HOST LISTS and KEYS

2 ANT and tibiae mainly pale. Dorsum with an extensive solid dark shield across ABD TERG 1-5, fused with marginal and antesiphuncular sclerites. Longest hairs on ANT III less than 0.5 × BD III …..Sitobion colei

- ANT and tibiae mainly dark. Dorsum without a complete dark shield, with or without a less extensive dark patch. Longest hairs on ANT III more than 0.5 × BD III …..3

3 Dorsal abdomen with a central dark patch. Head as dark as ANT. SIPH wholly dark. Process at base of prothoracic furca is tubercular, about as long as its basal width

…..Macrosiphum salviae

- Dorsal abdomen without a dark central patch. Head paler than ANT. SIPH usually with paler basal section. Process at base of prothoracic furca is broadly conical, much shorter than its basal width …..Macrosiphum mesosphaeri

Ocotea Lauraceae

Ocotea acutifolia Lizerius ocoteae

O. glomerata (?) Lizerius pustulatus

O. porphyria Lizerius ocoteae

Ocotea sp. Aphis (Toxoptera) aurantii; Lizerius tuberculatus

Key to species:-

1 Body of aptera with conical, club-shaped or crown-shaped processes .....2

- Body of aptera without processes .....go to key to polyphagous aphids

2 ABD TERG 1-5 each with 6 sclerites, the marginal ones developed into short conical processes, and transverse bars on ABD TERG 6-8; ABD TERG 8 bearing 2 large conical processes and 2-4 much smaller ones (fig. 63A). Antenna of aptera 6-segmented

.....Lizerius ocoteae

- Dorsal body membranous, with numerous short spinulose club-shaped or crown-shaped processes. ABD TERG 8 with 4 tapering or finger-like processes (e.g. fig. 63B). Antennae of aptera often 5-segmented .....3

3 Aptera with apical diameter of largest spinal process on ABD TERG V c. 30 μm, about as wide as SIPH pore. Processes are finger-like/tapering only on ABD TERG 8. Alata with ANT III bearing 8-17 secondary rhinaria in a row, and ANT PT/BASE 0.18-0.29

…..Lizerius tuberculatus

- Aptera with apical diameter of largest spinal process on ABD TERG V c. 20 μm, about 0.5 of width of SIPH pore. Marginal processes are finger-like/tapering on ABD TERG (4-)5-7. Alata with ANT III bearing 15-26 secondary rhinaria scattered all over segment, and ANT PT/BASE 0.30-0.36 …..Lizerius pustulatus

Octadesmia see Dilomilis Orchidaceae

Octomeron see Platostoma Lamiaceae

Ocymum see Ocimum Lamiaceae

×Odontioda Orchidaceae

×Odontioda sp. (hybrid) Aphis spiraecola

Odontites (including Orthantha) Orobanchaceae

Odontites lutea Brachycaudus mimeuri, persicae

O. purpureus Brachycaudus helichrysi

O. serotina = O. vulgaris

O. sicula Brachycaudus mimeuri

O. verna Brachycaudus mimeuri

O. vulgaris Aphis frangulae, sibirica; Brachycaudus persicae

Key to apterae on Odontites:-

1 Cauda short and rounded, not longer than its basal width …..2

- Cauda finger-like, longer than its basal width …..3

2 Dorsum with an extensive solid black shield covering almost all of metanotum and ABD TERG 1-6 …..Brachycaudus mimeuri (or persicae: see text)

- Dorsum without an extensive solid black shield …..Brachycaudus helichrysi

3 SIPH 0.4-0.9 × cauda, which is as dark as SIPH and bears 7-19 hairs …..Aphis sibirica

- SIPH (0.8-)0.9-2.1 × cauda, which is usually paler than SIPH and bears 4-11(-13) hairs

....Aphis frangulae group (or try key to polyphagous aphids)

Odontoglossum Orchidaceae

Odontoglossum sp. Sitobion luteum

(or try key to orchid-feeding aphids under Cymbidium)

Odontonema Acanthaceae

Odontonema strictum Myzus persicae

Odontospermum see Asteriscus Asteraceae

Oedibasis Apiaceae

Oedibasis platycarpa Aphis craccivora

Oemleria (including Osmaronia) Rosaceae

Oemleria cerasiformis Macrosiphum [euphorbiae], occidentale, osmaroniae

Key to apterae on Oemleria:-

- R IV +V short and blunt, about as long as its basal width, 0.7-0.8 × HT II. ANT BASE VI 1.5-2.3 × R IV+V. Cauda with 8-14 hairs …..Macrosiphum occidentale

- R IV+V much longer than its basal width, 0.9-1.1 × HT II. ANT BASE VI 1.0-1.5 × R IV+V. Cauda with 5-8 hairs …..Macrosiphum osmaroniae

Oenanthe Apiaceae

Oenanthe aquatica Anuraphis subterranea; Aulacorthum solani;

Cavariella aegopodii; Pemphigus protospirae

Oe. crocata Aphis fabae; Cavariella aegopodii, pastinacae, theobaldi;

Hyadaphis passerinii; Macrosiphum euphorbiae;

Myzus persicae

Oe. javanica Amphorophora cryptotaeniae;

Aphis craccivora, gossypii, spiraecola;

Brachycaudus helichrysi; Cavariella oenanthi, salicicola;

[Hyalopterus pruni]; Myzus persicae; Semiaphis heraclei

Oe. pimpinelloides Aphis fabae, spiraecola; Dysaphis apiifolia;

Hyadaphis passerinii

Oe. sarmentosa Cavariella aegopodii, konoi; Hyadaphis passerinii;

Pemphigus populicaulis

Oe. silaifolia Cavariella aegopodii; Macrosiphum euphorbiae

Oe. stolonifera = Oe. javanica

Oenanthe spp. [Aphis oenanthis Lichtenstein (nomen nudum)];

Cavariella salicis

Key to apterae on Oenanthe:-

1 ABD TERG 8 with a posteriorly projecting process above cauda bearing 2 hairs (e.g. Fig 10g); in 1 species (Cavariella oenanthi) this is reduced to a small warty knob in the centre of ABD TERG 8, with 2 associated hairs (Fig. 10i) .....2

- No supracaudal process, nor are there 2 hairs on ABD TERG 8 close together and associated with a warty knob .....8

2 SIPH clavate; swollen on distal half to at least 1.2 × narrowest part of basal half.

ANT PT/BASE 0.6-2.0 .....3

- SIPH tapering or cylindrical, or with slight subapical swelling. ANT PT/BASE 1.3-3.5

.….6

3 Supracaudal process conical or finger-like, not projecting to tip of cauda .....4

- Supracaudal process large, conical, extending beyond and usually covering cauda .....6

4 ANT PT/BASE 2.6-4.0 …..Cavariella pastinacae

- ANT PT/BASE 0.6-2.0 …..5

5 ANT PT/BASE 0.6-1.3. R IV+V 0.7-0.95 × HT II, and without accessory hairs

.….Cavariella aegopodii

- ANT PT/BASE 1.35-2.0. R IV+V 1.0-1.2 × HT II, with 2 accessory hairs

.....Cavariella konoi

6 R IV+V 1.05-1.2 × HT II. SIPH short and stout, narrowing only at base

.....Cavariella salicicola

- R IV+V 0.85-1.04 × HT II. SIPH with narrower basal stem extending over about 0.3 of length …..Cavariella salicis

7 Supracaudal process reduced to a warty knob, distinctly shorter than ANT II (Fig. 10i). Head and Cauda dark, tergum with variably developed dark markings. Secondary rhinaria sometimes present on ANT III-V or IV-V (of aptera). ANT PT/BASE 1.3-1.8. Femoral hairs numerous, long and fine, longer than 0.5 × width of hind femur .....Cavariella oenanthi

- Supracaudal process at least as long as ANT II. Head and cauda pale, tergum without dark markings. Antennae (of aptera) without secondary rhinaria. ANT PT/BASE 2.1-3.5. Femoral hairs sparse and shorter than 0.5 × width of hind femur .....Cavariella theobaldi

8 SIPH very small and flangeless; less than 0.5 × cauda and often not much longer (1.0-1.8 ×) than their diameter at midlength …..Semiaphis heraclei

- SIPH (if present at all) more than 0.6 × cauda, and with a flange …..9

9 Cauda helmet-shaped, a little shorter than its basal width. Spinal tubercles (STu) present on head and at least ABD TERG 8 …..10

- Cauda (if developed at all) tongue- or finger-shaped and distinctly longer than its basal width. STu usually not evident …..11

10 SIPH less than 2 × basal width with close-set rows of spinules. Cauda with c.10-12 hairs

…..Anuraphis subterranea

- SIPH more than 2 × basal width with normal imbrication. Cauda with 5 hairs

…..Dysaphis apiifolia

11 SIPH and cauda both dark, with SIPH swollen on distal 0.7, and 0.9-1.4 × cauda

…..Hyadaphis passerinii

- Without that combination of characters …..12

12 SIPH strongly clavate, with swollen part maximally 1.8-2.1 × minimum width on basal part, and with a subapical constriction bearing 2-3 rows of tranverse striae below the well-developed flange. R IV+V 1.5-1.7 × HT II. Apex of ANT PT pointed

…..Amphorophora cryptotaeniae

- Without that combination of characters .....go to key to polyphagous aphids

Oenocarpus Arecaceae

Oenocarpus distichus Cerataphis brasiliensis

Oenothera Onagraceae

Oenothera affinis Aphis oenotherae

Oe. amoena = Clarkia amoena

Oe. berteroana = Oenothera affinis

Oe. biennis Anoecia [cornicola], oenotherae, [setariae];

Aphis fabae, frangulae, gossypii, grossulariae,

holoenotherae, nasturtii, oenotherae, oestlundi;

Aulacorthum solani; Brachycaudus cardui;

Macrosiphum euphorbiae, gaurae,[pallidum];

Myzus [biennis], oenotherae, persicae;

[Pemphigus oenotherae (nomen nudum)];

[Uroleucon ambrosiae]

Oe. brevihypanthialis = Oe. deflexa var. brevihypanthialis

Oe. casimiri Aphis holoenotherae

Oe. cespitosa = Pachylophis cespitosa

Oe. deflexa Aphis holoenotherae

(incl. var. brevihypanthialis)

Oe. erythrosepala = Oenothera glazioviana

Oe. flaemingina [Aphis sp. nr. holoenotherae - Rakauskas 2008]

Oe. flava [Protaphis middletonii]

Oe. fruticosa = Kneiffia fruticosa

Oe. glazioviana Aphis epilobiaria, oenotherae, spiraecola;

[Macrosiphum rosae]; Myzus ornatus;

[Uroleucon nigrotuberculatum]

Oe. grandiflora = Oenothera glazioviana

Oe. hazelae var. subterminalis Aphis holoenotherae

Oe. javanica Aphis spiraecola

Oe. lamarckiana Aphis holoenotherae, oenotherae

Oe. megallanica Aphis grossulariae

Oe. missouriensis = Megapterium missouriense

Oe. muricata = Oenothera biennis

Oe. oakesiana Aphis holoenotherae, oenotherae

Oe. odorata Aphis gossypii, oenotherae, spiraecola;

Rhopalosiphoninus staphyleae

Oe. parviflora Aphis oenotherae

Oe. perangusta × biennis Aphis holoenotherae

Oe. picensis Aphis spiraecola

Oe. pilosella = Kneiffia pilosella

Oe. rosea Rhopalosiphoninus staphyleae

Oe. rubricauloides Aphis holoenotherae

Oe. sarmentosa [Cavariella aegopodii]

Oe. serrulata = Calylophus serrulata

Oe. spectabilis Aphis oenotherae

Oe. stricta Aphis oenotherae

Oe. strigosa var. subulifera Myzus oenotherae

Oe. stuchii [Aphis sp. nr holoenotherae – Rakauskas 2008]

Oe. subterminalis = Oenothera hazelae var. subterminalis

Oe. subulifera = Oenothera strigosa var. subulifera

Oe. versicolor Brachycaudus helichrysi

Oenothera sp. Aphis praeterita, sambuci;

[Protaphis sp. (Utah, USA; A. Jensen, aphidtrek.org)

Key to apterae on Oenothera:-

1 ANT PT/BASE less than 0.5, with numerous long hairs. SIPH as large pores with surrounding hairs on shallow pigmented cones …..Anoecia oenotherae

- ANT PT/BASE more than 1.4, with few hairs. SIPH tubular …..2

2 ANT tubercles undeveloped or weakly developed, so that front of head is convex, straight or sinuous in dorsal view …..3

- ANT tubercles well developed, so there is a deep frontal sinus in dorsal view …..16

3 Cauda helmet-shaped, not longer than its basal width, with 4-8 hairs. SIPH have a distinct annular subapical incision. Spiracular apertures are large and rounded. ABD TERG 1 and 7 are without marginal tubercles (MTu) …..4

- Cauda tongue-shaped, as long as or longer than its basal width, with 4-21 hairs. SIPH without a subapical annular incision. Spiracular apertures reniform. ABD TERG 1 and 7 with MTu

…..5

4 Dorsal abdomen with an extensive solid black shield. ANT III 0.31-0.47 mm, 2.4-3.4 × HT II. R IV+V 0.17-0.24 mm. SIPH dark, imbricated, 1.7-3.4 × cauda .....Brachycaudus cardui

- Dorsal abdomen without a black shield. ANT III 0.07-0.25 mm, 0.9-2.2 × HT II. R IV+V 0.10-0.15 mm. SIPH pale, smooth, 0.8-2.0 × cauda ......Brachycaudus helichrysi

5 Cauda bluntly triangular, about as long as its basal width or only a little longer. ANT III with (0-)1-12 rhinaria on distal half …..Protaphis middletonii

- Cauda tongue-shaped, distinctly longer than its basal width. ANT III without rhinaria (except in alatiform specimens) …..6

6 SIPH 2.2-4.5 × cauda, which is black and bears 9-20 hairs. ABD TERG 2-4(-6) as well as 1 and 7 with well-developed MTu …..Aphis sambuci

- SIPH 0.7-2.5 × cauda, if more than 2.1 × then cauda is pale or dusky and bears fewer hairs. ABD TERG 2-6 with or without small MTu …..7

7 SIPH pale. R IV+V 0.13-0.18 mm long, with 5-12 accessory hairs. Cauda with 8-24 hairs

…..8

- SIPH pale, dark, or dark-tipped. R IV+V 0.075-0.145 mm long, with 2 accessory hairs. Cauda with 4-24 hairs …..11

8 ABD TERG 2-6 mostly with MTu, as well as ABD TERG 1 and 7 …..Aphis grossulariae

- ABD TERG 2-6 without MTu …..9

9 Tarsi almost completely smooth. Cauda with 16-24 hairs …..Aphis epilobiaria

- Tarsi distinctly imbricated. Cauda with 8-16 hairs …..10

10 ANT PT/BASE 1.9-2.5 (usually more than 2) …..Aphis oenotherae

- ANT PT/BASE 1.5-2.3 (usually less than 2) …..Aphis holoenotherae

11 ANT PT/BASE 3.3-4.7. Cauda with 5-8 hairs …..Aphis praeterita

- ANT PT/BASE 1.2-3.5 (if more than 3.1 then cauda has 11-24 hairs) …..12

12 ANT PT/BASE 1.2-1.9. R IV+V 1.35-1.7 × HT II. Anterior half of subgenital plate with

4-6 hairs …..Aphis oestlundi

- ANT PT/BASE 1.9-3.5. R IV+V 0.9-1.4 × HT II. Anterior half of subgenital plate with

2-9 hairs …..13

13 SIPH pale except at apices .….Aphis nasturtii

- SIPH dark …..14

14 SIPH clearly darker than cauda, which bears 4-8 hairs. Longest hind femoral hairs only 0.4-0.7 × diameter of trochantro-femoral suture ......Aphis gossypii

- Cauda always dark like SIPH, and bearing 7-24 hairs. Longest hind femoral hairs usually more than 0.7 × diameter of trochantro-femoral suture .....15

15 Dorsal abdomen without any dark markings. Cauda usually with a midway constriction, and bearing 7-15 hairs .....Aphis spiraecola

- Dorsal abdomen with dark bands on ABD TERG 8, or 7 and 8, and often with dark markings anterior to SIPH. Cauda without any midway constriction, and bearing 11-24 hairs

…..Aphis fabae

16 SIPH with subapical reticulation (at least 4-5 rows of closed polygonal cells). Head smooth, with inner faces of ANT tubercles divergent …..17

- SIPH without subapical polygonal reticulation. Head spiculose, with inner faces of ANT tubercles parallel or apically convergent …..18

17 SIPH variably pigmented, often dark distally. ANT VI BASE 0.65-0.95 × R IV+V.

R IV+V 1.1-1.3 × HT II …..Macrosiphum gaurae

- SIPH usually pale, or only dusky at apices. ANT VI BASE 0.9-1.3 × R IV+V.

R IV+V 0.85-1.1 × HT II …..Macrosiphum euphorbiae

18 Longest hairs on ANT III more than 0.5 × BD III (?). ANT dark beyond basal half of ANT V. SIPH 1.4-1.9 × cauda (?) …..Myzus biennis (or oenotherae? - see text)*

- Longest hairs on ANT III less than 0.5 × BD III. ANT pale except for segmental apices. SIPH 1.9-2.5 × cauda …..19

19 ANT III with (0-) 1-2 (-3) small rhinaria near base. Inner faces of ANT tubercles approximately parallel-sided. SIPH tapering/cylindrical on distal half

…..Aulacorthum solani

- ANT III without rhinaria. Inner faces of ANT tubercles apically convergent. SIPH slightly swollen on distal half …..Myzus persicae

Ohwia Fabaceae

Ohwia caudata Aphis gossypii

Oldenlandia Rubiaceae

Oldenlandia corymbosa Aphis gossypii; Myzus persicae

O. herbacea Aphis gossypii

O. sclerophylla Aphis gossypii

Oldenlandia spp. [Acyrthosiphon pisum]; Aulacorthum solani;

[Lipaphis pseudobrassicae]; Myzus cymbalariae;

Uroleucon compositae

Use key to polyphagous aphids.

Oldfeltia Asteraceae

Oldfeltia polyphlebia see Senecio polyphlebius

Olea Olives Oleaceae

Olea europaea Prociphilus oleae; [Tetraneura agnesii del Guercio 1920]

Olearia Asteraceae

Olearia bullata [Aphis sp. near coprosmae (New Zealand; Teulon et al.

2013)]

O. gunniana Aphis gossypii; [Uroleucon sp. (Leonard 1972a)]

O. lirata [Uroleucon sp. (Leonard 1972a)]

O. passerinoides Myzus persicae; [Uroleucon sp. (Leonard 1972a)]

O. pimeleoides [Uroleucon sp. (Leonard 1972a)]

O. viscidula Myzus persicae; [Uroleucon sp. (Leonard 1972a)]

Use key to polyphagous aphids. (Note: the Uroleucon is a large, red, apparently undescribed species.)

Oligostachyum Poaceae

Oligostachyum shiuyingianum Ceratovacuna hoffmanni; Chaitoregma tattakana

Use key to aphids on Arundinaria.

Oligotrichum Polytrichaceae

Oligotrichum aligerum Myzodium modestum

Use key to apterae of moss-feeding aphids under Polytrichum.

Omalotheca Asteraceae

Omalotheca caucasica = Gnaphalium sylvaticum

Oncidium Orchidaceae

Oncidium altissimum Cerataphis orchidearum; Myzus persicae; Sitobion luteum

O. cebolleta = Trichocentrum cebolleta

O. sphacelatum Aphis (Toxoptera) aurantii

Use key to apterae on orchids under Cymbidium.

Oncoba Salicaceae

Oncoba spinosa Aphis (Toxoptera) aurantii; Schoutedenia ralumensis

Key to apterae on Oncoba:-

- ABD TERG 7 with a pair of long, pointed backwardly-directed processes. SIPH as short broad cones. ANT 5-segmented. ANT PT/BASE less than 1 .…Schoutedenia ralumensis

- ABD TERG 7 without long processes. SIPH tubular, dark, much longer than wide. ANT

6-segmented, with ANT PT/BASE 3.5-5.0 ….. Aphis (Toxoptera) aurantii

Oncosiphon Asteraceae

Oncosiphon piluliferum Aphis craccivora

Onobrychis Fabaceae

Onobrychis arenaria ssp. sibirica Aphis craccivora

O. argentea ssp. hispanica = O. conferta ssp. hispanica

O. conferta ssp. hispanica Aphis craccivora

O. cyri Aphis craccivora

O. gracilis Acyrthosiphon pisum

O. kachetica Acyrthosiphon pisum; Aphis craccivora, fabae;

Therioaphis trifolii

O. micrantha Aphis craccivora

O. montana Acyrthosiphon pisum; Aphis craccivora

O. pulchella Aphis craccivora, [ “laburni” (= cytisorum?)]

O. sativa = O. viciifolia

O. sibirica = O. arenaria ssp. sibirica

O. squarrosa Acyrthosiphon pisum

O. tanaitica (= O. arenaria) Aphis craccivora

O. transcaucasica Aphis craccivora

O. viciifolia Acyrthosiphon loti, pisum;

Aphis [craccae], craccivora, fabae, pseudocomosa;

[Brachycaudus persicae]; Therioaphis trifolii

Onobrychis sp. [Smynthurodes betae]

Key to apterae on Onobrychis:-

1 Fore coxae greatly enlarged. SIPH in form of truncate cones. Cauda knobbed, anal plate bilobed. Dorsal hairs with expanded apices, and arising from pigmented, tuberculate bases

.….Therioaphis trifolii

- Fore coxae normal. SIPH tubular. Cauda tongue- or finger-shaped, anal plate entire. Dorsal hairs with blunt or pointed apices, not arising from tuberculate bases ..…2

2 Body pale, spindle-shaped; BL 2.0-4.4 mm. ANT tubercles well developed with inner faces divergent. SIPH and cauda pale …..3

- Body oval, with an extensive dark dorsal shield; BL 1.4-2.2 mm. ANT tubercles weakly developed. SIPH and cauda both dark …..4

3 ANT I longer than wide and bearing 9-23 hairs. SIPH attenuate distally, thinner than hind tibia at midlength …..Acyrthosiphon pisum

- ANT I not longer than wide, bearing 6-10 hairs. SIPH not attenuate distally, as thick as or thicker than hind tibia at midlength …..Acyrthosiphon loti

4 Longest ANT hairs 0.67-1.4 × ANT BD III. Femoral hairs about as long as trochantro-femoral suture. Cauda with 8-19 hairs (rarely less than 10) …..Aphis pseudocomosa

- Longest ANT hairs 0.37-0.75 × ANT BD III. Femoral hairs shorter. Cauda with 4-9 hairs

…..Aphis craccivora

Onoclea Woodsiaceae

Onoclea sensibilis Amphorophora ampullata, ampullata ssp. laingi;

Aulacorthum solani; Neomyzus circumflexus

O. struthiopteris see Matteuccia

Use key to fern-feeding aphids under Polypodium.

Ononis Fabaceae

Ononis alba Therioaphis obscura

O. antiquorum = O. spinosa ssp. antiquorum

O. aragonensis Aphis fabae

O. arvensis = O. spinosa ssp. hircina

O. austriaca = O. spinosa ssp. austriaca

O. diffusa Therioaphis ononidis

O. fruticosa Acyrthosiphon loti, ononis; Aphis brunnea

O. hircina = O. spinosa ssp. hircina

O. leiosperma = O. spinosa ssp. leiosperma

O. minutissima Aphis craccivora; Therioaphis alatina

O. natrix (incl. sspp. Acyrthosiphon pilosum, pisum;

angustissima, ramosissima) Aphis brunnea, craccivora, [medicaginis];

[Myzus persicae]; Therioaphis alatina, natricis, trifolii

O. pseudohircina = spinosa ssp. hircina

O. pubescens Aphis brunnea

O. pusilla Therioaphis alatina

O. ramosissima = natrix ssp. ramosissima

O. reclinata Therioaphis obscura

O. repens Acythrosiphon loti, ononis, pisum; Aphis kaltenbachi;

(= O. spinosa ssp. procurrens) Macrosiphum euphorbiae; Therioaphis ononidis, trifolii

O. repens var. mitis = O. spinosa ssp. hircina

O. serrata Therioaphis ononidis

O. spinosa Acyrthosiphon ononis, pilosum, pisum;

(incl. ssp. antiquorum, austriaca, Aphis brunnea, craccivora, cytisorum, kaltenbachi,

hircina) ?medicaginis;

Brachycaudus helichrysi; Macrosiphum euphorbiae;

[Myzus sp. (Bozhko 1976a)];

Therioaphis alatina, hungarica, natricis, obscura,

ononidis, trifolii

O. stenophylla Therioaphis natricis

O. tridentata Aphis cytisorum, kaltenbachi, ononidis

O. viscosa Aphis brunnea; Therioaphis alatina

Key to apterae on Ononis:-

(Couplets 1-3 can be applied to alatae as well as apterae.)

1 Fore coxae greatly enlarged. SIPH in form of truncate cones. Cauda knobbed, anal plate bilobed. Dorsal hairs with expanded apices, and arising from tuberculate bases that are often pigmented .….2

- Fore coxae normal. SIPH tubular. Cauda tongue- or finger-shaped, anal plate entire. Dorsal hairs with blunt or pointed apices, not arising from tuberculate bases ..…7

2 ABD TERG 1-4 each bearing 7-10 (mostly 8) long hairs …..Therioaphis trifolii

- ABD TERG 1-4 each with 4 long hairs (one spinal pair and one marginal pair; occasionally there are also one or two much smaller hairs) …..3

3 R IV+V distinctly longer than HT II, and bearing 8-27 accessory hairs …..4

- R IV+V 0.7-0.95 × HT II, and bearing 2-8 (-9) accessory hairs …..6

4 All adult viviparae alate. ABD TERG 8 with 2 (-3) hairs. (R IV+V with 17-25 accessory hairs) …..Therioaphis alatina

- Predominant morph apterous. ABD TERG 8 with 4-6 hairs …..5

5 R IV+V with 14-27 accessory hairs …..Therioaphis natricis

- R IV+V with 8-12 accessory hairs …..Therioaphis ononidis

6 ABD TERG 1-7 with very large paired variably pigmented sclerotic cross-bars, often fused across midline. R IV+V with 2-4 accessory hairs …..Therioaphis obscura

- ABD TERG 1-7 with hairs arising from separate sclerotic plates that are rarely fused across midline. R IV+V with 6-9 accessory hairs …..Therioaphis hungarica

7 Body spindle-shaped. ANT tubercles well developed, with inner faces smooth and divergent. ANT often longer than BL …..8

- Body oval. ANT tubercles undeveloped or weakly developed, ANT shorter than BL …..12

8 SIPH with subapical polygonal reticulation. Longest hairs on ANT III more than 0.5 × basal diameter of segment …..Macrosiphum euphorbiae

- SIPH without subapical polygonal reticulation. Longest hairs on ANT III usually less than 0.5 × basal diameter of segment …..9

9 R IV+V with 19-36 accessory hairs. First tarsal segments usually with 5 hairs. Prominent marginal tubercles present on several of ABD TERG 2-4(-5) …..Acyrthosiphon pilosum

- R IV+V with 3-12 accessory hairs. First tarsal segments with 3 hairs. Abdominal marginal tubercles either absent or small and inconspicuous …..10

10 ANT I with 6-9 hairs. ANT BASE VI 1-1.5 × longer than R IV+V. SIPH not attenuate distally; diameter at midlength greater than middle diameter of hind tibia

..…Acyrthosiphon loti

- ANT I with 9-23 hairs. ANT BASE VI 1.6-2.9 × longer than R IV+V. SIPH attenuate distally, with diameter at midlength similar to or less than middle diameter of hind tibia ..…11

11 ANT VI BASE 1.6-1.9 × R IV+V, which bears (6-) 8-12 accessory hairs. R IV+V 0.75-0.95 × HT II. Cauda with 11-23 hairs …..Acyrthosiphon ononis

- ANT VI BASE 1.9-2.9 × R IV+V which bears 3-7 (-8) accessory hairs. R IV+V 0.67-0.85 × HT II. Cauda with 8-14 hairs …..Acyrthosiphon pisum

12 Cauda helmet-shaped, not longer than its basal width. SIPH pale, smooth, with a subapical annular incision. Spiracular apertures large and rounded. ABD TERG 1 and 7 without marginal tubercles (MTu). Dorsal abdomen without dark markings

…..Brachycaudus helichrysi

- Cauda tongue- or finger-shaped, longer than its basal width. SIPH dark, imbricated, without a subapical annular incision. Spiracular apertures reniform. ABD TERG 1 and 7 always with MTu. Dorsal abdomen usually with dark markings …..13

13 SIPH very short, flangeless, 0.2-0.3 × cauda. Dorsum usually with a solid dark shield from metanotum to ABD TERG VI …..Aphis kaltenbachi

- SIPH with a distinct flange, and at least 0.8 × cauda. Dorsum with or without a solid dark shield …..14

14 Very short haired; hairs on ABD TERG 8 are 11-16 μm, and on ABD TERG 3 marginally 11-12 μm. Posterior hair on hind trochanter 16-24 μm, 0.29-0.52 × length of

trochantro-femoral suture …..Aphis ?medicaginis (see text)

- Longer haired; hairs on ABD TERG 8 are 18-85 μm, and on ABD TERG 3 marginally 12-85 μm. Posterior hair on hind trochanter (0.34-) 0.5-2.0 × length of trochantro-femoral suture

…..15

15 ABD TERG 1-4 and 7, and sometimes also 5 and 6, with MTu. R IV+V 1.1-1.45 × HT II and bearing 2-6 (usually 4-5) accessory hairs …..Aphis brunnea

- MTu only sporadically present on ABD TERG 2-4. R IV+V 0.9-1.2 × HT II, with 2 accessory hairs …..16

16 Cauda with 11-25 hairs. Dorsal abdomen usually with a few small dark spots anterior to SIPH

…..Aphis fabae

- Cauda with 4-13 hairs. Dorsal abdomen usually with extensive dark sclerotisation …..17

17 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

Onopordum Asteraceae

Onopordum acanthium Aphis craccivora, fabae, gossypii, solanella, [symphyti];

Brachycaudus cardui, cardui ssp. turanica, helichrysi;

Capitophorus carduinus, elaeagni;

Dysaphis lappae ssp. cynarae; Macrosiphum euphorbiae;

Myzus persicae;

Protaphis anuraphoides, [elongata], pseudocardui,

terricola;

Trama troglodytes;

Uroleucon aeneum, bicolor (?), [sonchi]

O. anisacanthum = O. heteracanthum

O. davisii Aphis craccivora, spiraecola; Brachycaudus cardui

O. heteracanthum Aphis fabae; Myzus persicae

O. illyricum Aphis fabae; Brachycaudus cardui, helichrysi;

Uroleucon aeneum, [sonchi]

O. leptolepis Brachycaudus cardui; Protaphis [carthami], terricola

O. nervosum Brachycaudus cardui

O. olgae Pemphigus bursarius; Rectinasus buxtoni;

Smynthurodes betae

O. sibthorpianum Protaphis terricola

O. tauricum Brachycaudus cardui

Key to apterae on Onopordum:-

1 SIPH absent. ANT PT/BASE less than 0.5. Eyes reduced, often to triommatidia …..2

- SIPH present. ANT PT/BASE more than 0.6. Eyes well-developed …..5

2 Body and antennae sparsely hairy. Wax glands present on ABD TERG 3-7

…..Pemphigus bursarius

- Body and antennae densely hairy, e.g. base of last antennal segment with more than 20 hairs. Wax glands absent or inconspicuous …..3

3 HT II elongate, at least 0.5 × hind tibia. ANT 6-segmented …..Trama troglodytes

- HT II of normal length. ANT 5-segmented …..4

4 ANT V BASE and R IV+V both very long, respectively about 1.7 and 2.5 × width of head between antennal bases. ANT II similar in length to ANT I, much shorter than III

.….Rectinasus buxtoni

- ANT V BASE and R IV+V of normal length , both about 0.5 × width of head between antennal bases. ANT II about twice as long as ANT I, similar in length to III

..…Smynthurodes betae

5 Cauda short, helmet-shaped or bluntly triangular, shorter than or not clearly longer than its basal width in dorsal view .....6

- Cauda elongate triangular, tongue-or finger-shaped, clearly longer than its basal width in dorsal view .....11

6 ANT PT/BASE 0.75-1.15. Cauda bluntly triangular with 10-24 hairs. ABD TERG 1 and 7 with well-developed marginal tubercles (MTu) .....7

- ANT PT/BASE 2.3-5.1. Cauda helmet-shaped, with 5-8 hairs. If ABD TERG 1 and 7 have MTu then these are also present on ABD TERG 2-5 …..9

7 ANT III usually without secondary rhinaria (rarely with 1-3). (Longest hairs on ABD TERG 3 are 0.7-1.1 × ANT BD III) …..Protaphis pseudocardui

- ANT III and IV usually with rhinaria (0-12 on III and 0-4 on IV) .....8

8 Longest hairs on ABD TERG 3 are 1.2-1.3 × ANT BD III. SIPH 0.9-1.2 × cauda, and with a distinct flange. R IV+V 1.45-1.65 × HT II …..Protaphis anuraphoides

- Longest hairs on ABD TERG 3 are 0.3-0.9 × ANT BD III. SIPH 0.67-0.92 × cauda, with a weak flange . R IV+V 1.2-1.4 (-1.5) × HT II …...Protaphis terricola

9 Dorsal abdomen with an extensive solid black patch. SIPH 0.10-0.15 × BL. Mesosternum with a pair of dark mammariform processes .....Brachycaudus cardui

- Dorsal abdomen without a solid black patch, at most with scattered dark markings. SIPH 0.05-0.10 × BL. Mesosternum without mammariform processes .....10

10 BL 0.9-2.0 mm. SIPH smooth, short and broad-based, 1.5-2.0 × their diameter at midlength. Spinal and marginal tubercles (STu and MTu) rare or absent

......Brachycaudus helichrysi

- BL 2.1-3.0 mm. SIPH imbricated and about 3 × their diameter at midlength. Numerous

well-developed STu and MTu present .....Dysaphis lappae ssp. cynarae

11 Hairs on front of head and dorsal body mostly long and capitate, and arising from tuberculate bases .....12

- Hairs on front of head and dorsal body not capitate .....13

12 Cauda 1.1-1.5 × R IV+V, and bearing 5-8 hairs. ANT PT 3.1-4.4 × R IV+V, and ANT PT/BASE 4.6-6.3. SIPH without dark apices …..Capitophorus carduinus

- Cauda 1.4-2.3 × R IV+V, and bearing 7-13 hairs. ANT PT 4.5-6.3 × R IV+V, and ANT PT/BASE 6.0-9.2. SIPH with dark apices …..Capitophorus elaeagni

13 BL 3.5-5.0 mm. ANT III with 17-45 rhinaria. SIPH dark, with reticulation extending over distal 0.15-0.25 of length …..14

- BL less than 3.5, and other characters not in that combination

…..go to key to polyphagous aphids

14 Cauda black. ABD TERG 2-4 consistently with well-developed MTu. R IV+V 1.2-1.3 × HT II …..Uroleucon aeneum

- Cauda pale. ABD TERG 2-3 irregularly with very small MTu. R IV+V 0.79-0.84 × HT II

…..Uroleucon bicolor (? – see text)

Onosma Boraginaceae

Onosma stellulata Brachycaudus cardui

Onosmodium Boraginaceae

Onosmodium bejariense

var. occidentale Brachycaudus helichrysi

Onychium Adiantaceae

Onychium japonicum Idiopterus nephrelepidis

Ophiopogon Asparagaceae

Ophiopogon japonicus Hydronaphis sp. (Japan – Moritsu 1983)

Ophiorrhiza Rubiaceae

Ophiorrhiza sp. Aphis spiraecola

Ophiuros Poaceae

Ophiuros exaltatus [Iowana zhangi]; Rhopalosiphum maidis

Ophrys Orchidaceae

Ophrys apifera Aphis fabae

O. fusca Dysaphis neostroyani

O. sphegodes (incl. arenifera) Aphis fabae

O. ×todaroana Aphis fabae

Use key to apterae of orchid-feeding aphids under Cymbidium.

Oplismenus Poaceae

Oplismenus burmannii Hysteroneura setariae; Tetraneura fusiformis

O. compositus Asiphonella dactyloni; [Ceratovacuna nekoashi];

[Hyalomyzus raoi]; Hysteroneura setariae;

Micromyzodium spinulosum; Pentalonia gavarri;

Pseudoregma panicola; Sitobion miscanthi

O. hirtellus Pseudoregma panicola

O. imbecillis = O. hirtellus

O. setarius = O. compositus

O. undulatifolius [Ceratovacuna nekoashi]; Pseudoregma panicola;

Sitobion akebiae

Oplismenus spp. Baizongia pistaciae; Ceratovacuna lanigera;

[Pseudoregma koshunensis]

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

Oplopanax Araliaceae

Oplopanax horridum Aphis asclepiadis;

Macrosiphum sp. nr euphorbiae (see aphidtrek.org)

Use key to polyphagous aphids.

Opopanax Apiaceae

Opopanax chironius Anuraphis pyrilaseri, shaposhnikovi; Aphis fabae;

Dysaphis apiifolia

Key to apterae on Opopanax:-

(All 4 species have undeveloped or weakly-developed ANT tubercles, dark SIPH, dark cross-bands on ABD TERG 8 or 7-8, and usually some scattered dark markings on ABD TERG 1-6.)

1 Cauda distinctly longer than its basal width. Spinal tubercles (STu) absent, abdominal marginal tubercles (MTu) consistently present only on ABD TERG 1 and 7 …..Aphis fabae

- Cauda helmet-shaped, a little shorter than its basal width. STu present on head and at least some ABD TERG, and MTu on ABD TERG 1-5 or 1-7 …..2

2 R IV+V much shorter than SIPH. SIPH more than 3 × basal width with normal imbrication. Cauda with 5 hairs …..Dysaphis apiifolia

- R IV+V longer than SIPH. SIPH less than 2.5 × basal width with close-set rows of spinules. Cauda with 11-18 hairs …..3

3 MTu on ABD TERG 1-5 only. R IV+V 1.6-2.1 × HT II …..Anuraphis pyrilaseri

- MTu on ABD TERG 1-7. R IV+V 1.2-1.6 × HT II …..Anuraphis shaposhnikovi

Opulaster Rosaceae

Opulaster malvaceus Utamphorophora humboldti

O. opulifolius Aphis neilliae, [pomi], spiraecola;

[Chaetosiphon tetrarhodum]; Rhopalosiphum padi;

Utamphorophora humboldti;

[aphid gall – Wahlgren 1956, 51]

See key to apterae under Physocarpus.

Opuntia Cactaceae

Opuntia aurantiaca Protaphis middletonii

O. dillenii Aphis gossypii

O. ficus-indica Aphis craccivora, fabae; Myzus persicae;

Protaphis middletonii

O. inermis = O. stricta

O. stricta Pentalonia nigronervosa; Protaphis middletonii

O. vulgaris = O. ficus-indica

Opuntia sp. Aphis gossypii

Key to apterae on Opuntia:-

- ANT longer than BL, with ANT PT/BASE 5-8. Femora with basal 0.6 or more of length pale, rest contrastingly black. SIPH pale basally and dark distally. (Al. with broad-banded wing-veins, and radius fused with media to form a closed cell below pterostigma)

…..Pentalonia nigronervosa

- Without that combination of characters …..go to key to polyphagous aphids

Orchis Orchidaceae

Orchis anthropophora Aphis fabae

O. coriophora = Anacamptis coriophora

O. purpurea Aphis orchidis

Orchis spp. Aulacorthum solani; Dysaphis neostroyani;

Myzus persicae; Neomyzus circumflexus

Use key to apterae of orchid-feeding aphids under Cymbidium.

Oreocnide (including Villebrunea) Urticaceae

Oreocnide frutescens Aulacorthum solani

O. integrifolia [Greenidea bucktonis]

Oreopanax Araliaceae

Oreopanax guatemalensis Myzus persicae

Origanum (including Majorana) Lamiaceae

Origanum compactum Aphis sp. near gossypii

O. creticum = O. vulgare

O. heracleoticum = O. vulgare ssp. viridulum

O. majorana (= Majorana Myzus ornatus; Neomyzus circumflexus

hortensis)

O. ×paniculatum Aphis origani

O. syriacum Eucarazzia elegans

O. tyttanthum = O. vulgare ssp. gracile

O. virens = O. vulgare ssp. virens

O. vulgare (incl. sspp. gracile, Aphis fabae, gossypii, nasturtii, origani;

virens, viridulum) Aulacorthum solani; Kaltenbachiella pallida;

Myzus ornatus, persicae; [Ovatomyzus chamaedrys];

Ovatus crataegarius

Key to apterae on Origanum:-

1 ANT usually 4-segmented, 0.12-0.15 × BL, with PT/BASE less than 0.5. Eyes 3-facetted. SIPH absent. Legs very short, with fore- and mid-tarsi usually 1-segmented. Dorsal wax glands present on head, thorax and ABD TERG 1-8, comprising facets surrounding an elongate central area …..Kaltenbachiella pallida

- ANT 5- or 6-segmented, more than 0.5 × BL, with PT/BASE more than 1. Eyes multifacetted, SIPH present, tarsi 2-segmented and wax glands not evident …..2

2 SIPH strongly swollen, 5.4-8.2 × cauda, with maximum diameter of swollen part more than 2 × minimum diameter of stem, smooth except for a little subapical polygonal reticulation

…..Eucarazzia elegans

- SIPH not swollen or much less swollen, and less than 3.5 × cauda …..3

3 Head smooth, ANT tubercles weakly developed. Marginal tubercles (MTu) present on ABD TERG 1 and 7 …..4

- Head spiculose with well-developed ANT tubercles, their inner faces spiculose or scabrous and steep-sided. MTu absent from ABD TERG 1 and 7 …..7

4 SIPH pale with dark apices …..Aphis nasturtii

- SIPH wholly dark …..5

5 Cauda with 11-24 hairs. Hairs on ANT III 0.8-3.4 × BD III …..Aphis fabae

- Cauda with 4-8 hairs. Hairs on ANT III 0.3-0.7 × BD III …..6

6 SIPH 0.10-0.12 × BL, 1.05-1.45 × cauda. ABD TERG 7 and 8 usually with dark cross-bands

…..Aphis origani

- SIPH 0.12-0.26 × BL, 1.3-2.5 × cauda. ABD TERG 7 and 8 rarely with dark cross-bands

…..Aphis gossypii

7 Dorsal abdomen without any dark markings …..8

- Dorsal abdomen with dark markings …..10

8 SIPH slightly but distinctly swollen on distal half. ANT 0.7-1.0 × BL …..Myzus persicae

- SIPH tapering/cylindrical on distal half. ANT 1.1-1.5 × BL …..9

9 Inner faces of ANT tubercles with convergent, rounded, scabrous processes. ANT III without rhinaria. ANT PT/BASE 5.2-7.6. R IV+V 1.3-1.6 × HT II, with 2-4 accessory hairs

…..Ovatus crataegarius

- Inner faces of ANT tubercles without processes, approximately parallel. ANT III usually with 1-2 small rhinaria near base. ANT PT/BASE 4.0-5.4. R IV+V 1.1-1.4 × HT II, with 5-7 accessory hairs …..Aulacorthum solani

10 Dorsal abdomen with a large, roughly U-shaped black patch. ANT PT/BASE 4.3-5.2

…..Neomyzus circumflexus

- Dorsal abdomen with a pattern of dark intersegmental markings. ANT PT/BASE 1.7-2.8

…..Myzus ornatus

Orixa Rutaceae

Orixa japonica ?Aulacorthum ?solani (as Myzus kusaki Shinji);

Pseudomegoura magnoliae

Use key to polyphagous aphids.

Orlaya Apiaceae

Orlaya grandiflora Aphis solanella; Cavariella theobaldi; Dysaphis crataegi;

Hyadaphis passerinii

Key to apterae on Orlaya:-

1 SIPH dark, clavate and about equal in length to the dark cauda …..Hyadaphis passerinii

- SIPH pale or dark, tapering/cylindrical, longer than cauda, which may also be pale or dark

…..2

2 ABD TERG 8 with a backwardly-pointed process bearing 2 hairs …..Cavariella theobaldi

- No process on ABD TERG 8 …..3

3 Cauda helmet-shaped, not longer than its basal width, usually with 5 hairs. Spinal tubercles (STu) present on head and ABD TERG 8 or, 7 and 8, and marginal tubercles (MTu) on ABD TERG 1-5, but not usually on 7 .....Dysaphis crataegi

- Cauda tongue-shaped, longer than its basal width, with 11-23 hairs. STu absent, and MTu only regularly present on ABD TERG 1 and 7 .....Aphis fabae group (incl. solanella)

Ormenis see Chamaemelum Asteraceae

Ornithidium Orchidaceae

Ornithidium adendrobium Cerataphis orchidearum

Ornithogalum Asparagaceae

Ornithogalum dubium Aphis gossypii

Ornithogalum spp. Myzus persicae; Rhopalosiphum nymphaeae, padi

Key to apterae on Ornithogalum:-

- Dorsal cuticle with a pattern of spinules arranged in polygons, with 1-3 spicules in the centre of each polygon. SIPH clavate …..Rhopalosiphum nymphaeae

- Without the above combination of characters; if dorsal cuticle has a pattern of spinules arranged in polygons then SIPH not clavate …..go to key to polyphagous aphids

Ornithopus Fabaceae

Ornithopus compressus Aphis craccivora

O. isthmocarpus = O. sativus ssp. isthmocarpus

O. perpusillus Acyrthosiphon pisum; Aphis craccivora

O. sativus (incl. ssp. isthmocarpus) Aphis craccivora

Key to apterae on Ornithopus:-

- Body oval, with an extensive black sclerotic dorsal shield, BL 1.4-2.2 mm. SIPH and cauda black …..Aphis craccivora

- Body spindle-shaped, pale, BL 2.5-4.4 mm. SIPH and cauda pale. (Additional check - ANT VI BASE 0.25-0.4 mm, 1.8-2.3 × R IV+V – otherwise go to key to polyphagous aphids)

…..Acyrthosiphon pisum

Orobanche (including Aphyllon) Orobanchaceae

Orobanche aegyptiaca Aphis gossypii, [Aphis sp. (Davletshina 1964)];

Rectinasus buxtoni; Smynthurodes betae

O. foetida [Geoica utricularia]

O. crenata Smynthurodes betae

O. hederae Macrosiphum euphorbiae

O. lutea [Aphis orobanches]

O. mutelii [Aphis orobanches]

O. ramosa [Aphis orobanches]; [Dysaphis candicans];

[Brachycaudus cardui (? – as Aphis phelipaeae Passerini)];

Smynthurodes betae

O. variegata Smynthurodes betae

Orobanche sp. [Anuraphis subterranea]; Protaphis middletonii;

[Siphonophora orobanches Lichtenstein (nomen nudum)];

Myzus persicae; Rhopalosiphum rufiabdominale;

Trama orobanches

Key to apterae on Orobanche:-

[Only the original descriptions of Aphis orobanches and Dysaphis candicans are available (Passerini 1879), and are insufficient to include these species in the key; see text under these names for further information.]

1 ANT 5-segmented, with ANT V BASE very long, more than 15 × longer than the short

peg-like PT. R IV+V extremely long, similar in length to hind femur …..Rectinasus buxtoni

- ANT 5- or 6-segmented, base of last segment and R IV+V relatively much shorter …..2

2 HT II greatly elongated, more than 0.5 × hind tibia …..Trama orobanches

- HT II of normal length …..3

3 Thoracic spiracles greatly enlarged, rounded, much larger than abdominal spiracles. ANT PT/BASE 7.0-11.4, usually more than 8.0. ANT III with 14-36 rhinaria

…..Nasonovia ribisnigri

- Thoracic spiracles similar in size to abdominal ones. ANT PT/BASE less than 6. ANT III with 0-10 rhinaria …..go to key to polyphagous aphids

Orostachys Crassulaceae

Orostachys spinosa Aphis sedi

Ortantha see Odontites Orobanchaceae

Orthilia (including Ramischia) Ericaceae

Orthilia secunda Aulacorthum pirolacearum

Orthocarpus Orobanchaceae

Orthocarpus luteus Nasonovia alpina

O. purpurascens Macrosiphum orthocarpus

(= Castelleja exserta)

Key to apterae on Orthocarpus:-

- BL 1.9-2.5 mm. ANT III-V dark only at apices, and SIPH pale or uniformly pigmented, without subapical polygonal reticulation. (Also check: thoracic spiracular apertures much larger than abdominal ones, which are almost covered by cowl-like opercula. R IV+V

1.6-2.1 × HT II with 12-18 accessory hairs) …..Nasonovia alpina

- BL more than 3 mm. ANT black beyond basal part of III. SIPH black on distal c.0.7 (and with subapical reticulation?) …..Macrosiphum orthocarpus*

Orthostemon = Acca Myrtaceae

Oryza Poaceae

Oryza sativa Anoecia corni, fulviabdominalis; Aphis gossypii;

Brachysiphoniella montana; Chaetogeoica polychaeta;

Diuraphis noxia; Forda orientalis;

Geoica lucifuga, setulosa, utricularia;

Hyalopterus amygdali; Hysteroneura setariae;

Melanaphis sacchari; Metopolophium dirhodum;

Paracletus cimiciformis; [Prociphilus sp.];

Rhopalosiphum maidis, nymphaeae, padi, rufiabdominale,

rufulum;

Schizaphis graminum; Sipha flava, glyceriae, maydis;

Sitobion akebiae, avenae, graminis, miscanthi;

Tetraneura basui, fusiformis, javensis, nigriabdominalis,

radicicola, ulmi

Use key to apterae of grass-feeding aphids under Digitaria, or for a simple key to common aphids on rice see Blackman & Eastop 2000.

Oryzopsis (including Eriocoma, Piptantherum) Poaceae

Oryzopsis cuspidata = O. hymenoides

O. hymenoides Forda marginata

O. lateralis Sitobion himalayensis

O. miliacea Melanaphis sacchari; Myzus persicae; Sitobion avenae

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

Osbeckia Melastomataceae

Osbeckia capitata Aphis gossypii, nasturtii; [Capitophorus carduinus];

Myzus ornatus, persicae

O. chinensis Aphis nasturtii; Brachycaudus helichrysi;

[Rhopalosiphum rufiabdominale]

O. crinata Aphis aurantii, gossypii; [Capitophorus sp.];

Myzus persicae

Use key to polyphagous aphids.

Osmanthus Oleaceae

Osmanthus aquifolius Prociphilus osmanthae

O. asiaticus [Shivaphis hangzhouensis]

O. aurantiacus Prociphilus osmanthae

O. aurantiacus var. thunbergii Pseudomegoura magnoliae

O. × burkwoodii Prociphilus osmanthae

O. heterophyllus Prociphilus osmanthae

O. insularis Aphis odinae

- SIPH absent. ANT PT/BASE less than 1 …..Prociphilus osmanthae

- SIPH present. ANT PT/BASE more than 1 …..go to key to polyphagous aphids

Osmaronia see Oemleria Rosaceae

Osmia see Eupatorium Asteraceae

Osmorhiza Apiaceae

Osmorhiza aristata Aphis fabae; Cavariella aegopodii, theobaldi;

(incl. var. longistylis) Semiaphis heraclei; [Uroleucon parvotuberculatum]

O. chilensis Macrosiphum euphorbiae; Myzus ascalonicus;

[Rhopalosiphoninus staphyleae]

O. claytoni = O. aristata

O. longistylis see aristata

Osmorhiza sp. Aphis asclepiadis

Use key to apterae on Apium.

Osmunda Osmundaceae

O. cinnamomea Amphorophora ampullata ssp. laingi

O. japonica Amphorophora ampullata; Aulacorthum solani;

Taiwanomyzus babai, filicis

O. regalis Aulacorthum solani; Macrosiphum walkeri;

Micromyzella pterisoides; Neomyzus circumflexus

Osmunda sp. Macrosiphum euphorbiae

Use key to apterae on ferns under Polypodium.

Osmundastrum Osmundaceae

Osmundastrum asiaticum Micromyzus nikkoensis, osmundae

O. claytonianum Micromyzus osmundae

Use key to apterae on ferns under Polypodium.

Osteomeles Rosaceae

Osteomeles schwerinae Myzus persicae

O. subrotunda Aphis gossypii

Use key to polyphagous aphids.

Osteospermum Asteraceae

Osteospermum ecklonis Macrosiphum euphorbiae; Uroleucon compositae

O. moniliferum = Chrysanthemoides monilifera

O. spinescens Aphis craccivora

O. vaillantii = Tripteris vaillantii

Use key to polyphagous aphids.

Ostericum Apiaceae

Ostericum melanotilingia = Angelica decursiva

Ostrya Hop-hornbeams Corylaceae

Ostrya carpinifolia Pterocallis ostryae

O. japonica Mesocallis pteleae

O. virginiana Macrosiphum (Neocorylobium) pseudocoryli

Key to aphids on Ostrya:-

1 SIPH long, tubular, dark, with subapical zone of polygonal reticulation. Cauda long and tongue-shaped, anal plate entire. ANT PT/BASE more than 5

.....Macrosiphum (Neocorylobium) pseudocoryli

- SIPH as short, truncated cones. Cauda knobbed, anal plate bilobed. ANT PT/BASE 1.2 or less

.....2

2 ANT III of alata dark, with 7-14 secondary rhinaria. ANT PT/BASE 0.9-1.2

.....Mesocallis pteleae

- ANT III of alata pale with 4-7 secondary rhinaria. ANT PT/BASE 0.3-0.6

.....Pterocallis ostryae

Ostryoderris = Aganope Fabaceae

Ostryopsis Betulaceae

Ostryopsis davidiana Corylobium avellanae

Othonna (including Hertia, Othonnopsis) Asteraceae

Othonna cheirifolia Macrosiphum euphorbiae

Othonnopsis see Othonna Asteraceae

Otites see Silene Caryophyllaceae

Otochilus Orchidaceae

Otochilus porrectus Sitobion indicum, luteum

Use key to apterae on orchids under Cymbidium.

Ottelia Hydrocharitaceae

Ottelia alismoidis Rhopalosiphum nymphaeae

Ourisia Plantaginaceae

Ourisia microphylla Neomyzus circumflexus

Ourouparia see Uncaria Rubiaceae

Oxalis Oxalidaceae

Oxalis acetosella Aphis nasturtii; Aulacorthum solani;

[Hyperomyzus lactucae]; [Jacksonia papillata];

[Metopolophium frisicum]; Myzus ascalonicus, persicae;

Rhopalosiphoninus staphyleae

O. articulata Myzus ornatus; Neomyzus circumflexus

O. cernua = O. pes-caprae

O. corniculata Aphis aurantii, craccivora, gossypii, nasturtii, spiraecola;

Aulacorthum solani; Brachycaudus helichrysi;

Macrosiphum euphorbiae;

Myzus cymbalariae, ornatus, persicae;

Indomasonaphis anaphalidis; Neomyzus circumflexus;

Neotoxoptera oliveri;

Rhopalosiphoninus latysiphon, staphyleae

O. debilis var. corymbosa Aphis fabae; Myzus persicae

O. deppei Aphis fabae; Neomyzus circumflexus

O. enneaphylla Myzus ascalonicus

O. latifolia Aphis gossypii; Macrosiphum euphorbiae;

[Micromyzodium filicium]; Myzus persicae

O. laxa Myzus cymbalariae

O. martiana = O. debilis var. corymbosa

O. oregana Macrosiphum sp. (Oregon, USA; BMNH collection, leg. D.

Hille Ris Lambers);

Rhopalosiphoninus staphyleae

O. pes-caprae Aphis aurantii, craccivora, fabae, gossypii, solanella,

spiraecola;

Aulacorthum solani;

Macrosiphum euphorbiae; Myzus persicae;

Rhopalosiphoninus staphyleae

O. purpurea Myzus persicae

O. rosea Myzus persicae; Neomyzus circumflexus

O. semiloba Aphis gossypii; Myzus persicae

O. stricta Abstrusomyzus reticulatus; Protaphis middletonii

O. trilliifolia Myzus ornatus, persicae

O. variabilis = O. purpurea

O. versicolor Aphis fabae

O. violacea = O. debilis var. corymbosa

Oxalis sp. [Rhopalosiphum maidis]

Key to apterae on Oxalis:-

1 BL 3.8-4.7 mm. SIPH pale, smooth and markedly swollen on distal 0.7 (Fig.34a). Dorsal hairs long, thick, and blunt or slightly expanded apically …..Indomasonaphis anaphalidis

- Without that combination of characters …..2

2 Dorsum with an extensive solid dark sclerotic shield, with very conspicuous, dark,

non-spinulose reticulation. SIPH slightly swollen near apex …..Abstrusomyzus reticulatus

- Dorsum with or without dark markings; if with a solid dark sclerotic dorsal shield then this either lacks reticulation, or the reticulation is either pale or finely spinulose, and SIPH are either markedly inflated over more than half of length or completely lack any trace of swelling …..3

3 SIPH cylindrical/tapering, with polygonal reticulation on distal 0.12-0.26 of length …..4

- SIPH if cylindrical/tapering then without polygonal reticulation

…..go to key to polyphagous aphids

4 ABD TERG 7 and 8 mostly with spinal tubercles (STu) and ABD TERG 2-5 often with marginal tubercles (MTu) …..Macrosiphum sp. (Oregon, BMNH collection)

- Stu and MTu only sporadically present …..Macrosiphum euphorbiae

Oxybaphus Nyctaginaceae

Oxybaphus angustifolius = Mirabilis nyctaginea var. angustifolia

O. nyctagineus Aphis asclepiadis, fabae; Macrosiphum euphorbiae

Use key to polyphagous aphids.

Oxycoccus see Vaccinium Ericaceae

Oxydendrum Ericaceae

Oxydendrum arboreum Aulacorthum solani

Oxylobium Fabaceae

Oxylobium callistachys Aphis gossypii

O. lineare Aphis gossypii

Oxylobus Asteraceae

Oxylobus sp. Aphis solitaria

Oxypetalum Apocynaceae

Oxypetalum sp. Aphis gossypii, nerii

Use key to polyphagous aphids.

Oxypogon see Lathyrus Fabaceae

Oxyria Polygonaceae

Oxyria digyna Aphis fabae; Indomasonaphis rumicis;

Nasonovia ribisnigri

Key to apterae on Oxyria:-

1 BL more than 3.5 mm. SIPH pale and strongly swollen on distal part

…..Indomasonaphis rumicis*

- BL less than 3 mm. SIPH pale or dark, and tapering or cylindrical on distal part …..2

2 ANT tubercles well-developed. ANT PT/BASE 7.0-11.4. Thoracic spiracles much larger than abdominal ones, with apertures rounded …..Nasonovia ribisnigri

- ANT tubercles weakly developed. ANT PT/BASE 1.7-3.5. Thoracic spiracles similar in size to abdominal ones, with apertures reniform …..Aphis fabae

Oxytropis Fabaceae

Oxytropis campestris Acyrthosiphon churchillense; Aphis astragali;

Nearctaphis vera

O. deflexa (incl. var. sericea) Acyrthosiphon churchillense

O. glabra Megoura viciae (ssp. turanica Nevsky 1929)

O. hudsonica = viscida var. hudsonica

O. lambertii Aphis ?craccivora (as medicaginis)

O. microphylla Aphis craccivora

O. myriophylla Aphis craccivora

O. oxyphylla Aphis craccae, oxytropis

O. pilosa Aphis craccivora; Acyrthosiphon pisum

O. sordida Aphis astragali; Nearctaphis vera

O. viscida var. hudsonica Acyrthosiphon churchillense; Aphis masoni

Oxytropis spp. Acyrthosiphon kondoi; Aphis oxytropiradicis, [polaris]

Key to apterae on Oxytropis:-

1 (Only al. known, but the following should also apply to apt.) Cauda as short as or shorter than its basal width in dorsal view. SIPH with transverse rows of spinules. Longest hairs on ANT III 60-70 μm, c.2.5 × BD III …..Nearctaphis vera*

- Cauda tongue- or finger-shaped, longer than its basal width. SIPH with normal imbrication. Longest hairs on ANT III 0.3-2.2 × BD III …..2

2 ANT tubercles well developed, with smooth divergent inner faces. ABD TERG 1 and 7 without marginal tubercles (MTu). (SIPH without subapical reticulation) …..3

- ANT tubercles undeveloped or weakly developed. ABD TERG 1 and 7 with MTu …..6

3 SIPH black, black, swollen in middle (cigar-shaped), similar in length to cauda, which is also black …..Megoura viciae

- SIPH mainly pale, tapering/cylindrical, longer than cauda, which is also pale …..4

4 SIPH very attenuate distally, thinner than hind tibiae at their respective midlengths. ANT BASE VI 1.9-2.9 × R IV+V …..Acyrthosiphon pisum

- SIPH gradually tapering, not attenuate distally, thicker than hind tibia at their respective midlengths. ANT BASE VI 1.1-1.8 × R IV+V …..5

5 ANT III with (2-) 4-11 rhinaria in a row on basal half. SIPH 1.2-1.6 × cauda

.....Acyrthosiphon churchillense

- ANT III with 1 (-3) rhinaria near base. SIPH 1.6-2.1 × cauda .....Acyrthosiphon kondoi

6 Dorsal abdomen without any sclerotisation. Large MTu consistently present on ABD TERG 2-4 as well as 1 and 7. R IV+V c. 1.5 × HT II …..Aphis oxytropiradicis*

- Dorsal abdomen with at least some sclerotisation. MTu absent from ABD TERG 2-4 or only sporadically present, and small. R IV+V less than 1.4 × HT II …..7

7 Hairs on ANT III 0.3-0.75 × BD III. Dorsal abdomen usually with a solid black shield extending over all of ABD TERG 1-6. SIPH 1.2-2.2 × cauda, which bears 4-9 hairs

..…Aphis craccivora

- Hairs on ANT III 0.8-2.2 × BD III. Dorsal abdomen with scattered or segmentally-divided black markings, or with a variably developed or fragmented black shield that does not usually extend laterally to unite with marginal sclerites on ABD TERG 1-3. SIPH 0.5-1.1 × cauda, which bears 6-16 hairs …..8

8 R IV+V markedly narrowed subapically, with acute apex; 1.2-1.3 × HT II

…..Aphis oxytropis*

- R IV+V tapering gradually to blunt apex; 0.8-1.1 × HT II …..9

9 Dorsal abdomen with solid black shield extending over middle parts of ABD TERG 1-3 or 1-4 and completely across ABD TERG 4-6 or 5-6. ANT PT/BASE (1.7-)1.9-2.4

…..Aphis craccae

- Dorsal abdominal sclerotisation variable but all tergites with at least some intersegmental division. ANT PT/BASE 1.3-1.9 (-2.0) …..10

10 SIPH 0.50-0.65 (-0.67) × cauda …..Aphis masoni

- SIPH (0.65-) 0.70-1.1 × cauda …..11

11 Dorsal abdomen with spino-pleural bars on ABD TERG 4-6 or 5-6, but ABD TERG 1-2 (-3) only ever with scattered small sclerites (Fig.16i). Cauda tongue-shaped, 0.23-0.33 mm

…..Aphis astragali

- Dorsal abdomen variably but more evenly sclerotised. Cauda elongate triangular, 0.16-0.21 mm …..Aphis polaris

Ozoroa Anacardiaceae

Ozoroa insignis Aphis gossypii

O. paniculosa Aphis gossypii

Ozothamnus Asteraceae

Ozothamnus diosmifolius Myzus persicae

O. leptophyllus [?Casimira sp. (New Zealand; see Teulon et al. 2013)]