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

*Sorbaria*	Rosaceae
*Sorbaria sorbifolia*	[Aphis gossypii]; Chusiphuncula sorbarisucta;
(incl. var. stellipila)	Macrosiphum sorbi; [Rhopalosiphum nymphaeae];
	[Myzus ornatus]
*S. tomentosa*	Myzus [formosanus], sorbi

Key to apterae on Sorbaria:-

(All three species keyed have SIPH more than 2.7 × cauda, which has 5-8 hairs.)

1	SIPH clavate. Head smooth	….. Chusiphuncula sorbarisucta
–	SIPH tapering/cylindrical. Head with spicules at least on ventral surface	…..2
2	SIPH dark, 0.25-0.35 × BL, with moderate imbrication and a subapical zone of polygonal reticulation	…..Macrosiphum sorbi
–	SIPH pale, 0.21-0.23 × BL, with coarse imbrication and no subapical reticulation	…..Myzus sorbi

*Sorbaronia*	Rosaceae
*Sorbaronia hybrida*	Aphis pomi

*Sorbus* Rowans, Whitebeams	Rosaceae
*Sorbus alnifolia*	Nippolachnus micromeli; [Muscaphis japonica];
	[Rhopalosiphum rufiabdominale];
	Sappaphis piri
*S. americana*	American Mountain Ash
(= Aucuparia americana)	Aphis pomi; [Dysaphis sorbi]; Eriosoma lanigerum;
	Ericaphis gentneri; Rhopalosiphum oxyacanthae;
	Muscaphis escherichi
*S. amurensis* = S. pohuashanensis
*S. aria*	Whitebeam
	Aphis [fabae], pomi, lantanae ( as Doralis setacea);
	Dysaphis ariae; Myzus persicae;
	Rhopalosiphum oxyacanthae
*S. aucuparia*	European Mountain Ash or Rowan
	Aphis pomi, spiraecola; Brachycaudus helichrysi;
	Dysaphis [aucupariae], [devecta], [pyri], sorbi;
	Eriosoma [pyricola], sorbiradicis;
	Macrosiphum euphorbiae, pyrifoliae;
	Muscaphis escherichi (incl. ssp. irae);
	Myzus [ascalonicus], ornatus; Nearctaphis californica;
	Ovatus insitus;
	Rhopalosiphum [nymphaeae], oxyacanthae;
	Sorbaphis chaetosiphon;
	[Staegeriella sp. (Bozhko, 1976 – a Muscaphis?)]
*S. caucasigena* = S. aucuparia
*S. commixta*	Japanese Rowan
	Aphis [gossypii], pomi;
	[Myzaphis komatsubarae Shinji 1922c – possibly
	a Dysaphis];
	Nippolachnus micromeli (?); Prociphilus oriens;
	Rhopalosiphum oxyacanthae; Sorbaphis chaetosiphon
*S. corymbifera*	Nippolachnus bengalensis
*S. cuspidata*	Brachycaudus helichrysi; Dysaphis indica;
(= Pyrus vestita)	Eumyzus eastopi
*S. domestica*	Service Tree
(= Cormus domestica)	Dysaphis [aucupariae], [pyri], [reaumuri], sorbi;
	Rhopalosiphum oxyacanthae
*S. foliolosa*	Aspidophorodon (Eoessigia) sorbi
*S. graeca*	Dysaphis pavlovskyana
*S. hybrida*	Aphis pomi; Dysaphis sorbi;
	Rhopalosiphum oxyacanthae
*S. intermedia*	Aphis pomi; Dysaphis sorbi;
	[Metopolophium dirhodum];
	Rhopalosiphum oxyacanthae
*S. japonica* (error for Sorbaria?)	[Macrosiphum (Unisitobion) sorbi]
*S. khasiana*	Dysaphis pyri; Nippolachnus micromeli (?)
*S. lanata*	Dysaphis pavlovskyana
*S. minima* (= Hedlundia minima)	Aphis pomi
*S. persica*	Dysaphis pavlovskyana
*S. pohuashanensis*	Brachycaudus helichrysi; Muscaphis escherichi;
	[Schizaphis piricola]
*S. polycarpa*	Eriosoma lanigerum
*S. quercifolia*	Rhopalosiphum oxyacanthae
*S. randaiensis*	[Rhopalosiphum padi]
*S. sambucifolia*	Muscaphis escherichi
*S. scopulina*	Nearctaphis yohoensis
*S. serotina* = S. commixta
*S. sibirica*	Aphis pomi; Dysaphis pavlovskyana, sorbi;
	Rhopalosiphum oxyacanthae
*S. sitchensis*	Brachycaudus helichrysi;
	Macrosiphum opportunisticum, pyrifoliae;
	Muscaphis escherichi
*S. subsimilis*	Rhopalosiphum oxyacanthae
*S. tianshanica*	Dysaphis pavlovskyana, sorbi;
	Rhopalosiphum oxyacanthae
*S. torminalis*	Wild Service Tree
	Aphis pomi; Dysaphis aucupariae, sorbi;
	Rhopalosiphum oxyacanthae
*S. turkestanica*	Aphis pomi; Dysaphis pavlovskyana
*Sorbus* spp.	[Dysaphis plantaginis]; Prociphilus corrugatans

Key to species on Sorbus (apterous viviparae except where otherwise stated):-

1	ANT PT/BASE less than 0.5. Cauda broadly rounded	…..2
–	ANT PT/BASE more than 0.5. Cauda semicircular, helmet-shaped, tongue- or finger-shaped	…..7

2	Wax glands absent. Eyes multifaceted, without an ocular tubercle. Body pale, elongate, more than 2 × longer than wide. (Alata with a quadrate black dorsal abdominal patch)	…..3
–	Wax glands present. Eyes 3-faceted. Body broad, less than 2 × longer than wide. (Alata without dorsal abdominal pigment)	…..4
3	ANT PT/BASE 0.25-0.35, without any long fine hairs distal to primary rhinarium. R IV+V bearing 9-16 accessory hairs	…..Nippolachnus bengalensis
–	ANT PT/BASE 0.45-0.75, with some long fine hairs distal to primary rhinarium. R IV+V bearing more than 20 accessory hairs	…..Nippolachnus micromeli
4	SIPH present as pores with surrounding hairs. Wax pore plates each comprising a ring or group of facets around one or more clear central areas	…..5
–	SIPH absent or inconspicuous. Wax pore plates honeycomb-like, without clear central areas	…..6
5	BL more than 1.5 mm. Total antennal length 0.29-0.46 mm. Wax pore plates with central areas of irregular shape, often subdivided (fig. 60C)	…..Eriosoma lanigerum
–	BL less than 1.4 mm, with total antennal length only 0.12-0.18 mm. Wax pore plates with always undivided, approximately circular, central areas (fig. 109A)	…..Eriosoma sorbiradicis

6	R IV+V (of fundatrix) more than 0.2 mm long and bearing 7 or more accessory hairs. BL of spring migrant alata more than 4 mm	…..Prociphilus oriens
–	R IV+V (of fundatrix) less than 0.2 mm long with 2-4 accessory hairs. BL of spring migrant alata less than 3 mm	…..Prociphilus corrugatans
7	Cauda short; helmet-shaped, triangular or semicircular, shorter than or about as long as its basal width in dorsal view	…..8
–	Cauda tongue- or finger-shaped, clearly longer than its basal width in dorsal view	…..18
8	Dorsal cuticle of aptera (fundatrix) very rough with numerous small denticulate projections, and with fine, long hairs (fig. 109B). Alata with transverse bars of dorsal abdominal pigment, often broken, never fused between tergites	…..Muscaphis escherichi
–	Dorsal cuticle of aptera (fundatrix or subsequent generation) smooth or weakly reticulate, with long or short hairs. Alata with a solid black dorsal abdominal patch, or with extensive bars fused between some tergites	…..9
9	SIPH more than 4 × cauda and bearing a number of long hairs (in both fundatrix and spring migrant alata)	…..Sorbaphis chaetosiphon
–	SIPH less than 4 × cauda and without hairs	…..10
10	SIPH with closely-spaced rows of imbrications bearing small nodules or spinules (e.g. fig. 42M)	…..11
–	SIPH smooth or normally imbricated, the imbrications sometimes spinulose but not in regular closely-spaced rows	…..12
11	ABD TERG 2-4 each with incomplete double rows of 6-10 spinopleural hairs 50-70 µm long with fine apices. Tergum rough, with numerous spinules arranged on a distinct reticulation (fig. 109C), and with an extensive solid black abdominal patch	…..Nearctaphis yohoensis

–	ABD TERG 2-4 each with a single row of 4 spinopleural hairs that are blunt or acuminate. Tergum with faint reticulation and few spinules, and broad transverse sclerotic bars that are not or only partially fused between tergites	…..Nearctaphis californica
12	SIPH smooth, less than 2 × width at base. Spiracular apertures rounded	…..Brachycaudus helichrysi

–

SIPH imbricated, more than 2 × width at base. Spiracular apertures small and reniform

…..13

13	SIPH pale and swollen on distal half, with narrower region proximal to swelling (fig. 109D)	…..14
–	SIPH pale or dark, cylindrical or tapering, or with hardly perceptible swelling	…..15
14	R IV+V 0.13-0.195 mm. SIPH less than 2.5 × longer than cauda. Head with granulate spinulosity	…..Dysaphis pavlovskyana
–	R IV+V 0.20-0.22 mm. SIPH more than 2.5 × longer than cauda. Head cuticle without granulate spinulosity	…..Dysaphis indica
15	SIPH pale. Marginal tubercles present on ABD TERG 1-7 (sometimes absent from 6). Cauda with 6-12 hairs	…..Dysaphis sorbi
–	SIPH dark, at least on distal part. Marginal tubercles present on ABD TERG 1-4 or 1-5, absent from 6 and 7. Cauda with 5, or rarely 6, hairs	…..16
16	Hairs on ANT III pointed, maximally 0.9-1.5× basal diameter of segment	…..Dysaphis aucupariae

–	Hairs on ANT III blunt, maximally 0.3-0.8 × basal diameter of segment	…..17
17	Hairs on ABD TERG 1-3 consistently short and blunt, maximally 15-20 µm	…..Dysaphis ariae

–	Hairs on ABD TERG 1-3 of variable length, often short and blunt but usually with some pointed hairs 20-60 µm long, especially marginally	…..Dysaphis plantaginea
18	ANT PT/BASE 0.55-0.66. Body with finger-like dorsal processes (head with 2 pairs, thoracic segments and ABD TERG 1-4 each with one spinal and one marginal pair, and ABD TERG 5-8 each with a single medial process	…..Aspidophorodon (Eoessigia) sorbi
–	ANT PT/BASE more than 1. Body without finger-like dorsal processes …..19	…..19
19	Dorsal cuticle sclerotic and strongly corrugated. R IV+V 1.68-1.90 × HT II and with 2 accessory hairs	…..Eumyzus eastopi
–	Dorsal cuticle not strongly corrugated. R IV+V either less than 1.6 × HT II or with more than 2 accessory hairs	…..20
20	Antennal tubercles undeveloped or weakly developed, not exceeding height of central part of frons in dorsal view. Cauda and anal plate dusky to dark	…..21
–	Antennal tubercles moderately to well developed, clearly exceeding height of central part of frons in dorsal view. Cauda and anal plate pale or only slightly dusky	…..24
21	SIPH slightly swollen or cylindrical over most of length, constricted subapically and with a large flange (as in fig. 60H). Marginal tubercles on ABD TERG 7 placed posterio-dorsad of spiracle and with basal diameter usually smaller than spiracular aperture	…..Rhopalosiphum oxyacanthae

–	SIPH tapering from base to flange, which is only moderately developed. Marginal tubercles on ABD TERG 7 placed posterioventrad of spiracle, and usually larger than spiracular aperture	…..22
22	Longest hairs on ANT III more than 2 × basal diameter of segment. ANT PT/BASE more than 3. Alata with secondary rhinaria distributed ANT III 19-28, IV 1-11, V 0-3. Cauda tapering, less than 2 × its basal width	…..Aphis lantanae (or setacea? – see text)
–	Longest hairs on ANT III less than 1.8 × basal diameter of segment. ANT PT/BASE less than 3. Alata with secondary rhinaria distributed ANT III 6-11, IV 0-4, V 0. Cauda finger-like, more than 2 × its basal width	…..23
23	Marginal tubercles present on ABD TERG 2-4. Cauda with 10-19 hairs (rarely less than 13). R IV+V more than 0.13 mm	…..Aphis pomi
–	Marginal tubercles absent from ABD TERG 2-4. Cauda with 7-15 hairs (rarely more than 12). R IV+V less than 0.125	…..Aphis spiraecola
24	Inner faces of antennal tubercles scabrous and convergent in dorsal view (e.g. fig. 42I)	…..25

–	Inner faces of antennal tubercles smooth or nearly so, and divergent in dorsal view (e.g. fig. 42K)	…..27
25	Dorsal abdomen with a pattern of dark intersegmental spots and flecks (fig. 121J). ANT PT/BASE less than 2.5	…..Myzus ornatus
–	Dorsal abdomen without clear intersegmental dark markings. ANT PT/BASE more than 3	…..26

26	SIPH slightly swollen on distal half (fig. 121H). ANT PT/BASE less than 5. (Alata with secondary rhinaria only on ANT III)	…..Myzus persicae
–	SIPH tapering or cylindrical on distal half. ANT PT/BASE more than 5. (Alata with secondary rhinaria distributed ANT III 60-83, IV 36-52, V 13-22)	…..Ovatus insitus
27	Body oval. SIPH without any polygonal reticulation (fig. 42Q). ANT III with one small rhinarium near base, and with minute hairs less than half basal diameter of segment	…..Ericaphis gentneri
–	Body spindle-shaped. SIPH with a subapical zone of polygonal reticulation (fig. 121C). ANT III usually with several secondary rhinaria near base, and with longest hairs more than half basal diameter of segment	…..28
28	Cauda with 6-9 hairs. ANT BASE VI 0.20-0.27 mm. Longest hairs on ANT III 10-24 μm, 0.4-0.7 × BD III. (Al. with paired pleural dark patches and large marginal and postsiphuncular sclerites)	…..Macrosiphum opportunisticum
–	Cauda with 8-13 hairs. ANT BASE VI 0.14-0.20 mm. Longest hairs on ANT III 25-40 μm, 0.6-1.0 × BD III. (Al. without dark dorsal abdominal sclerites)	…..Macrosiphum pyrifoliae/euphorbiae

*Sorghastrum*	Poaceae
*Sorghastrum nutans*	Hysteroneura setariae
Sorghastrum sp.	Sipha flava
Use key to apterae of grass-feeding aphids under Digitaria.

*Sorghum*	Poaceae
*Sorghum arundinaceum*	Melanaphis sacchari, sorghi; Rhopalosiphum maidis
S. bicolor (incl. vars	Anoecia corni, fulviabdominalis, krizusi;
drummondii, saccharatum)	Aphis fabae, gossypii; Diuraphis noxia;
	[Chaitophorus populialbae (as Myzocallis saccharinus)?];
	Forda hirsuta, orientalis;
	Geoica lucifuga; Hysteroneura setariae;
	Melanaphis sacchari, sorghi; Myzus persicae;
	Paracletus cimiciformis; Rhopalosiphum maidis, padi;
	Schizaphis grmainum; Sipha flava, maydis;
	Sitobion africanum, avenae, leelamaniae, miscanthi,
	[Sitobion sp. (Millar 1994)];
	Tetraneura capitata, chui, fusiformis, javensis,
	nigriabdominalis, nigriabdominalis ssp. shanxiensis,
	triangula, ulmi
S. caffrorum = S. bicolor
*S. caudatum* = S. bicolor
*S. cernuum* = S. bicolor
*S. dochna* = S. bicolor
*S. dora* = S. bicolor
S. durra = S. bicolor
*S. fulvum* = S. nitidum
*S. guineense* = S. bicolor
*S. halepense*	Anoecia corni, mirae, vagans; Aphis fabae;
	Forda marginata; Geoica lucifuga, utricularia;
	Melanaphis pyraria, sacchari, sorghi;
	Metopolophium dirhodum, festucae;
	Paracletus bykovi ssp. uzbekistanicus, cimiciformis;
	[Prociphilus bumeliae]; Pseudaphis sijui;
	Rhopalosiphum maidis, padi, rufiabdominale;
	Schizaphis agrostis, graminum; Sipha flava, maydis;
	Sitobion avenae; [Slavum lentiscoides];
	Tetraneura africana, caerulescens, fusiformis, ulmi
S. *“kavirondo”* see S. arundinacearum
*S. nervosum* = S. bicolor
*S. nigricans* = S. bicolor
S. nitidum	Rhopalosiphum maidis
*S. roxburghii*	Melanaphis sorghi; Rhopalosiphum maidis
*S. saccharatum* = S. bicolor
S. sudanense	Rhopalosiphum maidis; Sipha elegans
S. verticilliflorum = S. arundinacearum
*S. virgatum*	Rhopalosiphum maidis, padi; Schizaphis graminum;
	Sitobion avenae
*S. vulgare* = S. bicolor

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

*Sparaxis*	Iridaceae
Sparaxis bulbifera	Myzus persicae
S. tricolor	Aphis gossypii; Macrosiphum euphorbiae;
	Smynthurodes betae
Sparaxis spp. (and hybrids)	Myzus persicae; Neomyzus circumflexus

Use key to polyphagous aphids.

*Sparganium*	Typhaceae
*Sparganium emersum*	Rhopalosiphum nymphaeae
*S. erectum* (incl. ssp. neglectum)	Rhopalosiphum nymphaeae; Schizaphis scirpi
S. neglectum = S. erectum ssp. neglectum
*S. ramosum* = S. erectum
S. simplex = S. emersum
Sparganium sp.	Rhopalosiphum enigmae

Key to apterae on Sparganium:-

1	ANT and dorsal body with very long, fine hairs, up to 3 × ANT BD III. Dorsal cuticle without spiculose ornamentation	…..Schizaphis scirpi
–	ANT and dorsal body with shorter hairs. Dorsal cuticle with a pattern of spicules arranged in polygons, each polygon enclosing one or more additional spicules	…..2
2	SIPH clavate. Longest hairs on ANT III less than 0.8 × BD III	…..Rhopalosiphum nymphaeae
–	SIPH not clavate. Longest hairs on ANT III 0.8-2.0 × BD III	…..Rhopalosiphum enigmae

*Sparmannia*	Malvaceae
*Sparmannia africana*	Uroleucon compositae
*Sparmannia* sp.	Myzus ornatus

Use key to polyphagous aphids.

*Spartina*	Poaceae
*Spartina cynosuroides*	Anoecia corni
S. juncea = S. patens
S. maritima	Sipha littoralis
S. patens	Prociphilus erigeronensis
S. stricta = S. maritima
S. × townsendii	Sipha littoralis
Use key to apterae of grass-feeding aphids under Digitaria.

*Spartium*	Fabaceae
Spartium junceum	Acyrthosiphon gossypii, pisum;
	Aphis craccivora, cytisorum, fabae, genistae,
	[pseudocytisorum]
	[Eriosoma sparthani (Boisduval; nomen dubium)]
S. scoparium = Cytisus scoparius
*S. supranubium* = Cytisus supranubius

Key to apterae on Spartium:-

1	Body spindle-shaped, pale. ANT longer than BL. SIPH pale, thin and cylindrical on distal half. Cauda elongate finger-shaped, pale	…..2
–	Body oval, often with dark dorsal markings. ANT shorter than BL. SIPH dark, tapering from base to apex. Cauda tongue-shaped, pale or dark	…..3
2	SIPH 0.42-0.50 × BL and 2.5-3.5 × cauda	…..Acyrthosiphon gossypii
–	SIPH 0.23-0.38 × BL and 1.2-1.9 × cauda	…..Acyrthosiphon pisum
3	Cauda with 11-25 hairs. Dorsal abdomen usually with a few small dark spots on tergites anterior to SIPH	…..Aphis fabae
–	Cauda with 4-13 hairs. Dorsal abdomen usually with extensive dark sclerotisation	…..4
4	SIPH 0.5-0.8 × cauda. Hairs on ANT III 0.8-1.3 × BD III	…..Aphis genistae
–	SIPH 1.1-2.2 × cauda. Hairs on ANT III 0.05-0.75 × BD III	…..5
5	R IV+V 0.88-1.16 × HT II (mostly 0.9-1.05 ×). Anterior half of genital plate with 2 (-3) hairs	…..Aphis craccivora

–

R IV+V 0.97-1.3 × HT II (mostly 1.06-1.2 ×). Anterior half of genital plate with 2-8 hairs (mode 4, mean 5.2)

…..Aphis cytisorum

*Spathiphyllum*	Araceae
*Spathiphyllum floribundum*	Pentalonia nigronervosa

*Spathodea*	Bignoniaceae
*Spathodea campanulata*	Aphis gossypii, spiraecola;
	Neomyzus circumflexus
*S. diepenhorstii*	Aphis odinae
*S. nilotica*	Aphis gossypii

Use key to polyphagous aphids.

*Spatularia*	Saxifragaceae
*Spatularia michauxii*	Nasonovia carolinensis

Or use key to apterae on Saxifraga.

*Specklinia*	Orchidaceae
*Specklinia corniculata*	Cerataphis orchidearum

Specularia see Legousia

Campanulaceae

*Spergula*	Caryophyllaceae
*Spergula arvensis*	Aphis gossypii, nasturtii, sambuci; Myzus persicae;
	Neomyzus circumflexus; Sitobion avenae

See key under Spergularia.

*Spergularia*	Caryophyllaceae
*Spergularia diandra*	Myzus persicae
S. marina	Aphidura urmiensis; Aphis nasturtii;
	[Myzus sp. (Leonard 1968:357)]
*S. media*	Myzus persicae
S. rubra	Macrosiphum euphorbiae; Myzus certus, persicae
S. rupicola	Myzus persicae
Spergularia spp.	Aphis sambuci; Sitobion avenae

Key to aphids on Spergula and Spergularia:-

1	Anterior part of mesosternum with a pair of rounded mammariform processes	…..Aphidura urmiensis
–	Mesosternum without mammariform processes	…..2
2	Head without spicules	…..3
–	Head densely spiculose	…..7
3	SIPH with a subapical zone of polygonal reticulation. ABD TERG 1 and 7 without marginal tubercles (MTu)	…..4
–	SIPH without subapical reticulation. ABD TERG 1 and 7 with MTu	…..5
4	SIPH dark, 1.1-1.4 × cauda, with reticulation on distal 0.19-0.35 of length. ANT hairs maximally 0.3-0.5 × BD III	…..Sitobion avenae
–	SIPH pale, 1.7-2.2 × cauda, with reticulation on distal 0.13-0.2 of length. ANT hairs maximally 0.6-1.0 × BD III	…..Macrosiphum euphorbiae
5	SIPH black, 2.1-3.5 × cauda which is short and bears 10-20 hairs. ABD TERG 2-4 consistently with well-developed flat MTu	…..Aphis sambuci
–	SIPH pale or dark, 0.9-2.2 × cauda which is much longer than its basal width and bears 4-11 hairs. ABD TERG 2-4 only sporadically with small MTu	…..6
6	SIPH uniformly dark. Hairs on hind femur all shorter than diameter of femur at its base	…..Aphis gossypii

–	SIPH usually rather pale, darker at apex. Hairs on hind femur mainly longer, some of them about as long as, or longer than, diameter of femur at its base	…..Aphis nasturtii
7	Dorsal abdomen with a large roughly horseshoe-shaped patch, and dark cross bars on thorax. SIPH not clavate	…..Neomyzus circumflexus
–	Dorsum without any distinctive dark markings. SIPH at least slightly clavate	…..8
8	R IV+V in most specimens with only one pair of lateral accessory hairs (plus 0-3 ventral accessory hairs). Value of function CAUDA/(ANT III × PT) in range 0.80-1.52, but rarely more than 1.25 except in small specimens (those with ANT III less than 0.32 mm)	…..Myzus persicae

–

R IV+V in most specimens with two pairs of lateral accessory hairs. Value of function CAUDA/(ANT III × PT) in range 1.2-2.7 (rarely less than 1.25)

…..Myzus certus

*Spermacoce* (including Borreria)	Rubiaceae
*Spermacoce* spp.	Aphis gossypii, spiraecola; Macrosiphum euphorbiae;
	Myzus persicae; Uroleucon compositae

[One or more of the above polyphagous aphid species have been recorded from each of the following Spermacoce spp.: chaetocephala, densiflora, eupatorioides, hispida, laevis, octodon, ocymifolia, ocymoides, princeae, pusilla, ruelliae, scabra, senensis, stachydea, verticillata.]

Use the key to polyphagous aphids.

*Spermadictyon*	Rubiaceae
*Spermadictyon suaeveolens*	Aphis gossypii, spiraecola

Use key to polyphagous aphids.

*Sphaeralcea*	Malvaceae
*Sphaeralcea coccinea*	Myzus persicae; Neomyzus circumflexus
S. fendleri	Aphis gossypii
S. miniata	Aphis craccivora
*Sphaeralcea* sp.	Uroleucon ambrosiae

Use key to polyphagous aphids.

*Sphaeranthus*	Asteraceae
*Sphaeranthus flexuosus*	Aphis gossypii
S. suaeveolens	Myzus ornatus

Use key to polyphagous aphids.

*Sphaerophysa*	Fabaceae
*Sphaerophysa salsula*	Aphis craccivora (? – as laburni)

*Sphagneticola*	Asteraceae
*Sphagneticola trilobata*	Acyrthosiphon bidenticola; Aphis fabae, gossypii;
	Neomyzus circumflexus; Rhopalosiphum nymphaeae;
	Uroleucon ambrosiae

Use key under Wedelia.

*Sphagnum*	Sphagnaceae
*Sphagnum capillifolium*	[Pachypappa sacculi]
*S. magellanicum*	Pseudacaudella rubida
*S. recurvum*	Pseudacaudella rubida
S. rubellum	Myzodium modestum; [Pachypappa sacculi]
S. russowii	[Pachypappa rosettei]
*Sphagnum* sp.	Melaphis rhois; [Prociphilus xylostei]

Use key to aphids on mosses under Polytrichum.

*Sphallerocarpus*	Apiaceae
*Sphallerocarpus gracilis*	[Dysaphis sibirica (?)]

Sphenogyne see Ursinia

Asteraceae

*Sphenomeris*	Dennstaedtiaceae
*Sphenomeris chinensis*	Micromyzella filicis

(or use key to fern-feeding aphids under Polypodium)

*Sphenopholis*	Poaceae
*Sphenopholis nitida*	Carolinaia rhois

(or use key to apterae of grass-feeding aphids under Digitaria)

*Spilanthes*	Asteraceae
*Spilanthes acmella*	Aphis gossypii, spiraecola; Brachycaudus helichrysi;
	Myzus persicae; Uroleucon compositae
S. acuminata (?)	Myzus persicae
S. iabadicensis = Acmella uliginosa
S. urens	Aphis coreopsidis, gossypii

Key to apterae on Spilanthes:-

–	ANT III-VI dark, contrasting with pale ANT I-II and head, which has ANT tubercles weakly developed. SIPH long, thin and black, 0.24-0.4 × BL, contrasting with pale cauda, and without polygonal reticulation	…..Aphis coreopsidis
–	Without the above combination of characters	…..go to key to polyphagous aphids

*Spinacia*	Amaranthaceae
*Spinacia oleracea*	Aphis craccivora, fabae, gossypii, solanella, spiraecola;
	Aulacorthum solani; Hayhurstia atriplicis;
	[Lipaphis erysimi]; Macrosiphum euphorbiae;
	Myzus ornatus, persicae; Neomyzus circumflexus;
	Pemphigus sp(p); [Sitobion miscanthi]

Use key to apterae on Beta.

*Spiraea* (including Opulaster)	Rosaceae
*Spiraea alba*	Acyrthosiphon ignotum; Aphis pomi, spiraecola;
	Brachycaudus spiraeae
S. alba var. latifolia	Acyrthosiphon ignotum, pseudodirhodum;
	Aphis spiraecola, spiraephila; Illinoia spiraecola
S. aquilegifolia	Aphis spiraephaga
S. ×arguta	Acyrthosiphon ignotum;
	Aphis fabae, spiraecola, spiraephaga;
	Brachycaudus spiraeae; Illinoia spiraeae
S. aruncus = Aruncus sylvester
S. baldshuanica	Tricaudatus polygoni
S. bella	Acyrthosiphon ignotum; Aphis fabae, spiraecola;
	Brachycaudus helichrysi; Myzus ornatus, persicae;
	Tricaudatus polygoni
S. betulifolia	Aphis spiraecola, spiraephaga, spiraephila
S. betulifolia var. corymbosa	Aphis spiraecola; Brachycaudus helichrysi;
	[Schoutedenia ralumensis]; Sitobion rosaeiformis;
	Tricaudatus polygoni
S. billardii	Acyrthosiphon ignotum; Aphis spiraephaga;
	Brachycaudus spiraeae
S. blumei	Aphis spiraecola; Myzus persicae
S. bullata = S. japonica var. bullata
S. ×bumalda	Acyrthosiphon ignotum;
	Aphis fabae, spiraecola, spiraephaga;
	Brachycaudus spiraeae; Illinoia spiraeae;
	Macrosiphum euphorbiae
S. callosa = S. japonica
S. canescens	Acyrthosiphon ignotum; Aphis spiraephaga;
	[Cavariella himachali]
*S. cantoniensis*	Aphis fabae, gossypii, [odinae], pomi, spiraecola,
	spiraephaga;
	Macrosiphum euphorbiae; Parachaitophorus spiraeae
S. chamaedryfolia	Acyrthosiphon ignotum;
	Aphis fabae, grandis, pomi, spiraecola, spiraephaga,
	ucrainensis;
	Brachycaudus spiraeae; Pseudomegoura magnolia;
	Tricaudatus polygoni
S. chartacea	Aphis spiraecola
S. ×cinerea	Acyrthosiphon ignotum
S. corymbosa = S. betulifolia var. corymbosa
*S. crenata*	Acyrthosiphon ignotum;
	Aphis pomi, spiraecola, spiraephaga, ucrainensis;
	Macrosiphum euphorbiae; Myzus persicae
S. densiflora var. splendens	Aphis spiraecola
S. douglasii	Acyrthosiphon ignotum;
	Aphis fabae, pomi, spiraecola, spiraephila;
	Aspidophorodon longicauda; Brachycaudus spiraeae;
	Illinoia spiraeae;
	Macrosiphum euphorbiae, willamettense;
	[aphid gall – Wahlgren 1956, 51]
*S. douglasii* ssp. menziesii	Aspidophorodon longicauda; Brachycaudus spiraeae;
	Macrosiphum euphorbiae
*S. elegans*	Aphis spiraephila
S. filipendula see Filipendula vulgaris
S. flexuosa	Aphis spiraephaga; Tricaudatus polygoni
S. florepleno = S. prunifolia var. florepleno
*S. fritschiana*	Aphis spiraecola
S. gemmata = S. mongolica
S. hypericifolia	Acyrthosiphon ignotum, soldatovi
	Aphis [craccivora], grandis, spiraecola, spiraephaga,
	ucrainensis;
	[Avicennina sogdiana]; Brachycaudus spiraeae;
	Tricaudatus polygoni
S. japonica (incl. vars acuminata,	Aphis fabae, gossypii, pomi, spiraecola, spiraephaga;
alpina, bullata)	Brachycaudus spiraeae; Illinoia spiraeae;
	Macrosiphum euphorbiae, Macrosiphum sp. (Canada, BMNH collection);
	Myzus ornatus, persicae; Parachaitophorus spiraeae
S. koreana = S. fritschiana
S. lanceolata	Aphis neospiraeae
S. lasiocarpa	Aphis spiraephaga, ucrainensis; Brachycaudus spiraeae
S. latifolia = S. alba var. latifolia
S. lindleyana	Myzus sp. (primary host form of M. ornatus? – see text)
S. longigemmis	Aphis spiraecola; Myzus persicae
S. media	Acyrthosiphon ignotum, soldatovi;
	Aphis grandis, grata, mutini, pomi, spiraecola,
	spiraephaga, ucrainensis;
	Brachycaudus spiraeae; Tricaudatus polygoni
S. menziesii = S. douglasii var. menziesii
S. microgyna	Aphis spiraecola
S. mongolica	Aphis spiraecola; Myzus persicae
S. nipponica (incl. var. tosaensis)	Acyrthosiphon ignotum; Aphis spiraecola, spiraephaga;
	Myzus persicae
S. obovata	Acyrthosiphon ignotum; Aphis fabae
S. opulifolia = Opulaster opulifolius
*S. pilosa*	Aphis spiraecola
*S. plena* = S. prunifolia
S. prunifolia (incl. vars florepleno, Acyrthosiphon ignotum; Aphis spiraecola, spiraephaga; simpliciflora)
	Brachycaudus spiraeae
S. ×pseudosalicifolia	Brachycaudus spiraeae
*S. salicifolia*	Acyrthosiphon ignotum, [leleji], soldatovi;
	Aphis fabae, neospiraeae, pomi, spiraecola, spiraephaga,
	ucrainensis, ulmariae;
	Brachycaudus spiraeae; Illinoia spiraecola;
	Macrosiphum cholodkovskyi, rosae;
	Parachaitophorus spiraeae
S. sargentiana	Aphis pomi
S. ×semiflorens	Acyrthosiphon ignotum
S. sericea	Acyrthosiphon ignotum
S. sorbifolia = Sorbaria sorbifolia
S. splendens = S. densiflora var. splendens
S. stevenii	Aphis grata, kamtchatica
S. thalictroides = S. aquilegifolia
S. thunbergii	Acyrthosiphon ignotum;
	Aphis [kogomecola], spiraecola, spiraephaga;
	Illinoia spiraecola; [aphid gall – Wahlgren 1956, 51];
	Parachaitophorus spiraeae
*S. tomentosa*	Aphis spiraecola
*S. tosaensis* = S. nipponica var. tosaensis
*S. trichocarpa*	Acyrthosiphon ignotum; Aphis spiraecola, spiraephaga;
	Myzus persicae
S. trilobata	Aphis [craccivora], spiraephaga, ucrainensis;
	Brachycaudus spiraeae
S. ulmaria = Filipendula ulmaria
S. ulmifolia	Aphis spiraecola; Brachycaudus spiraeae;
	Myzus persicae
S. ussuriensis = S. chamaedryfolia
S. vaccinifolia	Aphis fabae
S. ×vanhouttei	Acyrthosiphon ignotum;
	Aphis gossypii, pomi, spiraecola, spiraephaga,
	ucrainensis;
	Brachycaudus spiraeae; Illinoia spiraeae
S. vestita = Filipendula vestita
S. wilsonii	Aphis spiraephaga
Spiraea spp.	Acyrthosiphon rubi; [Aphis (Toxoptera) citricidus];
	[Clethrobius dryobius]; Illinoia macgillivrayae;
	Macrosiphum [opportunisticum], pachysiphon;
	[Metopolophium sonchifoliae]; Myzus cymbalariae;
	[Myzakkaia verbasci]; [Neobetulaphis immaculata];
	Neomyzus circumflexus; [Schoutedenia emblica];
	[Semiaphis heraclei]; [Tuberaphis indica]

Key to apterae on Spiraea:-

1	Dorsal body hairs very long and thick, arising from tuberculate bases on dark scleroites. Eyes reduced, often to 3 facets. SIPH as dark, very broad-based cones. Cauda with just 2 long hairs	…..Parachaitophorus spiraeae
–	Dorsal body hairs shorter or fine if long, not arising from tuberculate bases on dark scleroites. Eyes large, multifacetted. SIPH tubular, pale or dark. Cauda with 4 or more hairs	…..2

2	ABD TERG 1 and 7 with marginal tubercles (MTu)	…..3
–	ABD TERG 1 and 7 without MTu	…..15
3	SIPH short, only 0.4-0.5 × cauda, which bears 13-16 hairs. ANT PT/BASE 1.3-1.5	…..Aphis spiraephila

–	SIPH 0.6-2.5 × cauda. ANT PT/BASE 1.0-2.9, but if less than 1.7 then cauda bears less than 13 hairs	…..4
4	Abdomen with either a dark dorsal shield or at least some scattered dark markings on ABD TERG 1-6, following the polygonal pattern of reticulation of the cuticle, and usually with dark transverse sclerites on ABD TERG 7 and 8	…..5
–	Abdomen without any dark markings on ABD TERG 1-6, and without or with only lightly-pigmented sclerites on 8, or 7 and 8	…..12
5	ABD TERG 2-4 as well as 1 and 7 with well-developed marginal tubercles (MTu)	……6
–	MTu only consistently present on (prothorax and) ABD TERG 1 and 7	…..7
6	ABD TERG 1-6 with an extensive dark shield. SIPH 0.7-1.15 × cauda. Longest hairs on ANT III 0.5-1.0 × BD III	…..Aphis ucrainensis*
–	ABD TERG 1-6 with scattered dark markings. SIPH at least 1.5 × cauda. Longest hairs on ANT III more than 1.5 × BD III	…..Aphis kamtchatica*
7	ANT III with 1-6 rhinaria. ANT PT/BASE 1.0-1.5. Tergum with extensive dark sclerotisation	…..Aphis mutini*
–	ANT III usually without rhinaria (except in alatiform specimens). ANT PT/BASE 1.4-3.5. Tergum with or without extensive dark sclerotisation	…..8
8	Longest hairs on ANT III 0.5-0.9 × BD III. R IV+V 0.65-0.92 × HT II	…..Aphis spiraephaga

–	Longest hairs on ANT III 0.8-3.4 × BD III, but if shorter than BD III then R IV+V is more than 0.92 × HT II	…..9
9	ABD TERG 1-6 as well as 7 and 8 with broad dark cross-bands. BL 2.7-3.1 mm	…..Aphis grandis*

–	ABD TERG 1– 6 without broad dark cross bands. BL 1.3-3.6 mm	…..10
10	ABD TERG 7 and 8 (or 6-8) with dark dorsal cross-bands, but ABD TERG 1-5 with only small, scattered sclerites. SIPH 0.8-1.6 × cauda. R IV+V 0.9-1.1 × HT II	…..Aphis fabae
–	ABD TERG 7 and 8 with or without narrow cross-bands, but ABD TERG 1-5 with more extensive sclerotisation, usually comprising an irregular perforated and often incomplete spinal stripe or central patch. SIPH 0.6-1.0 × cauda. R IV+V 0.7-1.0 × HT II	…..11
11	Longest hairs on ANT III 1.6-2.2 × BD III. ANT PT/BASE 1.8-2.45. R IV+V 0.85-1.2 × HT II. Cauda with 9-23 hairs	…..Aphis neospiraeae
–	Longest hairs on ANT III 1.1-1.6 × BD III. ANT PT/BASE 1.4-2.0. R IV+V 0.7-0.9 × HT II. Cauda with 3-11 hairs	…..Aphis grata
12	Femoral hairs all shorter than trochantro-femoral suture. Longest hairs on ANT III 0.4-0.8 × BD III. Cauda with 4-8 hairs	…..Aphis gossypii
–	Femora with at least some long, fine-pointed hairs, longer than trochantro-femoral suture. Longest hair on ANT III 0.5-1.7 × BD III. Cauda with 6-19 hairs	…..13
13	Cauda pale or dusky, without any constriction at midlength, less than 2 × longer than its midlength width. SIPH pale, dusky or dark, if dark then often less so in middle region. ABD TERG 2-4 often with MTu	…..Aphis ulmariae
–	Cauda dark, with a midlength constriction, and more than 2 × longer than its width at the narrowest midlength point. SIPH dark. ABD TERG 2-4 with or without MTu	…..14
14	Marginal tubercles (MTu) present on ABD TERG 2-4. Cauda with 10-19 hairs (rarely less than 13) R IV+V more than 0.13 mm	…..Aphis pomi
–	MTu absent from ABD TERG 2-4. Cauda with 7-15 hairs (rarely more than 12). R IV+V less than 0.125 mm	…..Aphis spiraecola
15	SIPH with subapical reticulation (at least 3-4 rows of closed polygonal cells)	…..16
–	SIPH without subapical polygonal reticulation (sometimes with a few transverse interconnected striae)	…..25
16	SIPH dark for at least distal half of length	…..17
–	SIPH pale, or dark only towards apices	…..19
17	SIPH thick, tapering, c. 6-7 × longer than their diameter at midlength, with a very small flange	…..Macrosiphum pachysiphon
–	SIPH almost cylindrical for most of length, 9-19 × longer than their diameter at midlength, with a rather well-developed flange	…..18
18	Front of head black. ANT III with 10-35 rhinaria. Longest hairs on ANT III 0.7-1.1 × BD III. SIPH 1.9-2.4 × cauda	…..Macrosiphum rosae
–	Front of head pale/dusky. ANT III with 3-5 rhinaria. Longest hairs on ANT III 0.4-0.55 × BD III. SIPH 1.5-2.0 × cauda	…..Sitobion rosaeiformis
19	SIPH swollen on distal third to 1.2-1.5 × their minimum diameter basad. Longest hairs on ANT III 0.2-0.45 × BD III	…..20
–	SIPH cylindrical on distal half (except that subapical reticulated section may be somewhat constricted). Longest hairs on ANT III 0.5-1.2 × BD III	…..22
20	First tarsal joints with 3 hairs. Longest hairs on ANT III 0.30-0.45 × BD III. ANT V 1.8-2.4 × cauda. Swollen part of SIPH very lightly imbricated	…..Illinoia spiraecola
–	First tarsal joints with 4-5 hairs. Longest hairs on ANT III 0.20-0.25 × BD III. ANT V 1.2-1.8 × cauda. Swollen part of SIPH moderately imbricated	…..21
21	SIPH 1.65-2.3 × cauda. R IV+V 0.125-0.141 mm long, 0.85-1.15 × HT II	…..Illinoia spiraeae
–	SIPH 2.35-2.6 × cauda. R IV+V 0.150-0.177 mm long, 1.05-1.25 × HT II	…..Illinoia macgillivrayae

22	SIPH dark distally. R IV+V 1.0-1.2 × HT II. Cauda with 9-19 hairs	…..23
–	SIPH pale or only slightly dusky towards apices. R IV+V 0.7-1.0 × HT II. Cauda with 6-12 hairs	…..24
23	Longest hairs on ANT III 0.8-1.2 × BD III. Cauda with 11-19 hairs	…..Macrosiphum cholodkovskyi
–	Longest hairs on ANT III 0.6-0.8 × BD III. Cauda with 9-10 hairs	…..Macrosiphum sp. (B.C., Canada, on S. japonica, BMNH collection, leg. C.-k. Chan)

24	Longest hairs on ANT III 0.52-0.55 × BD III. Cauda 1.3-1.8 × ANT VI BASE, with 6-9 (usually 7)	hairs. ANT VI BASE 2.0-2.6 × R IV+V …..Macrosiphum willamettense
–	Longest hairs on ANT III 0.6-1.0 × BD III. Cauda 2.1-3.5 × ANT VI BASE, with 8-12 hairs. ANT VI BASE 0.9-1.5 × R IV+V	…..Macrosiphum euphorbiae
25	Cauda short, helmet-shaped, not longer than its basal width in dorsal view	…..26
–	Cauda finger-shaped, much longer than its basal width in dorsal view	…..28
26	SIPH clavate. Spiracular apertures small and reniform	…..Avicennina sogdiana*
–	SIPH conical, with a subapical annular incision. Spiracular apertures large and rounded	…..27
27	R IV+V 1.2-1.3 × HT II. HT I with 3 hairs (sense peg present). Dorsal abdomen pale	…..Brachycaudus helichrysi

–	R IV+V 0.8-1.0 × HT II. HT I with 2 hairs (no sense peg). Dorsal abdomen often with dark sclerotisation	…..Brachycaudus spiraeae
28	ABD TERG 8, or 7 and 8, with conical or finger-like hair-bearing spinal processes. SIPH smooth	…..29
–	ABD TERG 7 and 8 without any projections. SIPH smooth or imbricated	…..30
29	SIPH dusky/dark, longer than cauda, markedly inflated distally over c.0.75 of length, with maximum width of swollen part c.2.5 × minimum width of stem, and with a distinct flange. ABD TERG 7 and 8 with bluntly conical spinal tubercles	…..Tricaudatus polygoni
–	SIPH pale, not longer than cauda, cylindrical or only slightly clavate, and completely flangeless. ABD TERG 8 with a finger-like projection above cauda	…..Aspidophorodon longicauda

30	Head densely spiculose, at least on ventral side	…..31
–	Head not spiculose	…..32
31	ABD TERG (1-) 2-3 (-5) with conspicuous papillate marginal tubercles (MTu). Head, prothorax (sometimes) and ABD TERG 7 and 8 (often) with paired spinal tubercles (STu). ANT PT/BASE 1.9-2.4. Dorsum pale. SIPH tapering/cylindrical and coarsely imbricated	…..Myzus sp. on S. lindleyana (possible primary host forms of M. ornatus?)
–	ABD TERG without or with only sporadic flat inconspicuous MTu, and STu absent from head and prothorax and sporadic on ABD TERG 7-8. If ANT PT/BASE less than 2.5 then dorsum has pattern of intersegmental markings	…..go to key to polyphagous aphids, starting at couplet 5
32	ANT PT more than 2.2 × SIPH, which are only 0.8-1.2 × cauda. ANT III with 5-30 rhinaria	…..Acyrthosiphon pseudodirhodum

–	ANT PT 0.8-1.4 × SIPH, which are 1.7-2.5 × cauda. ANT III with 1-8 rhinaria	…..33
33	SIPH 1.7-2.0 × cauda. R IV+V 0.55-0.85 × HT II	…..Acyrthosiphon ignotum
–	SIPH 2.1-2.9 × cauda. R IV+V 0.9-1.1 × HT II	…..34
34	Dorsal cuticle papillated or markedly wrinkled. R IV+V 0.9-1.1 × ANT BASE VI, and bearing 7-10 accessory hairs	…..Acyrthosiphon rubi
–	Dorsal cuticle rather smooth. R IV+V c.0.7 × ANT BASE VI, with 6 accessory hairs	…..Acyrthosiphon soldatovi

*Spiranthes*	Orchidaceae
*Spiranthes grayi* = S. tuberosa
*S. tuberosa*	Rhopalosiphum nymphaeae

*Spirodela*	Araceae
*Spirodela polyrrhiza*	Rhopalosiphum nymphaeae
S. punctata	Rhopalosiphum nymphaeae

*Spodiopogon* (including Eccoilopus)	Poaceae
*Spodiopogon cotulifer*	Sitobion yasumatsui
S. rhizophorus	Hysteroneura setariae
S. sibiricus	Sitobion avenae

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

*Spondias*	Anacardiaceae
*Spondias cirouella* = S. purpurea
*S. mombin*	Aphis aurantii, spiraecola
*S. purpurea*	Aphis aurantii, spiraecola; Myzus persicae
*Spondias* sp.	Aphis odinae

Use key to polyphagous aphids.

*Sporobolus*	Poaceae
*Sporobolus africanus*	Hysteroneura setariae; Sitobion graminis
S. berteroanus = S. indicus
*S. diander* = S. diandrus
*S. diandrus*	Hysteroneura setariae
*S. festivus*	Hysteroneura setariae
*S. indicus*	Hysteroneura setariae; [Pterasthenia shiraensis];
	Rhopalosiphum padi; Schizaphis graminum; Sipha flava;
	Sitobion africanum, graminis; Tetraneura fusiformis
S. junceus	Hysteroneura setariae
S. mildbraedii	Hysteroneura setariae; Myzus ornatus; Sitobion graminis
S. mysorensis (?)	Rhopalosiphum rufiabdominale
S. neglectus	Schizaphis graminum
*S. poiretii* = S. junceus
*S. pyramidalis*	Hysteroneura setariae; Myzus ornatus;
	Rhopalosiphum maidis, padi; Sitobion graminis
*S. virginicus*	Rhopalosiphum maidis
Sporobolus sp.	Geoica lucifuga
Use key to apterae of grass-feeding aphids under Digitaria.

Spuriopimpinella see Pimpinella

Apiaceae

*Stachyopsis*	Lamiaceae
Stachyopsis lamiiflora	[Brachycaudus cerasicola];
	Cryptomyzus malkovskii, transiliensis
S. marrubioides	Cryptomyzus malkovskii
S. oblongata	Cryptomyzus malkovskii
S. ovata	[Brachycaudus cerasicola]; Cryptomyzus transiliensis

Key to apterae on Stachyopsis:-

(Both the keyed species have long capitate dorsal hairs arising from tuberculate bases.)

–	Cauda helmet-shaped, not longer than its basal width. ANT III with numerous (18-53) rhinaria, and also 3-15 on ANT IV. SIPH tapering to apex	…..Cryptomyzus malkovskii
–	Cauda tongue-shaped, much longer than its basal width. ANT III with 1-4 rhinaria near base, IV with 0. SIPH swollen on distal half	…..Cryptomyzus transiliensis

*Stachys*	Lamiaceae
*Stachys ajugoides*	Aulacorthum solani
S. alpina	Cryptomyzus ribis; Ovatomyzus ribis, stachyos
*S. annua*	Aphis frangulae, stachydis; Cryptomyzus korschelti, ribis;
	Kaltenbachiella pallida; [Pemphigus sp.];
	Roepkea marchali
*S. arvensis*	Aphis frangulae ssp. beccabungae, gossypii, stachydis;
	Aulacorthum solani; Cryptomyzus ribis
S. betonica see S. officinalis
S. betoniciflora Rupr.	Brachycaudus cerasicola; Cryptomyzus karzhantavicus
S. bullata	Amphorophora stachyophila; Aulacorthum solani;
	Neomyzus circumflexus
S. byzantina	Cryptomyzus korschelti; Ovatomyzus stachyos
S. californica = S. bullata
*S. ciliata* = S. mexicana
S. cooleyae	Cryptomyzus ribis
S. cretica	Aphis stachydis (? – see text); Roepkea marchali
*S. foliosa* Regel = S. betoniciflora
S. germanica	Cryptomyzus galeopsidis, korschelti;
	Ovatomyzus stachyos
S. glutinosa	Aphis stachydis
*S. heraclea*	Ovatomyzus chamaedrys
S. japonica = S. riederi
S. lanata = S. byzantina
S. mexicana	Cryptomyzus ribis
S. officinalis (incl. betonica)	Aulacorthum solani;
	Cryptomyzus heinzei, korschelti, ribis
S. olympica = S. byzantina
*S. palustris*	Aphis frangulae ssp. beccabungae, stachydis;
	Aulacorthum solani;
	Cryptomyzus korschelti, ribis, stachydis;
	Myzus persicae; Uroleucon stachydis
S. pilosa	Aphis stachydis, [Aphis (Cerosipha) sp. (Weiss 1955)];
	Cryptomyzus galeopsidis, korschelti, ribis, stachydis;
	Uroleucon stachydis
S. recta	Aphis [eupatorii], [origani], stachydis; Cryptomyzus ribis
S. riederi (incl. vars. hispidula, Aphis gossypii; Cryptomyzus ribis japonica)
S. rigida (incl. ssp. quercetorum)	Amphorophora stachyophila
S. scopulorum = S. pilosa
S. sericea	Aphis stachydis; Myzus ornatus
S. sideritoides = S. sericea
S. sylvatica	Aphis stachydis; Aulacorthum solani;
	Cryptomyzus galeopsidis, korschelti, ribis, stachydis;
	Uroleucon stachydis
Stachys sp.	Aphis tashevi

Key to apterae on Stachys:-

1	ANT 4- (occasionally 5-) segmented, less than 0.15 × BL, with PT/BASE less than 1. SIPH absent. All segments with wax glands, each consisting of a ring of roundish facets around a central field	…..Kaltenbachiella pallida
–	ANT usually 6-segmented, more than 0.2 × BL, with PT/BASE more than 1.5. No evident dorsal wax glands	…..2
2	Cauda semicircular to helmet-shaped, shorter than its basal width in dorsal view. Dorsum often with an extensive black sclerotic shield	…..3
–	Cauda finger-like, longer than its basal width. Dorsum without an extensive black sclerotic shield	…..4
3	SIPH shorter than R IV+V, lightly imbricated, without spicules. Dorsal cuticle not spiculose	….. Brachycaudus cerasicola
–	SIPH longer than R IV+V, with transverse rows of spicules. Dorsal cuticle spiculose	…..Roepkea marchali
4	Dorsal body hairs long and thick, much longer than ANT BD III, and many or all of them with knobbed or expanded apices, and arising from tuberculate bases (e.g. Fig.50a)	…..5
–	Dorsal body hairs mostly shorter than BD III; pointed or blunt, or if with somewhat expanded apices then without tuberculate bases	…..9
5	SIPH 5.1-6.5 × cauda	….. Cryptomyzus karzhantavicus*
–	SIPH 1.1-4.0 × cauda	…..6
6	SIPH 1.1-2.1 × cauda. R IV+V 0.9-1.1 × HT II, and bearing 2-5 accessory hairs. Longest hairs on ANT III 1.0-1.3 × BD III	…..Cryptomyzus galeopsidis
–	SIPH 2.4-4.0 × cauda. R IV+V 0.9-1.8 × HT II, and bearing 6-17 accessory hairs. Longest hairs on ANT III 0.4-0.9 × BD III	…..7
7	SIPH 2.3-3.1 × cauda. R IV+V 1.3-1.4 × HT II, and bearing 6-8 accessory hairs	…..Cryptomyzus ribis

–	SIPH 3.1-4.0 × cauda. R IV+V 1.5-1.8 × HT II, and bearing 8-17 accessory hairs	…..8
8	R IV+V with 11-17 accessory hairs. Longest hairs on ANT I much longer and thicker than any hairs on ANT III. Longest dorsal hairs more than 100 μm long	…..Cryptomyzus korschelti

–	R IV+V with 7-9 accessory hairs. Longest hair on ANT I similar in size to longest hair on ANT III. Longest dorsal hairs less than 80 μm long	…..Cryptomyzus heinzei
9	Head densely spinulose, with ANT tubercles well developed, their inner faces scabrous and parallel of apically convergent	…..go to key to polyphagous aphids, starting at couplet 5
–	Head without spicules, ANT tubercles undeveloped, weakly developed, or if well developed then with inner faces smooth and divergent	…..10
10	ANT tubercles well developed. ABD TERG 1 and 7 without marginal tubercles (MTu)	…..11

–	ANT tubercles undeveloped or weakly developed. ABD TERG 1 and 7 with MTu	…..15
11	ANT III with 44-72 rhinaria. SIPH dusky to dark, with a distal zone of polygonal reticulation. Cauda dusky to dark with c.20-22 hairs	…..Uroleucon stachydis
–	ANT III with 0-25 rhinaria. SIPH pale, without polygonal reticulation. Cauda pale with 5-13 hairs	…..12
12	BL 2.5-3.5 mm. ANT III with 2-25 rhinaria. SIPH smooth, distinctly clavate	…..13
–	BL 0.9-1.6 mm. ANT III without rhinaria. SIPH imbricated, cylindrical or only slightly swollen subapically	…..14
13	SIPH 2.9-4.1 × cauda and markedly swollen over distal 0.7, with maximum width of swollen part 1.7-2.0 × minimum width basad (Fig.50b). ANT PT/BASE 8.4-9.8. R IV+V with 5-8 accessory hairs	…..Cryptomyzus stachydis
–	SIPH 1.7-2.4 × cauda, swollen on distal 0.5 to a maximum of c.1.6 × minimum width basad (Fig.50c). ANT PT/BASE 6.2-8.1. R IV+V with 26-30 accessory hairs	…..Amphorophora stachyophila

14	SIPH 15-23 × longer than their midlength diameter (Fig.50d). Longest hair on ANT tubercles 0.9-1.3 × BD III	…..Ovatomyzus stachyos
–	SIPH 9-14 × longer than their midlength diameter (Fig.50e). Longest hair on ANT tubercles 0.5-0.8 × BD III	…..Ovatomyzus chamaedrys
15	ANT III with 0-10 sec. rhinaria on distal part, IV with 3-9 and V with 0-4. Rostrum very short, length of sclerotised part of stylet groove less than 0.4 mm	…..Aphis tashevi
–	ANT without sec. rhinaria (except in alatiform specimens). Rostrum longer, length of sclerotised part of stylet groove more than 0.4 mm)	…..Aphis stachydis (or A. gossypii?)

*Stachytarpheta*	Verbenaceae
*Stachytarpheta angustifolia*	Aphis gossypii
S. jamaicensis	Aphis gossypii
Stachytarpheta sp.	[Hysteroneura setariae]

*Stachyurus*	Stachyuraceae
*Stachyurus praecox*	Xenosiphonaphis conandri, japonica

Key to alate fundatrigeniae:-

(Populations on Stachyurus consist of fundatrices and alatae only, and the fundatrix of X. conandri is undescribed.)

–	BL 1.6-2.1 mm. Dorsal abdomen with very broad dark cross-bands on ABD TERG 1-7, partially fused across ABD TERG 3-6 with only small gaps between them. Sec. rhin. III 17-20, IV 7-8, V 0-1	…..Xenosiphonaphis conandri
–	BL 2.4-3.0 mm. Dorsal abdomen with dark cross-bands partly fused marginally, but with wide gaps between them in spinal region. Sec. rhin. III 22-26, IV 4-9, V 0-1	…..Xenosiphonaphis japonica

*Stanhopea*	Orchidaceae
*Stanhopea graveolens*	Sitobion luteum

*Staphylea*	Staphyleaceae
Staphylea bumalda	Aphis gossypii; Indomegoura indica, nigrotibiae
S. colchica	Rhopalosiphoninus staphyleae
S. pinnata	Aphis fabae; Rhopalosiphoninus staphyleae
S. trifolia	Aphis fabae

Key to apterae on Staphylea:-

1	SIPH dark and tapering from base to flange	…..go to key to polyphagous aphids, staring at couplet 14
–	SIPH pale or dark, swollen over part of length	…..2
2	Legs mainly pale. Head spiculose, with inner faces of antennal tubercles approximately parallel. SIPH pale except distally, swollen on distal 0.7, without subapical reticulation; maximum diameter of swollen part more than 1.5 × minimum width of proximal “neck” region (fig. 110C)	…..Rhopalosiphoninus staphyleae
–	Legs dark. Dorsal cuticle of head smooth or slightly wrinkled, inner faces of antennal tubercles broadly divergent. SIPH uniformly dark, more-or-less barrel-shaped, thickest in middle, with subapical reticulation (figs 110A, B)	…..3
3	BL more than 3 mm. Cauda elongate, much longer than wide, more than 0.5 × SIPH. R IV+V 0.7-0.9 × HT II. SIPH almost cylindrical on proximal 0.7 of length, narrowing only subapically (fig. 110A)	…..Indomegoura indica
–	BL less than 3 mm. Cauda triangular, about as long as its basal width, less than 0.5 × SIPH. R IV+V 0.9-1.1 × HT II. SIPH narrowing proximad as well as distad of swelling (fig. 110B)	…..Indomegoura nigrotibiae

Statice see Limonium

Plumbaginaceae

*Stauntonia*	Lardizabulaceae
*Stauntonia hebandra* = S. obovata
*S. hexaphylla*	Sitobon akebiae
S. obovata	Amphicercidus laniger

Couplet to separate these two species:-

(Both species have dark SIPH, non-spiculose head and low, broadly divergent ANT tubercles.)

–	Cauda short, conical with rounded apex, about as long as its basal width in dorsal view. SIPH without polygonal reticulation. ANT with finely pointed hairs, many of them longer than BD III	…..Amphicercidus laniger
–	Cauda much longer than its basal width. SIPH with distal polygonal reticulation. ANT with short blunt hairs, less than 0.5 × BD III	…..Sitobion akebiae

*Steganotaenia*	Apiaceae
*Steganotaenia araliacea*	Aphis fabae; Hyadaphis coriandri

Use key to apterae on Coriandrum.

*Steirodiscus* see Euryops	Asteraceae
*Steirodiscus chrysanthemoides* = Euryops chyrysanthemoides

Steironema see Lysimachia

Primulaceae

*Stelechocarpus*	Annonaceae
*Stelechocarpus burahol*	Aphis (Toxoptera) aurantii

*Stelis*	Orchidaceae
*Stelis aprica*	Aphis (Toxoptera) aurantii; Sitobion luteum
*S. cubensis* = S. aprica
S. ekmanii	Sitobion luteum
*S. ophioglossoides*	Aphis (Toxoptera) aurantii; Sitobion luteum
S. velaticaulis	Aphis (Toxoptera) aurantii; Sitobion luteum

Use key to aphids on orchids under Cymbidium.

*Stellaria*	Caryophyllaceae
*Stellaria alsine* = S. uliginosa
*S. aquatica* = Myosoton aquaticum
S. crispata = S. monosperma
S. dichotoma	Stellariopsis songini
S. graminea	Aulacorthum solani; Brachycolus stellariae;
	Macrosiphum stellariae; Myzus ascalonicus
S. holostea	Aphis fabae; Brachycolus stellariae;
	Macrosiphum euphorbiae, [hartigi], stellariae, [ gei];
	Myzus ascalonicus, [dianthicola], persicae, titschaki
*S. jamesiana* = Pseudostelleria jamesiana
S. longipes	Brachycaudus helichrysi; Brachycolus brachysiphon
S. media	Acyrthosiphon auctum
	Aphis craccivora, fabae, gossypii, nasturtii,
	[rhamnicola], sambuci;
	Aulacorthum solani; Brachycaudus helichrysi;
	Macrosiphum euphorbiae;
	Myzus ascalonicus, certus, cymbalariae, icelandicus,
	ornatus, persicae;
	Neomyzus circumflexus;
	Neotoxoptera oliveri, [sunkangensis];
	Rhopalosiphoninus latysiphon;
	Rhopalosiphum rufiabdominale; [Sipha maydis]
*S. monosperma*	Abstrusomyzus phloxae;
	Myzus ascalonicus, ornatus, persicae
S. neglecta	Myzus ascalonicus
*S. nemorum*	Aphis nasturtii; Aulacorthum solani;
	[Brachycaudus lychnidis]; Brachycolus stellariae;
	[Jacksonia papillata]; Macrosiphum stellariae;
	Myzus ascalonicus
*S. peduncularis* = S. longipes
S. uliginosa	Aphis nasturtii; Macrosiphum stellariae; [Myzus cerasi]
Stellaria sp.	[Macrosiphum incertum Mordvilko (= stellariae?)]

Key to apterae on Stellaria:-

1	SIPH pale with subapical polygonal reticulation (at least 4-5 rows of closed cells). ANT III with 1-13 rhinaria, and with longest hairs 0.6-1.2 × BD III	…..2
–	SIPH pale or dark, without polygonal reticulation (unless strongly swollen). ANT III with 0-3 rhinaria, if with any then longest hairs less than 0.5 × BD III	…..3
2	Femora usually with a dark spot or patch near apices (Fig.51a). ABD TERG 2-3 with longest hair 26-56 μm, usually as long as or longer than ANT BD III. Subgenital plate with 2-13 hairs in addition to those on posterior margin	…..Macrosiphum stellariae
–	Femora pale or only slightly dusky at apices. ABD TERG 2-3 with longest hair 21-37 μm, usually shorter than ANT BD III. Subgenital plate with 2(-4) hairs on anterior part	…..Macrosiphum euphorbiae

3	Head not spiculose, with ANT tubercles undeveloped or weakly developed, or if well developed then having smooth, broadly divergent inner faces	…..4
–	Head spiculose, with well-developed ANT tubercles, their inner faces scabrous and parallel or apically convergent	…..12
4	ANT 5-segmented, bearing long hairs up to 4-5 × BD III	…..Rhopalosiphum rufiabdominale

–	ANT usually 6-segmented, with much shorter hairs	…..5
5	SIPH very small, flangeless, conical or barrel-shaped (e.g Fig. 51b), less than 0.3 × cauda	…..6

–	SIPH more than 0.6 × cauda	…..7
6	ANT PT/BASE 2.4-3.6. Cauda triangular, much shorter than PT	…..Brachycolus stellariae
–	ANT PT/BASE 1.2 –1.5. Cauda elongate, longer than PT	…..Brachycolus brachysiphon*
7	ABD TERG 1-5 each with 10-12 hairs (2 marginal, 1 pleural and 2-3 spinal pairs), which have capitate or spatulate apices and arise from rough wart-like tubercles (Fig.51c)	…..Stellariopsis songini

–	ABD TERG 1-5 each usually with 6 hairs with blunt or pointed apices, not on tubercles	…..8
8	ABD TERG 1 and 7 without marginal tubercles (MTu). SIPH pale	…..9
–	ABD TERG 1 and 7 with MTu. SIPH pale or dark	…..11
9	Cauda helmet-shaped, not longer than its basal width, with 4-6 hairs. SIPH conical, with a subapical annular incision. Spiracular apertures large and rounded. ANT III without rhinaria	…..Brachycaudus helichrysi

–	Cauda tongue-shaped, much longer than its basal width, with 7-13 hairs. SIPH tubular, without a subapical annular incision. Spiracular apertures reniform. ANT III usually with 1-3 rhinaria	…..10
10	SIPH 0.15-0.20 × BL and 0.8-1.4 × cauda. ANT PT/BASE 1.8-3.0	…..Acyrthosiphon auctum

–	SIPH 0.23-0.33 × BL and 1.5-2.5 × cauda. ANT PT/BASE 3.0-4.4	…..Acyrthosiphon ilka
11	ABD TERG 2-4 or 2-5 as well as 1 and 7 with large flat MTu. SIPH black, 2.1-3.5 × cauda	…..Aphis sambuci

–	ABD TERG 2-4 without MTu, or occasionally with small papilliform MTu. SIPH pale or dark, 0.7-2.5 × cauda	…..polyphagous Aphis spp.; go to key to polyphagous aphids, starting at couplet 24
12	SIPH gradually tapering from base to apex	…..13
–	SIPH with slight, moderate or marked swelling of distal part	…..15
13	ANT PT/BASE 1.7-2.8. ANT III without rhinaria. Dorsal abdomen with a pattern of dark intersegmental spots	…..Myzus ornatus
–	ANT PT/BASE 4.0-5.5. ANT III usually with 1-3 smll rhinaria near base. Dorsal abdomen pale or with more extensive dark markings	…..14
14	Dorsum with extensive dark markings, including an approximately U-shaped abdominal patch	…..Neomyzus circumflexus
–	Dorsum without dark markings	…..Aulacorthum solani
15	SIPH black and very strongly swollen on distal half, with polygonal reticulation distal to swelling. Dorsum with an extensive dark sclerite	…..Rhopalosiphoninus latysiphon
–	SIPH pale or dusky and only slightly to moderately swollen, without any distal polygonal reticulation. Dorsum without dark sclerotisation	…..16
16	SIPH 0.82-1.34 × ANT III	…..17
–	SIPH 0.54-0.81 × ANT III	…..19
17	ANT tubercles themselves rather low, but with scabrous processes extending forward from ANT bases. SIPH weakly swollen subapically (over about distal 0.25). Dorsum with an evident reticulate pattern	…..Abstrusomyzus phloxae
–	ANT tubercles broadly rounded, without forwardly-directed processes. SIPH slightly to moderately swollen over about distal 0.5. Dorsum without a reticulate pattern	…..18
18	R IV+V in most specimens with only one pair of lateral accessory hairs (plus 0-3 ventral accessory hairs). Value of function CAUDA/(ANT III × PT) in range 0.80-1.52, but rarely more than 1.25 except in small specimens (those with ANT III less than 0.32 mm)	…..Myzus persicae

–	R IV+V in most specimens with two pairs of lateral accessory hairs. Value of function CAUDA/(ANT III × PT) in range 1.2-2.7 (rarely less than 1.25)	…..Myzus certus
19	SIPH with a narrow basal stem, its narrowest part thinner than, or as thin as, hind tibia at midlength. R IV+V 1.4-1.6 × HT II, with 7-15 accessory hairs	…..Myzus ascalonicus
–	SIPH thicker on basal half, its narrowest part thicker than hind tibia at midlength. R IV+V 0.9-1.6 × HT II, with 2-8 accessory hairs	…..20
20	R IV+V 0.9-1.05 × HT II. SIPH c.1.8 × the tongue-shaped cauda	…..Myzus titscheki
–	R IV+V 1.2-1.6 × HT II. SIPH more than 2 × the triangular (tapering) cauda	…..21
21	ANT PT/BASE 2.5-3.3. SIPH very coarsely imbricated on swollen part. Dorsal cuticle very rugose	…..Myzus cymbalariae
–	ANT PT/BASE 3.5-4.8 SIPH smooth or normally imbricated on swollen part. Dorsal cuticle not rugose	…..22
22	ANT PT/BASE 4.3-4.8. (Al. with wing-veins not dark-bordered, with a solid black patch on ABD TERG 3-4, fused across tergites and constricted in midline, and with secondary rhinaria distributed III 39-52, IV 29-31, V 6-11)	…..Myzus stellariae
–	ANT PT/BASE 3.5-4.3. (Al. with wing-veins black-bordered, with broad dark cross-bands on ABD TERG 2-5 only partially fused between tergites, and with secondary rhinaria distributed III 12-47, IV 0-13, V 0-2)	…..Noetoxoptera oliveri (or sungkangensis*?)

*Stellera*	Thymelaeaceae
*Stellera chamaejasme*	Aphis brachychaeta

*Stemmacantha*	Asteraceae
*Stemmacantha carthamoides*	Aphis fabae; Aulacorthum solani; Brachycaudus helichrysi;
	Macrosiphum euphorbiae; Myzus persicae;
	Neomyzus circumflexus; Uroleucon gobonis
S. uniflora	Uroleucon mongolicum

See under Rhaponticum for combined key to apterae on Rhaponticum and Stemmacantha.

Stenactis see Erigeron

Asteraceae

*Stenosiphonium*	Acanthaceae
Stenosiphonium parviflorum	Aphis gossypii; [Hysteroneura setariae]
*S. russelianum*	Aphis gossypii

*Stenostomum*	Rubiaceae
*Stenostomum lucidum*	Aphis gossypii

*Stenotaphrum*	Poaceae
Stenotaphrum dimidiatum	Geoica lucifuga; Hysteroneura setariae;
	Sitobion africanum
S. secundatum	Hysteroneura setariae; Sipha flava
Use key to apterae of grass-feeding aphids under Digitaria.

*Stephanandra*	Rosaceae
Stephanandra incisa	Aphis odinae
S. tanakae	Pseudomegoura magnoliae

Use key to polyphagous aphids.

*Stephania*	Menispermaceae
Stephania abyssinica	Aphis fabae, gossypii; Brachycaudus helichrysi;
	[Sitobion sp. (Millar 1994)]
S. forsteri = S. japonica var. timoriensis
S. japonica (incl. var. timoriensis)	Aphis gossypii, odinae

Use key to polyphagus aphids.

*Stephanomeria* (including Ptilora)	Asteraceae
Stephanomeria pauciflora	Uroleucon bonitum
S. tenuifolia	Uroleucon bonitum
Stephanomeria sp.	[Uroleucon erigeronense]

*Stephanotis*	Apocynaceae
*Stephanotis floribunda*	Aphis nerii; Myzus persicae

*Sterculia*	Sterculiaceae
*Sterculia foetida*	Aphis (Toxoptera) aurantii
*Sterculia* sp.	Aphis odinae; [Rhopalosiphum rufiabdominale]

Use key to polyphagous aphids.

Steris see Lychnis

Caryophyllaceae

*Stevia*	Asteraceae
*Stevia glandulosa*	Hyperomyzus niger
*S. salicifolia*	Uroleucon mexicanum
*S. serrata*	Uroleucon paucosensoriatum
S. subpubescens	Aphis solitaria; Hyperomyzus niger
*Stevia* sp.	Ucrimyzus villalobosi; Uroleucon atsronomus

Key to apterae on Stevia:-

1	SIPH dark with distal reticulation consisting of numerous small polygonal cells	…..2
–	SIPH pale or dark, without a distal zone of polygonal reticulation	…..4
2	SIPH reticulated over distal 0.41-0.60 of length. Cauda with 7-14 hairs (usually less than 10). (R IV+V with 7-15 accessory hairs)	…..Uroleucon mexicanum
–	SIPH reticulated on less than 0.4 of length. Cauda with more than 11 hairs	…..3
3	R IV+V with 17-24 accessory hairs. ANT III with 10-30 rhinaria. Tibiae basally and distally dark contrasting with pale middle section. SIPH reticulated on more than 0.32 of length	…..Uroleucon astronomus
–	R IV+V with 5-8 accessory hairs. ANT III with 4-16 rhinaria. Tibiae entirely pigmented, usually darkening progressively from base to apex. SIPH reticulated on less than 0.33 of length	…..Uroleucon paucosensoriatum
4	SIPH tapering, pale with darker apices, cauda dark. Tergum mostly pale and membranous. ABD TERG 1 and 7 with marginal tubercles (MTu)	…..Aphis solitaria
–	SIPH clavate, pale or dark, cauda pale. Tergum either pale or with an extensive dark sclerotic shield. ABD TERG 1 and 7 without MTu	…..5
5	Tergum with an extensive dark sclerotic shield. ANT III with 19-30 sec. rhinaria, IV with 0-18, V 0-5	…..Hyperomyzus niger
–	Tergum mostly pale and membranous. ANT III with 1-20 rhinaria, IV and V with 0	…..Ucrimyzus villalobosi

Stewartia see Stuartia

Theaceae

*Stichorkis*	Orchidaceae
*Stichorkis nugentiae*	Sitobion luteum

*Stigmaphyllon*	Malpighiaceae
Stigmaphyllon affine	Aphis gossypii
*S. sagraeanum*	Aphis craccivora, gossypii, spiraecola
S. tomentosum	Aphis craccivora

Use key to polyphagous aphids.

*Stilbe*	Stilbaceae
Stilbe spp.	Macrosiphum euphorbiae

*Stipa* (including Achnatherum, Lasiagrostis)	Poaceae
Stipa arabica	Chaetosiphella longirostris
S. bromoides	Sitobion avenae, fragariae
S. calamagrostis	Chaetosiphella stipae, stipae ssp. setosa; Sipha elegans
S. capensis	Forda formicaria; Melanaphis pyraria;
	Paracletus cimiciformis; Rhopalosiphum maidis, padi;
	Schizaphis graminum; Sipha maydis; Sitobion avenae
S. capillata	Anoecia corni, stipae, [Anoecia sp. (Bozhko 1976a)];
	Atheroides serrulatus;
	Chaetosiphella massagetica, stipae, tschernavini;
	Forda marginata, orientalis, pawlowae;
	[Holmania chaetosiphon (al. vagrant)]; Sitobion avenae
S. comata	Diuraphis tritici
S. confusa	Chaetosiphella stipae; Sitobion avenae
S. dasyphylla	Chaetosiphella stipae
S. elegantissima	Rhopalosiphum padi
*S. gigantea*	Chaetosiphella stipae
S. joannis	Chaetosiphella stipae
S. kirghisorum	Chaetosiphella massegetica, stipae; Forda marginata
S. lagascae	Metopolophium dirhodum
S. lessingiana	Forda orientalis, pawlowae; Geoica utricularia;
	[Slavum lentiscoides]; Chaetosiphella stipae
S. leucotricha	Schizaphis graminum
S. orientalis	Chaetosiphella stipae
S. parviflora	Forda formicaria
S. pennata (incl. ssp. eriocaulis)	Chaetosiphella stipae; Sitobion avenae;
	[Slavum lentiscoides]
S. retorta = S. capensis
S. sareptana	Chaetosiphella stipae; Forda marginata;
	[Slavum lentiscoides]
S. sibirica	Chaetosiphella stipae; Forda marginata
S. speciosa	Hysteroneura setariae
S. splendens	Atheroides karakumi; Chaetosiphella stipae;
	Sipha elegans; Tetraneura africana
S. viridula	Schizaphis graminum
Stipa spp.	Carolinaia rhois; [Dysaphis ubsanurensis]; Sipha maydis

Use key to apterae on grasses under Digitaria.

*Stipagrostis*	Poaceae
*Stipagrostis pennata*	Sipha maydis

*Stipularia*	Rubiaceae
*Stipularia africana*	Aphis gossypii

*Stirlingia*	Proteaceae
*Stirlingia latifolia* (?)	Macrosiphum euphorbiae

*Stizolophus*	Asteraceae
*Stizolophus balsamita*	Uroleucon jaceae

*Stizolobium* see Mucuna	Fabaceae

*Stocksia*	Sapindaceae
*Stocksia brahuica*	Brachyunguis kaussarii

*Stoebe*	Asteraceae
*Stoebe* sp.	Aphis (Toxoptera) aurantii

*Stomatanthe*s	Asteraceae
*Stomatanthes africanus*	Aphis spiraecola

Stranvaesia see Photinia

Rosaceae

*Stratiotes*	Hydrocharitaceae
*Stratiotes* sp.	Rhopalosiphum nymphaeae

Straussiasee Psychotria

Rubiaceae

*Streblus*	Moraceae
*Streblus elongatus*	Tempinis Tree
	Greenidea ficicola
*Streblus* sp. (shrub)	[Greenideoida hannae]

*Strelitzia*	Strelitziaceae
*Strelitzia alba*	Cerataphis lataniae, brasiliensis
S. augusta = S. alba
S. nicolai	Aphis fabae; Cerataphis brasiliensis;
	Rhopalosiphum padi
S. reginae	Dysaphis tulipae; Rhopalosiphum musae;
	Schizaphis rosazevedoi
Strelitzia sp.	Pentalonia nigronervosa

Key to apterae on Strelitzia:-

1	Body dorso-ventrally flattened, almost circular, wholly sclerotic with a continuous crenulate margin of wax glands. Head with a pair of forwardly-directed horns. SIPH present as pores	…..2
–	Body not dorso-ventrally flattened, without marginal wax glands or frontal horns. SIPH tubular	…..3
2	Underside of head with at least one pair of thick, dagger-like hairs situated lateroventral to bases of frontal horns. Cauda with 5-7 mainly long hairs	…..Cerataphis brasiliensis
–	Underside of head with only fine hairs. Cauda with 10-16 hairs of various sizes	…..Cerataphis lataniae

3	SIPH and femora covered with irregular, transverse rows of spicules. ANT PT/BASE 5.8-8.1. (Alata with dark-bordered wing veins, with radius and costa fused for part of lengths to form a closed cell behind the pterostigma)	…..Pentalonia nigronervosa
–	SIPH and femora smooth or imbricated, not markedly spiculose. ANT PT/BASE 1.4-5.8. (Alata with normal wing venation, veins not dark-bordered)	…..4
4	Cauda helmet-shaped, a little shorter than its basal width. Spinal tubercles (STu) present on head and ABD TERG 8, or 7 and 8	…..Dysaphis tulipae
–	Cauda tongue-shaped, longer than its basal width in dorsal view. STu absent	…..5
5	SIPH short and thick (0.08-0.11 × BL, 2.9-3.3 × longer than their midlength diameter, and 1.2-1.5 × R IV+V), and strongly constricted subapically before the well-developed flange	…..Rhopalosiphum musae
–	SIPH 0.12-0.17 × BL, 3.5-6.0 × their midlength diameter and (1.3-) 1.5-2.9 × R IV+V, with or without a subapical constriction	…..6
6	Hairs on hind tibiae mostly shorter than diameter of hind tibia at midlength. SIPH cylindrical for most of length, with a smooth, constricted subapical region	…..Rhopalosiphum padi

–	Many of hairs on hind tibia much longer than its midlength diameter. SIPH gradually tapering from base to flange, with no smooth subapical constriction	…..7
7	Cauda pale, contrasting with black SIPH, and bearing 4-8 hairs. SIPH 1.7-2.5 × cauda	…..Schizaphis rosazevedoi
–	Cauda dark like SIPH, and bearing 11-24 hairs. SIPH 0.8-1.6 × cauda	…..Aphis fabae

*Streptocarpus*	Gesneriaceae
*Streptocarpus rexii*	Aulacorthum solani
S. saxorum	Myzus persicae
Streptocarpus spp. (and hybrids)	[Idiopterus nephrelepidis]; [Micromyzodium filicium];
	Myzus ornatus; Neomyzus circumflexus

Use key to polyphagous aphids.

*Streptopus*	Asparagaceae
*Streptopus amplexifolius*	[Ericaphis sp., coll. A.Jensen, Idaho; aphidtrek.org];
	Macrosiphum insularis

*Streptosolen*	Solanaceae
*Streptosolen jamesonii*	Macrosiphum euphorbiae

*Striga*	Orobanchaceae
*Striga hermonthica*	Aphis gossypii

*Strobilanthes* (including Goldfussia, Perilepta)	Acanthaceae
*Strobilanthes angustifrons*	Aphis gossypii
*S. atropurpureus*	Aphis craccivora, fabae, gossypii, nasturtii;
	Nasonovia rostrata; Neomyzus strobilantheae;
	[Tricaudatus polygoni]
*S. dalhousieanus*	Aphis gossypii; Micromyzodium strobilanthi;
	Nasonovia rostrata
S. dyerianus	Aphis gossypii
S. glutinosus	Aphis gossypii
S. helicta	Aphis gossypii
S. isophyllus	Neomyzus circumflexus
S. lactata	Myzus ornatus
S. penstemonoides	Aphis gossypii; Nasonovia rostrata;
	[Tricaudatus polygoni]
Strobilanthes sp.	Melanaphis strobilanthi; Myzus persicae

Key to apterae on Strobilanthes:-

1	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	…..2
2	Head not spiculose. ANT tubercles weakly developed. ABD TERG 1 and 7 with marginal tubercles (MTu)	…..3
–	Head spiculose. ANT tubercles variably developed. ABD TERG 1 and 7 without MTu	…..4
3	ANT PT/BASE 1.2-1.75. R IV+V c.1 6 × HT II. SIPH 0.8-1.0 × cauda, which bears 10-11 hairs	…..Melanaphis strobilanthi*
–	Without that combination of characters	…..go to key to polyphagous aphids, starting at couplet 24

4	SIPH slightly to moderately clavate	…..5
–	SIPH tapering/cylindrical	…..6
5	ANT III with 1-4 rhinaria near base. SIPH 3.0-3.5 × cauda, which bears 5 hairs. Dorsal abdomen with variably developed brownish sclerotisation	…..Neomyzus strobilantheae*
–	ANT III without rhinaria. SIPH 1.9-2.5 × cauda, which bears 5-8 hairs. Dorsal abdomen unsclerotised	…..Myzus persicae
6	ANT PT/BASE 5.5-6.8. Dorsal abdomen with extensive dark sclerotisation. Hairs on ABD TERG 1-5 longer than ANT BD III. ANT tubercles with broadly divergent, spiculose inner faces	…..Micromyzodium strobilanthi
–	ANT PT/BASE 1.7-2.8. Dorsal abdomen with a pattern of dark intersegmental spots. Hairs on ABD TERG 1-5 minute, much shorter than ANT BD III. ANT tubercles with steep-sided, scabrous inner faces	…..Myzus ornatus

*Strongylodon*	Fabaceae
*Strongylodon macrobotrys*	Aphis (Toxoptera) aurantii

*Strophanthus*	Apocynaceae
*Strophanthus divaricatus*	Aphis (Toxoptera) aurantii; Aulacorthum solani;
	Myzus persicae

Use key to polyphagous aphids.

*Struchium*	Asteraceae
*Struchium sparganophorum*	Aphis gossypii

*Strychnos*	Loganaceae
*Strychnos spinosa*	Aphis gossypii
*S. pseudoquina*	Aphis gossypii

*Stuartia*	Theaceae
*Stuartia monadelpha*	Aleurodaphis stewartiae
*S. sinensis*	Myzus persicae

–	Aptera (in leaf-roll gall) with ANT PT/BASE less than 0.5, reduced eyes, head fused with thorax, SIPH as sclerotic rings, and anal plate bilobed. Alata with antennae 5-segmented and bearing annular secondary rhinaria (III 25-29, IV 8-11, V 7-11)	….. Aleurodaphis stewartiae
–	Without that combination of characters	…..go to key to polyphagous aphids

*Stylochaeton*	Araceae
*Stylochaeton* sp.	Aphis gossypii

*Stylosanthes*	Fabaceae
*Stylosanthes guianensis*	Aphis craccivora

*Styphnolobium*	Fabaceae
*Styphnolobium japonicum*	Aphis odinae

Styrax

Styracaceae

The life cycles of many Hormaphidinae described from galls on Styrax are still unknown, although in recent years some have been elucidated. Most species were originally described in Astegopteryx, but as the secondary host forms have become known many have been transferred to other genera (Ceratovacuna, Pseudoregma, Tuberaphis), or synonymised with known species on secondary hosts (e.g. Astegopteryx styracicola= Ceratoglyphina bambusae). Some species have been shown to be monoecious on Styrax. At present generic concepts within the group are still rather hazy, but it seems likely that Astegopteryx, Ceratoglyphina, Ceratovacuna and Pseudoregma mostly alternate between Styrax and bamboos, and Tuberaphis mostly migrate to Loranthaceae.

The key which follows the host list below is somewhat tentative. Any identification should be checked against the description of the gall of the species given in the next section of the book.

Host List:-

*Styrax benzoides*	[Cerataphis sp. near brasiliensis (Aoki & Kurosu
	2010)]; Astegopteryx spinocephala; Pseudoregma carolinensis
*S. benzoin*	Astegopteryx [basalis], lambersi, [malaccensis], [nipae],
	pallida, styracophila;
	Cerataphis brasiliensis; [Ceratoglyphina bambusae]
*S. ferrugineus*	Aphis (Toxoptera) aurantii
*S. formosanus*	[Ceratoglyphina bambusae, styracicola];
	Ceratovacuna nekoashi, orientalis, oplismeni,
	subtropicana;
	Tuberaphis coreana
*S. fraserensis*	Ceratoglyphina bambusae
*S. hookeri*	“gall of unknown aphid” – Mani 1973:194
*S. japonicus*	Snowball Tree
	Aphis aurantii, craccivora; [Astegopteryx styracophila];
	Ceratovacuna japonica, nekoashi, oplismeni;
	Tuberaphis owadai, takenouchii
*S. obassia*	Aphis fabae; Ceratoglyphina bambusae;
	Ceratovacuna nekoashi; Tuberaphis styraci
*S. odoratissimus*	[Ktenopteryx eosocallis]
*S. officinalis*	Aphis (Toxoptera) aurantii
*S. paralleloneurus*	Cerataphis vandermeermohri; Ceratoglyphina roepkei;
	Pseudoregma sundanica
*S. serrulatus*	[Ceratovacuna sp. (Aoki & Kurosu 2010)]
*S. serrulatus* var. *mollissimus* = S. subpaniculatus
*S. subdenticulatus* = S. subpaniculatus
*S. suberifolius*	Aphis (Toxoptera) aurantii;
	Astegopteryx bambucifoliae, [basalis], [styracophila];
	Cerataphis bambusifoliae, jamaritsu;
	Ceratoglyphina [bambusae], styracicola;
	Ceratovacuna nekoashi; [Parathoracaphis setigera];
	Pseudoregma bambucicola, koshunensis
*S. subpaniculatus*	Cerataphis vandermeermohri;
	Tuberaphis leeuweni, sumatrana
*S. tonkinensis*	[Ceratovacuna sp. (Aoki & Kurosu 2010)];
	Tuberaphis owadai
*Styrax* spp.	[Eutrichosiphum (Paratrichosiphum) sp.]

Tentative key to alatae of Hormaphidinae from galls on Styrax:-

Check characters for group: 5-segmented antennae with short PT and annular secondary rhinaria. Alatae from galls of Astegopteryx basalis, A. malaccensis and Ceratoglyphina bambusae have not yet been described (but see text under these names). The species of host plant and the form of the gall will of course help to confirm an identification.

Note: Aoki et al. (1998) provided keys to identify the galls and soldiers of five species of Cerataphidini on Styrax suberifolius in Taiwan.

1	ANT IV and V without secondary rhinaria (rarely IV with 1)	…..2
–	Either ANT IV or ANT V, or both, usually with more than 1 secondary rhinarium	…..6
2	R IV+V longer than ANT IV	…..3
–	R IV+V shorter than ANT IV. (ANT III with 10-16 secondary rhinaria)	…..4
3	ANT III with 0-14 secondary rhinaria. ANT IV more than 0.75 × ANT V (incl. PT)	…..Cerataphis jamaritsu

–

ANT III with 17-25 secondary rhinaria. ANT IV less than 0.75 × ANT V

…..Tuberaphis sumatrana

4	ANT IV more than 0.9 × ANT V (incl. PT). The 2 outer hairs on first segments of fore and mid-tarsi about 1.5 × longer than medial hairs	…..Astegopteryx lambersi
–	ANT IV less than 0.75 × ANT V (incl. PT). The 2 outer hairs on first segments of fore and mid-tarsi very long and fine, about 2 × longer than medial hairs (e.g. fig. 111A)	…..5
5	Antennae with primary rhinaria broader than secondary ones. HT I with 4 hairs, as on fore and mid-tarsi. ABD TERG 8 slightly thickened and sclerotic. SIPH pores of embryos with dark sclerotic rims	….. Tuberaphis coreana
–	Antennae with primary rhinaria narrow resembling secondary ones. HT I with 3 or 4 hairs. ABD TERG 8 not sclerotic. SIPH pores of embryos pale, unsclerotised and inconspicuous	….. Cerataphis vandermeermohri

6	ANT III distinctly longer than (1.2-1.6 ×) IV+V (incl. PT) together	…..7
–	ANT III shorter than, about equal to, or up to 1.15 × longer than, IV+V together	…..13
7	ANT V with more than 11 secondary rhinaria	…..Astegopteryx chinensis*
–	ANT V with 0-11 secondary rhinaria	…..8
8	ANT III thicker than IV and bearing 25-39 closely-spaced secondary rhinaria (e.g. fig. 111B)	…..9
–	ANT III similar in thickness to IV and bearing 13-25 secondary rhinaria	…..10
9	ANT III 1.5-1.6 × longer than IV+V (incl. PT) together. Secondary rhinaria distributed III 28-39, IV 3-6, V 0-2 (sexuparae)	…..Tuberaphis leeuweni
–	ANT III 1.2-1.4 × longer than IV+V (incl. PT) together. Secondary rhinaria distributed III 25-30, IV 8-13, V 6-9 (emigrants)	…..Cerataphis bambusifoliae
10	Front of head with 32-50 minute (4-10 μm) spine-like hairs anterior to lateral ocelli	…..11
–	Front of head with less than 20 hairs anterior to lateral ocelli, and these are more than 20 μm long	…..12
11	Secondary rhinaria distributed ANT III 18-25, IV 6-10, V 6-11	…..Astegopteryx pallida*
–	Secondary rhinaria distributed ANT III 13-19, IV 3-5, V 4-7	…..Astegopteryx spinocephala*

12	ANT V with 0-4 secondary rhinaria, and with primary rhinarium extending across more than half width of segment (fig. 111C)	…..Cerataphis brasiliensis
–	ANT V with 4-8 secondary rhinaria, and with a very small primary rhinarium extending across less than half width of segment (fig. 111D)	…..Ceratoglyphina styracicola
13	ANT IV with 0-3(-5) secondary rhinaria, and V with 0-4(-5). (Embryos without marginal wax glands)	…..Tuberaphis owadai (sexupara)
–	ANT IV with more than 3 secondary rhinaria, and ANT V with 0-16. (Embryos often with marginal wax glands)	…..14
14	ANT V usually without secondary rhinaria, rarely with 1-2	…..Tuberaphis takenouchii
–	ANT V with 3-16 secondary rhinaria	…..15
15	ANT V with (8-)10-16 secondary rhinaria. SIPH with 0(-3) associated hairs	…..Ceratovacuna nekoashi group (nekoashi, oplismeni, orientalis, subtropicana) (see text under these names, and Aoki et al. 2013)

–	ANT V with 3-11 secondary rhinaria. SIPH with 2-7 associated hairs	…..16
16	ABD TERG 7-8 distinctly sclerotized, thickened and dusky	…..17
–	ABD TERG 7-8 not thickened, only sclerotized around hair bases if at all	…..18
17	Areas around SIPH pores distinctly sclerotised	…..Pseudoregma carolinensis
–	Areas around SIPH pores not distinctly sclerotised	…..Pseudoregmabambucicola, koshunensis, or sundanica (see text)

18	Hairs on ABD TERG 7-8 with small basal sclerites. (Secondary rhinaria distributed III 18-26, IV 7-10, V 6-9)	…..Ceratoglyphina roepkei
–	Hairs on ABD TERG 7-8 without basal sclerites	…..19
19	Head with small irregular pale dorsomedial areas. (Secondary rhinaria distributed III 18-20, IV 6-9, V 4-8)	…..Astegopteryx bambucifoliae
–	Head without paler dorsomedial areas	…..20
20	ANT III clearly thicker and less than 1.3 × longer than ANT IV. (Secondary rhinaria distributed III 10-15, IV 7-11, V 4-7)	…..Ceratovacuna japonica*
–	ANT III similar in thickness to and more than 1.6 × longer than ANT IV	…..21
21	ANT PT distinctly longer than its basal width. Fore tibia much shorter than ANT III+IV+V (incl. PT). Secondary rhinaria distributed III 12-19, IV 5-10, V 3-9. (Embryos are sexuales without marginal wax glands)	…..Tuberaphis styraci* (sexupara)
–	ANT PT only about as long as its basal width or shorter. Fore tibia almost as long as ANT III+IV+V together. Secondary rhinaria distributed III 17-25, IV 6-14, V 6-9. (Embryos with marginal wax glands)	…..Astegopteryx styracophila (emigrant)

*Suaeda* (including Schaginia)	Amaranthaceae
*Suaeda aegyptiaca*	[Aphis sp. (Israel: Arava valley, immatures only)];
	Brachyunguis harmalae
*S. asphaltica*	Brachyunguis harmalae
S. baccata = S. aegyptiaca
S. californica	Brachyunguis cahuille (as tetrapteralis)
S. fruticosa	Chaitaphis safavii, tenuicauda; Clypeoaphis suaedae
S. glauca	[Brachyunguis suaedus]; Clypeoaphis suaedae
S. linifolia	Aphis craccivora
S. maritima	Aphis fabae, salsolae;
	Clypeoaphis suaedae, suaedae ssp. suaedicola;
	Smynthurodes betae
S. monoica	Brachyunguis harmalae
S. palaestina	Brachyunguis harmalae
S. physophora	Aphis craccivora; Clypeoaphis suaedae
S. pruinosa = S. vermiculata
S. suffrutescens	Brachyunguis cahuille (as tetrapteralis)
S. vermiculata	Clypeoaphis suaedae
Suaeda sp.	Aphis sp. (Korea: BMNH collection, leg. W.H. Paik);
	Hayhurstia atriplicis;
	Xerobion sp. (Sinai: BMNH collection, leg. E.
	Mescheloff)

Key to apterae on Suaeda:-

1	SIPH (if present) tubular and 0.8-2.5 × cauda; if 0.8-1.0 × cauda then both SIPH and cauda are entirely dark	…..2
–	SIPH shorter than cauda; if tubular and more than 0.8 × cauda then pale, or only dark towards apices	…..3
2	SIPH a little longer than the similarly dark cauda, which is finger-like, somewhat constricted in middle and rounded at apex, and bears 4-5 hairs. ANT PT/BASE 1.5-1.7	…..Aphis sp. (Korea; BMNH collection)
–	Without that combination of characters	…..go to key to polyphagous aphids
3	Dorsal hairs with expanded, often furcate apices. Cauda long and thin, 4-5 × longer than its middle width	…..4
–	Dorsal hairs blunt or pointed. Cauda less than 4 × its middle width	…..5
4	ANT PT/BASE 1.4-1.9. SIPH 0.8-0.95 × cauda. Dorsal hairs with small pale tuberculate bases (Fig.36a)	…..Chaitaphis tenuicauda
–	ANT PT/BASE 2.1-2.9. SIPH 0.6-0.75 × cauda. Dorsal hairs arising from large, rather rugose, hemispherical, often pigmented, tuberculate bases (Fig.36b)	…..Chaitaphis safavii
5	SIPH black, volcano-shaped, much shorter than their basal diameters (e.g. Fig.36f). Cauda dusky and broadly rounded, about 0.5 × its basal width, with c.13 hairs	…..Xerobion sp. (Sinai: BMNH collection)
–	SIPH barrel-shaped, or weakly tapering to apex, pale or dark. Cauda at least as long as its basal width, with 4-9(-12) hairs	…..6
6	ANT PT/BASE 1.4-2.5. ANT, legs, SIPH and cauda all dark, or mainly dark	…..Hayhurstia atriplicis

–	ANT PT/BASE 0.4-1.0. ANT, legs, SIPH and cauda pale	…..7
7	SIPH tubular or barrel-shaped, much longer than their basal widths (Fig.36i). Cauda finger-like, more than 2 × its basal width. ANT PT/BASE 0.8-1.0. R IV+V with 4-6 accessory hairs. MTu absent, small or indistinct. Clypeus dark, globose (Fig. 36d)	…..Clypeoaphis suaedae

–	SIPH not longer than their basal widths (Fig.36g, h). Cauda conical, less than 2 × its basal width. ANT PT/BASE 0.4-0.7. R IV+V with 2 accessory hairs. MTu present on prothorax and ABD TERG 1 and 7. Clypeus pale or dark, swollen or globose	…..8
8	Clypeus strongly sclerotised, dark, globose. ABD TERG 8 with 2 hairs, the longest 15-25 μm long	…..Brachyunguis cahuille
–	Clypeus pale, swollen but not globose. ABD TERG 8 with (2-) 3-4 hairs, the longest 28-36 μm long	…..Brachyunguis harmalae

*Succisa*	Dipsacaceae
*Succisa pratensis*	Aphis confusa, craccivora, fabae, succisae;
	Macrosiphum euphorbiae, rosae, weberi

Key to apterae on Succisa:-

1	ANT tubercles undeveloped or weakly developed. ABD TERG 1 and 7 with marginal tubercles (MTu). SIPH without polygonal reticulation	…..2
–	ANT tubercles well developed, with smooth, divergent inner faces. ABD TERG 1 and 7 without MTu. SIPH with a subapical zone of polygonal reticulation	…..5
2	ANT hairs long, numerous, wavy and finely pointed, the longest 3-4 × BD III. ANT PT/BASE 4.4-6.0	…..Aphis succisae
–	Longest ANT hairs 0.4-2.1 × BD III. ANT PT/BASE 1.3-3.5	…..3
3	Dorsal abdomen with an extensive solid black sclerite centred on ABD TERG 4-5. Cauda black like SIPH and with 4-7 hairs	…..Aphis craccivora
–	Dorsal abdomen with or without dark markings, but without an extensive solid black sclerite. Cauda pale or dark, but if black then usually with more than 7 hairs	…..4
4	Femoral hairs all shorter than diameter of trochantro-femoral suture. Cauda pale, dusky or dark with 4-9 hairs	…..Aphis confusa (or Aphis gossypii – see text)
–	Many femoral hairs long and fine-pointed, exceeding diameter of trochantro-femoral suture. Cauda black with 11-24 hairs	…..Aphis fabae
5	Head, legs and SIPH mainly pale. ANT III with 1-10 rhinaria …..Macrosiphum euphorbiae
–	Head, legs and SIPH mainly dark. ANT III with 5-35 rhinaria	….6
6	Body spindle-shaped. SIPH thicker than hind tibiae at their respective midlengths, and 1.8-2.2 × head width across (and including) eyes	…..Macrosiphum rosae
–	Body oval. SIPH about equal in thickness to hind tibiae at midlength, and 1.1-1.5 × head width across eyes	…..Macrosiphum weberi

*Succisella*	Dipsacaceae
*Succisella inflexa*	Aulacorthum solani; Macrosiphum rosae

Use key to apterae on Scabiosa.

*Sutherlandia*	Fabaceae
*Sutherlandia frutescens*	Acyrthosiphon pisum

*Swainsona*	Fabaceae
*Swainsona formosa*	Acyrthosiphon kondoi, pisum; Aphis gossypii;
	Aulacorthum solani
*S. salsula* = Sphaerophysa salsula

Use key to apterae on Medicago.

*Swertia*	Gentianaceae
*Swertia eminii*	Myzus ornatus
S. iberica	Aphis fabae
*S. perennis*	Aphis fabae
*Swertia* sp.	[Capitophorus elaeagni]

Use key to polyphagous aphids.

Swietenia Mahoganies

Meliaceae

No aphids have been recorded from any plant species of this genus.

*Swinglea*	Rutaceae
*Swinglea glutinosa*	Aphis spiraecola

*Syagrus*	Arecaceae
*Syagrus botryophora*	Cerataphis brasiliensis
*S. coronata*	Cerataphis brasiliensis
*S. flexuosa*	Cerataphis brasiliensis
*S. romanzoffiana*	Cerataphis brasiliensis

*Symphoria*	Caprifoliaceae
*Symphoria racemosa*	Amphicercidus pulverulens; Aphthargelia symphoricarpi;
	Macrosiphum euphorbiae

Use key to apterae on Symphoricarpos.

*Symphoricarpos*	Caprifoliaceae
*Symphoricarpos albus*	Amphicercidus flocculosus, pulverulens;
	Aphis fabae, gossypii, spiraephaga;
	Aphthargelia symphoricarpi; Aulacorthum solani;
	Hyadaphis foeniculi; Macrosiphum euphorbiae, rosae;
	[Phorodon humuli]; Rhopalomyzus lonicerae
S. albus var. pauciflorus	Aphthargelia symphoricarpi
*S. microphyllus*	Amphicercidus flocculosus
*S. mollis*	[Aphthargelia sp. (Oregon; A. Jensen, aphidtrek.org)];
	Cedoaphis incognita
*S. occidentalis*	Amphicercidus pulverulens; Aphthargelia symphoricarpi;
	Cedoaphis incognita
S. orbiculatus (incl. vulgaris)	Amphicercidus pulverulens; Aphthargelia symphoricarpi;
	Hyadaphis foeniculi; Macrosiphum rosae
S. oreophilus	Aphthargelia symphoricarpi
S. parishii = S. rotundifolius var. parishii
S. pauciflorus = S. albus var. pauciflorus
*S. racemosus* = Symphoria racemosa
S. rivularis	Rhopalomyzus lonicerae
S. rotundifolius var. parishii	Aphthargelia symphoricarpi
S. symphoricarpos	Aphthargelia symphoricarpi
*S. vulgaris* see S. orbiculatus
Symphoricarpos spp.	[Aphthargelia rumbleboredomia (oviparae)];
	[Artemisaphis artemisicola];
	[Ericaphis harmstoni (al. only)];
	Macrosiphum opportunisticum, ?schimmelum

Key to apterae on Symphoricarpos:-

1	SIPH with subapical reticulation (at least 4-5 rows of clearly-defined polygonal cells)	…..2
–	SIPH without subapical polygonal reticulation	…..5
2	ANT PT 2.4-4.2 × SIPH. Cauda 0.9-1.3 × ANT BASE VI. R IV+V 0.5-0.6 × HT II	…..Macrosiphum schimmelum (but see text)

–	ANT PT 0.6-1.7 × SIPH. Cauda 2-4 × ANT BASE VI. R IV+V 0.8-1.2 × HT II	…..3
3	Head and ANT I-II black. SIPH black. ANT III with 10-36 rhinaria	…..Macrosiphum rosae
–	Head, ANT I-II and SIPH pale/dusky. ANT III with 1-10 rhinaria	…..4
4	Cauda with 6-9 hairs. ANT BASE VI 0.20-0.27 mm. Longest hairs on ANT III 10-24 μm, 0.4-0.7 × BD III. (Al. with paired pleural dark patches and large marginal and postsiphuncular sclerites)	…..Macrosiphum opportunisticum
–	Cauda with 8-13 hairs. ANT BASE VI 0.14-0.20 mm. Longest hairs on ANT III 25-40 μm, 0.6-1.0 × BD III. (Al. without dark dorsal abdominal sclerites)	…..Macrosiphum euphorbiae

5	ANT III or III-V with numerous small rhinaria along most of length of segment(s). Cauda short and rounded or helmet-shaped, not longer than its basal width in dorsal view	…..6
–	ANT III-V without rhinaria or with only 1-3 rhinaria near base of III. Cauda tongue- or finger-shaped, or triangular, as long as or longer than its basal width in dorsal view	…..8
6	Secondary rhinaria distributed ANT III 13-28, IV 8-18, V 1-8. Cauda with at least 20 long fine hairs. ABD TERG 1-7 with flat round marginal tubercles (MTu)	…..Cedoaphis incognita
–	Secondary rhinaria distributed ANT III 8-c.50, IV 0-3, V 0. Cauda with fewer and shorter hairs. If MTu are present they are very small, papilliform and restricted to ABD TERG 2-5	…..7

7	ANT III with c.50 secondary rhinaria and very long, about as long as IV+V together. SIPH about as long as HT II	…..Amphicercidus pulverulens
–	ANT III 8-20 secondary rhinaria and distinctly shorter than IV+V together. SIPH about 2 × longer than HT II	…..Amphicercidus flocculosus
8	Dorsal abdomen with extensive dark sclerotisation. SIPH black, 0.8-1.2 × the paler, triangular cauda. ABD TERG 1-5 with hemispherical MTu	…..Aphthargelia symphoricarpi
–	Dorsal abdomen pale, or if with any dark sclerotisation then cauda is tongue- or finger-shaped and both SIPH and cauda are equally dark. MTu absent or present on ABD TERG 1-5	…..9

9	SIPH swollen distally or in middle	…..10
–	SIPH tapering or cylindrical	…..11
10	SIPH 0.9-1.4 × cauda, which is rather long and finger-like. Prothorax with a dark trapezoid sclerite ventrally	…..Hyadaphis foeniculi
–	SIPH 1.3-1.6 × cauda, which is rather short, tongue-shaped. Prothorax without a dark ventral sclerite	…..Rhopalomyzus lonicerae (only oviparae recorded; see text)
11	Dorsal abdomen with variably developed dark sclerotisation on ABD TERG 1-6 as well as 7 and 8. Femora wholly dark. R IV+V 0.65-0.92 × HT II. Cauda with 7-17 hairs	…..Aphis spiraephaga
–	Without that combination of characters	…..go to key to polyphagous aphids

*Symphyotrichum*	Asteraceae
*S. cordifolium*	Uroleucon [ambrosiae], crepusisiphon, [luteolum], olivei
S. drummondii	[Uroleucon rudbeckiae]
S. dumosum	Neomyzus circumflexus; Prociphilus erigeronensis;
	Protaphis middletonii group;
	Uroleucon crepusisiphon, olivei, pseudambrosiae
S. ericoides (incl. multiflorus)	Acuticauda asterensis; [Anoecia cornicola];
	Aulacorthum solani; [Geoica squamosa];
	Neomyzus circumflexus; Pemphigus bursarius;
	Prociphilus erigeronensis; Protaphis middletonii;
	Smynthurodes betae; Uroleucon paucosensoriatum
S. foliaceum	Aulacorthum solani
S. laevi (incl. var. geyeri)	Aphis coreopsidis; Prociphilus erigeronensis;
	Uroleucon breviscriptum, crepusisiphon, katonkae,
	paucosensoriatum, tenuitarsum
S. lanceolatum (incl.	[Aphis oreaster Rafinesque (invalid name), see
paniculatus,	Hottes 1931a: 66];
ramosissimus, simplex)	Illinoia goldamaryae; Neomyzus circumflexus;
	Myzus ornatus, persicae; Prociphilus erigeronensis;
	Protaphis middletonii group; Uroleucon [ambrosiae], olivei, [luteolum]
S. lateriflorum	Prociphilus erigeronensis; Protaphis middletonii group;
	Uroleucon crepusisiphon, gravicorne, paucosensoriatum,
	[sonchi]
S. novae-angliae	Aphis spiraecola; Illinoia goldamaryae;
	[Macrosiphum pallens]; Myzus persicae;
	Pemphigus bursarius; Prociphilus erigeronensis;
	Protaphis middletonii group;
	Uroleucon anomalae, astronomus, paucosensoriatum
S. novi-belgii (incl. var. elodes)	Acuticauda asterensis; Aulacorthum solani;
	Macrosiphum euphorbiae; Myzus persicae;
	Prociphilus erigeronensis; Protaphis middletonii group;
	Uroleucon breviscriptum, paucosensoriatum
S. patens	Prociphilus erigeronensis; Protaphis middletonii group;
	Uroleucon crepusisiphon
S. pilosum	Uroleucon crepusisiphon, olivei, paucosensoriatum
S. prenanthoides	Uroleucon pseudambrosiae
S. puniceum	Aulacorthum solani; Protaphis middletonii group;
	Uroleucon crepusisiphon, macgillivrayae,
	olivei, paucosensoriatum
S. pygmaeum	Aleurodaphis asteris
S. squamatum	Aphis gossypii; Myzus persicae; [Uroleucon nuble]
S. tenuifolium	Aphis spiraecola
S. tradescantii	Aphis craccivora; Myzus persicae; Uroleucon erigeronense
S. undulatum	Uroleucon olivei, paucosensoriatum

Use key to apterae on Aster.

*Symphytum*	Boraginaceae
*Symphytum asperum*	Brachycaudus cardui; Macrosiphum symphyti;
	Ovatomyzus boraginacearum
S. caucasicum	Ovatomyzus boraginacearum
S. officinale	Aphis fabae, [frangulae], gossypii, symphyti;
(incl. ssp. bohemicum)	Aulacorthum solani;
	Brachycaudus cardui, helichrysi, mordvilkoi;
	Macrosiphum euphorbiae; Myzus ascalonicus, ornatus;
	Ovatomyzus boraginacearum
*S. orientale*	Aulacorthum solani; Ovatomyzus boraginacearum
S. ottomanum	Aphis symphyti
S. peregrinum	Ovatomyzus boraginacearum
S. popovii	Brachycaudus cardui, helichrysi
S. tauricum	Brachycaudus cardui
S. tuberosum = S. popovii
S. × uplandicum	Aulacorthum solani; Brachycaudus cardui;
	Macrosiphum euphorbiae; Myzus persicae;
	Ovatomyzus boraginacearum
Symphytum sp.	Brachycaudus virgatus; Myzus antirrhinii

Use key to apterae on Anchusa, which covers all these species.

Symphyzicarpus

see Heterostemma Apocynaceae

*Symplocos*	Symplocaceae
*Symplocos chinensis* = S. paniculata
*S. cochinchinensis* var. *laurina*	Aphis aurantii, gossypii, odinae; Greenidea symplocosis;
	Sinomegoura citricola
*S. crataegoides* (= S. paniculata?)	Aphis aurantii, spiraecola; Brachycaudus helichrysi;
	Greenidea symplocosis; Neomyzus circumflexus;
	[Rhopalosiphum rufiabdominale];
	Sinomegoura citricola, [rhododendri]
*S. laurina* = S.cochinchinensis var. laurina
*S. lucida*	Greenidea anonae
*S. paniculata*	Aphis nerii, Aphis (Toxoptera) aurantii
*S. sessilifolia*	Aphis (Toxoptera) aurantii; Sinomegoura symplocois
*S. spicata* = S.cochinchinensis var. laurina
S. “thisifolia” (error for theifolia?)	Aphis (Toxoptera) aurantii; Greenidea anonae
*Symplocos* sp.	[Micromyzus sp. (Basu, Ghosh & Raychaudhuri 1970)];
	[Tinocalloides montanus]

Key to apterae on Symplocos:-

1	SIPH with numerous long hairs	…..2
–	SIPH without hairs	…..3
2	SIPH long and pale, c. 0.6-0.75 × BL	…..Greenidea symplocosis
–	SIPH black, curved outwards distally, 0.18-0.25 × BL	…..Greenidea anonae
3	Cauda long, pointed and black, with 6-17 hairs. SIPH paler than cauda at least on basal half, darker towards apex, 0.8-1.1 × cauda. Antennal tubercles well developed, smooth, divergent. Hairs on ANT III less than half basal diameter of segment	…..4
–	Without that combination of characters	…..go to key to polyphagous aphids
4	SIPH with distal half dark, 0.8-1.0 × cauda which bears 10-19 hairs. (Alata with 13-21 secondary rhinaria on ANT III)	…..Sinomegoura citricola
–	SIPH only dark towards apex, about 1.1 × cauda which bears 6-9 hairs. (Alata with 25-30 secondary rhinaria on ANT III)	…..Sinomegoura symplocois

*Syncarpia* Turpentines	Myrtaceae
*Syncarpia glomulifera*	Aphis gossypii
*S. hillii*	[Aphis sp.]
*S. laurifolia* = S. glomulifera

*Synedrella*	Asteraceae
*Synedrella nodiflora*	Aphis gossypii, spiraecola; Geopemphigus floccosus;
	[Tetraneura nigriabdominalis]; Uroleucon ambrosiae

Key to apterae on Synedrella:-

–	ANT PT/BASE less than 0.5. SIPH absent. Groups of wax glands present dorsally on head, thorax and abdomen	…..Geopemphigus floccosus
–	ANT PT/BASE more than 1. SIPH tubular. No discrete groups of dorsal wax glands	…..go to key to polyphagous aphids

*Synedrella*	Asteraceae
*Synedrella nodiflora*	Aphis gossypii

*Syneilesis*	Asteraceae
*Syneilesis palmata*	Brachycaudus helichrysi

*Syngonium*	Araceae
*Syngonium podophyllum*	Aphis gossypii
*Syngonium* sp.	Aulacorthum solani

Use key to polyphagous aphids.

*Synnema*	Acanthaceae
*Synnema triflorum*	Rhopalosiphum nymphaeae

*Synosma*	Asteraceae
*Synosma suaveolens* = Hasteola suaveolens

Syntherisma see Digitaria

Poaceae

*Synurus*	Asteraceae
*Synurus deltoides*	Aphis fabae, shaposhnikovi;
	Capitophorus elaeagni, rostratus;
	Macrosiphum euphorbiae; Uroleucon giganteum, gobonis
*S. excelsus*	Uroleucon giganteum
S. palmatopinnatifidus = S. deltoides
S. pungens = S. deltoides

Key to apterae on Synurus:-

1	Dorsal body hairs with expanded apices, long and thick at least on head and ABD TERG 7-8, and arising from tuberculate bases	…..2
–	Dorsal hairs not long and capitate nor arising from tuberculate bases	…..3
2	R IV+V 2.6-3.7 × longer than HT II	…..Capitophorus rostratus
–	R IV+V c.1.4-1.5 × longer than HT II	…..Capitophorus elaeagni
3	SIPH with a distal zone of polygonal reticulation. ANT III with numerous rhinaria usually extending into distal half. SIPH and cauda both dark	…..4
–	SIPH without any distinct zone of polygonal reticulation, or if with then SIPH and cauda not dark. ANT III without rhinaria or with a few on basal half	……5
4	Cauda with more than 40 hairs. R IV+V 1.65-1.8 × HT II. Tibiae black	…..Uroleucon giganteum
–	Cauda with 13-20 hairs. R IV+V 1.1-1.3 × HT II. Tibiae pale in middle	…..Uroleucon gobonis (or compositae?)

5	ANT PT/BASE 1.5-2.0. MTu present and well-developed on ABD TERG 2-4 (-5) as well as 1 and 7. R IV+V 1.5-1.8 × HT II	……Aphis shaposhnikovi
–	Without that combination of characters	…..go to key to polyphagous aphids

*Syrenia*	Brassicaceae
*Syrenia angustifolia* = S. cana
S. cana	Smiela syreniae
S. sessiliflora	Smiela syreniae
S. siliculosa = Erysimum siliculosum

(or try key to apterae on Erysimum)

*Syringa*	Oleaceae
*Syringa amurensis* = S. reticulata ssp. amurensis
S. emodi	Aulacorthum syringae; Prociphilus oriens
S. japonica = S. reticulata
*S. josikaea*	Aulacorthum syringae
S. ×persica	Aphis craccivora
S. reticulata	Aulacorthum syringae; Prociphilus oriens
S. reticulata ssp. amurensis	Aulacorthum syringae;
	[Macrosiphum malvicola Matsumura (nomen dubium)];
	Prociphilus oriens
S. reticulata var. *mandshurica* = S. reticulata ssp. amurensis
*S. sweginzowii*	Aulacorthum syringae
S. vulgaris	Lilac
	[Aphis sambuci]; Aulacorthum syringae;
	Myzus persicae;
	Prociphilus americanus, bumeliae, oriens;
	[Rhopalosiphum padi (fundatrices)]
S. wolfii	Aulacorthum syringae
Syringa spp.	[Anoecia fulviabdominalis]; Aphis gossypii

Key to apterae on Syringa (except couplets 1-3 which can be applied to alatae):-

1	Wax pore plates present. ANT PT/BASE less than 0.5. (Spring colonies of fundatrices with all progeny alate)	…..2
–	No discrete wax glands. ANT PT/BASE more than 1	…..4
2	Al. (progeny of fundatrix) with at least 4 sec. rhin. on ANT V …..Prociphilus oriens
–	Al. (progeny of fundatrix) with 0-2 sec. rhin. on ANT V	…..3
3	ANT III more than 5 × ANT II, as long as or longer than ANT IV+V together. Head with a pair of large posterior wax pore plates, conspicuous as clearly delimited pale areas	…..Prociphilus bumeliae
–	ANT III less than 5 × ANT II, usually shorter than ANT IV+V together. Head without or with only small or ill-defined wax pore plates, not forming clearly delimited pale areas	…..Prociphilus americanus
4	ANT III-VI dark, with PT/BASE more than 5. Tibiae wholly dark, femora contrastingly pale except apices. SIPH dark, tapering, with a well-developed flange. Cauda pale	…..Aulacorthum syringae
–	Without that combination of characters	…..go to key to polyphagous aphids

*Syrmatium*	Fabaceae
*Syrmatium glabrum*	Acyrthosiphon kondoi

*Syzygium*	Myrtaceae
*Syzygium antisepticum*	Greenidea maculata; Mollitrichosiphum syzygii
*S. aqueum*	Aphis aurantii, gossypii; Greenidea (Trichosiphum) psidii
*S. aromaticum*	Cloves
	Greenidea (Trichosiphum) psidii; Prociphilus gambosae;
	[Rhopalosiphoninus deutzifoliae, tiliae]
*S. buxifolium*	Taiwanaphis decaspermi
*S. cumini*	Greenidea (Trichosiphum) [anonae], bucktonis, heeri
*S. hancei*	Taiwanaphis decaspermi
*S. heyneanum* =S. salicifolium
*S. jambos*	Aphis aurantii, spiraecola;
	Greenidea (Trichosiphum) heeri
*S. lineatum*	Greenidea (Trichosiphum) heeri;
	Taiwanaphis atuberculata
*S. pycnanthum*	Sinomegoura citricola
*S. racemosum*	Greenidea (Trichosiphum) heeri;
	Taiwanaphis montanicola
*S. salicifolium*	[Chaitophorus eugeniae]
*S. syzygioides*	Greenidea (Trichosiphum) heeri;
	Taiwanaphis pseudocaudata
*S. zeylanicum*	Greenidea (Trichosiphum) eugeniae, heeri
*Syzygium* spp.	Taiwanaphis atrovirens

Key to aphids on Eugenia and Syzygium:-

1	ANT PT/BASE less than 1.0. SIPH as raised pores or broad-based cones, or absent	…..2
–	ANT PT/BASE more than 1.0. SIPH tubular	…..8
2	SIPH absent. Head, thorax and abdomen of aptera with large wax pore plates	…..Prociphilus gambosae

–	SIPH present as raised pores or broad-based cones. Apterae (if present) without large wax pore plates	…..3
3	Aptera with 3-faceted eyes and head fused with prothorax. Alata with numerous annular rhinaria on ANT III, IV and V, and forewing veins not heavily bordered	…..Tuberaphis breviseta

–	Aptera (not known for most species) and 4^th instar nymph have multi-faceted eyes and head free from prothorax. Alata with oval or transversely elongate secondary rhinaria confined to ANT III, and forewing veins heavily bordered with fuscous	…..4
4	Alata with ANT III 2.1-2.9 × PT. Fourth instar nymph with an unpaired scabrous median process on ABD TERG 8, but without paired lateral processes (fig. 112A)	…..Taiwanaphis pseudocaudata

–	Alata with ANT III 3.1-7.0 × PT. Fourth instar nymph without a single median process on ABD TERG 8, with or without paired lateral processes	…..5
5	BL of alata 2.0-2.1 × total length of antenna, which is 1.9-2.1 × head width across (and including) eyes. Fourth instar nymph (and aptera) without paired lateral processes	…..Taiwanaphis atuberculata*

–	BL of alata 1.2-1.8 × total length of antenna, which is 2.2-3.2 × head width across eyes. Fourth instar nymph with or without paired lateral processes	…..6
6	Alata with ANT PT/BASE 0.8-1.15. ANT III 3.1-3.8 × PT. Fourth instar nymph with paired lateral processes on ABD TERG 6-8 (plus a subdivided medial process on ABD TERG 8; fig. 112B)	…..Taiwanaphis atrovirens*
–	Alata with ANT PT/BASE 0.4-0.7. ANT III 4.1-7.0× PT. Fourth instar nymph with or without paired lateral processes	…..7
7	Alata with ANT III pale, and bearing 11-18 secondary rhinaria. Fourth instar nymph without paired lateral processes	…..Taiwanaphis decaspermi
–	Alata with ANT III dark, bearing 19-41 secondary rhinaria. Fourth instar nymph with paired lateral processes (fig. 112C)	…..Taiwanaphis montanicola
8	SIPH without hairs	…..go to key to polyphagous aphids, starting at couplet 2
–	SIPH with numerous long hairs	…..9
9	SIPH without any pale reticulation. Cauda without a median papilla. Hind tibiae with many (20-100) transverse (stridulatory?) ridges	…..Mollitrichosiphum syzygii*
–	SIPH with pale reticulation of interconnected transverse striae, either basally or over most of length. Cauda with a median papilla. Hind tibiae without transverse ridges	…..10
10	SIPH reticulated over most of length. SIPH of aptera c.0.8× BL	…..Greenidea maculata*
–	SIPH reticulated only on basal part. SIPH of aptera 0.20-0.33× BL	…..11
11	R IV+V 1.8-2.4 × HT II	…..12
–	R IV+V 1.2-1.75 × HT II	…..13
12	ANT PT subequal to or slightly shorter than ANT III, less than 2× longer than R IV+V	…..Greenidea (Trichosiphum) bucktonis
–	ANT PT longer than ANT III, and more than 2× longer than R IV+V	…..Greenidea (Trichosiphum) psidii

13	ANT III more than 2× longer than ANT V. Dorsal abdomen with some spinules in central area	…..Greenidea (Trichosiphum) eugeniae
–	ANT III less than 2× longer than ANT V. Dorsal abdomen without spinules	…..Greenidea (Trichosiphum) heeri