Asteraceae

HOST LISTS AND KEYS FOR EACH PLANT GENUS

(in alphabetical order)

Obe-Par

Oberna

Obione

Ochetophila

Ochna

Ochradenus

Ochroma

Ochthodium

Ocimum

Ocotea

Octadesmia

Octomeron

Ocymum

Odontioda

Odontites

Odontoglossum

Odontonema

Odontospermum

Oedibasis

Oemleria

Oenanthe

Oenocarpus

Oenothera

Ohwia

Oldenlandia

Oldfeltia

Olea

Olearia

Oligostachyum

Oligotrichum

Omalotheca

Oncidium

Oncoba

Oncosiphon

Onobrychis

Onoclea

Ononis

Onopordum

Onosma

Onosmodium

Onychium

Ophiopogon

Ophiorrhiza

Ophiuros

Ophrys

Oplismenus

Oplopanax

Opopanax

Opulaster

Opuntia

Orchis

Oreocnide

Oreopanax

Origanum

Orixa

Orlaya

Ormenis

Ornithidium

Ornithogalum

Ornithopus

Orobanche

Orostachys

Ortantha

Orthilia

Orthocarpus

Orthostemon

Oryza

Oryzopsis

Osbeckia

Osmanthus

Osmaronia

Osmia

Osmorhiza

Osmunda

Osmundastrum

Osteomeles

Osteospermum

Ostericum

Ostrya

Ostryoderris

Ostryopsis

Othonna

Othonnopsis

Otites

Otochilus

Ottelia

Ourisia

Ourouparia

Oxalis

Oxybaphus

Oxycoccus

Oxydendrum

Oxylobium

Oxylobus

Oxypetalum

Oxypogon

Oxyria

Oxytropis

Ozoroa

Ozothamnus

Pachira

Pachycarpus

Pachylophis

Pachypleurum

Pachystachys

Pachystima

Packera

Padus

Paederia

Paeonia

Palaquium

Palicourea

Palisota

Paliurus

Pallenis

Palura

Panax

Pandanus

Pandiaka

Pandorea

Panicularia

Panicum

Panzeria

Panzerina

Papaver

Paphiopedalum

Pappea

Pappobolus

Parabenzoin

Parageum

Parahebe

Paraixeris

Parasenecio

Parathelypteris

Paratropia

Pardanthopsis

Parentucellia

Parietaria

Parinari

Parkia

Parkinsonia

Parmena

Parmentiera

Parodichloa

Paronychia

Parrotia

Parsonsia

Parthenium

Parthenocissus

ObernaCaryophyllaceae
Oberna behen = Silene vulgaris
O. multifidaMacrosiphum eastopi, stellariae
O. wallichiana Aphidura ornatella; Aphis craccivora;
Brachycolus cucubali

Use key to apterae on Silene.

Obione see AtriplexAmaranthaceae
OchetophilaRhamnaceae
Ochetophila nana Aphis conflicta
O. trinervisAphis conflicta
Ochna Ochnaceae
A single aphid species, Sitobion ochnearum, is recorded from 4 spp. of Ochna; O. afzelii, O. leptoclada, O. pretoriensis, O. pulchra.
OchradenusResedaceae
Ochradenus baccatus Myzus persicae
Ochroma Bombacaceae
Ochroma lagopus Aphis gossypii
OchthodiumBrassicaceae
Ochthodium aegyptiacum Brevicoryne brassicae
OcimumLamiaceae
Ocimum americanum Aphis gossypii
O. basilicumAphis [affinis], craccivora, fabae, gossypii;
Aulacorthum solani; Macrosiphum mesosphaeri;
Myzus ornatus, persicae; Neomyzus circumflexus;
[Ovatus crataegarius]; Sitobion colei
O. canum = O. americanum
O. gratissimumAphis gossypii; Aulacorthum solani;
Macrosiphum mesosphaeri, salviae; Myzus ornatus
O. minimumMyzus ornatus
O. obovatum Aphis gossypii
O. sanctum = O. tenuiflorum
O. tenuiflorumAphis gossypii; Macrosiphum mesosphaeri; Myzus ornatus
O. urticifolium = O. gratissimum
Ocimum sp.Aphis spiraecola; [Sitobion indicum]

Key to apterae on Ocimum:-

1SIPH mainly or wholly dark, with a subapical zone of reticulation (at least 4-5 rows of closed polygonal cells)…..2
SIPH pale or dark, without subapical polygonal reticulation…..go to key to polyphagous aphids
2ANT 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
3Dorsal 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 acutifoliaLizerius ocoteae
O. glomerata (?)Lizerius pustulatus
O. porphyriaLizerius ocoteae
Ocotea sp.Aphis (Toxoptera) aurantii; Lizerius tuberculatus

Key to species:-

1Body 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 DilomilisOrchidaceae
Octomeron see PlatostomaLamiaceae
Ocymum see OcimumLamiaceae
×OdontiodaOrchidaceae
×Odontioda sp. (hybrid) Aphis spiraecola
Odontites (including Orthantha)Orobanchaceae
Odontites luteaBrachycaudus mimeuri, persicae
O. purpureusBrachycaudus helichrysi
O. serotina = O. vulgaris
O. siculaBrachycaudus mimeuri
O. vernaBrachycaudus mimeuri
O. vulgarisAphis frangulae, sibirica; Brachycaudus persicae

Key to apterae on Odontites:-

1Cauda short and rounded, not longer than its basal width…..2
Cauda finger-like, longer than its basal width…..3
2Dorsum 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
3SIPH 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)
OdontoglossumOrchidaceae
Odontoglossum sp. Sitobion luteum

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

OdontonemaAcanthaceae
Odontonema strictum Myzus persicae
Odontospermum see AsteriscusAsteraceae
OedibasisApiaceae
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
OenantheApiaceae
Oenanthe aquatica Anuraphis subterranea; Aulacorthum solani;
Cavariella aegopodii; Pemphigus protospirae
Oe. crocataAphis fabae; Cavariella aegopodii, pastinacae, theobaldi;
Hyadaphis passerinii; Macrosiphum euphorbiae;
Myzus persicae
Oe. javanicaAmphorophora 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. sarmentosaCavariella aegopodii, konoi; Hyadaphis passerinii;
Pemphigus populicaulis
Oe. silaifoliaCavariella aegopodii; Macrosiphum euphorbiae
Oe. stolonifera = Oe.javanica
Oenanthe spp.[Aphis oenanthis Lichtenstein (nomen nudum)];
Cavariella salicis

Key to apterae on Oenanthe:-

1ABD 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
2SIPH 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
3Supracaudal 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
5ANT 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
6R 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
7Supracaudal 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
8SIPH 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
9Cauda 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
10SIPH 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
12SIPH 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
OenotheraOnagraceae
Oenothera affinis Aphis oenotherae
Oe. amoena = Clarkia amoena
Oe. berteroana = Oenothera affinis
Oe. biennisAnoecia [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. casimiriAphis 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. javanicaAphis spiraecola
Oe. lamarckiana Aphis holoenotherae, oenotherae
Oe. megallanicaAphis grossulariae
Oe. missouriensis = Megapterium missouriense
Oe. muricata = Oenothera biennis
Oe. oakesianaAphis holoenotherae, oenotherae
Oe. odorataAphis gossypii, oenotherae, spiraecola;
Rhopalosiphoninus staphyleae
Oe. parvifloraAphis oenotherae
Oe. perangusta × biennis Aphis holoenotherae
Oe. picensisAphis spiraecola
Oe. pilosella = Kneiffia pilosella
Oe. roseaRhopalosiphoninus staphyleae
Oe. rubricauloides Aphis holoenotherae
Oe. sarmentosa[Cavariella aegopodii]
Oe. serrulata = Calylophus serrulata
Oe. spectabilisAphis oenotherae
Oe. strictaAphis 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. versicolorBrachycaudus helichrysi
Oenothera sp.Aphis praeterita, sambuci;
[Protaphis sp. (Utah, USA; A. Jensen, aphidtrek.org)

Key to apterae on Oenothera:-

1ANT 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
2ANT 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
4Dorsal 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
7SIPH 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
8ABD TERG 2-6 mostly with MTu, as well as ABD TERG 1 and 7 …..Aphis grossulariae
ABD TERG 2-6 without MTu…..9
9Tarsi almost completely smooth. Cauda with 16-24 hairs …..Aphis epilobiaria
Tarsi distinctly imbricated. Cauda with 8-16 hairs…..10
10ANT 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
12ANT 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
13SIPH pale except at apices.….Aphis nasturtii
SIPH dark…..14
14SIPH 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
17SIPH 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
OhwiaFabaceae
Ohwia caudata Aphis gossypii
OldenlandiaRubiaceae
Oldenlandia corymbosa Aphis gossypii; Myzus persicae
O. herbaceaAphis gossypii
O. sclerophyllaAphis gossypii
Oldenlandia spp.[Acyrthosiphon pisum]; Aulacorthum solani;
[Lipaphis pseudobrassicae]; Myzus cymbalariae;
Uroleucon compositae

Use key to polyphagous aphids.

OldfeltiaAsteraceae
Oldfeltia polyphlebia see Senecio polyphlebius
Olea OlivesOleaceae
Olea europaeaProciphilus oleae; [Tetraneura agnesii del Guercio 1920]
OleariaAsteraceae
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. passerinoidesMyzus persicae; [Uroleucon sp. (Leonard 1972a)]
O. pimeleoides[Uroleucon sp. (Leonard 1972a)]
O. viscidulaMyzus persicae; [Uroleucon sp. (Leonard 1972a)]

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

OligostachyumPoaceae
Oligostachyum shiuyingianum Ceratovacuna hoffmanni; Chaitoregma tattakana

Use key to aphids on Arundinaria.

OligotrichumPolytrichaceae
Oligotrichum aligerum Myzodium modestum

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

OmalothecaAsteraceae
Omalotheca caucasica = Gnaphalium sylvaticum
OncidiumOrchidaceae
Oncidium altissimum Cerataphis orchidearum; Myzus persicae; Sitobion luteum
O. cebolleta = Trichocentrum cebolleta
O. sphacelatumAphis (Toxoptera) aurantii

Use key to apterae on orchids under Cymbidium.

OncobaSalicaceae
Oncoba spinosaAphis (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
OncosiphonAsteraceae
Oncosiphon piluliferum Aphis craccivora
OnobrychisFabaceae
Onobrychis arenaria ssp. sibirica Aphis craccivora
O. argentea ssp. hispanica = O. conferta ssp. hispanica
O. conferta ssp. hispanica Aphis craccivora
O. cyriAphis craccivora
O. gracilisAcyrthosiphon pisum
O. kacheticaAcyrthosiphon pisum; Aphis craccivora, fabae;
Therioaphis trifolii
O. micranthaAphis craccivora
O. montanaAcyrthosiphon pisum; Aphis craccivora
O. pulchellaAphis craccivora, [ laburni” (= cytisorum?)]
O. sativa = O. viciifolia
O. sibirica = O. arenaria ssp. sibirica
O. squarrosaAcyrthosiphon pisum
O. tanaitica (= O. arenaria) Aphis craccivora
O. transcaucasicaAphis craccivora
O. viciifoliaAcyrthosiphon loti, pisum;
Aphis [craccae], craccivora, fabae, pseudocomosa;
[Brachycaudus persicae]; Therioaphis trifolii
Onobrychis sp.[Smynthurodes betae]

Key to apterae on Onobrychis:-

1Fore 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
3ANT 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
4Longest 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
OnocleaWoodsiaceae
Onoclea sensibilis Amphorophora ampullata, ampullata ssp. laingi;
Aulacorthum solani; Neomyzus circumflexus
O. struthiopteris see Matteuccia

Use key to fern-feeding aphids under Polypodium.

OnonisFabaceae
Ononis alba Therioaphis obscura
O. antiquorum = O. spinosa ssp. antiquorum
O. aragonensisAphis fabae
O. arvensis = O. spinosa ssp. hircina
O. austriaca = O. spinosa ssp. austriaca
O. diffusaTherioaphis ononidis
O. fruticosaAcyrthosiphon loti, ononis; Aphis brunnea
O. hircina = O. spinosa ssp. hircina
O. leiosperma = O. spinosa ssp. leiosperma
O. minutissimaAphis 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. pubescensAphis brunnea
O. pusillaTherioaphis alatina
O. ramosissima = natrix ssp. ramosissima
O. reclinataTherioaphis 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. serrataTherioaphis ononidis
O. spinosaAcyrthosiphon 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. stenophyllaTherioaphis natricis
O. tridentataAphis cytisorum, kaltenbachi, ononidis
O. viscosaAphis brunnea; Therioaphis alatina

Key to apterae on Ononis:-

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

1Fore 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
2ABD 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
3R 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
4All 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
5R IV+V with 14-27 accessory hairs…..Therioaphis natricis
R IV+V with 8-12 accessory hairs…..Therioaphis ononidis
6ABD 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
10ANT 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
11ANT 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
13SIPH 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
14Very 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
15ABD 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
17R 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
OnopordumAsteraceae
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. davisiiAphis craccivora, spiraecola; Brachycaudus cardui
O. heteracanthum Aphis fabae; Myzus persicae
O. illyricumAphis fabae; Brachycaudus cardui, helichrysi;
Uroleucon aeneum, [sonchi]
O. leptolepisBrachycaudus cardui; Protaphis [carthami], terricola
O. nervosumBrachycaudus cardui
O. olgaePemphigus bursarius; Rectinasus buxtoni;
Smynthurodes betae
O. sibthorpianumProtaphis terricola
O. tauricumBrachycaudus cardui

Key to apterae on Onopordum:-

1SIPH 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
3HT II elongate, at least 0.5 × hind tibia. ANT 6-segmented …..Trama troglodytes
HT II of normal length. ANT 5-segmented…..4
4ANT 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
5Cauda 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
6ANT 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
7ANT 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
8Longest 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)
OnosmaBoraginaceae
Onosma stellulata Brachycaudus cardui
OnosmodiumBoraginaceae
Onosmodium bejariense
var. occidentale Brachycaudus helichrysi
OnychiumAdiantaceae
Onychium japonicum Idiopterus nephrelepidis
OphiopogonAsparagaceae
Ophiopogon japonicus Hydronaphis sp. (Japan – Moritsu 1983)
OphiorrhizaRubiaceae
Ophiorrhiza sp.Aphis spiraecola
OphiurosPoaceae
Ophiuros exaltatus [Iowana zhangi]; Rhopalosiphum maidis
OphrysOrchidaceae
Ophrys apiferaAphis fabae
O. fuscaDysaphis neostroyani
O. sphegodes (incl. arenifera)Aphis fabae
O. ×todaroanaAphis fabae

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

OplismenusPoaceae
Oplismenus burmannii Hysteroneura setariae; Tetraneura akinire
O. compositusAsiphonella dactyloni; [Ceratovacuna nekoashi];
[Hyalomyzus raoi]; Hysteroneura setariae;
Micromyzodium spinulosum; Pentalonia gavarri;
Pseudoregma panicola; Sitobion miscanthi
O. hirtellusPseudoregma 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.

OplopanaxAraliaceae
Oplopanax horridum Aphis asclepiadis;
Macrosiphum sp. nr euphorbiae (see aphidtrek.org)
Use key to polyphagous aphids.
OpopanaxApiaceae
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.)

1Cauda 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
2R 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
3MTu 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
OpulasterRosaceae
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.

OpuntiaCactaceae
Opuntia aurantiaca Protaphis middletonii
O. dilleniiAphis gossypii
O. ficus-indicaAphis craccivora, fabae; Myzus persicae;
Protaphis middletonii
O. inermis = O. stricta
O. strictaPentalonia 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
OrchisOrchidaceae
Orchis anthropophora Aphis fabae
O. coriophora = Anacamptis coriophora
O. purpureaAphis 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]
OreopanaxAraliaceae
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 hortensis) Myzus ornatus; Neomyzus circumflexus
O. ×paniculatumAphis origani
O. syriacumEucarazzia elegans
O. tyttanthum = O. vulgare ssp. gracile
O. virens = O. vulgare ssp. virens
O. vulgare (incl. sspp. gracile, virens, viridulum) Aphis fabae, gossypii, nasturtii, origani;
Aulacorthum solani; Kaltenbachiella pallida;
Myzus ornatus, persicae; [Ovatomyzus chamaedrys];
Ovatus crataegarius

Key to apterae on Origanum:-

1ANT 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
2SIPH 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
3Head 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
4SIPH pale with dark apices…..Aphis nasturtii
SIPH wholly dark…..5
5Cauda 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
7Dorsal abdomen without any dark markings…..8
Dorsal abdomen with dark markings…..10
8SIPH 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
9Inner 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
OrixaRutaceae
Orixa japonica?Aulacorthum ?solani (as Myzus kusaki Shinji);
Pseudomegoura magnoliae

Use key to polyphagous aphids.

OrlayaApiaceae
Orlaya grandiflora Aphis solanella; Cavariella theobaldi; Dysaphis crataegi;
Hyadaphis passerinii

Key to apterae on Orlaya:-

1SIPH 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
2ABD TERG 8 with a backwardly-pointed process bearing 2 hairs …..Cavariella theobaldi
No process on ABD TERG 8…..3
3Cauda 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 ChamaemelumAsteraceae
OrnithidiumOrchidaceae
Ornithidium adendrobium Cerataphis orchidearum
OrnithogalumAsparagaceae
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
OrnithopusFabaceae
Ornithopus compressus Aphis craccivora
O. isthmocarpus = O. sativus ssp. isthmocarpus
O. perpusillusAcyrthosiphon 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. crenataSmynthurodes betae
O. hederaeMacrosiphum euphorbiae
O. lutea[Aphis orobanches]
O. mutelii[Aphis orobanches]
O. ramosa[Aphis orobanches]; [Dysaphis candicans];
[Brachycaudus cardui (? – as Aphis phelipaeae Passerini)];
Smynthurodes betae
O. variegataSmynthurodes 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.]

1ANT 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
2HT II greatly elongated, more than 0.5 × hind tibia…..Trama orobanches
HT II of normal length…..3
3Thoracic 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
OrostachysCrassulaceae
Orostachys spinosa Aphis sedi
Ortantha see OdontitesOrobanchaceae
Orthilia (including Ramischia)Ericaceae
Orthilia secundaAulacorthum pirolacearum
Orthocarpus Orobanchaceae
Orthocarpus luteus Nasonovia alpina
O. purpurascensMacrosiphum 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 = AccaMyrtaceae
OryzaPoaceae
Oryza sativaAnoecia 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 akinire, basui, 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. hymenoidesForda marginata
O. lateralisSitobion himalayensis
O. miliaceaMelanaphis sacchari; Myzus persicae; Sitobion avenae

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

OsbeckiaMelastomataceae
Osbeckia capitataAphis gossypii, nasturtii; [Capitophorus carduinus];
Myzus ornatus, persicae
O. chinensisAphis nasturtii; Brachycaudus helichrysi;
[Rhopalosiphum rufiabdominale]
O. crinataAphis aurantii, gossypii; [Capitophorus sp.];
Myzus persicae

Use key to polyphagous aphids.

Osmanthus Oleaceae
Osmanthus aquifolius Prociphilus osmanthae
O. asiaticus[Shivaphis hangzhouensis]
O. aurantiacusProciphilus osmanthae
O. aurantiacus var. thunbergii Pseudomegoura magnoliae
O. × burkwoodiiProciphilus osmanthae
O. heterophyllusProciphilus 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 OemleriaRosaceae
Osmia see EupatoriumAsteraceae
OsmorhizaApiaceae
Osmorhiza aristata (incl. var. longistylis) Aphis fabae; Cavariella aegopodii, theobaldi;
Semiaphis heraclei; [Uroleucon parvotuberculatum]
O. chilensisMacrosiphum euphorbiae; Myzus ascalonicus;
[Rhopalosiphoninus staphyleae]
O. claytoni = O. aristata
O. longistylis see aristata
Osmorhiza sp.Aphis asclepiadis

Use key to apterae on Apium.

OsmundaOsmundaceae
O. cinnamomeaAmphorophora ampullata ssp. laingi
O. japonicaAmphorophora ampullata; Aulacorthum solani;
Taiwanomyzus babai, filicis
O. regalisAulacorthum solani; Macrosiphum walkeri;
Micromyzella pterisoides; Neomyzus circumflexus
Osmunda sp.Macrosiphum euphorbiae

Use key to apterae on ferns under Polypodium.

OsmundastrumOsmundaceae
Osmundastrum asiaticum Micromyzus nikkoensis, osmundae
O. claytonianumMicromyzus osmundae

Use key to apterae on ferns under Polypodium.

OsteomelesRosaceae
Osteomeles schwerinae Myzus persicae
O. subrotundaAphis gossypii

Use key to polyphagous aphids.

OsteospermumAsteraceae
Osteospermum ecklonis Macrosiphum euphorbiae; Uroleucon compositae
O. moniliferum = Chrysanthemoides monilifera
O. spinescensAphis craccivora
O. vaillantii = Tripteris vaillantii

Use key to polyphagous aphids.

OstericumApiaceae
Ostericum melanotilingia = Angelica decursiva
Ostrya Hop-hornbeams Corylaceae
Ostrya carpinifoliaPterocallis ostryae
O. japonicaMesocallis pteleae
O. virginianaMacrosiphum (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
2ANT 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 = AganopeFabaceae
Ostryopsis Betulaceae
Ostryopsis davidiana Corylobium avellanae
Othonna (including Hertia, Othonnopsis) Asteraceae
Othonna cheirifolia Macrosiphum euphorbiae
Othonnopsis see OthonnaAsteraceae
Otites see SileneCaryophyllaceae
OtochilusOrchidaceae
Otochilus porrectus Sitobion indicum, luteum

Use key to apterae on orchids under Cymbidium.

OtteliaHydrocharitaceae
Ottelia alismoidisRhopalosiphum nymphaeae
OurisiaPlantaginaceae
Ourisia microphylla Neomyzus circumflexus
Ourouparia see UncariaRubiaceae
OxalisOxalidaceae
Oxalis acetosellaAphis nasturtii; Aulacorthum solani;
[Hyperomyzus lactucae]; [Jacksonia papillata];
[Metopolophium frisicum]; Myzus ascalonicus, persicae;
Rhopalosiphoninus staphyleae
O. articulataMyzus ornatus; Neomyzus circumflexus
O. cernua = O. pes-caprae
O. corniculataAphis 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. deppeiAphis fabae; Neomyzus circumflexus
O. enneaphyllaMyzus ascalonicus
O. latifoliaAphis gossypii; Macrosiphum euphorbiae;
[Micromyzodium filicium]; Myzus persicae
O. laxaMyzus cymbalariae
O. martiana = O. debilis var. corymbosa
O. oreganaMacrosiphum sp. (Oregon, USA; BMNH collection, leg. D. Hille Ris Lambers);
Rhopalosiphoninus staphyleae
O. pes-capraeAphis aurantii, craccivora, fabae, gossypii, solanella,
spiraecola;
Aulacorthum solani;
Macrosiphum euphorbiae; Myzus persicae;
Rhopalosiphoninus staphyleae
O. purpurea Myzus persicae
O. roseaMyzus persicae; Neomyzus circumflexus
O. semilobaAphis gossypii; Myzus persicae
O. strictaAbstrusomyzus reticulatus; Protaphis middletonii
O. trilliifoliaMyzus ornatus, persicae
O. variabilis = O. purpurea
O. versicolorAphis fabae
O. violacea = O. debilis var. corymbosa
Oxalis sp.[Rhopalosiphum maidis]

Key to apterae on Oxalis:-

1BL 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
2Dorsum 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
3SIPH 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
4ABD 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
OxybaphusNyctaginaceae
Oxybaphus angustifolius = Mirabilis nyctaginea var. angustifolia
O. nyctagineusAphis asclepiadis, fabae; Macrosiphum euphorbiae

Use key to polyphagous aphids.

Oxycoccus see VacciniumEricaceae
OxydendrumEricaceae
Oxydendrum arboreum Aulacorthum solani
OxylobiumFabaceae
Oxylobium callistachys Aphis gossypii
O. lineareAphis gossypii
OxylobusAsteraceae
Oxylobus sp.Aphis solitaria
OxypetalumApocynaceae
Oxypetalum sp.Aphis gossypii, nerii

Use key to polyphagous aphids.

Oxypogon see LathyrusFabaceae
OxyriaPolygonaceae
Oxyria digynaAphis fabae; Indomasonaphis rumicis;
Nasonovia ribisnigri

Key to apterae on Oxyria:-

1BL 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
2ANT 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
OxytropisFabaceae
Oxytropis campestris Acyrthosiphon churchillense; Aphis astragali;
Nearctaphis vera
O. deflexa (incl. var. sericea) Acyrthosiphon churchillense
O. glabraMegoura viciae (ssp. turanica Nevsky 1929)
O. hudsonica = viscida var. hudsonica
O. lambertiiAphis ?craccivora (as medicaginis)
O. microphyllaAphis craccivora
O. myriophyllaAphis craccivora
O. oxyphyllaAphis craccae, oxytropis
O. pilosaAphis craccivora; Acyrthosiphon pisum
O. sordidaAphis 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
2ANT 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
4SIPH 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
5ANT 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
6Dorsal 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
7Hairs 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
8R 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
9Dorsal 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
OzoroaAnacardiaceae
Ozoroa insignisAphis gossypii
O. paniculosaAphis gossypii
OzothamnusAsteraceae
Ozothamnus diosmifolius Myzus persicae
O. leptophyllus[?Casimira sp. (New Zealand; see Teulon et al. 2013)]

P

PachiraMalvaceae
Pachira spp.Aphis craccivora, gossypii; Protaphis middletonii

Use key to polyphagous aphids.

PachylophisOnagraceae
Pachylophis cespitosa Aphis oenotherae
PachycarpusApocynaceae
Pachycarpus lineolatus Aphis nerii
P. schinzianusAphis nerii
Pachypleurum Apiaceae
Pachypleurum alpinum Cavariella nipponica
PachystachysAcanthaceae
Pachystachys lutea Aphis aurantii, gossypii; Myzus persicae

Use key to polyphagous aphids.

Pachystima Celastraceae
Pachystima myrsinites Wahlgreniella sp. (western USA; A. Jensen, aphidtrek.org)
Packera
see Senecio
Asteraceae
P. anonyma see Senecio anonymus
P. aurea see Senecio aureus
P. cana see Senecio canus
P. glabella see Senecio glabellus
P. paupercula see Senecio pauperculus
P. plattensis see Senecio plattensis
P. tomentosa see Senecio tomentosus
Padus see PrunusRosaceae
Padus avium see Prunus padus
PaederiaRubiaceae
Paederia chinensis = P. foetida
P. foetida (incl. chinensis, mairei, maritima, scandens, tomentosa) Aphis gossypii, spiraecola;
Aulacorthum esakii, [myriopteroni];
Pseudomegoura nipponica
P. scandens = P. foetida
P. tomentosa = P. foetida

Key to apterae on Paederia:-

1 Head dark and densely spiculose at least on ventral surface, with ANT tubercles well-developed and steep-sided…..2
Without that combination of characters …..go to key to polyphagous aphids
2 Tergum wholly dark sclerotic. SIPH cylindrical/tapering on distal half, mainly pale/dusky, sometimes darker at base and apex. Longest hairs on ANT III more than 0.5 × BD III…..Aulacorthum esakii
Tergum not wholly sclerotic, often with variably developed dark sclerites on ABD TERG 1-6. SIPH somewhat swollen on distal half, and wholly dark. Longest hairs on ANT III less than 0.5 × BD III…..Pseudomegoura nipponica
PaeoniaPaeoniaceae
Paeonia lactiflora Myzus persicae
P. ×suffruticosaAphis gossypii, spiraecola

Use key to polyphagous aphids.

Palaquium Sapotaceae
Palaquium sp.Parathoracaphis setigera
PalicoureaRubiaceae
Palicourea alpina Aphis (Toxoptera) aurantii; Aulacorthum solani

Use key to polyphagous aphids.

PalisotaCommelinaceae
Palisota ambigua Pentalonia nigronervosa
P. hirsutaPentalonia nigronervosa
P. thyrsiflora = P. ambigua
PaliurusRhamnaceae
Paliurus spina-cristi Aphis frangulae, gossypii, [paliuri Lichtenstein (nomen nudum)], nasturtii, Aphis sp. (Toros et al., 2002: 31)
Paliurus sp.[Aphis exploratus (= nasturtii?)]

Use key to aphids on Rhamnus.

PallenisAsteraceae
Pallenis maritima Brachycaudus helichrysi; Protaphis terricola
P. spinosa = Asteriscus spinosus

Use key to apterae on Asteriscus.

Palura see SymplocosSymplocaceae
Palura chinensis = Symplocos paniculata
Panax Araliaceae
Panax spp.Aphis aurantii, craccivora, odinae; Myzus persicae;
[Rhopalosiphoninus latysiphon]

Use key to polyphagous aphids.

Pandanus Pandanaceae
Pandanus tectorius Astegopteryx pandani
PandiakaAmaranthaceae
Pandiaka involucrata Aphis gossypii
PandoreaBignoniaceae
Pandorea pandorana Myzus ornatus
P. ricasolianaAphis gossypii

Use key to polyphagous aphids.

Panicularia see GlyceriaPoaceae
PanicumPoaceae
Panicum adenophorum Sitobion neusi, [Sitobion sp. (Millar 1994)]
P. afzeliiAphis gossypii
P. antidotaleAnoecia corni, furcata;
[Colopha ulmicola? (as Rhizobius spicatus)];
Hysteroneura setariae; Rhopalosiphum maidis
P. barbinode = Brachiaria mutica
P. boliviense = Polygonum polygonatum
P. capillareAnoecia corni, cornicola; Geoica setulosa;
Hysteroneura setariae; Protaphis middletonii;
Rhopalosiphum maidis
P. clandestinumHysteroneura setariae
P. colonum = Echinochloa colonum
P. coloratumRhopalosiphum maidis; [Sitobion sp. (Millar 1994)]
P. conjugatum = Paspalum conjugatum
P. crus-corvi = Echinochloa crus-galli
P. crusgalli = Echinochloa crus-galli
P. decompositumHysteroneura setariae
P. deustumRhopalosiphum maidis
P. dichotomiflorum Anoecia corni; Rhopalosiphum maidis
P. fasciculatum = Brachiaria fasciculata
P. fimbriatum = Digitaria ciliaris
P. flavidum = Paspalidium flavidum
P. germanicum = Setaria italica
P. glabrum = Digitaria ischaemum
P. glanduliferumSitobion neusi
P. glutinosumHysteroneura setariae; Rhopalosiphum padi
P. hemitomumRhopalosiphum maidis
P. hirticauleTetraneura akinire
P. infestumRhopalosiphum maidis
P. javanicum = Urochloa panicoides
P. laevifolium = Panicum schinzii
P. laxumHysteroneura setariae
P. maximumHysteroneura setariae; Rhopalosiphum maidis;
Sipha flava;
Sitobion africanum, lambersi, [Sitobion sp. (Millar 1994)];
Tetraneura akinire
P. miliaceumAnoecia corni, vagans; [Diuraphis muehlei];
Forda marginata; Geoica utricularia;
Hysteroneura setariae; Melanaphis pyraria, sacchari;
Myzus persicae; Neomyzus circumflexus;
Paracletus cimiciformis, cimiciformis ssp. panicumi;
[Prociphilus bumeliae];
Rhopalosiphum maidis, nymphaeae, padi;
Schizaphis graminum; Sipha maydis; Sitobion avenae;
Tetraneura akinire, caerulescens, javensis, ulmi, yezoensis
P. montanum = Panicum notatum
P. muticum = Brachiaria mutica
P. notatum Hysteroneura setariae
P. novemnerveTetraneura akinire
P. paludosumBrachysiphoniella montana
P. patens = Cyrtococcum patens
P. pilosumTetraneura akinire
P. plicatum = Setaria palmifolia
P. polycaulon = Panicum strigosum
P. polygonatum Aphis gossypii; Hysteroneura setariae
P. proliferum = P. antidotale
P. prostratum = Brachiaria reptans
P. psilopodium = P. sumatrense
P. purpurascens = Brachiaria mutica
P. repensBrachysiphoniella montana; Hysteroneura setariae;
Schizaphis hypersiphonata; Sitobion avenae, fragariae
P. reptans = Brachiaria reptans
P. sanguinale = Digitaria sanguinalis
P. schinzii Sitobion ?africanum
P. scopariumHysteroneura setariae; Tetraneura akinire
P. sellowiiTetraneura akinire
P. strigosum Hysteroneura setariae; Tetraneura akinire
P. sumatrenseHysteroneura setariae
P. teneriffae = Tricholaena teneriffae
P. trichoidesPseudoregma panicola
P. trigonum = Cyrtococcum trigonum
P. turgidumForda
P. virgatumAnoecia cornicola; Rhopalosiphum maidis
Panicum spp.Aphis craccivora, Aphis (Toxoptera) aurantii;
Anoecia fulviabdominalis;
Ceratovacuna graminum, panici; Colopha ulmicola;
Diuraphis noxia; Geoica utricularia;
[Kaltenbachiella nirecola]; Laingia psammae;
Prociphilus erigeronensis;
Sitobion miscanthi; Tetraneura ulmi

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

Panzeria see PanzerinaLamiaceae
Panzerina (including Panzeria)Lamiaceae
Panzerina lanataAphis panzeriae
PapaverPapaveraceae
Papaver alpinumAulacorthum solani; Rhopalosiphoninus staphyleae
P. arenariumAphis fabae
P. argemoneAphis solanella; Myzus ascalonicus
P. canescensAcyrthosiphon ilka
P. croceum = P. nudicaule
P. decaisneiAcyrthosiphon ilka
P. dubiumAphis fabae; Brachycaudus helichrysi; Myzus persicae
P. glaucum[Lipaphis pseudobrassicae]; Myzus persicae
P. hybridumAphis craccivora, fabae, solanella
P. laestadianumAphisfabae
P. macrostomumAphis fabae
P. nudicauleAcyrthosiphon ilka, [ilka ssp. montanum];
Aphis craccivora; Macrosiphum euphorbiae;
Myzus persicae; Neomyzus circumflexus
P. orientaleAphis fabae; Aulacorthum solani; Brachycaudus helichrysi;
Macrosiphum euphorbiae, [gei]; Neomyzus circumflexus
P. pavoninumAcyrthosiphon ilka; Aphis craccivora, fabae
P. pilosumAphis fabae; Brachycaudus cardui
P. pinnatifidumAphis fabae
P. rhoeasAphis fabae, gossypii, solanella; Aulacorthum solani;
Macrosiphum euphorbiae; Myzus persicae
P. somniferumAcyrthosiphon ilka, [papaverinum], papaverisuctum,
[titovi Mordvilko (nomen nudum)];
Aphis fabae, gossypii, [idaei], nasturtii, solanella,
[triglochinis];
Brachycaudus helichrysi; [Lipaphis pseudobrassicae];
Macrosiphum euphorbiae, [stellariae];
Myzus ascalonicus, persicae; Rectinasus buxtoni
Rhopalosiphum padi; Smynthurodes betae
P. strrigosum = P. rhoeas
P. subpiriformeMacrosiphum euphorbiae
P. tianschanicum = P. canescens
Papaver spp.[Macrosiphum stellariae]; Rhopalosiphum rufiabdominale

Key to apterae on Papaver:-

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, long, tapering or cylindrical on distal half, and without subapical polygonal reticulation. ANT tubercles with smooth, broadly divergent inner faces, and median frontal tubercle evident…..4
SIPH either not pale, long and tapering, or with subapical polygonal reticulation, and other characters not in above combination…..5
4 SIPH 1.67-2.2 × cauda. R IV+V 0.75-0.95 × HT II…..Acyrthosiphon ilka
SIPH 1.4-1.5 × cauda. R IV+V 0.69-0.77 × HT II …..Acyrthosiphon papaverisuctum
5 Cauda helmet-shaped, somewhat constricted at base, not longer than its basal width in dorsal view. SIPH with a subapical annular incision. Spiracular apertures large and rounded…..6
Cauda not helmet-shaped. SIPH without a subapical annular incision. Spiracular apertures small, usually reniform…..go to key to polyphagous aphids
(but note that specimens running to Macrosiphum euphorbiae could be M. stellariae)
6 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
PaphiopedilumOrchidaceae
Paphiopedilum insigne Neomyzus circumflexus; Sitobion indicum/luteum group
P. venustumAulacorthum solani
Paphiopedilum spp. Cerataphis orchidearum; [Pentalonia nigronervosa]

Use key to aphids on orchids under Cymbidium.

Pappea Sapindaceae
Pappea capensisAphis aurantii, citricidus, gossypii

Use key to polyphagous aphids.

PappobolusAsteraceae
Pappobolus microphyllus Uroleucon helianthicola, pseudambrosiae

Use key to apterae on Helianthus.

Parabenzoin see LinderaLauraceae
Parageum see GeumRosaceae
P. montanum see Geum montanum
ParahebePlantaginaceae
Parahebe catarractae Myzus ornatus
ParaixerisAsteraceae
Paraixeris denticulata Aphis gossypii (? – on roots with eggs; Chu 1949);
Hyperomyzus carduellinus; Uroleucon formosanum

Use key to apterae on Ixeris.

ParasenecioAsteraceae
Parasenecio auriculatus Aphis fabae; Uroleucon gobonis
P. delphiniifoliaBrachycaudus helichrysi
P. hastatus (incl. ssp. orientalis) Aphis fabae, gossypii, [grossmannae], jacobaeae, spiraecola;
Aulacorthum solani; Brachycaudus helichrysi;
Uroleucon fuchuense
Parasenecio sp.Aleurodaphis mikaniae
Key to apterae on Parasenecio :-
1Body elongate oval, sclerotic dorsally, with a crenulate margin due to a continuous fringe of wax glands. SIPH as pores with raised rims. Cauda knobbed, anal plate bilobed…..Aleurodaphis mikaniae
Body oval or spindle-shaped, without a marginal fringe of wax glands. SIPH tubular. Cauda tongue- or finger-shaped, anal plate entire…..2
2 SIPH dark with polygonal reticulation on distal 0.23-0.33 of length. Cauda pale. Hind tibia with a ventral row of short peg-like hairs. Dorsal abdominal hairs long and fine-pointed (longest more than 90 μm) ..…Uroleucon fuchuense
Without that combination of characters…..3
3 Abdomen with large marginal tubercles (MTu) placed on dark marginal sclerites on ABD TERG 1-4(-6) and 7. Antennae, legs, SIPH and cauda all almost entirely dark …..Aphis jacobaeae
MTu absent, small or only consistently present on ABD TERG 1 and 7. Appendages variously pigmented…..go to key to polyphagous aphids
(but note that specimens running to Uroleucon compositae may be U. gobonis).
ParathelypterisThelypteridaceae
Parathelypteris glanduligera Macromyzus maculata; Micromyzodium polypodii
P. nipponicaMacromyzus maculata
Paratropia see ScheffleraAraliaceae
Pardanthopsis see IrisIridaceae
Pardanthopsis dichotoma = Iris dichotoma
ParentucelliaOrobanchaceae
Parentucellia latifolia Brachycaudus mimeuri (?), persicae; [Myzus persicae]
P. viscosaBrachycaudus helichrysi, persicae

Key to apterae on Parentucellia:-

(All three species have a short, helmet-shaped cauda, somewhat constricted at base.)

Dorsal abdomen usually with an extensive solid black shield. Femora dark except basally. SIPH dark, 2.2-3.4 × cauda …..Brachycaudus persicae (or mimeuri? – see text)
Dorsal abdomen without a black shield. Femora mainly pale. SIPH pale, 0.8-2.0 × cauda……Brachycaudus helichrysi
ParietariaUrticaceae
Parietaria arborea = Gesnouinia arborea
P. debilisMyzus fataunae
P. diffusa = P. judaica
P. floridanaAphis gossypii
P. judaicaAphis craccivora, fabae, gossypii, parietariae
P. lusitanicaAphis parietariae
P. micrantha = P. debilis
P. officinalis Aphis gossypii, parietariae
P. punctataAphis parietariae
P. ramiflora = P. judaica
Parietaria spp. Myzus persicae

Key to apterae on Parietaria:-

1ANT tubercles well developed, with inner faces parallel or convergent and strongly nodulose or spiculose. SIPH pale. ABD TERG 1 and 7 without marginal tubercles (MTu)…..2
ANT tubercles weakly developed, cuticle of head not nodulose or spiculose. SIPH dark. ABD TERG 1 and 7 with MTu…..3
2 ANT 5-segmented, with PT/BASE less than 2.5. ABD TERG 7 extended posteriorly, cowl-like…..Myzus fataunae
ANT 6-segmented, with PT/BASE more than 2.8. ABD TERG 7 not extended posteriorly…..Myzus persicae
3 Cauda with 11-24 hairs. Longest hairs on ANT III 0.8-2.2 × BD III …..Aphis fabae
Cauda with 4-10 hairs. Longest hairs on ANT III 0.3-0.8 × BD III…..4
4 Dorsal abdomen with an extensive black sclerotic shield …..Aphis craccivora
Dorsal abdomen without dark markings…..5
5 SIPH 1.0-1.5 × cauda, which bears 6-10 hairs. R IV+V 1.36-1.63 × HT II…..Aphis parietariae
SIPH 1.3-2.5 × cauda, which bears 4-8 hairs. R IV+V 1.1-1.4 (-1.5) × HT II…..Aphis gossypii
ParinariChrysobalanaceae
Parinari curatellifolia Aphis gossypii
ParkiaFabaceae
Parkia roxburghii = P. timoriana
P. timorianaAphis odinae
ParkinsoniaFabaceae
Parkinsonia aculeata Aphis craccivora
Parmena see RubusRosaceae
Parmena spectabilis see Rubus spectabilis
ParmentieraBignoniaceae
Parmentiera aculeata Aphis (Toxoptera) aurantii
P. edulis = P. aculeata
Parodichloa see PoaPoaceae
ParonychiaCaryophyllaceae
Paronychia argentea Aphis craccivora
ParrotiaHamamelidaceae
Parrotia persicaAphis gossypii
ParsonsiaApocynaceae
Parsonsia heterophylla Paradoxaphis plagianthi
PartheniumAsteraceae
Parthenium argentatum Rhopalosiphum rufiabdominale;
Uroleucon ambrosiae ssp. lizerianum
P. bipinnatifidumUroleucon ambrosiae
P. hysterophorusAcyrthosiphon bidenticola;
Aphis coreopsidis, gossypii, spiraecola;
Brachycaudus helichrysi;
Geopemphigus sp. (Mexico, BMNH collection);
Uroleucon ambrosiae, ambrosiae ssp. lizerianum,
pseudambrosiae, tucumani
P. quinquefolia (?) Aulacorthum solani; Rhopalosiphoninus staphyleae

Key to apterae on Parthenium:-

1ANT PT/BASE less than 0.5. ANT V and VI with spinulose imbrication/reticulation. Eyes of 3 facets. SIPH absent. Paired spinal and marginal wax glands present…..Geopemphigus sp.
ANT PT/BASE more than 1.5. ANT V and VI not spinulose. Eyes multifaceted. SIPH present. No discrete wax glands…..2
2 ANT tubercles weakly developed, not extending forward beyond middle of front of head in dorsal view. ABD TERG 1 and 7 with or without marginal tubercles (MTu) ..…3
ANT tubercles moderately to well developed. ABD TERG 1 and 7 without MTu ..….5
3 Cauda helmet-shaped, not longer than its basal width in dorsal view, with a basal constriction. SIPH pale, smooth, with a subapical annular incision. Spiracular apertures large and rounded. ABD TERG 1 and 7 without MTu…..Brachycaudus helichrysi
Cauda tongue- or finger-shaped, longer than its basal width, without a basal constriction. SIPH dark, without a subapical annular incision. Spiracular apertures small and reniform. ABD TERG 1 and 7 with MTu…..4
4 SIPH 0.24-0.40 × BL, about twice as long as the much paler cauda. Head, ANT I, II and basal part of III very pale, contrasting with dark rest of ANT ..….Aphis coreopsidis
SIPH only up to 0.2 × BL. Cauda pale or dark. Head and antennal segments differently pigmented …..go to key to polyphagous aphids, starting at couplet 22
5 ANT tubercles with smooth, divergent inner faces. SIPH dark except for basal 0.2-0.3 of length, tapering/cylindrical on distal half, with subapical polygonal reticulation extending for much less than 0.1 of length…..Acyrthosiphon bidenticola
Without that combination of characters; if SIPH are mainly dark then they are either swollen distally or have polygonal reticulation on much more than 0.1 of length…..6
6 SIPH wholly dark with polygonal reticulation on distal 0.25-0.4 of length. At least some of dorsal hairs arising from small scleroites…..7
Without that combination of characters …..go to key to polyphagous aphids, starting at couplet 4
7 SIPH usually at least 1.6 × cauda, which bears 7-12 hairs …..Uroleucon tucumani
SIPH less than 1.5 × cauda, which bears 16-28 hairs …..8
8 HT II rather long and thin, 6 or more × longer than its maximum thickness, 0.9-1.1 × R IV+V…..Uroleucon pseudambrosiae
HT II less than 5 × its maximum thickness and 0.70-0.85 × R IV+V…..Uroleucon ambrosiae
ParthenocissusVitaceae
Parthenocissus inserta Aphis folsomii
P. quinquefoliaAphis fabae, folsomii, illinoisensis, spiraecola;
[Hysteroneura setariae]
P. semicordataGreenidea parthenocissi;
Neothelaxes parthenocissi, viticola;
Sinomegoura citricola
P. tricuspidataAphis folsomii; Myzus ornatus; Neomyzus parthenocissi;
[Sitobion akebiae]
P. vitacea = P. inserta

Key to apterae on Parthenocissus (except couplet 2, where only data for alatae are available):-

1 ANT 5-segmented, with ANT PT/BASE less than 1. SIPH as pores. Cauda with a midway constriction delimiting the distal part as a knob…..2
ANT 6-segmented, with ANT PT/BASE more than 1.5. SIPH tubular. Cauda not knobbed…..3
2 (Al.) ANT III with oval rhinaria arranged in a row. HT II tapering, with longest ventral hairs c.1.5 × maximum diameter of segment. ABD TERG 1-7 each with one pair of spinal hairs. ABD TERG 8 with 4 (-5) hairs…..Neothelaxes viticola*
(Al.) ANT III with oval to annular rhinaria scattered over whole surface. HT II parallel-sided, with longest ventral hairs c.4 × maximum diameter of segment. ABD TERG 1-7 each with 3-6 spinal hairs, and ABD TERG 8 with 6 or more hairs…..Neothelaxes parthenocissi*
3 SIPH 0.48-0.67 × BL and bearing numerous very long hairs. Longest hairs on ANT III more than 200 μm long, 5.5-7.6 × BD III…..Greenidea parthenocissi
SIPH less than 0.3 × BL, without hairs. Longest hairs on ANT III less than 100 μm long, less than 3.5 × BD III…..4
4 ANT tubercles well developed. ABD TERG 1 and 7 without marginal tubercles (MTu)…..5
ANT tubercles weakly developed. ABD TERG 1 and 7 always with MTu …..6
5 Dorsal abdomen with a large dark central sclerite on ABD TERG 2-4, large dark post-siphuncular sclerites present. ABD TERG 7 and 8 also heavily sclerotised, and with coarse, spinulose imbrication…..Neomyzus parthenocissi
Dorsal abdomen membranous or with different sclerotisation…..go to key to polyphagous aphids, starting at couplet 5
6 R IV+V with 8-10 accessory hairs. Cauda short and broad, about as long as its basal width, with more than 20 hairs…..Aphis folsomii
R IV+V with 2 accesory hairs. Cauda much longer than its basal width, with 7-19 (-24) hairs…..7
7Hind tibiae wholly black. Longest hairs on ANT III 0.33-0.5 × BD III…..Aphis illinoisensis
Hind tibiae mainly pale, with black apices. Longest hairs on ANT III 0.8-3.4 × BD III…..Aphis fabae