelos capensis*	Aphis gossypii
C. mucronata	Aphis gossypii
C. pareira	Aphis aurantii, gossypii; [Myzus formosanus]

Use key to polyphagous aphids

*Cissus*	Vitaceae
*Cissus ampelopsis* = Ampelopsis cordata
C. arborea	Macrosiphum euphorbiae
C. erosa	Aphis gossypii
C. grisebachii = Cissus microcarpa
C. hypoglauca (?)	Aulacorthum solani
C. japonica = Cayratia japonica
C. microcarpa	Aphis illinoisensis
C. sicyoides = Cissus verticillata
C. verticillata	Aphis aurantii, illinoisensis, spiraecola;
	Sitobion cuscutae; Myzus persicae
C. welwitschii	Aulacorthum solani; Myzus ornatus
Cissus spp.	Sitobion cissi

Key to apterae on Cissus:-

1	Hind tibiae entirely black	…..2
–	Hind tibiae pale, or at least with pale middle section	…..3
2	SIPH with a subapical zone of polygonal reticulation. ANT tubercles well-developed, divergent. ANT 1.4-1.7 × BL, with PT/BASE 5.5-6.8	…..Sitobion cuscutae
–	SIPH without any polygonal reticulation. ANT tubercles weakly developed. ANT 0.7-0.9 × BL, with PT/BASE 3.1-4.0	…..Aphis illinoisensis
3	SIPH dark with subapical polygonal reticulation, Cauda pale. ANT III with 1-6 rhinaria near base, and with hairs all very short, less than 0.5 × BD III	…..Sitobion cissi
–	Without this combination of characters	…..go to key to polyphagous aphids

*Cistus*	Rock-Roses Cistaceae
*Cistus albidus*	[Aphis sp. – Leonard 1972a, 99]
C. algarvensis	Neomyzus circumflexus
C. clusii	[Roepkea marchali]
C. × corbariensis	Myzus ornatus
C. creticus	[Aphis sp. – Leonard 1972a, 99];
	Brachycaudus [cardui], helichrysi; Myzus persicae
*C. crispus*	Aphis [cisti Lichtenstein of del Guercio 1911 (nomen
	nudum)], cisticola
*C. germanicus* (?)	Brachycaudus helichrysi
C. heterophyllus	Myzus persicae
C. hirsutus = Heliathemum appeninum
C. × incanus (incl. corsicus)	Aphis cisticola, lupoi
C. ladanifer	Aphis cisticola, lichtensteini, lupoi;
	Myzus ornatus, persicae
C. laurifolius	Aphis cisticola, fabae; Myzus persicae
C. monspeliensis	Aphis cisticola, lichtensteini
C. nehrodense (?)	Brachycaudus helichrysi
C. populifolius	Aphis fabae, lichtensteini, lupoi
C. × *purpureus*	Brachycaudus helichrysi
C. salviifolius	Aphis cisticola, lichtensteini, lupoi; Myzus persicae
C. symphytifolius	Myzus persicae
C. vaginatus = C. symphytifolius
C. villosus = C. creticus
Cistus spp.	Macrosiphum euphorbiae;
	[Myzus targionii Del Guercio 1894 – nomen dubium]

Key to apterae on Cistus:-

1	Body spindle-shaped. SIPH pale, with a subapical zone of polygonal reticulation	…..Macrosiphum euphorbiae
–	Body oval. SIPH dark or pale, without any polygonal reticulation	…..2
2	ANT tubercles well-developed, with inner faces scabrous and converging apically	…..3
–	ANT tubercles undeveloped or weakly developed, not projecting beyond middle of front of head in dorsal view	…..5
3	SIPH slightly clavate. Dorsal abdomen without any dark markings	…..Myzus persicae
–	SIPH tapering. Dorsal abdomen with dark markings	…..4
4	Dorsal abdomen with a large, roughly horseshoe-shaped patch. ANT PT/BASE 3.5-5.0	…..Neomyzus circumflexus
–	Dorsal abdomen with a pattern of paired intersegmental markings. ANT PT/BASE 1.7-2.5	…..Myzus ornatus
5	SIPH pale, conical, almost smooth, with an annular incision below the flange. Cauda helmet-shaped, not longer than its basal width. Spiracular apertures large and rounded	…..Brachycaudus helichrysi
–	SIPH dark, tapering, imbricated, without an annular incision below the flange. Cauda tongue-shaped, longer than its basal width. Spiracular apertures reniform	…..6
6	R IV+V less than 1.3 × HT II. Hairs on ANT and legs mostly fine-pointed and often long; those on ANT III usually longer than BD III. Cauda with 11-27 hairs	…..Aphis fabae
–	R IV+V more than 1.3 × HT II. Hairs on ANT and legs blunt or abruptly pointed; those on ANT III not longer than BD III. Cauda with 4-14 hairs	…..7
7	R IV+V 1.75-2.50 × HT II and bearing 6-10 accessory hairs. HT II very short, 0.65-0.83 × ANT BASE VI. Marginal tubercles (MTu) small and often absent from ABD TERG 1 and 7	…..Aphis lichtensteini
–	R IV+V 1.34-2.05 × HT II and bearing 2-6 accessory hairs. HT II 0.72-1.00 × ANT BASE VI. MTu always present and well developed on ABD TERG 1 and 7	…..8
8	SIPH rather short and thick, 0.13-0.18 × BL, and less than 2.8 × their basal widths. R IV+V with 2-6 accessory hairs (85% with 3 or more)	…..Aphis lupoi
–	SIPH 0.18-0.24 × BL and more than 2.9 × longer than their basal widths. R IV+V with 2-3 accessory hairs (94% with 2)	…..Aphis cisticola

*Citrullus* (including Colocynthis)	Cucurbitaceae
*Citrullus colocynthis*	Aphis fabae, frangulae, gossypii;
	Macrosiphum euphorbiae; Myzus persicae
C. lanatus	Aphis craccivora, fabae, frangulae, gossypii, nasturtii;
	Aulacorthum solani; Myzus persicae;
	Pseudomegoura magnoliae; Smynthurodes betae
C. vulgaris = C. lanatus

Use key to polyphagous aphids.

*Citrus*	Rutaceae
*Citrus ×acida* = C. aurantiifolia
C. aurantiifolia	Aphis aurantii, citricidus, gossypii, spiraecola
C. aurantium	Aphis aurantii, citricidus, craccivora, fabae, gossypii,
	odinae, nerii, spiraecola;
	Aulacorthum solani; Brachycaudus helichrysi;
	Macrosiphum euphorbiae; Myzus persicae;
	Neomyzus circumflexus; Sinomegoura citricola
C. clementina	Aphis aurantii, craccivora, fabae, spiraecola
C. glauca	Aphis citricidus
C. grandis = C. maxima
C. jambhiri (?)	Aphis citricidus
*C. japonica*	Aphis aurantii, odinae
C. junos	Aphis citricidus
*C. ×karna* = C. aurantium
*C. kinokuni* = C. japonica
*C. ×limettioides* = C. aurantiifolia
*C. limon*	Aphis aurantii, citricidus, craccivora, fabae,
	gossypii, solanella, spiraecola;
	Aulacorthum solani; Brachycaudus helichrysi;
	Macrosiphum euphorbiae; Myzus persicae;
	Neomyzus circumflexus
*C. maxima*	Aphis aurantii, citricidus, craccivora, gossypii,
	spiraecola;
	Aulacorthum solani; Macrosiphum euphorbiae;
	Myzus persicae
C. medica	Aphis aurantii, citricidus, fabae, gossypii, spiraecola;
	Brachycaudus helichrysi; Macrosiphum euphorbiae;
	Myzus persicae
C. ×myrtifolia = C. aurantium
*C. ×natsudaidai* = C. aurantium
*C. ×nobilis* = C. aurantium
C. paradisi	Aphis aurantii, gossypii, spiraecola;
	Brachunguis harmalae;
C. reticulata	Aphis aurantii, citricidus, craccivora, fabae, gossypii,
	odinae, spiraecola;
	Aulacorthum solani; Macrosiphum euphorbiae;
	Myzus ornatus, persicae; Sinomegoura citricola
C. sinensis	Aphis aurantii, citricidus, craccivora, fabae, gossypii,
	odinae, spiraecola;
	Aulacorthum solani; Brachycaudus [cardui], helichrysi;
	Macrosiphum euphorbiae; Myzus persicae;
	[Rhopalosiphum maidis]
C. tachibana = C. reticulata
C. unshiu = C. reticulata
*Citrus* spp.	Pseudomegoura magnoliae; [Pterochloroides persicae]

Key to apterae on Citrus:-

–	ANT PT/BASE less than 1. SIPH pale, only about as long as their width at base and 0.4-0.7 × the pale cauda	…..Brachyunguis harmalae
–	ANT PT/BASE more than 1.2. If SIPH are very short then both SIPH and cauda are dark	…..go to key to polyphagous aphids

*Cladanthus*	Asteraceae
*Cladanthus arabicus*	Metopeurum fuscoviride
*C. mixtus*	Aphis fabae, spiraecola,
	[Aphis (Protaphis) sp. – Mier Durante 1978: 93];
	Macrosiphum euphorbiae

Use key to apterae on Tanacetum.

*Cladrastis*	Fabaceae
*Cladrastis kentukea*	Aphis craccivora
*C. lutea* = C. kentukea

*Claopodium*	Thuidiaceae
Claopodium crispifolium	Melaphis rhois; [Pachpappa rosettei]

(or try key to moss-feeding aphids under Polytrichum)

*Clarkia* (including Godetia)	Onagraceae
*Clarkia amoena*	Aphis frangulae (as epilobiina: Börner 1952);
	Macrosiphum euphorbiae; [Myzus godetiae]
*C. concinna*	Myzus persicae
C. elegans	Aphis frangulae (as epilobiina: Börner 1952),
	oenotherae
*C. pulchella*	Myzus lythri, ornatus
Clarkia spp. (as Godetia spp.)	Aphis fabae, grossulariae, [triglochinis]

Use key to apterae on Epilobium.

*Clausena*	Rutaceae
*Clausena anisata*	Aphis (Toxoptera) aurantii

*Claytonia*	Montiaceae
*Claytonia lanceolata*	Aulacorthum solani; Macrosiphum claytoniae;
	Myzus ascalonicus; Neomyzus circumflexus
*C. perfoliata*	Myzus persicae
*C. sibirica*	Aulacorthum solani;
	Macrosiphum claytoniae, euphorbiae;
	Myzus ascalonicus, persicae; Neomyzus circumflexus

Key to apterae on Claytonia:-

1	Head densely spiculose or nodulose, ANT tubercles with inner faces steep-sided, parallel or apically convergent. SIPH tapering, cylindrical or slightly clavate, without polygonal reticulation	…..go to key to polyphagous aphids, starting at couplet 4
–	Head smooth or only sparsely spiculose, ANT tubercles with inner faces divergent. SIPH tapering or cylindrical, with a subapical zone of polygonal reticulation	…..2
2	Dorsal cuticle sclerotic, wrinkled, pigmented. Longest hair on ANT III 0.4-0.75 × BD III. SIPH 2.3-2.7 × cauda	…..Macrosiphum claytoniae
–	Dorsal cuticle membranous and pale. Longest hair on ANT III 0.7-1.0 × BD III. SIPH 1.7-2.2 × cauda	…..Macrosiphum euphorbiae

*Clematis* (including Atragene)	Ranunculaceae
*Clematis aethusifolia*	Aphis clematiphaga
C. alpina	Macrosiphum atragenae; Myzus varians
C. alpina ssp. ochotensis	Myzus varians
C. alpina ssp. sibirica	Aphis clematidis; [Macrosiphum chukotense]
C. apiifolia	[Brachycaudus klugkisti]; Colophina clematicola, clematis;
	Macrosiphum clematifoliae; Myzus persicae, varians
C. armandii	Myzus varians
C. brachiata	Myzus varians
C. brevicaudata	Aphis clematiphaga; Colophina arctica
C. buchananiana	Aphis clematidis, gossypii
C. chinensis	Myzus varians
C. chrysocarpa	[Sitobion sp. – South Africa (Millar 1994)]
C. cirrhosa	Aphis clematidis; Aulacorthum solani; Myzus persicae
C. connata	Tubaphis clematophila
C. crispa	Macrosiphum euphorbiae
C. dioica	Aphis (Toxoptera) aurantii
C. douglasii = C. hirsutissima
C. flammula	Aphis clematidis, vitalbae; Myzus varians
C. florida	Macrosiphum clematifoliae, clematophagum;
	Tubaphis clematophila
*C. foetida*	[Aphis sp. (New Zealand: Teulon et al. 2013)]
C. forsteri	Aphis clematidis
C. fusca	Aphis clematicola
C. glauca	Macrosiphum atragenae
C. gouriana	Colophina clematis; Macrosiphum clematifoliae
C. grata	Aphis longituba
C. hexapetala	Aphis clematidis, clematiphaga
C. hexasepala = C. forsteri
C. hirsutissima	Aphis clematidis
C. integrifolia	Aphis clematidis
C. ×jackmanii	Myzus varians
C. japonica	Colophina clematicola, clematis;
	Macrosiphum clematifoliae; Myzus varians
C. ×jouiniana	Colophina clematis
C. ×lawsoniana	Aphis (Toxoptera) aurantii
C. ligusticifolia	Illinoia brevitarsis; Macrosiphum clum; Myzus varians
C. mandshurica	Colophina clematis; Myzus varians;
	[Pseudomegoura nipponicum]
C. montana (var. rubens)	Colophina clematicola
C. ochotensis = C. alpina ssp. ochotensis
C. orientalis	Aphis brachysiphon, clematidis,
	[Aphis sp. (Davletshina 1964, 125)];
	Myzus ascalonicus, ornatus
C. paniculata	[Acyrthosiphon pisum]; Aphis clematidis;
	Aulacorthum solani
C. recta	Aphis clematidis; Colophina clematicola;
	Macrosiphum euphorbiae; Myzus varians
C. songorica	Acyrthosiphon heptapotamicum
C. stans	Colophina arma
C. terniflora (incl. var. robusta)	Colophina clematicola; Myzus varians
C. terniflora var. mandshurica see C. mandshurica
C. texensis	Colophina clematicola
C. tortuosa	Macrosiphum clematifoliae
C. trichotoma	Colophina clematicola, clematis;
	Macrosiphum clematifoliae
C. uncinata	Colophina monstrifica
C. vitalba	Aphis clematidis, longituba, [nasturtii], vitalbae;
	Aulacorthum solani; Macrosiphum euphorbiae;
	Myzus varians
C. viticella	Aphis clematidis, fabae; Colophina clematicola
C. vitifolia = C. tortuosa
Clematis spp.	Aphis nerii; [Macrosiphum gaurae]; Sitobion africanum

Key to apterae on Clematis:-

1	ANT PT/BASE more than 0.7. SIPH tubular. Cauda longer than its basal width. Dorsum without multifacetted wax glands	…..2
–	ANT PT/BASE much less than 0.5. SIPH as pores, or absent. Cauda broadly rounded, not evident. Dorsum with numerous multifacetted wax glands	…..24
2	SIPH with a subapical reticulated zone comprising at least 2-3 rows of closed polygonal cells	…..3
–	SIPH without subapical polygonal reticulation	…..9
3	SIPH wholly black, or black with pale bases	…..4
–	SIPH pale or slightly dusky, or dark only at apices	…..5
4	SIPH more than 0.33 × BL, distally black but with contrastingly pale basal part. ANT tubercles well developed. Dorsum pale	…..Macrosiphum clematifoliae
–	SIPH less than 0.33 × BL, wholly black. ANT tubercles rather weakly developed. Dorsum sometimes pale, sometimes with dark cross-bands	…..Sitobion africanum
5	Hairs on ANT III 0.7-1.0 × BD III. SIPH 1.7-2.2 × cauda	…..Macrosiphum euphorbiae
–	Hairs on ANT III 0.2-0.4 × BD III. SIPH 2.3-3.2 × cauda	…..6
6	ANT PT/BASE 6.5-7.8. SIPH somewhat swollen distally, tapering gradually through the subapical reticulated region, and with a small flange	…..Illinoia brevitarsis
–	ANT PT/BASE 4.0-6.1. SIPH cylindrical on distal half, or if appearing slightly swollen then the swelling does not include the subapical reticulated region, and there is a well-developed flange	…..7
7	ANT BASE VI wholly dark like apex of ANT V, and 1.05-1.25 × R IV+V. ANT III with 1-8 rhinaria	…..Macrosiphum clum
–	ANT BASE VI paler than apex of V except in region of primary rhinarium, and 1.7-2.1 × R IV+V. ANT III with 6-12 rhinaria	…..8
8	R IV+V 0.9-1.05 × HT II. SIPH 2.8-3.0 × cauda, which is rather short and thick, almost parallel-sided on basal half	…..Macrosiphum atragenae
–	R IV+V c.1.1 × HT II. SIPH c.2.3-2.4 × cauda, which tapers from base to apex	…..Macrosiphum clematophagum
9	Head spiculose, with well-developed, steep-sided or apically convergent ANT tubercles. ABD TERG 1 and 7 without marginal tubercles (MTu)	…..10
–	Head not spiculose, ANT tubercles undeveloped, weakly developed or if well developed then smooth and divergent. ABD TERG 1 and 7 with or without MTu	…..15
10	SIPH with contrastingly black distal sections	…..Myzus varians
–	SIPH pale, or dusky only at apices	…..11
11	Dorsal abdomen with an intersegmental pattern of dark ornamentation. SIPH tapering, with a slight S-curve, coarsely imbricated, 0.75-0.95 × head width across eyes. ANT PT/BASE 1.9-2.4	…..Myzus ornatus
–	Dorsal abdomen without intersegmental dark markings. SIPH clavate, or tapering and straight, 1.0-1.3 × head width across eyes. ANT PT/BASE 2.2-5.5	…..12
12	SIPH with coarse, scabrous imbrication, tapering or cylindrical on distal half, constricted near apex and with a small flange, the diameter at the flange not exceeding the diameter at midlength (Fig.23a). ANT PT/BASE 2.2-3.5. Cauda distinctly constricted at base, with 4-5 hairs (Fig.23b)	…..Tubaphis clematophila
–	SIPH with moderate imbrication, tapering or slightly clavate, with diameter of flange greater than diameter at midlength. ANT PT/BASE 2.8-5.5. Cauda not constricted at base, with 4-8 (usually 6-7) hairs	…..13
13	SIPH clavate. ANT III without rhinaria	…..14
–	SIPH tapering. ANT III usually with 1-2 small rhinaria near base	…..Aulacorthum solani
14	SIPH slightly clavate, with greatest width of swollen part 1.05-1.4 × least width of stem; normally imbricated, as long as or longer than ANT III	…..Myzus persicae
–	SIPH evidently clavate, with greatest width of swelling 1.3-1.8 × least width of stem; weakly imbricated with swollen part almost smooth, 0.5-0.75 × ANT III	…..Myzus ascalonicus
15	ANT tubercles well developed, smooth and divergent. ABD TERG 1 and 7 without MTu. SIPH pale, very long and distally attenuate, 0.32-0.42 × BL	…..Acyrthosiphon heptapotamicum*
–	ANT tubercles weakly developed or undeveloped. ABD TERG 1 and 7 with MTu. SIPH pale or dark, less than 0.33 × BL	…..16
16	Cauda black like SIPH, and with 9-27 hairs	…..17
–	Cauda pale or dusky, with 4-14 hairs (SIPH pale or dark)	…..19
17	Stridulatory apparatus present, consisting of cuticular ridges on abdominal sternites 5 and 6 and a row of short peg-like hairs on each hind tibia	….. Aphis (Toxoptera) aurantii
–	No stridulatory apparatus	…..18
18	ABD TERG 7 and 8 with dark transverse bars, and often with dark markings on more anterior segments. ANT PT/BASE 1.7-3.5. SIPH 0.7-1.8 × cauda	…..Aphis fabae
–	Dorsal abdomen without any dark markings. ANT PT/BASE 3.4-4.1. SIPH 1.7-2.7 × cauda	…..Aphis nerii
19	ANT III with pointed hairs, the longest of them 2.0-2.8 × BD III	…..Aphis clematiphaga*
–	ANT III with pointed or blunt hairs, maximally 0.4-1.5 × BD III	…..20
20	ANT PT/BASE 0.8-1.1. SIPH about equal in length to cauda	…..Aphis brachysiphon
–	ANT PT/BASE 1.7-3.5. SIPH more than 1.1 × cauda	…..21
21	R IV+V 1.1-1.7 × HT II	…..22
–	R IV+V 0.75-1.0 × HT II	…..23
22	SIPH (1.67-) 2.0-3.3 × cauda, which is 0.10-0.16 mm long and bears 5-8 hairs	…..Aphis longituba
–	SIPH 1.3-2.1 (-2.5) × cauda, which is 0.17-0.21 mm long and bears 7-14 hairs	…..Aphis vitalbae
23	Hairs on ANT III short and blunt, 0.5-0.7 × BD III	…..Aphis clematicola*
–	Hairs on ANT III pointed, 0.8-1.5 × BD III	…..Aphis clematidis
24	BL 0.8-1.3 mm. ANT 4-segmented. Tarsi 1-segmented (2 segments fused). SIPH absent	…..Colophina clematicola
–	BL more than 2 mm. ANT 6-segmented. Tarsi 2-segmented. Poriform SIPH present	…..25
25	ABD TERG 4 with 10-16 wax glands (2 spinal, 2 pleural, 6-12 marginal)	…..26
–	ABD TERG 4 with 17-24 wax glands (e.g. 4-6 spinal, 4-8 pleural, 8-12 marginal)	…..27
26	SIPH located just anterior to the row of wax glands on ABD TERG 5. Spinal wax glands on ABD TERG 6 with facets of diameter more than 20 μm (Fig.23c)	…..Colophina clematis
–	SIPH located between rows of wax glands on ABD TERG 5 and 6. Spinal wax glands on ABD TERG 6 with facets of diameter less than 20 μm (Fig.23d)	…..Colophina arctica
27	BL 2.4-3.3 mm. Wax plates composed of cells of more-or-less uniform size, even on ABD TERG 7 (Fig.23e)	…..Colophina arma
–	BL 3.6-5.4 mm. Some wax glands on ABD TERG 7 composed of cells differing greatly in size (Fig.23f)	…..Colophina monstrifica*

*Cleome*	Cleomaceae
*Cleome amblyocarpa*	Myzus persicae
C. chelidonii	Aphis craccivora, gossypii
C. coeruleorosea	Aphis gossypii
C. gynandra	Aphis craccivora, gossypii; Brachycaudus helichrysi;
	Lipaphis pseudobrassicae; Myzus persicae
C. monophylla	Aphis gossypii; Myzus persicae
C. pentaphylla = Cleome gynandra
C. rutidosperma	Lipaphis pseudobrassicae; Myzus persicae
C. serrulata	Aphis craccivora
C. speciosa = Cleoserrata speciosa
C. spinosa	Brevicoryne brassicae; Myzus persicae;
	[Sitobion pauliani]
C. viscosa	Aphis gossypii
Cleome sp.	Macrosiphum euphorbiae

Key to apterae on Cleome:-

1	Cauda short, rounded or broadly triangular, not longer than its basal width in dorsal view	…..2
–	Cauda distinctly longer than its basal width in dorsal view	…..3
2	Cauda broadly triangular. Dorsal abdomen with some dark segmental markings. SIPH dark, slightly swollen. Spiracular apertures reniform	…..Brevicoryne brassicae
–	Cauda helmet-shaped, rounded. Dorsal abdomen without dark markings. SIPH pale, tapering, conical. Spiracular apertures large and rounded	…..Brachycaudus helichrysi
3	ANT tubercles low, divergent and scabrous. Median frontal tubercle similarly developed, and scabrous, as also are ANT I and II. SIPH cylindrical for most of length or slightly thicker distally with a constriction before the flange	…..Lipaphis pseudobrassicae
–	ANT tubercles either undeveloped or low and rather smooth, or, if scabrous then well developed and steep-sided or apically convergent. SIPH tapering, cylindrical or moderately clavate, with or without a subapical constriction	…..go to key to polyphagous aphids

*Cleoserrata*	Cleomaceae
Cleoserrata speciosa	Lipaphis pseudobrassicae

*Clerodendrum*	Lamiaceae
(Some of the east Asian records of Aphis gossypii may refer to A. clerodendri.)
*Clerodendrum bungei*	Aphis gossypii
C. chinense	Aphis clerodendri, gossypii; Myzus ornatus, persicae
C. cyrtophyllum	Aphis clerodendri
C. floribundum	Aphis clerodendri
C. fortunatum	Aphis gossypii
C. fragrans = C. chinense
C. indicum	Aphis clerodendri, gossypii
C. inerme	Aphis gossypii, nasturtii; Myzus persicae
C. infortunatum	Aphis gossypii, nasturtii, spiraecola; Nasonovia rostrata
C. japonicum	Aphis gossypii; Myzus persicae
C. johnstonii	Aphis spiraecola; Myzus ornatus
C. longiflorum	Aphis clerodendri
C. myricoides	Aphis gossypii; Myzus ornatus, persicae
C. paniculatum	Aphis gossypii
C. phillipinum = C. chinense
C. quadriloculare	Aphis clerodendri
C. serratum (= Rotheca serrata)	Aphis gossypii; [Mollitrichosiphum nandii]
C. speciosissimum	Aphis gossypii; Myzus persicae
C. splendens	Aphis gossypii, spiraecola, Aphis sp. (India, BMNH
	collection)
*C. thompsoniae*	Aphis gossypii
C. tomentosum	Aphis clerodendri
C. tracyanum	Aphis clerodendri
C. trichotomum	Aphis clerodendri, gossypii; Prociphilus clerodendri;
	Pseudomegoura magnoliae
C. trichotomum var. fargesii	Aphis clerodendri ssp. amamiana
C. yakusimense = C. trichotomum var. fargesii
Clerodendrum spp.	Brachycaudus helichrysi; Sinomegoura citricola

Key ot apterae on Clerodendrum;-

1	Wax glands present. SIPH absent. ANT PT/BASE less than 0.5	…..Prociphilus clerodendri*
–	Wax glands absent. SIPH present, tubular. ANT PT/BASE more than 1	…..2
2	Spiracular pores on thorax very large and rounded, more than 4 × larger than those on abdomen. R IV+V 0.21-0.33 mm long, about 2 × HT II, and bearing 22-30 accessory hairs. Dorsal body hairs long with blunt or slightly expanded apices	…..Nasonovia rostrata
–	Spiracular pores on thorax not distinctly larger than those on abdomen. R IV+V shorter, with fewer accessory hairs. Dorsal body hairs if long then pointed	…..3
3	ANT tubercles absent or weakly developed. ABD TERG 1 and 7 with marginal tubercles (MTu). Cauda paler than at least distal part of SIPH, which are either wholly dark or have dark apices	…..4
–	Either ANT tubercles are well developed or, if they are absent or weakly developed, then either ABD TERG 1 and 7 are without MTu or both cauda and SIPH are entirely dark	…..6
4	SIPH pale basally, darker towards apices	…..Aphis nasturtii
–	SIPH uniformly dark	…..5
5	ANT V 2.5-4 × longer than hairs on ABD TERG 8, which are finely pointed. Cauda with 6-9 (usually 7-8) hairs	…..Aphis clerodendri
–	ANT V 4-9 × longer than hairs on ABD TERG 8, which are usually blunt. Cauda with 4-8 (usually 5-6) hairs	…..Aphis gossypii
6	SIPH black, 2.2-3.1 × cauda, which is also black and about as long as its basal width in dorsal view. ABD TERG 1 and 7 with MTu	…..Aphis sp. (India, BMNH collection)
–	SIPH pale or dark, but if dark they are less than 2 × cauda, and cauda is longer than its basal width. ABD TERG 1 and 7 with or without MTu	…..go to key to polyphagous aphids

*Clethra*	Clethraceae
*Clethra barbinervis*	Matsumuraja rubifoliae; Myzus persicae
C. cubensis	Aphis aurantii, spiraecola
C. delavayi	Myzus persicae
C. monostachya = C. delavayi

Key to apterae on Clethra:-

–	Head, thorax and abdomen with long paired finger-like tubercles, the tubercles near SIPH being about equal in length to SIPH and 2 × ANT III (fundatrix). (Al. second generation with secondary rhinaria distributed III 22-31, IV 9.18, V 3-10. Immatures with distal half of hind tibiae strongly spinulose.)	…..Matsumuraja rubifoliae
–	Without long finger-like tubercles	…..go to key to polyphagous aphids

*Cleyera*	Pentaphylacaceae
*Cleyera japonica*	Aphis gossypii
Cleyera sp.	Aphis (Toxoptera) aurantii

Use key to polyphagous aphids.

*Clianthus*	Fabaceae
*Cloianthus dampieri* = Swainsona formosa
C. formosus = Swainsona formosa
C. puniceus	Acyrthosiphon malvae, pisum; Aphis craccivora

Key to apterae on Clianthus:-

–	ANT VI BASE 0.25-0.4 mm, 1.8-2.3 × R IV+V. SIPH very attenuate distally, with minimum diameter less than 0.25 × width of cauda at midlength in dorsal view	…..Acyrthosiphon pisum
–	ANT VI BASE less than 0.2mm, less than 1.5 × R IV+V. SIPH clavate, cylindrical or tapering but not attenuate and of diameter more than 0.3 × width of cauda at midlength	…..go to key to polyphagous aphids

*Clibadium*	Asteraceae
*Clibadium erosum*	Aphis coreopsidis, gossypii; Aulacorthum solani
C. surinamense	Aphis eugeniae, spiraecola
C. terebinthinaceum	Aphis aurantii, spiraecola; Uroleucon ambrosiae

Use key to apterae on Eupatorium, which includes all these species.

*Clidemia*	Melastomataceae
*Clidemia hirta*	Aphis gossypii

*Cliffortia*	Rosaceae
*Cliffortia strobilifera*	Aphis gossypii

*Climacium*	Climaciaceae
*Climacium dendroides*	[Clydesmithia canadensis]; Pseudacaudella rubida

(or try key to moss-feeding aphids under Polytrichum)

*Climacoptera*	Amaranthaceae
*Climacoptera* sp.	Aphis craccivora

*Clinopodium*	Calamints Lamiaceae
*Clinopodium acinos*	Aphis calaminthae, clinopodii, craccivora, fabae;
	Ovatus chamaedrys
C. alpinum	Myzus ornatus
C. chinense	Aphis clinepetae
C. gracile	Aphis clinopodii, gossypii; Chaetosiphon hirticorne;
	Eumyzus clinopodii
C. grandiflorum	Aphis calaminthae, [Aphis sp. near clinepetae – Crimea,
	BMNH collection]
C. menthifolium	Aphis calaminthae
C. micranthum	Aphis gossypii
C. multicaule	[Hyperomyzus carduellinus]
C. nepeta	Aphis origani
C. nepeta ssp. glandulosum	Aphis calaminthae, fabae, gossypii
C. umbrosum	Aphis gossypii; Myzus ornatus
C. vulgare	Aphis clinopodii, [frangulae], origani;
	Cryptomyzus heinzei; Dysaphis microsiphon;
	Myzus ornatus; Ovatomyzus chamaedrys;
	[Ovatus crataegarius]

Key to aphids on Clinopodium, Acinos, Calamintha and Satureja:-

1	SIPH strongly swollen, with maximum diameter of swollen part more than 2× minimum diameter of stem (Fig.48a). SIPH 5.4-8.2 × cauda	…..Eucarazzia elegans
–	SIPH not swollen or less swollen, and less than 4 × cauda	…..2
2	Dorsal cuticle of head nodulose or spiculose	…..3
–	Dorsal cuticle of head more-or-less smooth, without nodules or spicules (although their may be some spicules ventrally)	…..5
3	Antennal hairs very long, 2-3 × BD III, arising from tuberculate bases. SIPH long, thin, cylindrical and straight	…..Chaetosiphon hirticorne
–	Antennal hairs short, 0.25-0.8 × BD III. SIPH thick, tapering, and often somewhat curved	…..4
4	Dorsal body hairs very long, 2-3 × BD III. Dorsum without any distinct dark intersegmental markings. ANT tubercles low, divergent. SIPH shorter than ANT III	…..Eumyzus clinopodii
–	Dorsal body hairs very short, less than 0.3 × BD III. Dorsum with a pattern of dark intersegmental markings. ANT tubercles well developed, with their inner faces apically convergent. SIPH longer than ANT III	…..Myzus ornatus
5	Dorsal body hairs long and rather thick, 2-3 × ANT BD III, with knobbed apices and mostly arising from distinctly tuberculate bases. ANT III with 2-10 rhinaria on basal part. ANT PT/BASE 7.8-9.5. SIPH clavate, 3-4 × cauda	…..Cryptomyzus heinzei
–	Dorsal body hairs shorter or with pointed apices, without tuberculate bases. ANT III without rhinaria. ANT PT/BASE less than 8. SIPH tapering, cylindrical or clavate, usually less than 3 × cauda	…..6
6	ANT 1.1-1.6 × BL, with PT/BASE 5.6-7.7. ANT tubercles distinctly developed. SIPH pale, cylindrical or slightly clavate (Fig.50e), 2.2-3.1 × cauda, which has a distinctly constricted base	…..Ovatomyzus chamaedrys
–	ANT 0.43-0.75 × BL, with PT/BASE 1.4-3.5. ANT tubercles undeveloped or weakly developed. SIPH dusky or dark, tapering, 0.4-2.5 × cauda which is not constricted at base	…..7
7	SIPH 0.4-0.8 (-1.2) × cauda which is helmet-shaped, shorter than its basal width	…..Dysaphis microsiphon
–	SIPH 0.8-2.5 × cauda which is tongue-shaped or tapering, longer than its basal width	…..8
8	Dorsal abdomen with an extensive black patch	…..Aphis craccivora
–	Dorsal abdomen membranous or with scattered dark markings or cross-bands	…..9
9	Hairs on legs very short; posterior hair on hind trochanter only about 0.33 × width of trochantro-femoral suture	…..Aphis calaminthae
–	Hairs on legs longer; posterior hair on hind trochanter 0.5-2.0 × width of trochantro-femoral suture	…..10
10	R IV+V 1.5-1.9 × HT II. ANT PT/BASE 1.4-2.1. Longest hair on ANT III 0.6-0.9 × BD III. (Al. with 2-6 secondary rhinaria on ANT IV)	…..Aphis clinepetae*
–	R IV+V 0.9-1.4 (rarely up to 1.5) × HT II. ANT PT/BASE 1.7-4.0. Longest hair on ANT III 0.3-3.4 × BD III. (Al. usually without, rarely with 1-2, secondary rhinaria on ANT IV)	…..11
11	SIPH 0.87-1.1 × cauda, which bears 4 – (more rarely) 5 hairs. ABD TERG 8 usually with a pale, dusky or dark sclerotic transverse band, and small spots at bases of SIPH	…..Aphis clinopodii
–	SIPH 0.8-2.5 × cauda, which bears 4-19 hairs (more than 5 hairs if SIPH are less than 1.1 × cauda). Dorsal abdomen with or without dark markings	…..12
12	Cauda black and bearing 11-19 hairs. Longest hairs on ANT III 0.8-2.2 × BD III	…..Aphis fabae
–	Cauda pale or dark, bearing 4-8 hairs. Longest hairs on ANT III 0.4-0.8 × BD III	…..13
13	SIPH 1.07-1.43 × cauda. ABD TERG 8 often with a pale, dusky or dark sclerotic transverse band, and small spots at bases of SIPH	…..Aphis origani
–	SIPH 1.3-2.5 × cauda. Dorsal abdomen usually without any dark markings (except in alatiform specimens)	…..Aphis gossypii

*Clintonia*	Asparagaceae
*Clintonia borealis*	Illinoia [borealis], pallida
*C. uniflora*	Ericaphis sp. (A. Jensen, Idaho; aphidtrek.org)
*Clintonia* sp(p).	Ericaphis sp. (A. Jensen, Washington; aphidtrek.org)

*Clitoria*	Fabaceae
*Clitoria ternatea*	Aphis gossypii
Clitoria sp.	Aphis craccivora; Brachycaudus helichrysi

Use key to polyphagous aphids.

*Clusia*	Clusiaceae
*Clusia gundlachii*	Aphis (Toxoptera) aurantii
C. rosea	Aphis (Toxoptera) aurantii

*Clutia*	Peraceae
*Clutia abyssinica*	Aphis citricidus, spiraecola
Clutia sp.	Aphis fabae

Use key to polyphagous aphids.

*Clypeola*	Brassicaceae
*Clypeola jonthiaspi*	Brevicoryne brassicae

*Cnicus*	Asteraceae
Cnicus argyrancanthus = Cirsium argyracanthum
C. arvensis = Cirsium arvense
C. benedictus	Brachycaudus cardui, [persicae]; Myzus persicae;
	Uroleucon aeneum, [sonchi]
C. edelbergii = Carduus edelbergii
C. pauciflorus = Carduus defloratus
C. syriaca = Notobasis syriaca
C. wallichii = Cirsium wallichii
“Cnicus” spp.	Aphis spiraecola; Bipersona ochrocentri, torticauda;
	Brachycaudus helichrysi;
	Capitophorus carduinus, elaeagni;
	Myzus ornatus; Neomyzus circumflexus;
	[Protrama longitarsus ssp. sclerodensis]

Use key to aphids on Cirsium.

*Cnidium*	Apiaceae
*Cnidium ajanense*	Dysaphis cnidii
C. dahuricum (= dauricum?)	Aphis fabae
C. monnieri	Dysaphis sp. near mordvilkoi (China, BMNH collection)
*C. officinale* = Ligusticum officinale
*C. silaifolium*	Cavariella aegopodii

Key to apterae on Cnidium:-

1	ABD TERG 8 with a posteriorly projecting process above cauda. ANT PT/BASE 0.6-1.4. SIPH clavate	…..Cavariella aegopodii
–	No supracaudal process. ANT PT/BASE 2.4-5.3. SIPH clavate, cylindrical or tapering	…..2
2	SIPH very small and flangeless, only about 0.5 of length of cauda or less, with aperture slanted towards midline	…..Semiaphis heraclei
–	SIPH at least 0.6 of length of cauda, and with a distinct flange	…..3
3	Cauda helmet-shaped or pentagonal, not longer than its basal width. Spinal tubercles (STu) present on head, and usually on ABD TERG 8, or 7 and 8. Longest hairs on ANT III 2.1-3.6 × BD III	…..4
–	Cauda tongue-shaped, clearly longer than its basal width. STu absent from head and not usually present on ABD TERG 7 and 8. Longest hairs on ANT III 0.3-2.1 × BD III	…..go to key to polyphagous aphids
4	R IV+V 1.54-1.81 × HT II. ABD TERG 8 with 7-9 hairs	…..Dysaphis cnidii
–	R IV+V 1.05-1.15(-1.33) × HT II. ABD TERG 8 with 4-7 hairs	…..Dysaphis sp. near mordvilkoi (China, BMNH collection)

*Cobaea*	Polemoniaceae
*Cobaea scandens*	Aphis fabae; Myzus persicae

Use key to polyphagous aphids.

*Coccinia*	Cucurbitaceae
*C. adoensis*	Aphis gossypii
C. cordifolia = C. grandis
*C. grandis*	Aphis craccivora, gossypii, nasturtii, [umbrella]
C. indica = C. grandis

Use key to polyphagous aphids.

*Coccocypselum*	Rubiaceae
*Coccocypselum herbaceum*	Aphis gossypii
C. lanceolatum	Aphis gossypii

*Coccoloba*	Polygonaceae
*Coccoloba borinquensis* = C. swartzii
C. diversifolia	Aphis gossypii, nasturtii
C. laurifolia = C. diversifolia
C. obtusifolia	Aphis craccivora
C. pyrifolia	Aphis (Toxoptera) aurantii
C. retusa	Aphis craccivora, spiraecola
C. swartzii	Aphis (Toxoptera) aurantii
C. uvifera	Aphis aurantii, craccivora, gossypii
C. wrightii	Aphis (Toxoptera) aurantii

Use key to polyphagous aphids.

*Cocculus*	Menispermaceae
*Cocculus orbiculatus*	[Schizaphis jaroslavi]
*C. trilobus* = C. orbiculatus

*Cochlearia*	Scurvy-Grasses Brassicaceae
*Cochlearia arctica*	Brevicoryne brassicae
C. armoracia = Armoracia rusticana
C. officinalis	Lipaphis cochleariae; Myzus ascalonicus

Key to apterae on Cochlearia:-

1	ANT tubercles undeveloped, or low with median frontal tubercle developed to a similar extent, so that front of head is convex or strongly sinuous (“W-shaped”) in dorsal view. Dorsal abdomen usually with some paired dark sclerites. ABD TERG 1 and 7 without marginal tubercles (MTu)	…..2
–	ANT tubercles well-developed (or if weakly developed then ABD TERG 1 and 7 always have MTu	…..go to key to polyphagous aphids
2.	Head cuticle smooth with ANT tubercles very low, so that front of head is convex in dorsal view. SIPH dark, 0.8-1.0 × cauda	…..Brevicoryne brassicae
–	Head cuticle rough, with ANT tubercles developed to a similar extent to median frontal tubercles, so that front of head is strongly sinuous (“W-shaped”) in dorsal view. SIPH pale, 1.1-1.5 × cauda	…..Lipaphis cochleariae

*Cocos*	Arecaceae
*Cocos nucifera*	Astegopteryx nipae, rappardi, rhapidis;
	Cerataphis brasiliensis, lataniae; Hysteroneura setariae;
	[Tuberaphis xinglongensis]
*Cocos* sp.	Cerataphis formosana, [freycinetiae]

For key to palm aphids see under Calamus.

*Codariocalyx*	Fabaceae
*Codariocalyx motorius*	Aphis craccivora

*Codonopsis*	Campanulaceae
*Codonopsis clematidea*	[Acyrthosiphon ilka]; [Aphis psammophila];
	Aulacorthum solani; Rhopalomyzus codonopsidis
C. javanica (incl. japonicus)	Neomyzus taiwanus
C. lanceolata	Codonopsimyzus sasammi;
	Meguroleucon codonopsidicola; Neomyzus codonopsis
C. ovata	Aphis fabae
C. pilosula	Meguroleucon codonopsicola

Key to apterae on Codonopsis:-

1	SIPH black and without any distal polygonal reticulation. Cauda black with 11-25 hairs. ABD TERG 1 and 7 with marginal tubercles (MTu)	…..Aphis fabae
–	SIPH pale or dark, if dark then with polygonal reticulation. Cauda pale/dusky, with 5-14 hairs. ABD TERG 1 and 7 without MTu	…..2
2	Head, ANT and SIPH entirely dark. Distal 0.2-0.3 of SIPH with polygonal reticulation	….. Meguroleucon codonopsidicola
–	Head pale, ANT and SIPH mainly pale, sometimes darker at apices. SIPH without polygonal reticulation, or with only a few closed cells near apices	…..3
3	Dorsum without dark markings. Head smooth ventrally as well as dorsally. Cauda with 9-14 hairs	…..4
–	Dorsum with or without a pattern of black markings. Head with spicules at least ventrally. Cauda with 5-7 hairs	…..5
4	SIPH markedly inflated over about distal 0.7 of length, the maximum width of the swelling being more than twice the minimum width of the basal part. ANT III without rhinaria. ANT tubercles low and bearing slightly capitate hairs longer than BD III	…..Rhopalomyzus codonopsidis
–	SIPH cylindrical or only slightly swollen on distal half. ANT III with 1-13 rhinaria distributed in a row over length of segment. ANT tubercles well developed and bearing blunt or capitate hairs less than 0.5 × BD III	…..Codonopsimyzus sasammi*
5	Dorsum without dark markings	…..Aulacorthum solani
–	Dorsum with a conspicuous pattern of black markings	…..6
6	Dorsum with dark transverse bands across pronotum, metanotum and ABD TERG 8, as well as broader bands across mesonotum and ABD TERG 2/3. Head with spicules dorsally as well as ventrally	…..Neomyzus taiwanus
–	Dorsum with broad dark bands across mesonotum and anterior abdomen, but pronotum and metanotum with paired dark patches, and ABD TERG 8 without any dark markings. Head without spicules dorsally	…..Neomyzus codonopsis