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

*Gamochaeta*	Asteraceae
*Gamochaeta americana*	Acyrthosiphon bidenticola; Aphis gossypii, spiraecola; Aulacorthum solani; Brachycaudus helichrysi; Myzus ornatus; Neomyzus circumflexus; Uroleucon ambrosiae
*G. antillana*	Aphis gossypii; Neomyzus circumflexus
*G. calviceps*	Aphis gossypii
*G. pensylvanica*	Aphis gossypii; Aulacorthum solani; Myzus ornatus, persicae; [Uroleucon rudbeckiae]
*G. purpurea*	Brachycaudus helichrysi; Protaphis middletonii
*G. spiciformis*	Macrosiphum euphorbiae

Use key to apterae on Gnaphalium.

Gamolepis see Steirodiscus

Asteraceae

*Garcinia*	Clusiaceae
*Garcinia madruno*	Aphis spiraecola
*G. multiflora*	Aphis odinae
*G. spicata*	Sinomegoura citricola

Use key to polyphagous aphids.

*Gardenia*	Rubiaceae
*Gardenia augusta* = G. jasminoides
*G. cornuta*	Aphis gossypii
*G. florida* = G. jasminoides
*G. jasminoides*	Aphis aurantii, citricidus, gossypii, nasturtii, odinae, spiraecola; Brachycaudus helichrysi; Macrosiphum euphorbiae; Myzus ornatus; Neomyzus circumflexus; Sinomegoura citricola
*G. radicans* = G. jasminoides
*G. thunbergia*	Aphis aurantii, gossypii; Myzus persicae
*Gardenia* spp.	Sinomegoura rhododendri; Smynthurodes betae

Key to apterae on Gardenia:-

1	Cauda black, long, finger-like and pointed, 0.18-0.25 × BL, as long as or slightly longer than SIPH, which are paler basally and darker distally	…..2
–	Cauda pale or dark, if dark then rounded at apex, less than 0.16 × BL, and SIPH are also uniformly dark (if present)	…..go to key to polyphagous aphids
2	Cauda with 12-24 hairs. SIPH dark on about distal 0.7 of length	….. Sinomegoura citricola
–	Cauda with at most 7 hairs. SIPH dark only at apices	….. Sinomegoura rhododendri

*Garnotia* (as Granotia?)	Poaceae
*Garnotia* sp.	Kaochiaoja arthraxonis (as Micromyzus granotiae)

*Garrya*	Garryaceae
*Garrya elliptica*	Myzus ornatus
*G. fadyenia*	Aphis (Toxoptera) aurantii

Use key to polyphagous aphids.

*Gastridium*	Poaceae
*Gastridium* sp.	Rhopalosiphum padi

*Gastrolobium*	Fabaceae
*Gastrolobium dilatatum*	Meringosiphon paradisicum

*Gaudinia*	Poaceae
*Gaudinia fragilis*	Sitobion fragariae

*Gaultheria* (including Pernettya)	Ericaceae
*Gaultheria mucronata* (incl. var. microphylla)	Aphis gaultheriae; Aulacorthum solani; Ericaphis scammelli; Macrosiphum euphorbiae, parvifolii; Myzus ornatus; Neomyzus circumflexus
*G. procumbens*	Illinoia borealis
*G. shallon*	Aulacorthum dorsatum, pterinigrum, solani; Ericaphis wakibae; Illinoia lambersi; Neomyzus circumflexus
*Gaultheria* sp.	Aphis (Toxoptera) aurantii; Ericolophium sp. (Meghalaya, India; BMNH colln, leg. AK Samanta)

Key to apterae on Gaultheria:-

1	SIPH and cauda both dark	…..2
–	SIPH pale or dark, cauda pale	…..3
2	Dorsal abdomen with dark sclerites divided into polygons. R IV+V not longer than HT II. No stridulatory apparatus	…..Aphis gaultheriae
–	Dorsal abdomen without dark sclerites. R IV+V longer than HT II. Stridulatory apparatus present (fig.122)	…..Aphis (Toxoptera) aurantii
3	Dorsal abdomen with dark markings. Head with spicules, at least ventrally	…..4
–	Dorsal abdomen without dark markings. Head with or without spicules	…..8
4	Dorsal abdomen with a pattern of intersegmental dark markings. ANT PT/BASE 1.7-2.8	…..Myzus ornatus
–	Dorsal thorax and abdomen usually with extensive dark sclerotisation. ANT PT/BASE 3.2-5.2	…..5
5	Dorsal abdomen with a roughly U-shaped dorsal patch. Head densely spiculose/nodulose dorsally and ventrally	…..Neomyzus circumflexus
–	Dorsal sclerotisation not U-shaped. Head with spicules mostly on ventral side surface	…..6
6	ANT III without rhinaria. SIPH 0.23-0.26 × BL	…..Ericaphis wakibae
–	ANT III with 1-5 rhinaria. SIPH 0.25-0.33 × BL	…..7
7	Dorsal cuticle very wrinkled, variably pigmented but often mostly dark, with large marginal and post-siphuncular sclerites forming a broad dark stripe on each side of body	…..Aulacorthum pterinigrum
–	Dorsal cuticle almost smooth, variably pigmented in spino-pleural region but without dark marginal sclerites anterior to SIPH	…..Aulacorthum dorsatum
8	ANT BASE VI 1.6-1.8 × R IV+V, which bears only 2 accessory hairs. SIPH c.0.24 × BL, 6.5-7.5 × their diameter at midlength and 1.8-2.2 × cauda. ANT III without rhinaria	…..Ericolophium sp. (Meghalaya, BMNH collection)
–	ANT BASE VI 0.8-1.55 × R IV+V, which bears 6-23 accessory hairs. SIPH either relatively shorter or more slender. ANT III often with 1 or more rhinaria on basal half	…..9
9	Inner faces of ANT tubercles rugose or spiculose. SIPH without a distinct subapical zone of polygonal reticulation (sometimes with subapical transverse striae and 1-2 rows of closed polygonal cells)	…..10
–	Inner faces of ANT tubercles smooth. SIPH with a distinct subapical zone of polygonal reticulation (at least 4-5 rows of closed cells)	…..11
10	SIPH 1.5-1.75 × cauda. ANT tubercles low, with inner faces divergent and median frontal tubercle well developed. ANT III without rhinaria	…..Ericaphis scammelli
–	SIPH 2.1-2.5 × cauda. ANT tubercles well-developed, with inner faces steep-sided, and median frontal tubercle much lower or undeveloped. 1-2 small rhinaria usually present on ANT III	…..Aulacorthum solani
11	Longest hairs on ANT III 0.5-1.0 × BD III. SIPH pale, or dusky only at apices; cylindrical or swollen on distal half proximal to reticulated region	…..12
–	Longest hairs on ANT III 0.2-0.4 × BD III. SIPH rather dark, and swollen on distal half proximal to reticulated section	…..13
12	SIPH distinctly swollen on distal half proximal to reticulated region. ANT BASE VI long and thin, 2.2-2.6 × R IV+V	…..Macrosiphum parvifolii
–	SIPH cylindrical on distal half, sometimes a little constricted in reticulated region. ANT BASE VI 0.9-1.3 × R IV+V	…..Macrosiphum euphorbiae
13	First tarsal segments with 5 hairs. RIV+V with 15-23 accessory hairs	…..Illinoia lambersi
–	First tarsal segments with 3 (-4) hairs. R IV+V with 7-11 accessory hairs	…..Illinoia borealis

*Gaura*	Onagraceae
*Gaura biennis*	Macrosiphum gaurae, [pallidum]
*G. coccinea*	Aphis craccivora
*G. lindheimeri*	Macrosiphum gaurae
*G. mollis*	Macrosiphum gaurae
*G. parviflora* = G. mollis
*Gaura* sp.	[Aphis costalis]; Macrosiphum euphorbiae

Key to apterae on Gaura:-

1	Oval aphid, BL 1.1-2.3 mm. Dorsum with a black sclerotic shield. SIPH and cauda both entirely black, SIPH without polygonal reticulation	…..Aphis craccivora
–	Spindle-shaped aphid, BL 2.0-3.9 mm. Dorsum pale. SIPH pale at least basally, with a subapical zone of polygonal reticulation	…..2
2	SIPH dark brown to black for most of length, paler basally. ANT dark. R IV+V 1.1-1.25 × HT II	…..Macrosiphum gaurae
–	SIPH mainly pale, sometimes darker towards apices. ANT mainly pale. R IV+V 0.8-1.0 × HT II	…..Macrosiphum euphorbiae

*Gaya*	Malvaceae
*Gaya parviflora*	Macrosiphum euphorbiae

*Gaylussacia*	Ericaceae
*Gaylussacia frondosa*	[Illinoia sp. (Leonard 1971: 80)]
Gaylussacia sp.	Illinoia finni

*Gazania*	Asteraceae
*Gazania* “*elegans”* (?)	Aphis craccivora
G. linearis	Myzus ornatus, persicae
*G. longiscapa* = G. linearis
*G. pectinata*	Aphis gossypii
*G. rigens*	Aphis gossypii; Brachycaudus cardui, helichrysi; Myzus persicae; Protaphis terricola; [Uroleucon sp(p). (Leonard 1968, 344 and 1972a, 111)]
*G. uniflora* = G. rigens
Gazania sp.	Aulacorthum solani

Key to apterae on Gazania:-

1	ANT PT/BASE 0.7-1.5. SIPH dark, shorter than the short triangular, very hairy cauda	….. Protaphis terricola
–	ANT PT/BASE more than 1.5. SIPH if dark then longer than cauda	…..2
2	Dorsum with an extensive black sclerotic shield. Mesosternum with a pair of dark mammariform processes. Cauda short and rounded	….. Brachycaudus cardui
–	Without this combination of characters	…..go to key to polyphagous aphids

*Geissorhiza*	Iridaceae
*Geissorhiza inaequalis*	Macrosiphum euphorbiae; Myzus persicae

Use key to polyphagous aphids.

*Geitonoplesium*	Philesiaceae
*Geitonoplesium cymosum*	Aulacorthum solani; Myzus persicae

Use key to polyphagous aphids.

*Gelsemium*	Gelsemiaceae
*Gelsemium sempervirens*	[Hyalomyzus eriobotryae]

*Genipa*	Rubiaceae
*Genipa americana*	Aphis (Toxoptera) aurantii

*Genista* (including Chamaemelum, Teline)	Fabaceae
*Genista aetnensis*	Aphis cytisorum
*G. anglica*	Acyrthosiphon ericetorum; Aphis genistae, ononidis
G. balansae ssp. europaea	Aphis cytisorum
*G. canariensis*	Aphis craccivora, gossypii; Myzus persicae
*G. capitata* = Cytisus hirsutus
*G. cinerascens*	Aphis fabae
*G. cinerea*	Acyrthosiphon pisum; Aphis cytisorum, fabae, gossypii
*G. fasselata*	Aphis craccivora/ cytisorum group (Israel, BMNH colln)
*G. florida*	Acyrthosiphon pisum; Aphis cytisorum
*G. germanica*	Acyrthosiphon pisum; Aphis genistae
*G. horrida* = Echinospartum horridum
*G. humifusa*	Aphis genistae
*G. lydia* (incl. “Cytisus rhodopeus”)	Acyrthosiphon parvum, pisum
*G. monosperma* = Retama monosperma
*G. monspessulana*	Acyrthosiphon parvum
*G. myriantha* = G. scorpius ssp. myriantha
*G. ovata* = G. tinctoria
*G. pilosa*	Acyrthosiphon parvum, pisum; Ctenocallis dobrovljanskyi
*G. radiata*	Aphis genistae
*G. sagittalis*	Acyrthosiphon pisum; Aphis cytisorum, genistae
*G. scorpius* (incl. ssp. myriantha)	Aphis craccivora, cytisorum, genistae
*G. sessilifolia*	Aphis cytisorum
*G. sphacelata* = G. fasselata
*G. sphaerocarpa* see Retama sphaerocarpa
*G. tinctoria*	Acyrthosiphon genistae, pisum; Aphis craccivora, cytisorum, genistae
*G. tridentata*	Aphis craccivora
*G. umbellata*	Aphis cytisorum
Genista sp.	[Acyrthosiphon echinospartii]

Key to apterae on Genista:-

1	Body with a complete segmental series of long finger-like marginal processes. Cauda knobbed	…..Ctenocallis dobrovljanskyi
–	Body without long marginal processes. Cauda not knobbed	…..2
2	Body spindle-shaped, pale. ANT longer than BL. SIPH pale or dark, thin and cylindrical on distal half. Cauda elongate finger-shaped, pale	…..3
–	Body oval, often with dark dorsal markings. ANT shorter than BL. SIPH dark, tapering from base to apex. Cauda tongue-shaped, pale or dark	…..6
3	ANT VI BASE less than 2 × R IV+V. SIPH tapering, not attenuated, less than 10 × their width at midlength. Cauda with 6-9 hairs	…..Acyrthosiphon parvum
–	ANT VI BASE more than 2 × R IV+V. SIPH attenuated, more than 10 × longer than their width at midlength. Cauda with 8-14 hairs	…..4
4	Cauda very thick; at midpoint at least 3 × width of SIPH at midpoint. Femoral apices pale. SIPH pale, or only dusky at extreme apices	…..Acyrthosiphon pisum
–	Cauda thinner; at midpoint less than 2.5 × width of SIPH at midpoint. Femoral apices usually dark. SIPH dark, or darkening gradually from base to apex	…..5
5	BL less than 2.5 mm. SIPH darkening towards apex	…..Acyrthosiphon ericetorum
–	BL more than 2.5 mm. SIPH wholly dark	…..Acyrthosiphon genistae*
6	Cauda paler than SIPH. Dorsal abdomen without any dark markings	…..Aphis gossypii
–	Cauda as black as SIPH. Dorsal abdomen with at least some dark markings	…..7
7	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	…..8
8	SIPH 0.2-0.8 × cauda	…..9
–	SIPH 1.1-2.2 × cauda	…..10
9	SIPH 0.2-0.3 × cauda. Hairs on ANT III 0.3-0.4 × BD III	…..Aphis ononidis
–	SIPH 0.5-0.8 × cauda. Hairs on ANT III 0.8-1.3 × BD III	…..Aphis genistae
10	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

*Gentiana*	Gentianaceae
*Gentiana asclepiadea*	Aphis fabae, gentianae, [gentianella Tashev (nomen nudum)]; Metopeurum gentianae
*G. aurea* = Gentianella aurea
*G. cruciata*	Aphis gentianae; [Myzus cerasi]
*G. kurroo*	Aphis gossypii
*G. lutea*	Aphis fabae, orocantabrica, solanella, [Aphis sp. (French Alps, BMNH collection, leg G. Remaudière)]; Aulacorthum solani
*G. olgae*	Brachycaudus gentianae
*G. panonnica*	Aphis fabae
*G. punctata*	Aphis fabae
*G. purpurea*	Aphis fabae
*G. scabra*	Macrosiphum euphorbiae
*G. schistocalyx* = G. asclepiadea
*G. septemfida*	Macrosiphum euphorbiae
*G. tianschanica*	Brachycaudus cerasicola, gentianae
*G. turkestanorum* = Gentianella turkestanorum
*G. verna*	Aphis gossypii
Gentiana sp.	Aphis sp. (Austria, BMNH collection, leg. R.N.B. Prior)

Key to apterae on Gentiana:-

1	SIPH with a distal zone of polygonal reticulation	…..2
–	SIPH without polygonal reticulation	…..3
2	ANT tubercles well developed. ANT III with 1-10 rhinaria. SIPH long, more than 10 × their width at midlength, with a well-developed flange and reticulation on distal 0.13-0.2 of length	…..Macrosiphum euphorbiae
–	ANT tubercles not well developed. ANT III with 7-16 rhinaria. SIPH less than 6 × their width at midlength, with a small flange and reticulation on at least distal 0.33 of length	…..Metopeurum gentianae
3	Cauda helmet-shaped, shorter than its basal width, with 5 hairs	…..Brachycaudus gentianae (or cerasicola)
–	Cauda tongue-like, much longer than its basal width, with 4-25 hairs	…..4
4	Cauda with 4-12 hairs. Longest hairs on outer side of hind tibia less than 35 μm	…..5
–	Cauda with 11-25 hairs. Longest hairs on outer side of hind tibia more than 40 μm	…..7
5	ABD TERG 1-5 and 7 with large domed marginal tubercles (MTu)	…..Aphis gentianae
–	Only ABD TERG 1 and 7 constantly with MTu; smaller MTu irregularly present on some of ABD TERG 2-6	…..6
6	ANT PT/BASE 2.1-3.2	…..Aphis gossypii
–	ANT PT/BASE 1.1-1.8(-2.2)	…..Aphis orocantabrica
7	SIPH 0.6-0.75 × cauda (pale red-brown in life)	…..Aphis sp., Austria (BMNH collection)
–	SIPH 0.8-1.9 × cauda (black in life)	…..8
8	SIPH 4.9-17 × longer than the longest marginal hairs on ABD TERG 2-4	…..Aphis solanella
–	SIPH 2.4-5.4 × longer than the longest marginal hairs on ABD TERG 2-4	…..Aphis fabae

*Gentianella*	Gentianaceae
*Gentianella aurea*	Myzus icelandicus
*G. decumbens*	Brachycaudus cerasicola
*G. turkestanorum*	Brachycaudus cerasicola

*Geoffroea*	Fabaceae
*Geoffroea decorticans*	Aphis craccivora

*Geophila*	Rubiaceae
*Geophila macropoda*	Aphis gossypii

*Geraea*	Asteraceae
*Geraea* sp.	Uroleucon ambrosiae

*Geranium*	Geraniaceae
*Geranium affine*	Acyrthosiphon malvae
*G. bicknellii*	Amphorophora geranii
*G. caeruleatum*	Acyrthosiphon malvae
*G. caespitosum*	Amphorophora coloutensis
*G. collinum*	Acyrthosiphon malvae; Maculolachnus submacula; [Trama troglodytes]
*G. columbianum*	Acyrthosiphon malvae
*G. dahuricum*	Cryptaphis geranicola
*G. dalmaticum*	Acyrthosiphon malvae
*G. dissectum*	Acyrthosiphon malvae; Aulacorthum solani
*G. divaricatum*	[Aphis urticata]; Indoidiopterus geranii; Macrosiphum pseudogeranii; [Micromyzodium filicium]; Myzus sp.( India; BMNH collection, leg. A.N. Chowdhuri)
*G. erianthum*	Acyrthosiphon malvae; Cryptaphis geranicola
*G. fremontii* = G. caespitosum
*G. guatemalense* = G. seemannii
*G. koreanum*	Cryptaphis geranicola
*G. lucidum*	Acyrthosiphon malvae; Aulacorthum solani; [Cavariella konoi]; Macrosiphum pseudogeranii; [Micromyzodium filicium]
*G. macrorrhizum*	Amphorophora tuberculata
*G. maculatum*	Acyrthosiphon malvae; Macrosiphum geranii
*G. maderense*	Acyrthosiphon malvae
*G. mascatense*	Aphis gossypii; Brachycaudus helichrysi; Indoidiopterus geranii; Myzus ornatus
*G. molle*	Acyrthosiphon malvae; Aulacorthum solani; Macrosiphum euphorbiae; Maculolachnus submacula; Myzus ascalonicus, persicae
*G. nepalense*	Aphis fabae; Cryptaphis geranicola; Macrosiphum pseudogeranii
*G. ocellatum* = G. mascatense
*G. phaeum*	Acyrthosiphon malvae; [Macrosiphum gei]
*G. potentilloides*	Acyrthosiphon malvae; Aulacorthum solani
*G. pratense*	Acyrthosiphon malvae; Macrosiphum ?geranii
*G. pseudosibiricum*	Acyrthosiphon malvae
*G. purpureum*	Acyrthosiphon malvae
*G. pusillum*	Acyrthosiphon malvae; Aphis fabae; Aulacorthum solani; Myzus ascalonicus; [Nasonovia ribisnigri]
*G. pyrenaicum*	Acyrthosiphon malvae
*G. renardii*	Myzus ornatus
*G. richardsonii*	Acyrthosiphon malvae; Amphorophora coloutensis, geranii; Macrosiphum aetheocornum, euphorbiae; Nasonovia crenicorna
*G. robertianum*	Acyrthosiphon malvae; Aphis nasturtii; Aulacorthum solani; Brachycaudus helichrysi; [Macrosiphum funestum, gei]; Maculolachnus submacula; Myzus ascalonicus, ornatus, persicae; Indoidiopterus geranii
*G. rotundifolium*	Acyrthosiphon malvae; Aphis fabae; Myzus persicae
*G. ruprechtii*	Acyrthosiphon malvae
*G. sanguineum*	Acyrthosiphon malvae; Aulacorthum solani; Myzus ascalonicus
*G. saxatile*	Acyrthosiphon malvae
*G. seemannii*	Acyrthosiphon malvae
*G. sibiricum*	Acyrthosiphon malvae; Cryptaphis geranicola; Maculolachnus submacula
*G. sylvaticum*	Acyrthosiphon malvae; Aulacorthum solani
*G. thunbergii*	Cryptaphis geranicola
*G. tuberosum*	Macrosiphum euphorbiae
*G. viscosissimum*	Amphorophora geranii, [Amphorophora sp. (see aphidtrek.org)]; Aulacorthum solani; Brachycaudus helichrysi; Macrosiphum aetheocornum; Nasonovia crenicorna
*G. wallichianum*	Macrosiphum pseudogeranii; Indoidiopterus geranii
Geranium spp.	[Acutosiphon obliquoris]; Aphis craccivora, [geranii Hereman 1840 (nomen nudum)], Aphis sp. (Pakistan, BMNH collection); [Capitophorus carduinus]; [Dysaphis microsiphon]; [Macrosiphoniella sanborni]; Macrosiphum aetheocornum, [solutum Blanchard 1939 (= Acyrthosiphon malvae?)]; Macrosiphum sp.(Manitoba; BMNH collection, leg. A.G. Robinson); Rhopalosiphoninus staphyleae; [Thecabius affinis]

Key to apterae on Geranium (N.B. for florists’ geraniums, see Pelargonium):-

1	SIPH as pores on broad dark hairy cones	…..Maculolachnus submacula
–	SIPH tubular	…..2
2	SIPH with a subapical zone of polygonal reticulation (at least 4-5 rows of closed cells)	…..3
–	SIPH without polygonal reticulation, or with only 1-3 rather indistinct rows of cells	…..7
3	Distal 0.3-0.4 of femore black. SIPH wholly black. First tarsal segments with 4 hairs (including 2 sense pegs)	…..Macrosiphum pseudogeraniae
–	Femora dusky or dark only at apices. SIPH pale, dusky, or pale at bases. First tarsal segments with 3 hairs (1 sense peg)	…..4
4	R IV+V 0.8-1.0 × HT II	…..Macrosiphum euphorbiae
–	R IV+V 1.2-1.7 × HT II	…..5
5	SIPH 1.5-1.8 × cauda, mainly dark, with paler basal part. R IV+V with 9-11 accessory hairs	…..Macrosiphum sp. (cult. Geranium sp., Manitoba: BMNH colln)
–	SIPH 2.0-2.4 × cauda, mainly pale, dusky or dark towards apices. R IV+V with either 5-8 or 12-16 accessory hairs	…..6
6	R IV+V bearing 12-16 accessory hairs. SIPH sometimes bearing 1-4 hairs (Fig.30a; but often without any)	…..Macrosiphum aetheocornum
–	R IV+V bearing 5-8 accessory hairs. SIPH without hairs	…..Macrosiphum geranii
7	Dorsal body hairs very long, the longest of them 3 or more × ANT BD III. Dorsal cuticle sclerotic, dark	…..Cryptaphis geranicola
–	Dorsal body hairs less than 2 × BD III. Dorsal cuticle pale or dark	…..8
8	SIPH with 5-11 blunt or capitate hairs (Fig.30b)	…..Nasonovia crenicorna
–	SIPH without hairs	…..9
9	Cuticle of head smooth, without spicules. ANT tubercles well developed, with inner faces smooth and divergent	…..10
–	Either cuticle of head spiculose, or ANT tubercles weakly developed or undeveloped	…..13
10	SIPH cylindrical on distal half (Fig.30c). Longest hairs on ANT III 0.3-0.6 × BD III	…..Acyrthosiphon malvae
–	SIPH swollen on distal half. Longest hairs on ANT III 0.7-1.0 × BD III	…..11
11	ABD TERG 2-5 with marginal tubercles (MTu), usually well-developed, with 2 marginal hairs of very unequal length situated anterio-dorsad and posterio-vantrad of each tubercle (Fig.30d)	…..Amphorophora tuberculata
–	ABD TERG 2-5 usually without MTu, and marginal hairs all of similar length	…..12
12	R IV+V 1.1-1.6 × HT II, with 15-25 accessory hairs. ANT III with 0-2 rhinaria	…..Amphorophora coloutensis
–	R IV+V 1.9-2.2 × HT II, with 30-40 accessory hairs. ANT III with 4-8 rhinaria	…..Amphorophora geranii
13	Hairs on ABD TERG 1-5 very short and thick, with clubbed apices (Fig.30f). Abdominal spiracular plates raised as rounded tubercles (Fig.30g). (Head spiculose, SIPH slightly clavate. Al. with forewing veins fuscous-bordered and media fused with R_s)	…..Indoidiopterus geranii
–	Hairs on ABD TERG 1-5 thin; long or short, blunt or pointed. Abdominal spiracular plates not raised. (Head smooth or spiculose, SIPH clavate, cylindrical or tapering)	…..14
14	Head spiculose, tergum very rugose. SIPH coarsely imbricated (scaly), slightly clavate, longer than ANT III. R IV+V 1.3-1.5 × HT II	…..Myzus sp. H.P., India (BMMH collection)
–	If head spiculose then other characters are not in that combination	…..15
15	SIPH black, 0.08-0.12 × BL, about equal in length to the dark cauda. ANT PT/BASE 1.7-2.4 (only more than 2.0 in small specimens of BL c.1mm)	…..Aphis sp. (near spiraecola), Pakistan (BMNH collection)
–	SIPH pale or dark, if dark then relatively longer, and ANT PT/BASE also longer	…..go to key to polyphagous aphids

Gerardia see Agalinis

Orobanchaceae

*Gerbera*	Asteraceae
*Gerbera hybrida*	Aphis gossypii
*G. jamesonii*	Aphis craccivora, fabae, gossypii, solanella, spiraecola; Aulacorthum solani; Brachycaudus cardui, helichrysi; Capitophorus elaeagni; Macrosiphum euphorbiae; Myzus cymbalariae, ornatus, persicae; Neomyzus circumflexus; Uroleucon ambrosiae, compositae
*G. macrophylla*	Aphis gossypii; [Trichosiphonaphis gerberae]
Gerbera spp.	[Aphis sp. (imm. only; Portugal, BMNH collection)]; Indomasonaphis anaphalidis, rumicis; Myzus ascalonicus

Key to apterae on Gerbera:-

1	SIPH strongly swollen over about distal 0.7 of length, with greatest diameter of swelling more than twice the least diameter of the ‘stem’. Cauda bearing 14-32 hairs	…..2
–	If SIPH are at all swollen then cauda has less than 12 hairs	…..3
2	Cauda with 25-32 hairs. R IV+V with 9-12 accessory hairs	…..Indomasonaphis anaphalidis
–	Cauda with about 14-15 hairs. R IV+V with 2 accessory hairs	….. Indomasonaphis rumicis*
3	Cauda helmet-shaped, a little shorter than its basal width. Spiracular apertures large and rounded. SIPH with a subapical annular incision	…..4
–	Cauda tongue- or finger-shaped, longer than its basal width. Spiracular apertures small and reniform. SIPH without a subapical annular incision	…..5
4	Abdomen without extensive dark markings. SIPH pale, smooth, 0.9-1.5 × cauda. Mesosternum without mammariform processes	…..Brachycaudus helichrysi
–	Abdomen with a extensive dark dorsal shield. SIPH dark, imbricated, 2.1-3.4 × cauda. Mesosternum with a pair of dark mammariform processes	…..Brachycaudus cardui
5	Long, thick capitate dorsal hairs present on head and posterior abdomen, arising from tuberculate bases. SIPH slender, pale, about as thick as hind tibia at midlength. ANT PT/BASE 6.0-9.2	…..Capitophorus elaeagni
–	Dorsal hairs, not long, thick and capitate, without tuberculate bases; if long and slightly expanded apically then SIPH are much thicker than hind tibiae at midlength, or clavate. ANT PT/BASE 1.7-7.3	….. go to key to polyphagous aphids

*Geropogon*	Asteraceae
*Geropogon hybridus*	Brachycaudus helichrysi, tragopogonis ssp. setosus; Uroleucon sonchi

Use key to apterae on Tragopogon.

*Gesneria*	Gesneriaceae
*Gesneria cuneifolia*	Myzus persicae

*Gesnouinia*	Urticaceae
*Gesnouinia arborea*	Aphis parietariae

*Geum* (including Parageum)	Rosaceae
*Geum aleppicum*	Amphorophora gei; [Aphis diluta]; Macrosiphum euphorbiae; Myzus ornatus; Eriosoma japonicum (as Schizoneurella gei)
*G. calthifolium* (incl. ssp. nipponicum)	Acyrthosiphon shinanonus; Macrosiphum euphorbiae; Myzus persicae
*G. canadense*	Acyrthosiphon pseudodirhodum; Amphorophora gei, rossi; Macrosiphum pallidum, rosae
*G. ciliatum* = G.triflorum var. ciliatum
*G. coccineum* = G. quellyon
*G. hispidum*	Macrosiphum gei
*G. involucratum*	Amphorophora gei; Macrosiphum gei; Ovatomyzus boraginacearum
*G. japonicum*	Eriosoma japonicum
*G. laciniatum*	Macrosiphum gei
*G. macrophyllum*	Amphorophora gei, rossi; Aulacorthum solani; Macrosiphum euphorbiae, gei, valerianae; Myzus ascalonicus
*G. montanum*	[Hyperomyzus lactucae]; Ovatomyzus boraginacearum
*G. parviflorum* = G. involucratum
*G. peruvianum*	Aulacorthum solani; Rhopalosiphoninus staphyleae
*G. pyrenaicum*	Macrosiphum gei
*G. quellyon*	Amphorophora gei; [Aphis sp. (Daveltshina 1964)]; Aulacorthum solani; Macrosiphum gei
*G. rivale*	Acyrthosiphon malvae ssp. potha; Amphorophora gei; Aulacorthum solani; Macrosiphum gei, valerianae; Myzus ascalonicus, ornatus
**G. rivale × urbanum**	Myzus ornatus
*G. schofieldii*	Macrosiphum euphorbiae; Myzus ornatus
*G. strictum* = G. aleppicum
*G. sylvaticum*	Macrosiphum euphorbiae
*G. triflorum*	Myzus ornatus; Macrosiphum euphorbiae, garyreed, valerianae
G. triflorum var. ciliatum	Macrosiphum kiowanepum
*G. urbanum*	Acyrthosiphon malvae; Amphorophora gei; Aphis fabae; Aulacorthum solani; Macrosiphum euphorbiae, gei; Myzus ascalonicus, ornatus, persicae; Ovatomyzus boraginacearum; Sitobion fragariae
*G. virginianum*	Amphorophora rossi; Macrosiphum pallidum
Geum spp.	Chaetosiphon janetscheki; [“Nectarophora sp.” (Cockerell 1903: 17)]

Key to apterae on Geum:-

1	ANT PT/BASE less than 0.5. Eyes with only 3 facets. Wax gland plates present on thorax and abdomen. SIPH as raised pores with sclerotic rims and surrounding hairs	…..Eriosoma japonicum
–	ANT PT/BASE more than 1. Eyes multifaceted. No wax gland plates. SIPH tubular	…..2
2	SIPH with a subapical zone of polygonal reticulation (at least 4-5 rows of closed cells)	…..3
–	SIPH without polygonal reticulation, or with only 1-3 rather indistinct rows of cells	…..9
3	Longest hairs on ANT III 0.3-0.5 × BD III. ANT III with 1-4 very small rhinaria. ANT tubercles rather low, and median frontal tubercle distinctly developed	…..Sitobion fragariae
–	Longest hairs on ANT III 0.6-1.3 × BD III. ANT III with 1-35 rhinaria of various sizes. ANT tubercles well developed, median frontal tubercle undeveloped	…..4
4	Front of head pale, SIPH pale or dark only towards apices	…..5
–	Front of head dusky to dark. SIPH dark, or pale only at bases	…..7
5	R IV+V 1.20-1.43 × HT II	…..Macrosiphum garyreed
–	R IV+V 0.78-1.09 × HT II	…..6
6	Longest hair on ABD TERG 8 is 38-63 μm, 0.6-1.4 × ANT BD III. Anterior half of subgenital plate usually (77%) with only 2 hairs (18% with 3, 5% with 4-6 hairs)	…..Macrosiphum euphorbiae
–	Longest hair on ABD TERG 8 is 66-106 μm, 1.4-2.0 × ANT BD III. Anterior half of subgenital plate with 2-11 hairs, usually (77%) with 4-8 hairs	…..Macrosiphum gei
7	Head as dark as SIPH. Hind tibiae with pale middle sections	…..Macrosiphum rosae
–	Head dusky, paler than SIPH. Hind tibiae uniformly dark or with dark apices	…..Macrosiphum pallidum
8	SIPH 0.73-0.95 × ANT III	…..Macrosiphum pallidum
–	SIPH 1.03-1.30 × ANT III	…..Macrosiphum valerianae
9	Dorsal body hairs long, thick and capitate, maximally c. 3 × ANT III, with prominently tuberculate bases. SIPH also with 3-4 thick capitate hairs on basal part	…..Chaetosiphon janetscheki
–	Dorsal body hairs not thick and capitate, without tuberculate bases. SIPH without hairs	…..10
10	ANT tubercles very well developed, with divergent inner faces. Cuticle of head smooth or with a few spinules ventrally. ANT III with 0-24 rhinaria	…..11
–	Either ANT tubercles weakly developed and head without spicules, or ANT tubercles with well-developed steep-sided inner faces and cuticle of head densely spiculose or nodulose. ANT III with 0-2(-4) rhinaria	…..go to key to polyphagous aphids
11	BL 0.7-1.6 mm. SIPH 0.15-0.33 mm, slender and usually slightly swollen on distal half. ANT III without rhinaria. (Al. with a dorsal abdominal black patch and sec. rhinaria on ANT III, IV and V)	…..Ovatomyzus boraginacearum
–	BL 1.8-4.0 mm. SIPH 0.45-1.0 mm, tapering, cylindrical or evidently swollen on distal half. ANT III with 1-24 rhinaria. (Al. pale dorsally and with sec. rhinaria restricted to ANT III	…..12
12	SIPH markedly swollen on distal half, the swollen part being smooth-surfaced. ANT III with 1-7 small rhinaria near base	…..13
–	SIPH tapering or cylindrical, and with imbrication throughout. ANT III with 1-30 rhinaria	…..14
13	SIPH 2.2-2.8 × cauda. R IV+V 1.2-1.4 × HT II. ANT III with 1-3 rhinaria	…..Amphorophora gei
–	SIPH 1.7-2.0 × cauda. R IV+V 1.4-1.6 × HT II. ANT III with 1-7 rhinaria	…..Amphorophora rossi
14	SIPH 0.8-1.2 × cauda	…..Acyrthosiphon pseudodirhodum
–	SIPH 1.5-1.5 × cauda	…..15
15	R IV+V 0.8-0.9 × HT II	…..Acyrthosiphon shinanonum
–	R IV+V 0.92-1.4 × HT II	…..Acyrthosiphon malvae group

*Gigantochloa*	Poaceae
*Gigantochloa apus*	[Aphis gossypii]; Astegopteryx minuta, pallida, unimaculata; Ceratoglyphina bambusae; Pseudoregma bambusicola

Use key to aphids on Bambusa)

*Gilia*	Polemoniaceae
*Gilia aggregata* = Ipomopsis aggregata
*G. capitata*	[Aphis sp. (Leonard 1974: 101)]
*G. linearis* = Collomia linearis
*G. tricolor*	Macrosiphum euphorbiae

*Gilibertia* see Dendropanax	Araliaceae
*Gilibertia pellucidopunctata* = Dendropanax dentiger
*G. trifida* = Dendropanax trifidus

*Ginoria*	Lythraceae
*Ginoria americana*	Aphis spiraecola

*Girardinia*	Urticaceae
*Girardinia cuspidata*	Microlophium carnosum; Myzus dycei
*G. diversifolia*	Aphis gossypii; Dysaphis microsiphon
*G. heterophylla* = G. diversifolia

Key to apterae on Girardinia:-

1	SIPH very small and thin, 0.03-0.08 mm long. Well-developed marginal tubercles (MTu) present on ABD TERG 1-5, and head with a large pair of spinal tubercles (STu). Cauda helmet-shaped, shorter than its basal width in dorsal view	…..Dysaphis microsiphon
–	SIPH larger, and MTu, STu and cauda not as above	…..2
2	Large spindle-shaped aphid, BL more than 3 mm, ANT much longer than BL. ANT tubercles smooth, with inner faces divergent. Dorsal hairs long and pointed. SIPH long, tapering and normally imbricated, with flared apices	…..Microlophium carnosum
–	Small oval aphid, BL less than 2 mm, ANT much shorter than BL. ANT tubercles scabrous, with inner faces apically convergent. Dorsal hairs inconspicuous. SIPH thick and scaly for most of length, with smooth tapering distal part that is somewhat bent outwards	…..Myzus dycei

*Girgensohnia*	Amaranthaceae
*Girgensohnia oppositiflora*	Brachyunguis salsolaceanum

*Gladiolus*	Iridaceae
*Gladiolus communis*	Aphis gossypii; Macrosiphum euphorbiae; [Myzaphis rosarum]; Myzus persicae
*G. dalenii*	Myzus ascalonicus
*G. × gandavensis*	[Aphis newtoni]; Dysaphis tulipae; Metopolophium dirhodum; Sitobion akebiae
*G. hortulanus*	Aphis fabae, spiraecola; Macrosiphum euphorbiae
*G. × hybridus*	Dysaphis tulipae; Myzus persicae; Neomyzus circumflexus
*G. italicus*	Aphis fabae, gossypii; Dysaphis tulipae
*G. primulinus* = G. dalenii
*G. watsonioides*	Aphis gossypii
Gladiolus ssp.	Aphis craccivora; Aulacorthum solani; Myzus cymbalariae, ornatus; Rhopalosiphoninus latysiphon, staphyleae; Sitobion africanum, fragariae, graminis, [phyllanthi], [wikstroemiae]; Smynthurodes betae

Key to apterae on Gladiolus:-

1	Cauda helmet-shaped (“pentagonal”), not longer than its basal width, with 4-6 hairs. Head and ABD TERG 8, or 7 and 8, with paired spinal tubercles (STu), and marginal tubercles (MTu) present on prothorax and ABD TERG 1-5, or 1-5 and 7	…..Dysaphis tulipae
–	Cauda (if at all evident) triangular or tongue-shaped, longer than its basal width, with 4-25 hairs. STu absent from head, rarely on ABD TERG 7-8. MTu absent or only regularly present on ABT TERG 1 and 7	…..2
2	SIPH dark, tapering, with a subapical zone of polygonal reticulation. Hairs on ANT III less than 0.6 × BD III	…..3
–	SIPH (if present) pale or dark, but if dark then either without subapical polygonal reticulation, or strongly swollen. Hairs on ANT III more or less than 0.6 × BD III	…..6
3	Cauda dark like SIPH	…..Sitobion graminis
–	Cauda pale	…..4
4	R IV+V 0.65-0.75 × HT II. Longest hairs on ANT III 20-30 μm	…..Sitobion akebiae
–	R IV+V 0.75-0.9 × HT II. Longest hairs on ANT III 12-20 μm	…..5
5	Cauda 0.43-0.55 SIPH and 1.9-2.6 × HT II. Dorsal abdominal sclerotisation often extensive, but not segmentally divided and with ill-defined edges	…..Sitobion fragariae
–	Cauda 0.53-0.6 × SIPH and 2.4-3.0 × HT II. Dorsal abdominal sclerotisation very variable, but when well developed it is segmentally divided and has well-defined edges	…..Sitobion africanum
6	SIPH cylindrical, pale, without subapical polygonal reticulation. R IV+V 0.55-0.75 × HT II	…..Metopolophium dirhodum
–	Without that combination of characters; if SIPH are pale, cylindrical (i.e not swollen) and lack subapical reticulation then R IV+V is 0.95-1.35 × HT II	…..go to key to polyphagous aphids

*Glandora*	Boraginaceae
*Glandora diffusa*	Aphis fabae; Brachycaudus helichrysi; [Ovatomyzus chamaedrys]

Use key to polyphagous aphids.

*Glandularia*	Verbenaceae
*Glandularia bipinnatifida*	Aphis gossypii
*G. canadensis*	[Aphis aubletia]; Myzus ornatus; Protaphis middletonii
*G. peruviana*	Acyrthosiphon malvae; Aphis [capsellae], gossypii; Brachycaudus helichrysi; Myzus ornatus

Use key to polyphagous aphids.

*Glaucium*	Papaveraceae
*Glaucium corniculatum*	Acyrthosiphon glaucii, ilka
*G. elegans*	Acyrthosiphon glaucii
*G. fimbrilligerum*	Acyrthosiphon glaucii
*G. flavum*	Acyrthosiphon ilka, lambersi; Aphis fabae; Aulacorthum solani; Brachycaudus helichrysi; [Cavariella theobaldi]; Macrosiphum euphorbiae; [Sitobion avenae]
*G. grandiflorum*	Acyrthosiphon lambersi
*G. leiocarpum*	Acyrthosiphon ilka, lambersi
*G. luteum* = G. flavum
*G. squamigerum*	Acyrthosiphon glaucii
Glaucium spp.	[Siphonophora glaucii Lichtenstein (nomen nudum)]

Key to apterae on on Glaucium:-

1	SIPH pale, or only dusky towards apex, cylindrical for most of length, normally imbricated, without subapical polygonal reticulation	…..2
–	SIPH pale or dark, but if pale then either very short, smooth and conical, or with subapical polygonal reticulation	…..go to key to polyphagous aphids
2	Head spinulose, with inner faces of ANT tubercles steep-sided, almost parallel	…..Aulacorthum solani
–	Head smooth with ANT tubercles, either weakly developed or with inner faces divergent	…..3
3	SIPH short, less than 0.15 × BL, and less than 1.5 × cauda	…..Acyrthosiphon glaucii
–	SIPH 0.18-0.34 × BL, more than 1.7 × cauda	…..4
4	ANT tubercles well developed. ANT PT/BASE 3.0-3.7. SIPH without any trace of subapical swelling	…..Acyrthosiphon ilka
–	ANT tubercles weakly developed. ANT PT/BASE 1.9-2.8. SIPH with a very slight swelling immediately proximal to flange	…..Acyrthosiphon lambersi

*Glaux* see Lysimachia	Primulaceae
*Glaux maritima* = Lysimachia maritima

*Glechoma*	Lamiaceae
*Glechoma grandis*	Aulacorthum glechomae
*G. hederacea*	Aphis nasturtii; Aulacorthum glechomae, solani; [Cavariella aegopodii]; [Cryptomyzus galeopsidis]; Macrosiphum euphorbiae; Myzus ascalonicus, ornatus; Ovatus glechomae; Prociphilus erigeronensis; Rhopalosiphoninus staphyleae ssp. tulipaellus

Key to apterae on Glechoma:-

1	ANT 0.25-0.3 × BL, with PT/BASE less than 1. Cauda and anal plate both extended posteriorly, together forming a dark hairy rounded protruberance. SIPH absent	…..Prociphilus erigeronensis
–	ANT 0.5-1.6 × BL, with PT/BASE 1.7-5. Cauda and anal plate normal. SIPH present	…..2
2	SIPH evidently swollen, with maximum diameter of swollen part 1.3-2.1 × minimum diameter of basal part	…..3
–	SIPH tapering or cylindrical	…..4
3	SIPH with minimum diameter of basal part (“stem”) greater than that of hind tibia at midlength, and swollen part as wide as base of cauda. SIPH 3.1-4.3 × R IV+V. ANT III with 1-3 rhinaria near base. Dorsum with dark markings	…..Rhopalosiphoninus staphyleae ssp. tulipaellus
–	SIPH with minimum diameter of “stem” less than that of hind tibia at midlength, and swollen part about half as wide as base of cauda. SIPH 1.8-2.5 × R IV+V. ANT III without rhinaria. Dorsum without dark markings	…..Myzus ascalonicus
4	Front of head smooth, with ANT tubercles either very weakly developed or well-developed with divergent inner faces	…..go to key to polyphagous aphids, starting at couplet 16
–	Front of head scabrous or spiculose, and ANT tubercles well-developed with steep-sided, almost parallel or convergent inner faces	…..5
5	ANT III without rhinaria. Inner faces of ANT tubercles convergent or with convergent processes	…..6
–	ANT III usually with 1-3 small rhinaria near base. Inner faces of ANT tubercles approximately parallel	…..7
6	Head and appendages mainly dark. ANT PT/BASE 3.5-4.3. R IV+V with 4-6 accessory hairs. Dorsal abdomen without small dark intersegmental spots. (Immatures with smooth hind tibiae)	…..Ovatus glechomae
–	Head and appendages pale. ANT PT/BASE 1.7-2.8. R IV+V with 2 accessory hairs. Dorsal abdomen ornamented with a pattern of small dark intersegmental spots. (Immatures with spinulose hind tibiae)	…..Myzus ornatus
7	Cauda with 6-8, usually 7, hairs. R IV with 5-7 accessory hairs. (Immatures with smooth hind tibiae)	…..Aulacorthum solani
–	Cauda with 4-5 hairs. R IV with 2 accessory hairs. (Immatures with spinulose hind tibiae)	…..Aulacorthum glechomae*

*Gleditsia*	Fabaceae
*Gleditsia japonica*	[Aphis gossypii]; Astegopteryx minuta, pallida, unimaculata; Ceratoglyphina bambusae; Pseudoregma bambusicola
*G. triacanthos*	Aphis craccivora, fabae; Myzus persicae

Use key to polyphagous aphids.

*Glehnia*	Apiaceae
*Glehnia littoralis*	Macrosiphum euphorbiae; Semiaphis heraclei

*Gleichenia*	Gleicheniaceae
*Gleichenia* sp.	Amphorophora ampullata ssp. bengalensis

*Glinus*	Molluginaceae
*Glinus lotoides*	Aphis gossypii
*G. radiatus*	Aphis gossypii

*Gliricidia*	Fabaceae
*Gliricidia maculata*	Indomyzus glaricae (nomen nudum)
G. *sepium*	Aphis craccivora, gossypii

Key to apterae on Gliricidea:-

–	Head spinulose with inner faces of antennal tubercles scabrous, divergent. ANT III with c. 4 secondary rhinaria. Dorsal cuticle dark, sclerotic, with dorsal hairs c.2× longer than BD III	….. Indomyzus glaricae (nomen nudum)
–	Without that combination of characters	…..go to key to polyphagous aphids

*Glochidion*	Euphorbiaceae
*Glochidion assamicum* = G. ellipticum
*G. billardierei* = Phyllanthus billardierei
*G. cyrtostylum*	Aphis eugeniae
*G. ellipticum*	Schoutedenia ralumensis
*G. fagifolium* = G. hohenackeri
*G. fortunei*	Aphis eugeniae
*G. hohenackeri*	Greenidea kheemothicola
*G. hongkongense*	Aphis eugeniae
*G. obscurum*	Aphis eugeniae
*G. philippinense*	Schoutedenia ralumensis
*G. puberum*	[Greenidea (Trichosiphum) anonae]; Micromyzus hangzhouensis; Schoutedenia ralumensis
*G. sphaerostigmum*	Schoutedenia ralumensis
*G. wilsonii*	Schoutedenia ralumensis
*G. wrightii*	Schoutedenia ralumensis
*G. zeylanicum*	Schoutedenia ralumensis
Glochidion spp.	Aphis aurantii, craccivora, fabae, spiraecola; [Eutrichosiphum makii, pasaniae, takahashii]; [Greenidea (Trichosiphum) quercicola]; [Taoia indica]

Key to species:-

1	SIPH tubular with numerous long hairs	…..2
–	SIPH if tubular then without hairs	…..3
2	Body elongate, 2.4-2.7 times longer than wide. Cauda with a median papilla. SIPH with reticulation throughout length. R IV+V 1.50-1.62 × HT II	…..Greenidea kheemothicola*
–	Without that combination of characters (Glochidion may be visited casually or used as a reserve host by various Greenideini)	…..Greenideini spp.
3	ABD TERG 7 with a pair of large backward-pointed processes. Antenna 5-segmented, ANT PT/BASE less than 1. Aptera with 3-facetted eyes	…..Schoutedenia ralumensis
–	ABD TERG 7 without large processes. Antennae 6-segmented, ANT PT/BASE more than 1. Aptera with multifacetted eyes	…..3
4	Antennal tubercles well developed. Aptera with 1-3 secondary rhinaria on ANT III	…..Micromyzus hangzhouensis
–	Antennal tubercles weakly developed. Aptera without secondary rhinaria on ANT III	…..go to key to polyphagous aphids, starting at couplet 14

*Glossanthus*	Gesneriaceae
*Glossanthus* sp.	[Aphis verticolor Rafinesque 1817 (invalid name)]

*Gloxinia*	Gesneriaceae
*Gloxinia digitaliflora*	Myzus persicae; Neomyzus circumflexus
Gloxinia spp.	Aphis craccivora; Aulacorthum solani; Myzus ornatus
Use key to polyphagous aphids.

*Glyceria*	Poaceae
*Glyceria aquatica* = G. maxima
*G. declinata*	Sipha glyceriae
*G. fluitans*	Laingia psammae; Metopolophium dirhodum; Rhopalomyzus lonicerae, poae; Rhopalosiphum oxyacanthae, nymphaeae, padi; Sipha glyceriae; Sitobion avenae, graminis, fragariae
*G. grandis*	Sitobion avenae
*G. maritima* = Puccinellia maritima
*G. maxima*	Metopolophium dirhodum; Rhopalomyzus poae; Rhopalosiphum oxyacanthae, padi; Sipha glyceriae; Sitobion avenae, fragariae
*G. natans* = Torreyochloa natans
*G. nemoralis*	Rhopalosiphum padi; Sitobion avenae
*G. notata*	Melanaphis pyraria; Metopolophium dirhodum; Rhopalosiphum padi; Sipha glyceriae; Sitobion avenae
*G. plicata* = G. notata
*G. pulchella*	Metopolophium dirhodum; Sitobion fragariae
*G. striata* (incl. nervata)	Carolinaia howardii; Sipha glyceriae

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

*Glycine*	Fabaceae
*Glycine hispida* = G. max
*G. javanica* = Neonotonia wightii
*G. max* (incl. ssp. soja)	Acyrthosiphon gossypii, kondoi, pisum; Aphis craccivora, fabae, glycines, gossypii; Aulacorthum solani; [Hyadaphis coriandri]; Macrosiphum euphorbiae; Myzus [dycei], persicae; Neomyzus circumflexus; [Pemphigus sp.]; Smynthurodes betae
*G. ussuriensis* = G. max ssp. soja

Key to apterae on Glycine:-

1	ANT PT/BASE less than 0.5. SIPH absent. Body and appendages densely clothed in fine hairs	…..Smynthurodes betae
–	ANT PT/BASE more than 0.7. SIPH present. Body and appendages not so hairy	…..2
2	SIPH with a subapical zone of polygonal reticulation (at least 4-5 rows of closed cells)	…..3
–	SIPH without polygonal reticulation	…..4
3	SIPH black. R IV+V 1.1-1.2 × HT II. ABD TERG 8 with 4-6 hairs	…..Sitobion nigrinectarium
–	SIPH pale or dusky. R IV+V 0.95-1.1 × HT II. ABD TERG 8 with 6-8 hairs	…..Macrosiphum euphorbiae
4	ANT tubercles well-developed. SIPH pale or dusky. ABD TERG 1 and 7 without MTu	…..5
–	ANT tubercles weakly developed. SIPH dark. ABD TERG 1 and 7 with MTu	…..10
5	Head smooth, with divergent ANT tubercles	…..6
–	Head spiculose or nodulose, with inner faces of ANT tubercles parallel or convergent apically	…..8
6	SIPH not attenuated distally, thicker than hind tibiae at their respective midlengths. ANT BASE VI 1.0-1.5 × longer than R IV+V	…..Acyrthosiphon kondoi
–	SIPH attenuated distally, as thin as or thinner than hind tibiae at their respective midlengths. ANT BASE VI 1.8-2.9 × R IV+V	…..7
7	SIPH 0.42-0.50 × BL and 2.5-3.5 × cauda	…..Acyrthosphon gossypii
–	SIPH 0.23-0.38 × BL and 1.2-1.9 × cauda	…..Acyrthosiphon pisum
8	Dorsum with a large black roughly U-shaped patch, and black cross-bands on thorax. (Immatures with spinulose hind tibiae)	…..Neomyzus circumflexus
–	Dorsum without dark markings. (Immatures with smooth hind tibiae)	…..9
9	SIPH tapering or cylindrical. ANT III almost always with 1-2 small rhinaria near base	…..Aulacorthum solani
–	SIPH slightly clavate. ANT III without rhinaria	…..Myzus persicae
10	Dorsal abdomen with an extensive black shield. Cauda black	…..Aphis craccivora
–	Dorsal abdomen without dark markings. Cauda paler than SIPH	…..11
11	Cauda 0.08-0.135 × BL (only more than 0.12 × BL in very small specimens with BL less than 1 mm), and 0.8-1.25 × ANT V; pale to dusky, without a constriction, less than 3 × longer than its width at midlength, and bearing 4-7 (usually 5-6) hairs	…..Aphis gossypii
–	Cauda 0.12-0.175 × BL, and 1.05-1.7 × ANT V; very pale, usually with a slight mid-way constriction, more than 3 × longer than its narrowest width at midlength, and bearing 5-10 (usually 7-9) hairs	..…Aphis glycines

*Glycosmis*	Rutaceae
*Glycosmis arborea*	Aphis spiraecola
*G. pentaphylla*	Greenidea ficicola, heeri

Key to apterae on Glycosmis:-

(The Greenidea spp. may be vagrants or using this plant as a “reserve host”.)

1	SIPH covered with numerous long hairs	…..2
–	SIPH without hairs	…..Aphis spiraecola (or try key to polyphagous aphids)
2	SIPH reticulated only at base, and rather densely spinulose over most of length	…..Greenidea heeri
–	SIPH reticulated over most of length, spinulose only on distal part	…..Greenidea ficicola

*Glycyrrhiza*	Fabaceae
*Glycyrrhiza aspera*	Acyrthosiphon gossypii; Aphis craccivora, medicaginis
*G. astragalina*	Aphis ortegoi
*G. echinata*	Aphis craccivora
*G. glabra*	Acyrthosiphon gossypii, pisum; Aphis coronillae, craccivora, cytisorum, gossypii, medicaginis
*G. lepidota*	Aphis craccivora
*G. triphylla*	Acyrthosiphon pisum; Aphis craccivora
*G. uralensis*	Acyrthosiphon gossypii, pisum; Aphis craccivora
Glycyrrhiza sp.	Aphis fabae

Key to apterae on Glycyrrhiza:-

1	ANT tubercles very well developed, with smooth divergent inner faces. SIPH pale and attenuated distally, thinner than hind tibiae at their respective midpoints	…..2
–	ANT tubercles weakly developed. SIPH dark, thicker than hind tibiae at their respective midpoints	…..3
2	SIPH 0.42-0.50 × BL and 2.5-3.5 × cauda	…..Acyrthosiphon gossypii
–	SIPH 0.22-0.37 × BL and 1.2-1.9 × cauda	…..Acyrthosiphon pisum
3	Dorsum usually with a black sclerotic shield, which under the microscope has a distinct pale reticulation that follows the reticulate sculpturing of the cuticle; sometimes this shield is reduced of fragmented (especially in small specimens developing at higher temperatures), but there are usually at least some small fragments showing a reticulate pattern. SIPH and cauda both black	…..4
–	Dorsum without a black sclerotic shield or reticulated sclerites. SIPH and cauda pale, dusky or dark	…..7
4	ABD TERG 2-4 (-6) rather regularly bearing dome-shaped marginal tubercles (MTu), totalling 4-10 on these tergites	…..5
–	ABD TERG 2-6 usually without MTu, rarely with 1-3 small ones	…..6
5	Cauda with most hairs short, blunt, and often rather straight. Dorsal sclerotisation often fragmented intersegmentally. Longest hairs on ANT III 5-8 μm, 0.15-0.33 × BD III	…..Aphis medicaginis
–	Cauda with long, curved, finely-pointed hairs. Dorsal sclerotisation usually forming a solid patch. Longest hairs on ANT III 8-16 μm, 0.36-0.72 × BD III	…..Aphis coronillae
6	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
7	Aptera with small, oval secondary rhinaria distributed on ANT III (1-15), and with 0-5 on IV and 0-1 on V. SIPH mainly pale, darker towards apices	…..Aphis ortegoi*
–	Aptera without secondary rhinaria. SIPH uniformly dark	…..8
8	SIPH and cauda both black, the latter bearing 11-25 hairs	…..Aphis fabae
–	SIPH distinctly darker than cauda, which bears 4-7(-8) hairs	…..Aphis gossypii

*Gmelina*	Lamiaceae
*Gmelina arborea*	Aphis gossypii

*Gnaphalium* (including Omalotheca)	Asteraceae
*Gnaphalium affine*	[Aphis gnaphalii Shinji 1927]; [Macrosiphoniella yomogifoliae]
*G. americanum* = Gamochaeta americana
*G. antillanum* = Gamochaeta antillana
*G. arenarium* = Helichrysum arenarium
*G. argenteum*	Macrosiphum euphorbiae
*G. attenuatum*	Aphis spiraecola; Brachycaudus helichrysi
*G. beneolens* = Pseudognaphalium microcephalum
*G. bicolor* = Pseudognaphalium bioletti
*G. brachypterum* = Pseudognaphalium brachypterum
*G. californicum* = Pseudognaphalium californicum
*G. caucasicum* = Gnaphaliumsylvaticum
*G. chilense* = Helichrysum chilense
*G. declinatum*	Aphis spiraecola
*G. decurrens*	[“Nectarophora sp.” – Cockerell 1903: 171]
*G. dioicum* = Antennaria dioica
*G. erectum*	Pemphigus populinigrae
*G. germanica* = Filago vulgaris
*G. hypoleucum*	Capitophorus gnathalifoliae
*G. indicum*	Aphis gossypii
*G. inornatum* = Pseudognaphalium inornatum
*G. japonicum*	Aphis gossypii; Brachycaudus helichrysi; Oedisiphum compositarum
*G. leontopodium* = Leontopodium alpinum
*G. luteoalbum* = Helichrysum luteoalbum
*G. multiceps* = Helichrysum luteoalbum
*G. norvegicum*	Brachycaudus helichrysi
*G. obtusifolium* = Pseudognaphalium obtusifolium
*G. peregrinum* = Gamochaeta pensylvanica
*G. polycephalum*	Aphis gossypii; [Uroleucon sp. (as Dactynotus – Leonard 1968, 345)]
*G. portoricense*	Uroleucon ambrosiae
*G. purpureum* = Gamochaeta purpurea
*G. spathulatum* = Gamochaeta pensylvanica
*G. supinum*	Macrosiphoniella olgae
*G. sylvaticum*	Brachycaudus helichrysi; Macrosiphoniella olgae; Oedisiphum compositarum; Pemphigus populinigrae; Pleotrichophorus filaginis, [?glandulosus]; [Trama troglodytes]; [Uroleucon cichorii]
*G. uliginosum*	Aphis nasturtii, [Aphis sp.(Davletshina 1964)]; Aulacorthum solani; Brachycaudus helichrysi; Myzus ornatus; Pemphigus populinigrae; Uroleucon gobonis
*G. undulatum*	Aulacorthum solani; Brachycaudus helichrysi; Myzus persicae; Uroleucon compositae
Gnaphalium spp.	Aphis craccivora, [Aphis (Protaphis) sp.(Mier Durante 1978, 93)]; [Cavariella salicicola]; [Dysaphis microsiphon]; Hyperomyzus (Neonasonovia) sp. (U.P., India; BMNH collection, leg. D. Bhattacharya); Pemphigus sp. (India, U.P., BMNH collection); Rhopalosiphum rufiabdominale; Tuberocephalus sp. nr tsengi (Japan, BMNH collection); Uroleucon erigeronense, sinuense

Key to apterae on Gnaphalium and Pseudognaphalium:-

1	SIPH absent. ANT about 0.2 × BL, with PT/BASE 0.17-0.20. ABD TERG 3-7 with wax gland plates	…..2
–	SIPH present, ANT more than 0.3 × BL, with PT/BASE more than 0.5. No wax gland plates	…..3
2	R IV+V 1.2-1.4 × HT II	…..Pemphigus populinigrae
–	R IV+V 0.8-0.9 × HT II	…..Pemphigus sp. (?mordwilkoi; India, BMNH collection)
3	Dorsal hairs numerous, with fan-shaped or capitate apices, arising from tuberculate bases	…..4
–	Dorsal hairs without fan-shaped or capitate apices, with or without tuberculate bases	…..5
4	SIPH swollen on distal part. ANT I with capitate hairs arising from tuberculate bases	…..Capitophorus gnathalifoliae*
–	SIPH cylindrical (slightly flared at apex). ANT I without capitate hairs	…..Pleotrichophorus filaginis
5	Cauda helmet-shaped, slightly constricted near base, shorter than or not clearly longer than its basal width, and bearing 4-6 hairs	…..6
–	Cauda bluntly conical, tongue- or finger-shaped, either distinctly longer than its basal width or bearing more than 10 hairs	…..8
6	RIV+V less than 0.15 mm long, 1.1-1.5 × HT II. SIPH conical, pale, almost smooth. Spiracular apertures large and rounded. Tergum membranous	…..Brachycaudus helichrysi
–	R IV+V more than 0.20 mm long, more than 2 × HT II. SIPH dark, cylindrical or slightly swollen, imbricated. Spiracular apertures small and reniform. Tergum with variably developed dark sclerotisation	…..7
7	Longest hairs on ANT III 12-15 μm, shorter than ANT BD III, and longest hairs on ABD TERG 3 15-36 μm, less than 2 × ANT BD III	…..Oedisiphum compositarum
–	Longest hairs on ANT III 18-21 μm, as long as or longer than ANT BD III, and longest hairs on ABD TERG 3 50-60 μm, more than 2 × ANT BD III	…..Oedisphum soureni
8	ANT tubercles undeveloped or weakly developed, or if well developed then densely spiculose or scabrous and with parallel or apically convergent inner faces. SIPH without a subapical zone of polygonal reticulation	…..9
–	ANT tubercles well developed, with almost smooth, divergent inner faces. SIPH often with distal or subapical polygonal reticulation	…..10
9	Eyes reduced to 10-30 facets, with no distinct ocular tubercle (triommatidium). ANT I very wide, 2 or more × thicker than ANT II	…..Tuberocephalus sp. near tsengi (Japan, BMNH collection)
–	Eyes with many more than 30 facets and a distinct ocular tubercle. ANT I less than 2 × thicker than ANT II	…..go to key to polyphagous aphids
10	SIPH pale, or dusky towards apices	…..11
–	SIPH uniformly dark, or paler only in middle	…..13
11	SIPH cylindrical on distal half, with reticulation on subapical 0.13-0.20 of length. R IV+V 0.9-1.1 × HT II	…..Macrosiphum euphorbiae
–	SIPH swollen on distal half, if with reticulation than this does not extend beyond 0.07 of length. R IV+V 1.5-2.3 × HT II	…..12
12	Thoracic spiracles similar in size to abdominal ones. R IV+V 1.5-1.7 × HT II. SIPH 2.2-2.5 × cauda, imbricated and with some subapical reticulation. ANT III with rhinaria regularly spaced in a row	…..Illinoia richardsi
–	Thoracic spiracles much larger than abdominal ones. R IV+V c.2.3 × HT II. SIPH 1.4-1.5 × cauda, almost smooth, without subapical reticulation. ANT III with rhinaria clustered on swollen part near base	……Hyperomyzus (Neonasonovia) sp. (U.P., India; BMNH collection, leg. D. Bhattacharya)
13	SIPH more than 10 × longer than their width at midlength, with at most 1-3 rows of subapical polygonal reticulation. Hairs on ABD TERG 1-5 much shorter than ANT BD III, and without pigmented basal scleroites	…..Acyrthosiphon bidenticola
–	SIPH thicker, less than 10 × their width at midlength, with many rows of polygonal reticulation. Hairs on ABD TERG 1-5 longer than ANT BD III and often arising from pigmented scleroites	…..14
14	SIPH about 1.1-1.2 × cauda, and reticulated over about half of length	…..Macrosiphoniella olgae*
–	SIPH 1.1-2.3 × cauda, and reticulated over distal 0.23-0.40 of length	…..15
15	Cauda dark. SIPH 1.8-2.1 × cauda. ANT III with 51-77 rhinaria	…..Uroleucon compositae (or gobonis?)
–	Cauda either entirely pale or faintly smoky on distal half. SIPH 1.1-2.3 × cauda. ANT III with 5-46 rhinaria	…..16
16	Coxae dark. Dorsal hairs not arising from dark scleroites	…..Uroleucon sonchi
–	Coxae pale. Dorsal hairs with or without dark basal scleroites	…..17
17	SIPH distally dark and basally pale. Cauda with one or more distal hairs short and blunt or capitate. ANT III with 5-17 rhinaria. R IV+V longer than HT II. Dorsal cephalic hairs 18-36 μm	…..Uroleucon erigeronense
–	SIPH entirely dark. Cauda with all hairs of normal length. Other characters not in that combination	…..18
18	R IV+V with no more than 10 accessory hairs	…..19
–	R IV+V with 12-32 accessory hairs	…..22
19	Cauda faintly dusky to brown on distal half only	…..Uroleucon chani
–	Cauda pale or uniformly dusky over entire length	20
20	R IV+V 1.8-2.3 × HT II. SIPH 1.5-1.8 × cauda, which is dusky	…..Uroleucon russellae
–	R IV+V 0.9-1.5 × HT II. SIPH 1.1-1.3 × cauda, which is pale	21
21	HT II rather long and thin, about 6 × its maximum thickness, and 0.9-1.1 × R IV+V	…..Uroleucon pseudambrosiae
–	HT II shorter, less than 5 × its maximum thickness and 0.7-0.85 × R IV+V	…..Uroleucon ambrosiae
22	R IV+V 0.25-0.27 mm, with 12-19 accessory hairs that are 22-35 μm long. SIPH reticulated over 0.30-0.41 of length	…..Uroleucon sinuense
–	R IV+V 0.14-0.23 mm, with 20-32 accessory hairs that are 32-50 μm long. SIPH reticulated over 0.21-0.35 of length	…..Uroleucon gnaphalii

*Gnetum*	Gnetaceae
*Gnetum parvifolium*	Aphis gnetuma

*Gnidia*	Thymelaeaceae
*Gnidia* sp.	Sitobion wikstroemiae

*Gochnatia*	Asteraceae
*Gochnatia* sp.	Uroleucon gochnatiae

Godetia see Clarkia

Onagraceae

Goebelia see Sophora

Fabaceae

*Goldbachia*	Brassicaceae
*Goldbachia laevigata*	Aphis gossypii

Goldfussia see Strobilanthes

Acanthaceae

*Gomphocarpus*	Apocynaceae
*Gomphocarpus cornutus* = G. fruticosus
*G. fruticosus*	Aphis fabae, gossypii, nerii; Myzus persicae
*G. lanatus* = G.tomentosus
*G. physocarpus*	Aphis gossypii, nerii
*G. purpurascens*	Aphis nerii
*G. sinaicus*	Aphis nerii
*G. tomentosus*	Aphis nerii

Use key to polyphagous aphids.

*Gomphrena*	Amaranthaceae
*Gomphrena celosioides*	Aphis gossypii; [Hysteroneura setariae]
*G. globosa*	Aphis gossypii; Aulacorthum solani; Macrosiphum euphorbiae, [salviae], stellariae; Myzus certus, persicae; Rhopalosiphoninus staphyleae

Use key to polyphagous aphids, but note that specimens running to Macrosiphum euphorbiae could be M. stellariae, and those running to Myzus persicae could be M. certus; for separation of these species-pairs see the key to aphids on Dianthus, couplets 3 and 16 respectively.

*Gonatanthus*	Araceae
*Gonatanthus* sp.	Aphis asclepiadis

*Gongronema*	Apocynaceae
*Gongronema latifolium*	Aphis gossypii
*G. nepalense*	[Greenidea ficicola]

*Goniolimon*	Plumbaginaceae
*Goniolimon rubellum*	Staticobium latifoliae
*G. speciosum*	Rhopalosiphoninus staphyleae
*G. tataricum*	Staticobium gmelini, insularum

Use key to aphids on Limonium.

*Gonolobus* see Ampelamus	Apocynaceae
*Gonolobus laevis* = Ampelamus laevis

*Gonospermum*	Asteraceae
*Gonospermum fruticosum*	[Brevicoryne brassicae]

*Gonostegia*	Urticaceae
*Gonostegia hirta*	Aphis citricidus, gossypii, nasturtii, spiraecola; Brachycaudus helichrysi

Use key to polyphagous aphids.

*Gonzalagunia* (including Duggena)	Rubiaceae
*Gonzalagunia brachyantha*	Aphis (Toxoptera) aurantii
*G. hirsuta*	Aphis aurantii, gossypii
*G. spicata* = G. hirsuta

Use key to polyphagous aphids.

*Goodenia*	Goodeniaceae
*Gooodenia brunnea*	Brachycaudus helichrysi

*Goodyera*	Orchidaceae
*Goodyera* sp.	Ericaphis ?wakibae (see aphidtrek.org)

*Gordonia*	Theaceae
*Gordonia axillaris*	Aphis (Toxoptera) aurantii
*G. ekmanii*	Aphis (Toxoptera) aurantii
*G. obtusa*	Aphis (Toxoptera) aurantii

*Gossypium*	Malvaceae
*Gossypium arboreum*	Aphis gossypii; Myzus persicae
*G. barbadense*	Aphis gossypii
*G. herbaceum*	Acyrthosiphon gossypii, [gossypicola]; Aphis craccivora, fabae, frangulae, gossypii, spiraecola; Brachyunguis harmalae (as plotnikovi); Macrosiphum euphorbiae; Myzus persicae; Protaphis middletonii; Rhopalosiphum rufiabdominale; Smynthurodes betae
*G. hirsutum*	Acyrthosiphon gossypii; Aphis craccivora, gossypii; Brachyunguis harmalae (as plotnikovi); Myzus persicae; Neomyzus circumflexus; Smynthurodes betae
*G. indicum* = G. arboreum
*G. nanking* = G. herbaceum
*G. sturtianum*	Aphis gossypii
Gossypium spp.	Aphis [poacyni], [umbrella]; Rectinasus buxtoni

Key to apterae on Gossypium:-

1	ANT PT/BASE less than 0.3. Body and appendages densely hairy. SIPH absent	…..2
–	ANT PT/BASE at least 0.5. Body and appendages not densely hairy. SIPH present	…..3
2	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
3	SIPH pale and attenuated distally, thinner than hind tibia at their respective midpoints, and 2.5-3.5 × cauda	…..Acyrthosiphon gossypii
–	SIPH pale or dark, thicker than hind tibia at their respective midpoints, and less than 2.5 × cauda	…..4
4	ANT 5-segmented, bearing long, fine hairs, many of them more than 2 × BD III. SIPH cylindrical for most of length but markedly constricted just proximal to flange	…..Rhopalosiphum rufiabdominale
–	ANT usually 6-segmented, with shorter hairs. SIPH without a marked subapical constriction	…..5
5	ANT PT/BASE less than 1. SIPH pale, 0.4-0.6 × cauda	…..Brachyunguis harmalae
–	ANT PT/BASE 1.4-6.2. SIPH pale or dark, 0.8-2.5 × cauda	…..go to key to polyphagous aphids

*Gouania*	Rhamnaceae
*Gouania polygama*	Aphis gossypii

*Gourliea*	Fabaceae
*Gourliea decorticans* = Geoffroea decorticans

*Graffenrieda*	Melastomataceae
*Graffenrieda rufescens*	Aphis spiraecola

*Graphistemma*	Apocynaceae
*Graphistemma pictum*	Aphis nerii

*Gratiola*	Plantaginaceae
*Gratiola officinalis*	Aphis [chloris], gratiolae, nasturtii; Aulacorthum solani; Brachycaudus helichrysi; Macrosiphum euphorbiae

Key to apterae on Gratiola:-

–	SIPH dark, about 1.2 × cauda, which bears 4-5 hairs. R IV+V c. 0.75 × HT II	….. Aphis gratiolae
–	Without this combination of characters	…..go to key to polyphagous aphids

*Gravesia*	Melastomataceae
*Gravesia* sp.	Brachycaudus helichrysi

*Greigia*	Bromeliaceae
*Greigia* sp.	Aphis sp. – Leonard 1972a: 101

*Grevillea*	Proteaceae
*Grevillea robusta*	Aphis aurantii, gossypii; Myzus persicae
*G. thelemanniana*	Aphis gossypii
Grevillea sp.	Aulacorthum solani

Use key to polyphagous aphids.

*Grewia*	Malvaceae
*Grewia biloba*	Aphis gossypii
*G. mollis*	Aphis gossypii
*G. occidentalis*	Aphis (Toxoptera) aurantii
*G. oppositifolia*	Sinomegoura citricola
*G. optiva*	Sinomegoura citricola
*G. ovalis* (?)	Aphis gossypii
*G. tiliifolia*	Aphis aurantii, gossypii; Sinomegoura citricola
Grewia sp. (?tomentosa)	Cervaphis schouteniae

Key to apterae on Grewia:-

–	Body with very long, branched hair-bearing marginal processes	….. Cervaphis schouteniae
–	Body without such processes	…..go to key to polyphagous aphids

*Greyia*	Melianthaceae
*Greyia sutherlandii*	Aphis odinae; Aulacorthum solani; Macrosiphum euphorbiae

Use key to polyphagous aphids.

*Grindelia*	Asteraceae
*Grindelia chiloensis*	Aphis melosae; Myzus persicae; Uroleucon payuniense
*G. cuneifolia* = G. hirsutula
*G. hirsutula*	Brachycaudus helichrysi; [Illinoia grindeliae]; Uroleucon chani, grindeliae, richardsi
*G. integrifolia*	Aulacorthum solani; Uroleucon erigeronense, penderum
*G. nana* = G. hirsutula
*G. perennis* = G. hirsutula
*G. squarrosa*	[Anoecia corni], Atarsos grindeliae; Illinoia grindeliae, grindeliae ssp. palmerae; Uroleucon richardsi, robinsoni
*G. stricta* = G. hirsutula
Grindelia sp.	[Protaphis middletonii]; [Uroleucon brevisiphon]

Key to apterae on Grindelia:-

1	Tarsi absent. ANT III-V with secondary rhinairia (sometimes III and IV are fused). ANT PT/BASE 1.0-1.4	…..Atarsos grindeliae
–	Two-segmented tarsi present. Secondary rhinaria absent or on ANT III only. ANT PT/BASE 1.4-6.5	…..2
2	ANT tubercles weakly developed or undeveloped. SIPH without subapical reticulation	…..3
–	ANT tubercles well developed. SIPH with or without subapical reticulation	…..4
3	Cauda helmet-shaped, shorter than its basal width in dorsal view, with 4-7 hairs. SIPH pale, smooth, conical, with an annular subapical incision. Spiracular apertures rounded. Dorsum without dark markings or reticulate sculpturing. No marginal tubercles (MTu)	…..Brachycaudus helichrysi
–	Cauda tongue-shaped, longer than its basal width, with 6-12 hairs. SIPH dark, coarsely imbricated, with no annular subapical incision. Spiracular apertures reniform. Dorsum with variably developed dark markings and reticulate sculpturing. Large MTu present on prothorax and ABD TERG 1 and 7	…..Aphis melosae
4	SIPH without a distinct zone of reticulation, at most with subapical transverse striae and 1-2 rows of indistinct polygonal cells	…..5
–	SIPH with a distinct distal zone of reticulation extending 0.2 or more of its length and with numerous polygonal cells	…..7
5	Head spiculose, with inner faces of ANT tubercles approximately parallel. SIPH tapering or cylindrical on distal half. ANT III with 0-3 (usually 1) rhinaria	…..Aulacorthum solani
–	Head smooth, with inner faces of ANT tubercles divergent. SIPH slightly swollen on distal half. ANT III with 2-5 rhinaria	…..6
6	ANT PT/BASE 4.0-4.3. Cauda 1.5-1.8 × R IV+V, which is 1.25-1.5 × HT II	…..Illinoia grindeliae
–	ANT PT/BASE 4.5-4.9. Cauda 1.9-2.4 × R IV+V which is 1.1-1.2 × HT II	…..Illinoia grindeliae ssp. palmerae
7	SIPH entirely dark	…..Uroleucon chani
–	SIPH pale, at least on basal part	…..8
8	ANT III with 12-31 rhinaria extending to 0.80-0.98 from base, with the majority on distal half	…..Uroleucon richardsi
–	ANT III with 5-26 rhinaria extending to 0.4-0.8 from base, with the majority on basal half	…..9
9	R IV+V 0.9-1.2 × HT II, with 6-10 accessory hairs. SIPH 1.85-2.5 × cauda. ANT PT/BASE 3.2-5.7	…..10
–	R IV+V 1.15-1.5 × HT II, with 7-13 accessory hairs. SIPH 1.5-2.6 × cauda. ANT PT/BASE 3.0-5.2	…..11
10	Siphunculi pale at base, dark over most of length. Distal caudal hairs usually short and blunt or capitate. Dorsal cephalic hairs 18-35 μm long	…..Uroleucon erigeronense
–	Siphunculi pale. Distal caudal hairs pointed. Dorsal cephalic hairs 45-55 μm long	…..Uroleucon payuniense
11	ANT PT/BASE 3.0-3.5. ANT PT 1.0-1.1 × cauda. R IV+V with 6-9 accessory hairs	..…Uroleucon grindeliae
–	ANT PT/BASE 3.6-5.2. ANT PT 1.5-2.0 × cauda. R IV+V with 9-13 accessory hairs	…..12
12	SIPH 2.2-2.6 × cauda. R IV+V 1.15-1.3 × HT II. Tibiae dusky/dark for most of length	…..Uroleucon robinsoni
–	SIPH 1.65-1.95 × cauda. R IV+V 1.3-1.6 × HT II. Tibiae pale except at apices	…..Uroleucon penderum

*Grisebachianthus*	Asteraceae
*Grisebachianthus libanotica*	Aphis aurantii, gossypii, spiraecola; Neomyzus circumflexus

Use key to polyphagous aphids.

Gronophyllum see Hydriastele

Arecaceae

Grossularia see Ribes

Grossulariaceae

*Guaiacum* Lignum vitae	Zygophyllaceae
No aphids recorded

*Guapira*	Nyctaginaceae
*Guapira fragrans*	Aphis (Toxoptera) aurantii

*Guazuma*	Malvaceae
*Guazuma tomentosa* = G. ulmifolia
*G. ulmifolia*	Aphis aurantii, gossypii; Cervaphis schouteniae

See couplet under Grewia.

*Guettarda*	Rubiaceae
*Guettarda krugii*	Aphis spiraecola
*G. scabra*	Aphis gossypii
Use key to polyphagous aphids

*Guiera*	Combretaceae
*Guiera senegalensis*	Aphis gossypii

*Guizotia*	Asteraceae
*Guizotia abyssinica*	Aphis craccivora, fabae; Macrosiphum euphorbiae;[Melanaphis sp.]; [Rhopalosiphum maidis]; Uroleucon compositae (as jaceae)
*G. aethiopica* (?)	Aphis gossypii, spiraecola

Use key to polyphagous aphids.

*Gundelia*	Asteraceae
*Gundelia tournefortii*	Aphis gossypii; Brachycaudus cardui, helichrysi; Myzus persicae; Uroleucon iranicum
Gundelia sp.	Aphis craccivora; [Protaphis iliensis]

Key to apterae on Gundelia:-

1	SIPH dark with distal polygonal reticulation extending over 0.33-0.44 of length. ANT III bearing 27-51 rhinaria extending over most of length. Cauda pale, 2.5-2.9 × ANT BASE VI and bearing 8-12 hairs	…..Uroleucon iranicum
–	Without that combination of characters	…..2
2	Dorsum with an extensive black sclerotic shield. Mesosternum with a pair of dark mammariform processes. Cauda short and rounded	…..Brachycaudus cardui
–	Without that combination of characters	…..go to key to polyphagous aphids

*Gunnera*	Gunneraceae
*Gunnera chilensis* = G. tinctoria
*G. magellanica*	Aphis carrilloi; Myzus ornatus
*G. tinctoria*	Neuquenaphis valdiviana

Key to apterae on Gunnera:-

1	Cauda knobbed. Head, thorax and abdomen with finger-like processes. (Al. also with such processes on ABD TERG 1-3)	….. Neuquenaphis valdiviana
–	Cauda not knobbed. Body without finger-like processes	…..2
2	Head smooth with ANT tubercles undeveloped. SIPH dark, similar in length to the equally dark cauda, which bears 8-16 hairs. First tarsal segments with 3-5 (commonly 4) hairs	….. Aphis carrilloi
–	Head nodulose with ANT tubercles well-developed and apically convergent. SIPH pale/dusky, more than twice as long as the pale cauda which bears 4-6 hairs. First tarsal segments with 3 hairs (or try key to polyphagous aphids)	….. Myzus ornatus

*Gurania*	Cucurbitaceae
*Gurania makoyana*	Aphis gossypii

*Gutenbergia*	Asteraceae
*Gutenbergia cordifolia*	Aphis gossypii, spiraecola; Brachycaudus helichrysi; Myzus ornatus; Uroleucon compositae

Use key to polyphagous aphids.

*Gutierrezia*	Asteraceae
*Gutierrezia bracteata* = G. californica
*G. californica*	Uroleucon erigeronense
*G. isernii*	Uroleucon riojanum
*G. longifolia* = G. sarothrae
*G. sarothrae*	Aphis crypta, gutierrezis; Pleotrichophorus utensus; Uroleucon escalantii, zerogutierrezis
Gutierrezia spp.	Pleotrichophorus pycnorhysus

These species are included in the key to aphids on the related genus Chrysothamnus.

Guttarda see Matthiola

Brassicaceae

*Guyonia*	Melastomataceae
*Guyonia ciliata*	Aphis (Toxoptera) aurantii

*Gymnadenia*	Orchidaceae
*Gymnadenia odoratissima*	Aphis fabae, [ilicis]

(or try key to orchid feeders under Cymbidium)

*Gymnaster*	Asteraceae
*Gymnaster pygmaeus* = Aster savatieri var. pygmaeus
*G. savatieri* = Aster savatieri

*Gymnema*	Apocynaceae
*Gymnema inodorum*	Pseudomegoura nipponica
*G. tingens* = G. inodorum

*Gymnocarpium*	Woodsiaceae
*Gymnocarpium dryopteris*	Amphorophora ampullata; Idiopterus nephrelepidis; Macrosiphum dryopteridis; Taiwanomyzus alpicola
*G. robertianum*	Macrosiphum dryopteridis; Taiwanomyzus alpicola

Use key to fern-feeding aphids under Polypodium.

*Gymnocarpos*	Caryophyllaceae
*Gymnocarpos decandrus*	Aphis craccivora; Brachyunguis harmalae; Myzus persicae

Key to apterae on Gymnocarpos:-

–	ANT PT/BASE less than 1. SIPH pale, 0.4-0.6 × cauda	….. Brachyunguis harmalae
–	ANT PT/BASE 2.0-5.3. SIPH pale or dark, longer than cauda	…..go to key to polyphagous aphids

*Gymnogramma*	Thelypteridaceae
*Gymnogramma totta*	Micromyzus nikkoensis

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

*Gymnophyton*	Apiaceae
*Gymnophyton polycephalum*	Aphis cuyana

*Gymnosperma*	Asteraceae
*Gymnosperma glutinosum*	Uroleucon erigeronense, zacatecense

Key to apterae on Gymnosperma:-

(Both species have SIPH pale basally and dark distally, with a distal zone of polygonal reticulation.)

–	ABD TERG 2-5 without marginal tubercles (MTu). ANT III with rhinaria restricted to basal 0.7 of length	….. Uroleucon erigeronense
–	ABD TERG 2-5 mostly with MTu. Rhinaria on ANT III distributed over 0.71-0.93 of length	….. Uroleucon zacatecense*

Gymnosporia see Maytenus

Celastraceae

*Gynandropsis* see Cleome	Capparaceae
*G. gynandra* = Cleome gynandra
*G. pentaphylla* = Cleome gynandra

*Gynerium*	Poaceae
*Gynerium sagittatum*	Hysteroneura setariae

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

*Gynura*	Asteraceae
*Gynura angulosa* = G.cusimbua
*G. aurantiaca*	Aphis gossypii; Brachycaudus helichrysi; Macrosiphum euphorbiae; Myzus ornatus
*G. crepidioides* = Crassocephalum crepidioides
*G. cusimbua*	Aphis gossypii, spiraecola; Brachycaudus helichrysi; Hyperomyzus carduellinus; [Brachysiphoniella montana]; Myzus persicae; [Sitobion rosaeiformis]
*G. guinensis* (?)	Aphis gossypii
*G. nepalensis*	Aphis aurantii, gossypii, spiraecola; Brachycaudus helichrysi; Hyperomyzus carduellinus; Myzus ornatus, persicae; Neomyzus circumflexus
*G. procumbens*	Aphis gossypii; Uroleucon vernoniae
*G. sarmentosa* = G. procumbens
*G. scandens*	Aphis fabae; Aulacorthum solani; Myzus ornatus
Gynura sp.	Uroleucon sonchi (ssp. afghanicum?)

Key to apterae on Gynura:-

1	SIPH dark, with a distal zone of polygonal reticulation, 1.4-1.9 × cauda, which is long, slender and pale and bears 23-30 hairs	…..Uroleucon sonchi
–	Without that combination of characters; if SIPH are dark and have polygonal reticulation then cauda is also dark	…..2
2	SIPH dark with polygonal reticulation, cauda also dark, R IV+V 1.5-1.8 × HT II, and ANT III with 23-57 rhinaria	…..Uroleucon vernoniae
–	Without that combination of characters	…..3
3	SIPH smooth, pale, and swollen on distal 0.7, maximum width of swollen part being 1.3-1.5 × minimum width of basal part. ANT III with 5-30 rhinaria. ANT PT/BASE 4.4-6.8	…..Hyperomyzus carduellinus
–	Without that combination of characters	…..go to key to polyphagous aphids

*Gypsophila*	Caryophyllaceae
*Gypsophila altissima*	Aphidura naimanica, togaica; Aphis craccivora
*G. arenaria* = G. fastigiata
*G. davurica*	Aphis gypsophilae
*G. elegans*	Myzus cymbalariae, persicae; Smynthurodes betae
*G. fastigiata*	Aphidura gypsophilae; Aphis craccivora, gypsophilae
*G. paniculata*	Aphidura gypsophilae, naimanica, pannonica; [Aphis sp. (Leonard 1973:16)]; [Brachycaudus amygdalinus]
*G. perfecta* (?)	Aulacorthum solani
*G. perfoliata*	Aphidura gypsophilae, naimanica, togaica
*G. polyclada*	Aphidura togaica
*G. porrecta* (?)	[Aphis sp. (Leonard 1973:16)]
*G. repens*	Myzus ornatus
**G. struthium ssp. hispanica**	Brachyunguis harmalae
Gypsophila sp.	Aphidura graeca; Aphis gossypii; Macrosiphum stellariae

Key to apterae on Gypsophila:-

(Couplets 3-7 are partly based on Nieto Nafría et al. 2013.)

1	ANT PT/BASE less than 1. SIPH pale, 0.4-0.6 ×cauda	…..Brachyunguis harmalae
–	ANT PT/BASE more than 1 (unless SIPH are absent). SIPH dark if shorter than cauda	…..2
2	SIPH very short and dark, only 0.35-0.4 × the long dark cauda	…..Aphis gypsophilae
–	SIPH (if present) pale or dark, as long as or longer than cauda	…..3
3	ANT tubercles low, somewhat scabrous, and median frontal tubercle (on ventral side of head) developed to a similar extent and also scabrous. ABD TERG 1 and 7 without marginal tubercles (MTu). Anterior part of mesosternum with a pair of spinal mammariform processes, ornamented with spinules	…..4
–	If ANT tubercles are low then ABD TERG 1 and 7 have marginal tubercles. Mesosternum without a pair of mammariform processes	…..8
4	SIPH distinctly clavate, with maximum width of swollen part at least 1.3 × minimum width basad	…..5
–	SIPH cylindrical or only slightly clavate; maximum width of swollen part less than 1.2 × minimum width basad	…..6
5	Abdominal dorsum membranous and pale with only intersegmental muscle plates pigmented. SIPH pale	…..Aphidura graeca*
–	Abdominal dorsum with pigmented patches and sclerites, usually comprising sclerotic bands on metanotum and ABD TERG 7 and 8, and a broken patch on ABD TERG 1-6. SIPH dark	…..Aphidura naimanica*
6	Head, prothorax (with a complete or fragmented transversal band) and SIPH brown. Abdominal spinopleural patch variably developed and pigmented and sometimes fragmented or (often in small specimens) absent	…..Aphidura pannonica
–	Head, prothorax and SIPH pale (SIPH sometimes brownish towards apices). Abdomen variably sclerotised and variably pigmented	…..7
7	ANT PT/BASE 3.4-4.4. R IV+V at least 1.0 × HT II	…..Aphidura togaica*
–	ANT PT/BASE 5.0-5.5. R IV+V shorter than HT II	…..Aphidura gypsophilae
8	SIPH with a subapical zone of polygonal reticulation. Femora usually with a dark spot or patch near apices. 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
–	SIPH without subapical polygonal reticulation, or if they have then other characters are not in that combination	…..go to key to polyphagous aphids

*Habenaria*	Orchidaceae
*Habenaria dilatata* = Piperia dilatata
*H. monorrhiza*	Aulacorthum solani; Neomyzus circumflexus
*H. tridactylites*	Aphis fabae

Use key to polyphagous aphids, or try key to orchid feeders under Cymbidium)

*Hackelia*	Boraginaceae
*Hackelia patens*	Macrosiphum euphorbiae

*Hackelochloa*	Poaceae
*Hackelochloa granularis*	Aphis gossypii

*Hacquetia*	Apiaceae
*Hacquetia epipactis*	Aphis fabae

*Haemaria* see Ludisia	Orchidaceae
Haemaria discolor = Ludisia discolor

*Hagenia*	Rosaceae
*Hagenia abyssinica*	Aphis gossypii; Aulacorthum solani; Macrosiphum euphorbiae; Myzus ornatus; [Sitobion leelamaniae (? – as chanikiwiti]

Use key to polyphagous aphids.

*Hakea*	Proteaceae
*Hakea leucoptera*	Macrosiphum euphorbiae; [Amphorophora sp., Leonard 1972a]
*H. sericea*	Aphis gossypii; Sitobion africanum
Hakea spp.	Aphis (Toxoptera) aurantii

Key to apterae on Hakea:-

–	SIPH dark with subapical polygonal reticulation (a few rows of large polygonal cells). Dorsum with variably developed dark cross-bands (often absent). Hairs on dorsal body body and antennae very short and blunt	….. Sitobion africanum
–	Without this combination of characters	…..go to key to polyphagous aphids

*Halesia*	Styracaceae
*Halesia carolina*	Macrosiphum euphorbiae; Myzus ornatus

Use key to polyphagous aphids.

*Halimione*	Amaranthaceae
*Halimione portulacoides* = Atriplex portulacoides

*Halimiocistus* (Halimium × Cistus)	Cistaceae
*Halimiocistus sahucii*	Myzus ornatus

*Halimium*	Cistaceae
*Halimium alyssoides*	Aphis cisticola, helianthemi, lichtensteini
*H. halimifolium*	Aphis helianthemi
*H. ocymoides* (= occimoides)	Aphis cisticola
*H. umbellatum*	Aphis cisticola, lichtensteini

Key to apterae on Halimium:-

1	R IV+V 1.75-2.50 × HT II and bearing 6-10 accessory hairs. HT II very short, 0.65-0.83 × ANT BASE VI. Marginal tubercles (MTu) small and often absent from ABD TERG 1 and 7	…..Aphis lichtensteini
–	R IV+V 1.28-2.05 × HT II and bearing 2-3 accessory hairs. HT II 0.72-1.20 × ANT BASE VI. MTu always present and well developed on ABD TERG 1 and 7	…..2
2	SIPH variably pigmented, rarely entirely dark, and 0.7-1.4 × cauda. ABD TERG 7 and 8 with faint and inconspicuous cross-bands	…..Aphis helianthemi
–	SIPH entirely dark, 1.1-3.6 × cauda. ABD TERG 7 and 8 with clearly defined dark cross-bands	…..Aphis cisticola

*Halimodendron*	Fabaceae
*Halimodendron argenteum*	Aphis craccivora
*H. halodendron*	Acyrthosiphon pisum; Aphis craccivora; [Therioaphis sp. (Kazakhstan; Kadyrbekov 2011a)]

Use key to apterae on Echinospartium.

*Halleria*	Stilbaceae
*Halleria lucida*	[Aphis sp.; Leonard 1972a, 101]; Myzus persicae

*Halocharis*	Amaranthaceae
*Halocharis hispida*	Brachyunguis salsolacearum

*Halogeton*	Amaranthaceae
*Halogeton* sp.	Aphis craccivora/salsolae group (Pakistan, BMNH colln)

*Haloragis*	Haloragaceae
*Haloragis* sp.	Myzus persicae

*Halothamnus* (including Aellenia)	Amaranthaceae
*Halothamnus hierochunticus*	Brachyunguis harmalae

*Haloxylon*	Amaranthaceae
*Haloxylon ammodendron*	Brachyunguis saxaulica; Ephedraphis haloxylon
*H. aphyllum* = H. ammodendron
*H. persicum*	[Aphis craccivora]; Brachyunguis saxaulica

Key to apterae on Haloxylon:-

–	Cauda tongue-shaped, longer than its basal width, similar in length to SIPH, with c.10 hairs. R IV+V with blunt apex. ANT PT/BASE c.1.0	….. Brachyunguis saxaulica
–	Cauda helmet-shaped, shorter than its basal width, with 5-6 hairs. R IV+V with a thin beak-like process. ANT PT/BASE 1.1-1.5	….. Ephedraphis haloxylon