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

*Paspalum*	Poaceae
*Paspalum alainii* = P. caespitosum
*P. arundinaceum*	Hysteroneura setariae; Tetraneura akinire
*P. auriculatum* = P. scrobiculatum
*P. blodgettii*	Tetraneura akinire
*P. boscianum* = P. scrobiculatum
*P. caespitosum*	Tetraneura akinire
*P. commutatum* = P. scrobiculatum
*P. conjugatum*	Geoica lucifuga; Hysteroneura setariae; Ceratovacuna panici; Rhopalosiphum maidis, padi, rufiabdominale; Schizaphis hypersiphonata (? – as graminum); Sipha flava; Sitobion africanum, avenae, lambersi, miscanthi; Tetraneura akinire, basui
*P. digitatum* = Digitaria nuda
*P. dilatatum*	Hysteroneura setariae; Rhopalosiphum maidis, padi; Schizaphis graminum, hypersiphonata (? – as graminum); Sipha flava; Sitobion avenae, fragariae, graminis, miscanthi, [Sitobion sp. (Millar 1994)]; Tetraneura akinire, yezoensis
*P. distichum*	Hysteroneura setariae; Melanaphis sacchari; Rhopalosiphum maidis, padi; Sipha glyceriae; Sitobion avenae
*P. fasciculatum*	Tetraneura akinire
*P. fimbriatum*	Hysteroneura setariae; Macrosiphum euphorbiae; Rhopalosiphum maidis; Tetraneura akinire
*P. laxum*	Hysteroneura setariae
*P. longifolium*	Hysteroneura setariae
*P. melanospermum*	Sipha flava
*P. notatum*	Hysteroneura setariae
*P. orbiculare* = P. scrobiculatum
*P. paniculatum*	Hysteroneura setariae; Sipha flava
*P. paspaloides* = P. distichum
*P. scrobiculatum*	Aphis gossypii; Geoica lucifuga; Hysteroneura setariae; Rhopalosiphum maidis; Sitobion graminis, indicum; Tetraneura akinire, basui
*P. secans* = P. arundinaceum
*P. thunbergii*	Sitobion akebiae
*P. urvillei*	Hysteroneura setariae
*P. vaginatum*	Rhopalosiphum padi; Sitobion avenae
*P. virgatum*	Rhopalosiphum maidis
Paspalum sp.	Forda marginata; Myzus obtusirostris

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

*Passiflora*	Passifloraceae
*Passiflora caerulea*	Macrosiphum euphorbiae
*P. edulis*	Aphis aurantii, gossypii; Aulacorthum solani; Brachycaudus helichrysi; Macrosiphum euphorbiae; Myzus persicae
*P. foetida*	Aphis (Toxoptera) citricidus; Brachycaudus helichrysi; Myzus ornatus
*P. ligularis*	Macrosiphum euphorbiae
*Passiflora* spp.	Aphis spiraecola; [Myzakkaia verbasci]; Pseudomegoura magnoliae; Neomyzus circumflexus

Use key to polyphagous aphids.

*Pastinaca*	Apiaceae
*Pastinaca armena*	Aphis fabae
*P. hirsuta*	Aphis fabae; Cavariella theobaldi
*P. pimpinellifolia*	Anuraphis subterranea; Dysaphis crataegi ssp. kunzei
*P. sativa*	Anuraphis [catonii], subterranea; Aphis asclepiadis, brohmeri, decepta, fabae, gossypii, spiraecola; Cavariella aegopodii, pastinacae, salicicola, theobaldi; Dysaphis apiifolia, bonomii, crataegi, crataegi ssp. kunzei, lauberti, [microsiphon]; Hyadaphis foeniculi, passerinii; Macrosiphum euphorbiae; Myzus ornatus, persicae; Protaphis middletonii; Semiaphis [dauci], pastinacae; Smynthurodes betae
*P. sylvestris*	Anuraphis subterranea; Cavariella aegopodii, angelicae, japonica, konoi, theobaldi; Hyadaphis passerinii
*P. umbrosa*	Anuraphis subterranea

Key to apterae on Pastinaca:-

1	ANT PT peg-like, with ANT PT/BASE less than 0.25. SIPH absent	…..Smynthurodes betae
–	ANT PT/BASE more than 1.0. Tubular SIPH present	…..2
2	ANT tubercles undeveloped or only weakly developed, not projecting forward beyond middle of head in dorsal view	…..3
–	ANT tubercles well developed, projecting forward far beyond middle of head, so there is a deep frontal sinus	…..24
3	ABD TERG 8 with a posteriorly projecting process above cauda	…..4
–	No supracaudal process	…..10
4	SIPH cylindrical /tapering, not clavate, or with only slight subapical or basal swelling	…..5
–	SIPH clavate, or at least somewhat swollen on distal part	…..7
5	ANT PT/BASE less than 2. Supracaudal process usually shorter than ANT II (Fig.10h)	…..Cavariella japonica
–	ANT PT/BASE more than 2. Supracaudal process usually longer than ANT II	…..6
6	ANT 6-segmented	….. Cavariella theobaldi
–	ANT 5-segmented	…..Cavariella angelicae
7	SIPH short and thick, less than 5 × their maximum width (Fig.10a)	…..Cavariella salicicola
–	SIPH clavate (with narrow region on basal half), more than 5 × their maximum width (e.g. Fig.10b)	…..8
8	ANT PT/BASE 0.6-1.3. R IV+V 0.7-0.9 (-1.1) × HT II, without accessory hairs	…..Cavariella aegopodii
–	ANT PT/BASE 1.4-4.0. R IV+V 1.0-1.2 × HT II, with 2 accessory hairs	…..9
9	ANT PT/BASE 2.6-4.0. SIPH smooth on basal part. Cauda with 6-8 hairs	…..Cavariella pastinacae
–	ANT PT/BASE 1.4-2.0. SIPH imbricated throughout. Cauda with 4-6 hairs	…..Cavariella konoi
10	SIPH very small, thin and flangeless, about 0.5 × cauda, with aperture slanted towards midline	…..Semiaphis pastinacae
–	SIPH more than 0.75 × cauda, with a distinct flange	…..11
11	Cauda helmet-shaped, a little shorter than its basal width in dorsal view. Head and ABD TERG 8 or 7-8 usually with spinal tubercles (STu)	…..12
–	Cauda tongue- or finger-shaped, or triangular but longer than or as long as its basal width. Head without, and ABD TERG 7-8 usually without, Stu	….16
12	SIPH less than 2 × their basal diameters, with close-set rows of fine spinules. Cauda bearing 9-16 hairs. R IV+V 0.24-0.37 mm, 1.3-1.8 × SIPH	…..Anuraphis subterranea
–	SIPH more than 2 × longer than their bsal diameters, with normal imbrication. Cauda bearing 4-8 hairs. R IV+V 0.13-0.19 mm, 0.5-1.0 × SIPH	…..13
13	Longest hairs on ANT III fine-pointed, 30-63 μm, 1.2-1.7 × BD III	…..Dysaphis lauberti
–	Longest hairs on ANT III 6-23 μm, 0.4-1.0 × BD III	…..14
14	SIPH 4 or more × longer than their basal diameters. Dorsal abdomen often with complete dark cross-bands on many or all of ABD TERG 1-8	…..Dysaphis bonomii
–	SIPH less than 3.5 × longer than their basal diameters. Dorsal abdominal pigmentation never in form of complete cross-bands on ABD TERG 1-5	…..15
15	Ventral hair on hind trochanter 0.24-0.56 × (rarely more than 0.5 ×) width of trochantro-femoral suture (see Fig. 1). Longest spinal hair on ABD TERG 8 is 11-38 μm long (rarely more than 30 μm). ABD TERG 7 frequently with marginal tubercles (MTu)	…..Dysaphis apiifolia
–	Ventral hair on hind trochanter 0.42-1.00 × (rarely less than 0.5×) width of trochantro-femoral suture. Longest spinal hair on ABD TERG 8 25-80 μm (rarely shorter than 30 μm). ABD TERG 7 rarely with MTu	…..Dysaphis crataegi (incl. ssp. kunzei)
16	SIPH clavate. ABD TERG 1 and 7 without marginal tubercles (MTu)	…..17
–	SIPH tapering/cylindrical. ABD TERG 1 and 7 with Mtu	…..18
17	Prothorax with ventral sclerite 1.3-2.6 × wider than long, with posterior margin often convex. SIPH 1.05-1.4 × cauda. (Alata often with secondary rhinaria on ANT V)	…..Hyadaphis foeniculi
–	Prothorax with ventral sclerite 2.2-3.6 × wider than long, with straight posterior margin. SIPH 0.85-1.2 × cauda (Alata rarely with secondary rhinaria on ANT V)	…..Hyadaphis passerinii
18	Cauda bluntly triangular, hardly longer than its basal width. SIPH less than 0.1 × BL, shorter than or as short as R IV+V. ANT III and IV often with secondary rhinaria. ANT PT/BASE less than 2	…..Protaphis middletonii
–	Cauda tongue- or finger-shaped, clearly longer than its basal width. SIPH 0.1-0.25 × BL, longer than R IV+V. No secondary rhinaria (except when alatiform). ANT PT/BASE usually more than 2	…..19
19	Cauda pale or dusky, distinctly paler than SIPH, and bearing 4-8 hairs	…..Aphis gossypii
–	Cauda dark, as dark or nearly as dark as SIPH, and bearing 7-31 hairs	…..20
20	ANT III 0.9-1.23 × cauda. ABD TERG 8 with 2 hairs, and usually no dark cross-band. Cauda usually with a distinct midlength constriction, and bearing 7-15 (mostly 8-12) hairs	…..Aphis spiraecola
–	ANT III 1.25-2.8 × cauda. ABD TERG 8 with (2-)3-11 hairs, usually on or just posterior to a dark cross-band. Cauda usually without a constriction, and bearing 10-31 hairs	…..21
21	R IV+V 1.1-1.4 × HT II. MTu on ABD TERG 1 and 7 only. Anterior half of subgenital plate with 2(-3) hairs. (ANT III of al. with 35-67 rather tuberculate rhinaria)	…..Aphis decepta
–	R IV+V 0.8-1.4 × HT II, but if more than 1.1 × HT II then there are at least some MTu on ABD TERG 2-4. Anterior half of subgenital plate with 2-14 hairs. (ANT III of al. with 7-33 rhinaria)	…..22
22	HT I with 3 hairs (sense peg present). ANT I dark, but ANT II pale or dusky, concolorous with basal half of III. Dorsal abdomen usually without any dark markings anterior to SIPH (except for dark intersegmental muscle sclerites). ANT III 1.05-1.95 × PT, (1.6-) 2.0-4.0 (-5.0) × R IV+V, and 1.5-2.9(-2.8) × cauda. SIPH 1.5-2.9 × cauda. (Al. with 14-40 rhinaria on ANT III)	….. Aphis asclepiadis
–	HT I with 2 hairs (no sense peg). ANT I and II both dark, contrasting with III. Dorsal abdomen usually with some dark markings anterior to SIPH (in addition to dark intersegmental muscle sclerites). ANT III 0.65-1.3 × PT, 1.2-2.6 (-3.0) × R IV+V and 1.2-1.6 (-1.9) × cauda. SIPH 0.7-1.6 × cauda. ABD TERG 8 with 2-5(-7) hairs. (Al. with 10-23 rhinaria on ANT III)	…..23
23	ABD TERG 2-6 bearing a total of 0-3 small MTu. Cauda with 11-24 hairs. ABD TERG 8 with 2-5(-7) hairs	…..Aphis fabae
–	ABD TERG 2-6 bearing a total of 5-9 often rather large MTu. Cauda with 20-31 hairs. ABD TERG 8 with 5-12 hairs	…..Aphis brohmeri
24	SIPH with a subapical zone of polygonal reticulation. Cuticle of head smooth, with inner faces of ANT tubercles divergent. ANT III with 1-7 rhinaria on basal half	…..Macrosiphum euphorbiae
–	Head without subapical reticulation. Head spiculose, with inner faces of ANT tubercles scabrous and apically convergent. ANT III without rhinaria	…..25
25	SIPH slightly clavate. ANT PT/BASE (2.8-)3.1-4.5. Dorsal abdomen without dark inter-segmental markings	…..Myzus persicae
–	SIPH tapering with a slight “S”-curve. ANT PT/BASE 1.75-2.8. Dorsal abdomen with a pattern of dark intersegmental markings	…..Myzus ornatus

*Patrinia*	Caprifoliaceae
*Patrinia intermedia*	Aphis patrinicola, patriniphila, patvaliphaga, spiraephaga
*P. rupestris*	Aphis patriniae, patriniphila
*P. scabiosifolia*	Aphis patriniae, patrinicola, patvaliphaga, spiraecola; [Uroleucon amamianum]
*P. sibirica*	Aphis patvaliphaga
*P. villosa*	Aphis patriniae

Key to apterae on Patrinia:-

1	Marginal tubercles (MTu) only constantly present on prothorax and ABD TERG 1 and 7. R IV+V 0.6-1.24 × HT II	…..2
–	Large dome-like MTu present on ABD TERG 2-4 (-5), as well as on prothorax and ABD TERG 1 and 7. R IV+V 1.38-1.68 × HT II	…..5
2	SIPH and cauda mainly pale. R IV+V 0.6-0.7 × HT II. Cauda with 3-6 hairs. Longest hairs on ANT III 0.3-0.6 × BD III	…..Aphis patvaliphaga*
–	SIPH and cauda dark. R IV+V 0.7-1.24 × HT II. Cauda with 7-17 hairs. Longest hairs on ANT III 0.5-1.7 × BD III	…..3
3	R IV+V 0.7-0.9 × HT II. Hind femora mainly dark. Dorsal abdomen with variably developed sclerotic dark markings	…..Aphis spiraephaga
–	R IV+V 0.95-1.24 × HT II. Hind femora mainly pale. Dorsal abdomen never with dark sclerotic markings	…..4
4	R IV+V 0.95-1.1 × HT II. SIPH usually shorter than (0.66-1.02 ×) cauda	…..Aphis patriniphila*
–	R IV+V 1.01-1.24 × HT II. SIPH usually longer than (0.86-1.71 ×) cauda	…..Aphis spiraecola
5	Longest hairs on ANT III 12-18 μm long, 0.7-1.0 × BD III. Femoral hairs long and fine, up to c. 50 μm long, 2.5-3 × BD III and longer than basal diameter of hind femur. Cauda with 6-10 hairs	…..Aphis patriniae
–	Longest hairs on ANT III and on femora 6-8 μm long, 0.3-0.5 × BD III and much shorter than basal diameter of hind femur. Cauda with 4-6 hairs	…..Aphis patrinicola*

*Paullinia*	Sapindaceae
*Paullinia pinnata*	Aphis spiraecola
Paullinia sp.	Aphis gossypii

Use key to polyphagous aphids.

*Paulownia*	Scrophulariaceae
*Paulownia coreana*	Aulacorthum solani
*P. fargesii*	Macrosiphum euphorbiae
*P. imperialis*	Macrosiphum euphorbiae
*P. tomentosa*	Aphis gossypii, spiraecola; Macrosiphum euphorbiae; Myzus persicae
*Paulownia* spp.	Aphis craccivora; [Cervaphis echinata]

Use key to polyphagous aphids

*Pavetta*	Rubiaceae
*Pavetta* sp.	Sitobion africanum

*Pavonia*	Malvaceae
*Pavonia candida*	Aphis gossypii; Aulacorthum solani
*P. fruticosa*	Aphis craccivora
*P. grandiflora*	Myzus persicae
*P. hastata*	Myzus persicae
*P. multiflora*	Myzus persicae
*P. paludicola*	Sitobion cuscutae
*P. spicata* = P. paludicola

Key to apterae on Pavonia:-

–	Head smooth with inner faces of ANT tubercles divergent. ANT III with 1-2 (-4) rhinaria. ANT III-VI, tibiae and SIPH wholly dark, contrasting with pale cauda. SIPH with polygonal reticulation on distal 0.11-0.16 of length	…..Sitobion cuscutae
–	Without that combination of characters	…..go to key to polyphagous aphids

*Paxistima*	Celastraceae
Paxistima myrsinites	Macrosiphum opportunisticum; Wahlgreniella nervata ssp. arbuti

Couplet to separate these two species:-

–	SIPH cylindrical or only very slightly swollen on distal half, with a subapical zone of polygonal reticulation. R IV+V 0.88-0.97 ×HT II	…..Macrosiphum opportunisticum
–	SIPH with distinct swelling of distal half, and without a zone of polygonal reticulation. R IV+V 1.33-1.51 ×HT II	…..Wahlgreniella nervata ssp. arbuti

*Pecluma*	Polypodiaceae
*Pecluma pectinata*	Idiopterus nephrelepidis

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

*Pectis*	Asteraceae
*Pectis elongata* var. floribunda	Macrosiphum euphorbiae
*Pectis* sp.	Aphis spiraecola

(Use key to polyphagous aphids, )

*Pedicularis*	Orobanchaceae
*Pedicularis achilleifolia*	Brachycaudus cerasicola
*P. brachyodonta*	Aulacorthum solani; Brachycaudus helichrysi
*P. bracteosa*	Macrosiphum euphorbiae; Nasonovia alpina
*P. canadensis*	Aulacorthum solani; Ericaphis wakibae
*P. densiflora*	Myzus sp. (California; BMNH collection, leg. D. Hille Ris Lambers)
*P. dolichorrhiza*	Brachycaudus cerasicola
*P. elongata*	Myzus cymbalariae
*P. gracilis*	Brachycaudus helichrysi; Dysaphis microsiphon
*P. grandiflora*	Aphis gossypii
*P. groenlandica*	Macrosiphum valerianae; [Nearctaphis bakeri]
*P. hirsuta*	Sitobion calvulum
*P. lasiostachys*	Brachycaudus cerasicola
*P. macrochila*	Brachycaudus cerasicola
*P. oederi*	Brachycaudus cerasicola
*P. olgae*	Brachycaudus cerasicola; Dysaphis emicis; Myzus persicae
*P. palustris* (incl. ssp. opsiantha)	Aphis nasturtii, sibirica; Brachycaudus helichrysi; Ericaphis wakibae
*P. pycnantha*	Brachycaudus cerasicola
*P. racemosa*	Nasonovia alpina
*P. resupinata*	Aphis fabae, frangulae, gossypii, pediculariphaga, septentrionalis; Aulacorthum solani; Myzus padellus (as Cyrtomyzus pedicularis)
*P. sceptrum-carolinum*	Myzus cerasi
*P. sudetica*	Brachycaudus helichrysi; [Macrosiphum chukotense]; Metopolophium pedicularis
*P. verticillata*	Hyperomyzus rhinanthi; Myzus padellus
*P. violascens*	Brachycaudus cerasicola
*Pedicularis* spp.	Aphis asclepiadis; Hyperomyzus luteus, zirnitsi; [Illinoia sp. (Washington, USA; aphidtrek.org)]; Macrosiphum constrictum; Nearctaphis yohoensis

Key to apterae on Pedicularis:-

1	Cauda short and broad; bluntly triangular, helmet- or broadly tongue-shaped, shorter than or only a little longer than its basal width in dorsal view	…..2
–	Cauda either tongue- or finger-shaped and longer than its basal width or, if short and triangular, then tapering to apex and often with a slight midlength constriction	…..8
2	Dorsal cuticle of head densely spiculose. SIPH pale with rows of spicules	…..Nearctaphis yohoensis
–	Dorsal cuticle of head without spicules. SIPH pale or dark, smooth or with normal imbrication	…..3
3	SIPH smooth, with a subapical annular incision. Spiracular apertures large and rounded. Spinal and marginal tubercles (STu and MTu) not usually present	…..4
–	SIPH imbricated, without a subapical annular incision. Spiracular apertures small and reniform. Some STu and/or MTu always present	…..5
4	Dorsum with an extensive black shield. Longest hairs on ANT III 1.0-1.33 × BD III	…..Brachycaudus cerasicola
–	Dorsum pale. Longest hairs on ANT III 0.5-0.7 × BD III	…..Brachycaudus helichrysi
5	Head with a pair of large STu. Well-developed MTu present on ABD TERG 1-5, or 1-7	…..6
–	Head without STu. MTu present on ABD TERG 1-4 and 7, or 1 and 7	…..7
6	STu present on head only. SIPH less than 1.3 × cauda, and less than half width of cauda at base	…..Dysaphis microsiphon
–	STu on all or most segments. SIPH more than 1.5 × cauda, and more than half as thick as cauda at base	…..Dysaphis emicis
7	Longest hairs on ANT III 2.2-2.3 × BD III. ABD TERG 8 with 5-7 hairs, Cauda with 7-11 hairs. MTu present on ABD TERG 2-4 (-5) as well as 1 and 7	…..Aphis pediculariphaga*
–	Longest hairs on ANT III 0.8-1.0 × BD III. ABD TERG 8 with 2-3 hairs, Cauda with 4-8 hairs. MTu usually only present on ABD TERG 1 and 7	…..Aphis septentrionalis*
8	Head spiculose, with scabrous, steep-sided, rounded or convergent ANT tubercles	…..9
–	Head smooth or with a few spicules ventrally. ANT tubercles either weakly developed or smooth and divergent	…..14
9	ANT longer than BL, with ANT PT/BASE 3.0-5.5	…..10
–	ANT 0.6-0.95 × BL, with ANT PT/BASE 1.8-3.2 (-3.5)	…..11
10	Head without spicules dorsally, or with very few. ANT III without rhinaria. Tergum sclerotic and variably pigmented, sometimes with a dark central dorsal abdominal area. Cauda with 4-6 hairs	…..Ericaphis wakibae
–	Head densely spiculose dorsally as well as ventrally. ANT III with 0-4 rhinaria near base (usuallly 1 or 2). Tergum unpigmented. Cauda with 7 hairs	…..Aulacorthum solani
11	SIPH pale, 8-14 × longer than their diameter at midlength, 0.65-1.3 × ANT III, normally imbricated, and slightly swollen on distal half. ANT 0.7-1.0 × BL, with PT/BASE 2.7-4.5. (Imm. with smooth hind tibiae)	…..12
–	SIPH dusky or dark, 3-9 × longer than their midlength diameters, 1-2 × ANT III, coarsely imbricated, and not at all swollen distally. ANT 0.6-0.8 × BL with PT/BASE 1.8-3.3. (Imm. with outer apices of hind tibiae spinulose)	…..13
12	SIPH 0.65-0.85 × ANT III, 8-11 × longer than their diameter at midlength. Hairs on front of head 0.6-0.9 × ANT BD III	…..Myzus sp. on P. densiflora, California
–	SIPH 1.0-1.3 × ANT III, 11-14 × longer than their diameter at midlength. Hairs on front of head 0.3-0.6 × ANT BD III	…..Myzus persicae
13	Tergum pale. SIPH slightly swollen on basal part, 2.2-2.7 × cauda, and less than 5 × longer than their width at midlength	…..Myzus padellus
–	Tergum with an extensive dark sclerotic patch. SIPH cylindrical, 2.7-3.3 × cauda, more than 6 × longer than their width at midlength	…..Myzus cerasi
14	ANT III without rhinaria. ABD TERG 1 and 7 with marginal tubercles (MTu)	…..15
–	ANT III usually with 1 or more rhinaria. ABD TERG 1 and 7 without MTu	…..16
15	SIPH 0.4-0.9 × cauda	…..Aphis sibirica
–	SIPH (0.8-)0.9-2.9 × cauda	…..go to key to polyphagous aphids, starting at couplet 30
16	SIPH smooth and markedly inflated over distal c.0.75, with maximum width of swollen part 1.6 or more × minimum width of basal part	…..17
–	SIPH imbricated and tapering/ cylindrical	…..19
17	Dorsal abdomen with a large black central patch	…..Hyperomyzus rhinanthi
–	Dorsal abdomen without a black patch	…..18
18	Maximum diameter of swollen part of SIPH less than R IV+V or ANT VI BASE	…..Hyperomyzus zirnitsi
–	Maximum diameter of swollen part of SIPH greater than R IV+V or ANT VI BASE	…..Hyperomyzus luteus*
19	ANT BASE VI 0.20-0.22 mm long. Distal 0.06 of SIPH with a band of polygonal reticulation	…..Macrosiphum constrictum*
–	ANT BASE VI 0.11-0.19 mm. SIPH either without polygonal reticulation, or with polygonal reticulation extending over at least distal 0.12 of length	…..20
20	SIPH with polygonal reticulation on distal 0.12-0.29 of length	…..21
–	SIPH without polygonal reticulation	…..22
21	SIPH pale, or only gradually darker towards apices. No presiphuncular sclerites	…..Macrosiphum euphorbiae
–	SIPH entirely dark, or only pale at base. Small presiphuncular sclerites usually present	…..Macrosiphum valerianae
22	R IV+V 1.6-2.1 × HT II, with 12-18 accessory hairs. Longest hairs on ANT III 1.1-1.5 × BD III. ANT PT/BASE 5.8-6.8	…..Nasonovia alpina
–	R IV+V 0.67-1.10 × HT II, with 4-9 accessory hairs. Longest hairs on ANT III 0.3-0.6 × BD III. ANT PT/BASE 2.2-3.9	…..23
23	ANT III with 0-1 rhinaria near base. ANT and dorsal hairs with pointed apices. R IV+V 0.10-0.11 × HT II. ANT PT/BASE 2.2-2.9	…..Sitobion calvulum
–	ANT III with 5-15 rhinaria extending onto distal half of segment. ANT and dorsal hairs with blunt apices. R IV+V 0.67-0.8 × HT II. ANT PT/BASE 3.5-3.8	…..Metopolophium pedicularis

*Pedilanthus* see Euphorbia	Euphorbiaceae
*Pedilanthus tithymaloides* = Euphorbia tithymaloides

*Peganum*	Zygophyllaceae
*Peganum harmala*	Acyrthosiphon gossypii, [pisum]; Aphis craccivora, fabae, gossypii, [umbrella]; Brachyunguis [flavidus], harmalae; Macrosiphum euphorbiae; Myzus persicae

Key to apterae on Peganum:-

1	SIPH pale, very long and attenuated distally, thinner than hind tibiae at their respective midlengths, 0.33-0.45 × BL and 2.5-3.5 × cauda	…..Acyrthosiphon gossypii
–	SIPH pale or dark, thicker and relatively shorter	…..2
2	ANT PT/BASE more than 1. SIPH pale or dark, longer than cauda	…..go to key to polyphagous aphids
–	ANT PT/BASE less than 1. SIPH pale, much shorter than cauda	…..Brachyunguis harmalae

*Peiranisia*	Fabaceae
*Peiranisia benitoensis* = Senna benitoensis

Peireskia see Pereskia

Cactaceae

Peireskiopsis see Pereskiopsis

Cactaceae

*Pelargonium*	Geraniaceae
*Pelargonium australe* (?)	Acyrthosiphon malvae
*P. crithmifolium*	Macrosiphum euphorbiae
*P. denticulatum*	Aulacorthum solani; Brachycaudus helichrysi
*P. × domesticum*	Acyrthosiphon malvae
*P. grandiflorum*	Acyrthosiphon malvae; Aulacorthum solani
*P. graveolens*	Acyrthosiphon malvae; Macrosiphum euphorbiae
*P. hederaefolium*	Aulacorthum solani; Myzus persicae
*P. hortorum*	Aphis gossypii; Aulacorthum solani; Neomyzus circumflexus
*P. inquinans*	[Cryptomyzus ribis]
*P. odoratissimum*	Acyrthosiphon malvae; Aphis fabae
*P. peltatum*	Acyrthosiphon malvae; Aulacorthum solani; Brachycaudus helichrysi
*P. quercifolium*	Acyrthosiphon malvae
*P. radula*	Acyrthosiphon malvae
*P. violareum*	Acyrthosiphon malvae
*P. zonale*	Acyrthosiphon malvae; Aphis fabae, gossypii; Aulacorthum solani; Myzus persicae
*Pelargonium* spp.	Aphis aurantii, [extranea Walker (nomen dubium)], spiraecola; Myzus ornatus, [targionii del Guercio (nomen dubium)]; [Pentalonia nigronervosa]

Use key to polyphagous aphids.

*Pellaea*	Adiantaceae
*Pellaea calomelanos*	Micromyzella sleonensis
*P. glabella* (?)	Macrosiphum adianti, walkeri; Neomyzus circumflexus
*P. hastata* = P. viridis
*P. ovata*	Shinjia orientalis
*P. viridis*	Idiopterus nephrelepidis
Pellaea sp.	Macrosiphum woodsiae

Use key to apterae of fern-feeding aphids under Polypodium.

*Peltandra*	Araceae
*Peltandra virginica*	Rhopalosiphum nymphaeae

*Peltaria*	Brassicaceae
*Peltaria alliacea*	Brevicoryne brassicae
*P. turkmena*	Brevicoryne brassicae

*Peltophorum*	Fabaceae
*Peltophorum africanum*	Myzus persicae
*P. ferrugineum* = P. pterocarpum
*P. pterocarpum*	Aphis gossypii; Tinocallis himalayensis

–	SIPH in form of short, truncate cones. Cauda knobbed, anal plate bilobed	…..Tinocallis himalayensis
–	SIPH tubular. Cauda tongue-shaped, anal plate entire	…..go to key to polyphagous aphids

*Pennisetum*	Poaceae
*Pennisetum alopecuroides*	Brachysiphoniella montana; [Melanaphis sp. (Japan – Moritsu 1983)]; Rhopalosiphum maidis, padi, rufiabdominale; Schizaphis aurea; Tetraneura akinire, yezoensis
*P. cenchroides* = Cenchrus ciliaris
*P. ciliare* = Cenchrus ciliaris
*P. clandestinum*	Hysteroneura setariae; Kugegania ageni; Rhopalosiphum maidis; Schizaphis rotundiventris; Sipha flava; Sitobion pauliani, [Sitobion sp. (Millar 1994)]; Tetraneura akinire, yezoensis
*P. flaccidum*	Sitobion avenae, miscanthi
*P. giganticum* (?)	Rhopalosiphum maidis
*P. glaucum*	Anoecia corni, cornicola, fulviabdominalis, vagans; Aphis gossypii; [Dysaphis microsiphon]; Forda hirsuta, orientalis; Geoica utricularia; Hysteroneura setariae; Melanaphis sacchari; Protaphis middletonii; Rhopalosiphum maidis, padi, rufiabdominale; Schizaphis graminum; Sipha elegans, glyceriae, maydis; Sitobion avenae, leelamaniae, miscanthi, pauliani; [Slavum lentiscoides]; Tetraneura africana, akinire, basui, radicicola/yezoensis
*P. japonicum* = P. alopecuroides
*P. macrourum*	Rhopalosiphum maidis
*P. mezianum*	Rhopalosiphum maidis
*P. orientale*	Sipha flava; Sitobion avenae
*P. pedicillare* (?)	Rhopalosiphum padi
*P. pedicellatum*	Aphis gossypii
*P. polystachion* (incl. ssp. atrichum)	Aphis gossypii; Hysteroneura setariae; Sitobion africanum, indicum, pauliani
*P. pseudotrichoides*	Sitobion africanum
*P. purpureum*	Aphis gossypii; Hysteroneura setariae; Melanaphis sacchari; Pseudaphis sijui; Rhopalosiphum maidis; Sipha flava; Sitobion avenae, bamendae, leelamaniae, papillatum, pauliani, yakini, [Sitobion spp.(Essig 1958, van Harten 1972a)]; Tetraneura akinire
*P. setaceum*	Pseudaphis arabica; Sitobion africanum, fragariae
*P. setosum* = P. polystachyon
*P. trachyphyllum*	Hysteroneura setariae; Pseudaphis sijui; Sitobion yakini
*P. typhoides* = P. glaucum	Forda orientalis; Melanaphis sacchari; Rhopalosiphum maidis, rufiabdominale; Sitobion leelamaniae, miscanthi
*P. typhoideum* = P. glaucum
*Pennisetum* sp.	Tetraneura kalimpongensis

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

*Penstemon*	Plantaginaceae
*Penstemon cordifolius* = Keckiella cordifolia
*P. diffusus*	[Aphis ramona]
*P. fruticosus* (incl. var. scouleri)	Aphis sierra
*P. glaber*	Aphis asclepiadis
*P. gloxinioides*	Aulacorthum solani; Macrosiphum euphorbiae; Myzus persicae
*P. laevigatus*	Aphis fabae; Macrosiphum euphorbiae
*P. newberryi*	Aphis sierra
*P. speciosus*	Aphis pentstemonicola
*P. spectabilis*	Myzus persicae; Neomyzus circumflexus
*P. vireus*	Aphis pentstemonicola
*Penstemon* spp.	[Aphis solitaria]; Brachycaudus helichrysi; [Hyadaphis foeniculi]; [Macrosiphum valerianae]; [Nasonovia alpina]; [Nearctaphis bakeri]; Rhopalosiphoninus staphyleae

Key to apterae on Penstemon:-

1	ANT tubercles weakly developed. ABD TERG 1 and 7 with well developed marginal tubercles (MTu). Cauda bluntly triangular, shorter than or hardly longer than its basal width in dorsal view, with 4-6 hairs. Often with large dark postsiphuncular sclerites and dark cross bands on ABD TERG 6, 7 and 8 (broadest on 6)	…..2
–	Without that combination of characters; i.e., if ANT tubercles are weakly developed and ABD TERG 1 and 7 have well-developed MTu then cauda is either tongue-shaped and clearly longer than its basal width, or bears more than 10 hairs	…..go to key to polyphagous aphids
2	ANT III-V usually with numerous secondary rhinaria. (Al. with secondary rhinaria distributed ANT III 20-43, IV 12-20, V 5-9)	…..Aphis pentstemonicola
–	ANT usually without secondary rhinaria. (Al. with secondary rhinaria distributed ANT III 11-18, IV 0-2, V 0)	…..Aphis sierra

*Pentacalia*	Asteraceae
*Pentacalia amplexicaulis*	Illinoia davidsoni

*Pentaglottis*	Boraginaceae
*Pentaglottis sempervirens*	Aphis fabae; Brachycaudus helchrysi; Myzus ascalonicus, ornatus, persicae; Ovatomyzus boraginacearum
Pentaglottis sp.	[Ovatomyzus chamaedrys]

Use key to apterae on Anchusa.

*Pentalinon* (including Urechtites)	Apocynaceae
*Pentalinon luteum*	Aphis aurantii, craccivora, gossypii

Use key to polyphagous aphids.

*Pentanema* (including Vicoa)	Asteraceae
*Pentanema leptoclada* = P. indicum
*P. indicum*	Aphis gossypii

*Pentaphylloides* see Potentilla	Rosaceae
*P. × friedrichsenii*	Myzaphis rosarum
*P. fruticosa* = Potentilla fruticosa
*P. parvifolia* see Potentilla parvifolia
*P. phyllocalyx* (?)	Myzaphis rosarum

*Pentapterygium* see Agapetes	Ericaceae
*Pentapterygium serpens* = Agapetes serpens

*Pentarhizidium*	Woodsiaceae
*Pentarhizidium intermedium* = Matteuccia intermedia

*Pentarrhinum*	Apocynaceae
*Pentarrhinum insipidum*	Aphis nerii

*Pentas*	Rubiaceae
*Pentas lanceolata*	Aphis gossypii
Pentas sp.	Aphis spiraecola

Use key to polyphagous aphids.

*Pentaschistis*	Poaceae
*Pentaschistis minor* = P. pictigluma var. minor
P. pictigluma var. minor	[Pterasthenia shiraensis]

*Pentzia*	Asteraceae
*Pentzia incana*	Coloradoa rufomaculata
*P. pilulifera* = Oncosiphon piluliferum

Key to apterae on Pentzia:-

–	Dorsal hairs spatulate or club-shaped (widening from base to rounded apex). R IV+V with a pointed apex and concave lateral margins. SIPH cylindrical for most of length, slightly swollen subapically. ANT PT/BASE 1.5-2.0	…..Coloradoa rufomaculata
–	Dorsal hairs with pointed, blunt or slightly expanded apices. R IV+V with straight or convex lateral margins, and other characters not in that combination	…..go to key to polyphagous aphids

*Peperomia*	Piperaceae
*Peperomia pellucida*	Aphis gossypii
*P. tenella*	Aphis gossypii
Peperomia sp.	Myzus persicae; Neomyzus circumflexus

Use key to polyphagous aphids.

Pepo see Curcubita

Cucurbitaceae

*Pereskia*	Cactaceae
*Pereskia aculeata*	Aphis aurantii, craccivora, fabae, nerii, spiraecola; Myzus ornatus, persicae

Use key to polyphagous aphids.

*Pereskiopsis*	Cactaceae
*Pereskiopsis diguetii*	Aphis fabae; Myzus persicae
*P. spathulata* = P. diguetii

Use key to polyphagous aphids.

*Perezia*	Asteraceae
*Perezia multiflora*	Aphis fabae

*Pergularia* (including Daemia)	Apocynaceae
*Pergularia daemia*	Aphis asclepiadis, aurantii, gossypii, nerii
*P. extensa* = P. daemia
*P. tomentosa* = Daemia tomentosa

Use key to apterae on Asclepias.

*Pericallis*	Asteraceae
*Pericallis cruenta* see Cineraria cruenta
*P. ×* *hybrida* see Cineraria cruenta
*P. lanata*	Brachycaudus helichrysi

*Perideridia*	Apiaceae
*Perideridia parishii*	Hyadaphis foeniculi

Perilepta see Strobilanthes

Acanthaceae

*Perilla*	Lamiaceae
*Perilla frutescens* (incl. vars argua, crispa, japonica)	Aphis egomae, gossypii, nasturtii; Aulacorthum perillae, [siniperillae]; Macrosiphum perillae; Micromyzodium nipponicum
*P. nankinensis* = P. frutescens var. crispa
*P. ocymoides* = P. frutescens
*P. sikokiana* (=P. frutescens?)	Aulacorthum perillae
*Perilla* spp.	[Myzus siegesbeckicola]; Sitobion aulacorthoides, plectranthi

Key to apterae on Perilla:-

1	ANT tubercles weakly developed, ABD TERG 1 and 7 with marginal tubercles (MTu)	…..2
–	ANT tubercles moderately to well developed, ABD TERG 1 and 7 without MTu	…..4
2	SIPH pale or only dark at apices	…..Aphis nasturtii
–	SIPH entirely dark	…..3
3	ANT 5-segmented	…..Aphis egomae*
–	ANT 6-segmented (except in hot-weather dwarfs)	…..Aphis gossypii
4	SIPH with a subapical zone of reticulation (at least 4-5 rows of closed polygonal cells). Head smooth, or with minute spinules only on ventral surface. Abdomen with or without dark markings, but these not forming an extensive dorsal sclerotic shield	…..5
–	SIPH without a distinct subapical zone of polygonal reticulation. Head usually spiculose both dorsally and ventrally. Dorsal abdomen with an extensive dusky/dark sclerotic shield	…..7
5	Abdomen with continuous broad dark marginal stripes, united by a dark band across ABD TERG 6	…..Macrosiphum perillae
–	Abdomen without extensive dark markings	…..6
6	ANT III with 1-7 rhinaria on basal half , ANT IV with 0. ANT PT/BASE 5.5-6.4	…..Sitobion aulacorthoides
–	ANT III with 4-15 rhinaria distributed over whole length, and ANT IV with 0-4. ANT PT/BASE 4.8-5.5	…..Sitobion plectranthi
7	ANT shorter than BL. ANT III without rhinaria	…..Micromyzodium nipponicum
–	ANT longer than BL. ANT III with rhinaria	…..Aulacorthum perillae

*Periploca*	Apocynaceae
*Periploca glabra* (?)	[Aphis sp. (Bozhko 1976a: 72)]
*P. graeca*	Aphis fabae, gossypii, nasturtii; Myzus persicae
*P. laevigata* (incl. ssp. angustifolia)	Aphis gossypii; Myzus persicae
*P. linearifolia*	Aphis (Toxoptera) aurantii
*P. sepium*	[Aphis periplocophila]

Use key to polyphagous aphids, but note that there are Aphis spp. on Periploca, recorded from Ukraine and China, that could not be included in a key on the basis of available information (Aphis periplocophila would probably key to Aphis gossypii).

*Pernettya* see Gaultheria	Ericaceae
*Pernettya mucronata* = Gaultheria mucronata var. microphylla

*Perotis*	Poaceae
*Perotis vaginata*	Hysteroneura setariae; Sitobion graminis, [Sitobion sp. (Millar 1994)]
Use key to apterae of grass-feeding aphids under Digitaria.

*Perovskia*	Lamiaceae
*P. abrotanoides*	Brachycaudus cerasicola
*P. atriplicifolia*	Aphis solanella
*P. scrophulariifolia*	Aphis craccivora

Key to apterae on Perovskia:-

–	Cauda semicircular to helmet-shaped, shorter than its basal width in dorsal view. Spiracular apertures large and rounded. SIPH shorter than R IV+V. ABD TERG 1 and 7 without marginal tubercles (MTu). Dorsal abdomen with an extensive black sclerotic shield	…..Brachycaudus cerasicola
–	Cauda not helmet-shaped, spiracular apertures reniform and other characters not in that combination	…..go to key to polyphagous aphids

*Persea*	Lauraceae
*Persea americana*	Aphis aurantii, craccivora, fabae, gossypii, spiraecola; [Lizerius jorgei]; Myzus persicae; Sinomegoura citricola
*P. bombycina* = Machilus gamblei
*P. bournei* = Phoebe bournei
*P. breviflora* = Machilus parabreviflora
*P. chekiangensis* = Machilus chekiangensis
*P. chinensis* = Machilus chiensis
*P. gamblei* = Machilus gamblei
*P. longipaniculata* = Machilus zuihoensis
*P. macrantha*	Aiceona pallida
*P. odoratissima*	Aiceona manipurensis, pseudosugii, retipennis; Machilaphis machili; Schizoneuraphis himalayensis
*P. oreophila* = Machilus oreophila
*P. thunbergii* = Machilus thunbergii
*P. villosa* = Machilus glaucescens
*P. wangchiana*	Aphis (Toxoptera) aurantii
*P. yunnanensis* = Machilus yunnanensis
*P. zuihoensis*	Sinomegoura citricola
*Persea* sp.	Aiceona osugii (?)

See combined key to aphids on Machilus and Persea spp. under Machilus.

*Persicaria*	Polygonaceae
*Persicaria acuminata*	[Anoecia cornicola]; Myzus persicae; Trichosiphonaphis polygoni
*P. alpina*	Brachycaudus brevirostratus; Capitophorus essigi, hippophaes; Macchiatella rhamni (incl ssp. tarani)
*P. amphibia*	Aphis fabae, middletonii, nasturtii, solanella; Aulacorthum solani; Capitophorus hippophaes; Macrosiphum euphorbiae; Rhopalosiphum nymphaeae; Trichosiphonaphis polygonifoliae
*P. amplexicaulis*	Aphis odinae; Tricaudatus polygoni
*P. attenuata*	Capitophorus hippophaes
*P. barbata*	Capitophorus mitegoni
*P. bistorta*	Acyrthosiphon bistorti; Aphis fabae, fabae ssp. cirsiiacanthoidis (?), solanella; Aulacorthum solani; Brachycaudus amygdalinus; Capitophorus hippophaes
*P. blumei* = Polygonum longisetum
*P. capitata*	Aphis gossypii; Capitophorus hippophaes ssp. javanicus; Myzus brevisiphon, formosanus; Sitobion miscanthi
*P. chinensis*	Aphis spiraecola; Brachycaudus helichrysi; Capitophorus hippophaes ssp. javanicus, mitegoni; [Greenidea bucktonis]; [Myzakkaia verbasci]; Myzus formosanus, ornatus; Sitobion miscanthi; Tricaudatus polygoni; Trichosiphonaphis polygoni
*P. decipiens*	Aphis spiraecola
*P. dubia*	Capitophorus hippophaes
*P. glabra*	Akkaia bengalensis; Capitophorus hippophaes, hippophaes ssp. javanicus, mitegoni; Neomyzus circumflexus
*P. hydropiper*	[Anoecia cornicola]; Aphis fabae, gossypii, nasturtii, spiraecola; Aulacorthum solani; Capitophorus [elaeagni], hippophaes, hippophaes ssp. javanicus, mitegoni; [Cryptomyzus galeopsidis, ribis]; Kaltenbachiella nirecola; Macrosiphum euphorbiae; Myzus persicae; Pemphigus sp.; Protaphis middletonii; Prociphilus erigeronensis; Sitobion miscanthi; Trichosiphonaphis polygoni, polygonifoliae, polygoniformosana
*P. hydropiperoides*	Protaphis middletonii
*P. lapathifolia* (incl. nodosa, pallida)	Aphis fabae, nasturtii, [sambuci], spiraecola; Aulacorthum solani; Capitophorus hippophaes, hippophaes ssp. javanicus; [Cryptomyzus galeopsidis, ribis]; Protaphis middletonii; Trichosiphonaphis polygonifoliae
*P. longiseta*	Capitophorus [elaeagni], hippophaes ssp. javanicus, mitegoni; Trichosiphonaphis polygoni, polygonifoliae
*P. maculosa*	Aphis craccivora, fabae, nasturtii, polygonata; Aspidaphis adjuvans; Aulacorthum solani; Brachycaudus amygdalinus, rumexicolens; Capitophorus hippophaes, hippophaes sspp. dubius, javanicus; [Cryptomyzus ribis]; [Hyperomyzus nigricornis]; Macchjiatella rhamni ssp. tarani; Macrosiphum euphorbiae; Myzus ascalonicus, [certus], persicae; Protaphis middletonii
*P. minor*	Aphis nasturtii; Capitophorus hippophaes, mitegoni
*P. mollis* = Polygonum molle
*P. nepalensis*	Akkaia bengalensis, polygoni; Aphis gossypii, nasturtii, spiraecola, [verbasci]; Aulacorthum solani; Brachycaudus helichrysi; Capitophorus hippophaes ssp. javanicus, mitegoni; Epipemphigus imaicus; [Melanaphis arundinariae]; Myzakkia polygonicola, verbasci; Myzus brevisiphon, ornatus, persicae; Trichosiphonaphis polygoni; [Vesiculaphis polygonii]
*P. orientalis*	Akkaia neopolygoni; Aphis fabae, gossypii; Capitophorus hippophaes ssp. javanicus, mitegoni; Kaltenbachiella nirecola; Pemphigus sp.
*P. pensylvanica*	Capitophorus hippophaes; Pemphigus sp.; Protaphis middletonii
*P. perfoliata*	Akkaia bengalensis; Aphis nasturtii; [Aulacorthum sp.]; Capitophorus hippophaes ssp. javanicus, mitegoni; Trichosiphonaphis gerberae, polygoni, polygoniformosana
*P. pulchra*	Aphis spiraecola; Aulacorthum solani; Capitophorus hippophaes; Myzus ornatus
*P. sagittata*	Trichosiphonaphis polygoni, polygoniformosana
*P. senegalensis* (incl. var. albotometosum)	Aphis gossypii; Capitophorus hippophaes, mitegoni
*P. senticosa* = Polygonum senticosum
*P. serrulata*	Akkaia neopolygoni; Aphis gossypii, spiraecola; Capitophorus hippophaes ssp. javanicus; [Matsumuraja capitophoroides]; Myzakkaia verbasci; Myzus ornatus, persicae; Tricaudatus polygoni; Trichosiphonaphis gerberae, polygoni, polygoniformosana
*P. tinctoria*	Capitophorus hippophaes ssp. javanicus
*P. vivipara*	Acyrthosiphon bistorti, [malvae], [sp. aff. knechteli]; Brachycaudus acaudatus; Capitophorus elaeagni; Macchiatiella rhamni ssp. tarani; [Macrosiphum chukotense]; Tricaudatus polygoni
*P. wallichii*	Dysaphis microsiphon; Tricaudatus polygoni
*Persicaria* sp.	[Aphis rumicis]
Use key to apterae on Polygonum, in which all Persicaria-feeding aphids have been included.

Persimmon see Diospyros

Ebenaceae

*Persoonia*	Proteaceae
*Persoonia* sp.	Aphis (Toxoptera) aurantii

*Perymenium*	Asteraceae
*Perymenium* sp.	Uroleucon astronomus, mexicanum

Key to apterae on Perymenium:-

(Both species have dark SIPH with a distal zone of polygonal reticulation.)

–	Coxae pale like trochanters. Tibiae dark basally and apically with middle parts contrastingly pale	…..Uroleucon astronomus
–	Coxae dusky and at least partly darker than trochanters. Tibiae uniformaly pigmented	…..Uroleucon mexicanum*

*Petasites*	Asteraceae
*Petasites albus*	Anuraphis farfarae; Aphis nasturtii; Aulacorthum solani; Capitophorus [elaeagni], similis; Dysaphis lappae; Uroleucon tussilaginis
*P. amplus* = P. japonicus ssp. giganteus
*P. fragrans*	Aulacorthum solani; Capitophorus similis; Myzus ornatus, persicae
*P. frigidus* (incl. var. palmatus)	Aphis torquens; Aulacorthum solani; Cedoaphis maxsoni; Macrosiphum chukotense
*P. georgicus* = P. hybridus
*P. hybridus*	Anuraphis farfarae; Aphis torquens; Brachycaudus cardui, helichrysi; Capitophorus similis; Uroleucon tussilaginis
*P. japonicus* (incl. ssp. giganteus)	Aphis fukii, gossypii, odinae; Capitophorus similis; Aulacorthum solani; Macrosiphoniella grandicauda; [Macrosiphum petasitis Matusumura (nomen dubium)]; Myzus persicae, [varians]
*P. kablikianus*	Aphis torquens; Aulacorthum solani; Uroleucon tussilaginis
*P. niveus* = P. paradoxus
*P. officinalis* = P. hybridus
*P. palmatus* = P. frigidus var. palmatus
*P. paradoxus*	Brachycaudus helichrysi; Capitophorus similis
*P. spurius*	Anuraphis farfarae; Brachycaudus helichrysi; Capitophorus similis; Chomaphis mira
*P. tatewakianus*	Aphis fukii, torquens
*P. tomentosus*	Chomaphis mira
*P. tricholobus*	Aphis fukii; Aulacorthum cirsicola; Capitophorus takahashii; Myzus persicae
*P. vulgaris*	Brachycaudus helichrysi
*Petasites* spp.	Aulacorthum kerriae; Myzus ascalonicus

Key to apterae on Petasites:-

1	Dorsal hairs long and thick with knobbed apices	…..2
–	Dorsal hairs not thick, if long then with fine apices	…..3
2	ANT III with 1-4 (-5) thick capitate hairs, c. 0.7-1.1 × BD III	…..Capitophorus similis
–	ANT III with c. 6 thick capitate hairs, longer than BD III	…..Capitophorus takahashii*
3	ANT tubercles undeveloped or weakly developed	…..4
–	ANT tubercles well developed, so that there is a deep frontal sinus	…..14
4	Cauda semicircular or helmet-shaped, shorter than its basal width in dorsal view	…..5
–	Cauda tongue- or finger-like, longer than its basal width in dorsal view	…..10
5	Prothorax with a pair of very large marginal tubercles (MTu), up to twice the diameter of the compound eye, and ABD TERG 1-5 also with very large MTu. SIPH long and flangeless, more than 7 × cauda, and bearing some small pointed hairs	…..Chomaphis mira
–	Prothorax if with MTu then these are smaller than compound eyes. ABD TERG 1-5 with or without MTu. SIPH less than 5 × cauda, and without hairs	…..6
6	Cuticle of head densely spinulose. ANT III with 12-30 secondary rhinaria distributed over most of length, and ANT IV with 0-16	…..Cedoaphis maxsoni
–	Cuticle of head without spinules. ANT III and IV without rhinaria, or if with rhinaria on ANT III then they are restricted to basal half	…..7
7	Spinal tubercles (STu) present on head, prothorax and some of ABD TERG 1-8. Well-developed MTu present on prothorax and ABD TERG 1-5	…..8
–	STu and MTu absent, or rarely present on 1-2 segments	…..9
8	ANT III with 6-19 rhinaria clustered near base. ABD TERG 8 without STu. SIPH with very close-set rows of fine spinules. SIPH 2.0-2.4 × cauda, which bears c.15 hairs	…..Anuraphis farfarae
–	ANT III without rhinaria. ABD TERG 7 and 8 both usually with STu. SIPH with normal inbrication. SIPH 1.5-2.0 × cauda, which bears 5-7 hairs	…..Dysaphis lappae
9	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
10	SIPH much shorter than (0.4-0.6 ×) cauda	…..Aphis odinae
–	SIPH at least 0.8 × cauda, and usually much longer	…..11
11	Cauda pale or dusky. Longest hairs on ANT III 0.4-0.8 × BD III	…..12
–	Cauda dark. Hairs on ANT III long and fine, the longest 1.6-2.7 × BD III	…..13
12	SIPH uniformly dark. Hairs on hind femur all shorter than diameter of femur at its base	…..Aphis gossypii
–	SIPH usually rather pale, darker at apex. Hairs on hind femur mainly longer, some of them about as long as, or longer than, diameter of femur at its base	…..Aphis nasturtii
13	SIPH 0.8-1.4 × cauda, which bears 16-21 hairs. Well-developed conical or hemispherical MTu present on ABD TERG 2-4 (-5) as well as 1 and 7. (Al. with 7-20 sec. rhinaria on ANT III, 0-4 on IV, 0 on V)	…..Aphis torquens
–	SIPH 1.7-2.1 × cauda, which bears 10-16 hairs. MTu only consistently present on ABD TERG 1 and 7. (Al. with 20-32 sec. rhinaria on ANT III, 5-11 on IV and 0-7 on V)	…..Aphis fukii
14	Cuticle of head smooth. SIPH with polygonal reticulation on distal 0.08-0.60 of length	…..15
–	Cuticle of head spiculose, at least ventrally. SIPH without polygonal reticulation	…..17
15	SIPH 1.5-1.8 × cauda, with reticulation on distal 0.5-0.6 of length. R IV+V acutely pointed, 0.7-0.9 × HT II, and bearing very long accessory hairs, much longer than the 3 subapical pairs	…..Macrosiphoniella grandicauda
–	SIPH 1.5-2.6 × cauda, with reticulation on distal 0.08-0.15 of length. R IV+V 0.8-1.5 × HT II, with accessory hairs of normal length	…..16
16	SIPH dark at both base and apex, paler in middle, 2.1-2.6 × cauda. R IV+V 1.3-1.5 × HT II. Abdomen with crescent-shaped presiphuncular and large postsiphuncular dark sclerites	…..Uroleucon tussilaginis
–	SIPH pale, or pale at base and gradally darkening distally, 1.5-2.2 × cauda. R IV+V 0.8-1.2 × HT II. Pre- and postsiphuncular sclerites absent	…..Macrosiphum chukotense (or possibly Macrosiphum euphorbiae? – see text)
17	Dorsum mainly dark and sclerotic, leaving only a large pale central abdominal region and small pale areas anterior to bases of SIPH. Cauda dark	…..Aulacorthum kerriae
–	Dorsum pale or with less extensive dark markings. Cauda pale	…..18
18	ANT 1.6-1.7 × BL, which is 2.7-4.1 mm. Hind tibiae very long, 0.9-1.5 × BL. ANT III with 3-12 rhinaria in a row on basal half	…..Aulacorthum cirsicola
–	ANT 0.5-1.5 × BL, which is 1.0-3.0 mm. Hind tibia 0.4-0.8 × BL. ANT III without rhinaria or with 1-3 rhinaria near base	..…go to key to polyphagous aphids, starting at couplet 5

*Petiveria*	Phytolaccaceae
*Petiveria alliacea*	Aphis (Toxoptera) citricidus; [Microparsus olivei]

*Petrea*	Verbenaceae
*Petrea volubilis*	Aphis aurantii, gossypii

Use key to polyphagous aphids

*Petrocoptis*	Caryophyllaceae
*Petrocoptis pyrenaica* = Silene glaucifolia

*Petrorhagia*	Caryophyllaceae
*Petrorhagia saxifraga*	Aphis ?craccivora, sambuci; Aulacorthum solani; Brachycaudus helichrysi; Myzus ascalonicus

Use key to apterae on Silene.

*Petroselinum*	Apiaceae
*Petroselinum crispum*	Aphis craccivora, fabae, gossypii, solanella, spiraecola; Aulacorthum solani; Brachycaudus helichrysi; Cavariella aegopodii, archangelicae, pastinacae, salicicola, theobaldi; Dysaphis apiifolia, apiifolia ssp. petroselini, [tulipae]; Hyadaphis coriandri, foeniculi; Myzus ascalonicus, ornatus, persicae; Neomyzus circumflexus; Rhopalosiphoninus latysiphon; Rhopalosiphum rufiabdominale; Semiaphis heraclei; Uroleucon compositae
*P. hortense* = P. crispum
*P. sativum* = P. crispum
*Petroselinum* sp.	Semiaphis sp. (Turkey; BMNH collection, leg. N. Tuatay)

Key to apterae on Petroselinum:-

1	ABD TERG 8 with a backward-pointing process above the cauda	…..Cavariella, 5 spp.; use couplets 2-14 of key to apterae on Angelica
–	No supracaudal process	…..2
2	SIPH very short, dark, slightly swollen and flangeless; 0.33-0.53 × cauda, shorter than R IV+V	…..3
–	SIPH pale or dark, 0.8-3.4 × cauda, longer than R IV+V	…..4
3	Hairs on ABD TERG 8 about 16μm. SIPH 0.45-0.53 × cauda	…..Semiaphis sp. (Turkey, BMNH collection)
–	Hairs on ABD TERG 8 31-41μm. SIPH 0.33-0.49 × cauda	…..Semiaphis heraclei
4	Cauda helmet-shaped, not longer than its basal width in dorsal view	…..5
–	Cauda tongue- or finger-shaped, distinctly longer than its basal width	…..6
5	Head and ABD TERG 7 and 8 usually with paired spinal tubercles (STu). Spiracles small and reniform. SIPH c.2 × cauda	…..Dysaphis apiifolia (incl. ssp. petroselini)
–	Head and ABD TERG 7-8 usually without STu. Spiracles large and rounded. SIPH truncate, c.1.1-1.3 × cauda	…..Brachycaudus helichrysi
6	ANT less than 0.5 × BL. SIPH slightly swollen distally, with a constriction proximal to the flange, and 0.6-1.4 × cauda	…..7
–	ANT 0.5-1.5 × BL. SIPH 0.8-3.4 × cauda, but if less than 1.6 × cauda then not swollen distally	…..go to key to polyphagous aphids
7	SIPH clavate, 0.88-1.4 × cauda, 1.7-3.1 × R IV+V and 3.1-5.1 × longer than their minimum diameter on basal half	…..Hyadaphis foeniculi
–	SIPH barrel-shaped, 0.6-0.82 × cauda, 0.9-1.6 × R IV+V and 1.6-2.7 × their minimum diameter on basal half	…..Hyadaphis coriandri

*Petrosimonia*	Amaranthaceae
*Petrosimonia brachiata*	Brachyunguis salsolacearum
*P. brachyptera*	Aphis craccivora
*P. sibirica*	Aphis craccivora

Key to apterae on Petrosimonia:-

–	ANT PT/BASE 0.5-0.7. SIPH very short, 0.5-0.7 × the short conical cauda. Clypeus globose	…..Brachyunguis salsolacearum*
–	ANT PT/BASE more than 1.8. SIPH more than 0.8 × cauda. Clypeus normal	….. go to key to polyphagous aphids

*Petteria*	Fabaceae
*Petteria ramentacea*	Aphis cytisorum

*Petunia*	Solanaceae
*P. × alba*	Aphis craccivora; [Lipaphis pseudobrassicae]; Myzus persicae; Rhopalosiphum rufiabdominale
*P. × atkinsiana*	Macrosiphum euphorbiae
*P. axillaris* (incl. P. ×hybrida)	Aphis craccivora, fabae, nasturtii; Macrosiphum euphorbiae; Myzus persicae; Rhopalosiphum rufiabdominale
*P. integrifolia*	[Anoecia corni, himalayensis]; Aphis craccivora, gossypii; Brachycaudus helichrysi; [Brevicoryne brassicae]; [Eutrichosiphum khasyanum]; Myzus persicae
*P. violacea* = P. integrifolia
*Petunia* spp.	Acyrthosiphon malvae; Nasonovia ribisnigri; [Paracletus cimiciformis]; [Rhopalosiphum maidis]

(The sticky hairs of Petunia may act as a trap for many aphids, resulting in spurious host records.)

Key to apterae on Petunia:-

–	Thoracic spiracles enlarged, much larger than abdominal spiracles. ANT PT/BASE 7.0-11.4, usually more than 8.0. Hairs on ANT III 0.7-1.1 × BD III. Dorsum usually with paired dark intersegmental markings	…..Nasonovia ribisnigri
–	Without that combination of characters	..…go to key to polyphagous aphids

*Peucedanum*	Apiaceae
*Peucedanum aculeolatum* = Afroligusticum aculeolatum
*P. aegopoidiodes*	Cavariella theobaldi
*P. alsaticum*	Aphis fabae, grosmannae, schilderi, umbelliferarum; Cavariella aegopodii; Dysaphis [crataegi], peucedani, uralensis; Hyadaphis foeniculi; Semiaphis horvathi
*P. arenarium*	Cavariella aegopodii
*P. austriacum*	Aphis fabae; Aulacorthum solani; Cavariella aegopodii
*P. baicalense*	Aphis fabae
*P. carvifolia*	Aphis peucedanicarvifoliae
*P. cervaria*	Aphis fabae, schilderi; Cavariella aegopodii; Dysaphis apifoliia; Semiaphis cervariae, horvathi, sphondylii
*P. deltoideum* = P. terebinthiaceum var. deltoideum
*P. fraxinifolium* = Steganotaenia araliacea
*P. graveolens* = Anethum graveolens
*P. kerstenii* = Afrosciadium kerstenii
*P. japonicum*	Aphis gossypii; Aulacorthum solani
*P. lubimenkoanum* = P. alsaticum
*P. morisonii*	Aphis [franzi], grossmanae, schilderi, umbelliferarum; Dysaphis uralensis; Semiaphis horvathi
*P. officinale*	Acyrthosiphon nigripes ssp. peucedani; Aphis fabae, peucedani, schilderi; Aulacorthum solani; Cavariella aegopodii; Defractosiphon franzi; Semiaphis horvathi
*P. oreoselinum*	[Anuraphis subterranea]; Aphis fabae, grosmannae, schilderi; Dysaphis apiifolia, oreoselini, peucedani; Hyadaphis foeniculi, passerinii; Semiaphis anthrisci, cervariae
*P. ostruthium*	Aphis fabae, [Aphis sp., Sweden (Ossiannilsson, 1964a)]; Cavariella aegopodii, pastinacae; Dysaphis apiifolia; Semiaphis sphondylii
*P. palustre*	Aphis fabae, grosmannae; Cavariella aegopodii; Semiaphis anthrisci
*P. pseudoreoselinum*	Brachyunguis peucedani
*P. ruthenicum*	Acyrthosiphon [gossypii], nigripes ssp. peucedani; Aphis umbelliferarum; Defractosiphon franzi; [Semiaphis dauci, pastinacae]
*P. sativum* = Pastinaca sativa
*P. terebinthaceum* (incl. var. deltoideum)	Cavariella japonica, konoi; Dysaphis deltoidei
*P. typherr* (?)	Aphis fabae
*Peucedanum* sp.	Cavariella archangelicae; [Dysaphis taisetsusana (?)]; [Semiaphis coryspermi], [Semiaphis sp. (Bozhko 1976: 70)]

Key to apterae on Peucedanum:-

1	SIPH less than 0.9 × cauda	…..2
–	SIPH at least 0.9 × cauda	…..10
2	ANT PT/BASE c. 0.6, PT being similar in length to SIPH	…..Brachyunguis peucedani*
–	ANT PT/BASE more than 1.5, and PT much longer than SIPH	…..3
3	Cauda broadly conical or triangular, not longer than its basal width in dorsal view, with 4-6 hairs	…..4
–	Cauda tapering, tongue- or finger-like, distinctly longer than its basal width, and often with more than 6 hairs	…..5
4	Flat dome-shaped marginal tubercles (MTu) consistently present on ABD TERG 1-5 and 7	…..Aphis umbelliferarum
–	MTu absent or inconspicuous, or not consistently present on any ABD TERG	…..Aphis peucedanicarvifoliae*
5	SIPH more than 0.6 × cauda, with or without a flange	…..6
–	SIPH less than 0.6 × cauda, flangeless, and usually curved towards midline	…..7
6	SIPH tapering almost to a point, with a narrow, rounded, flangeless apex (Fig.41a). ANT III with 0-6 rhinaria on distal part, and IV with 1-7 (1-11 on III + IV if fused)	…..Defractosiphon franzi
–	SIPH slightly swollen, with an apical flange (Fig.41b). ANT III and IV without rhinaria	…..Hyadaphis coriandri
7	SIPH very short and broad-based, 0.4-0.6 × as long as their basal widths (Fig.41c). R IV+V only 0.5-0.6 × HT II	…..Semiaphis cervariae
–	SIPH more than 0.8 × as long as their basal widths (e.g. Fig.41d). R IV+V 0.7-1.0 × HT II	…..8
8	ANT PT/BASE 1.6-2.5. Well-developed flat marginal tubercles (MTu) usually present on prothorax and ABD TERG 1-5, mostly much larger than spiracular apertures, and spinal tubercles (STu) usually present on ABD TERG 5-7	…..Semiaphis horvathi
–	ANT PT/BASE 2.5-3.5. MTu and STu irregularly present, MTu rarely larger than the spiracular apertures, except on ABD TERG 5	…..9
9	Longest hairs on ANT III 15-20 μm, 0.6-0.8 × BD III. Hairs on ABD TERG 8 are 30-50 μm, 1.0-1.7 × BD III	…..Semiaphis sphondylii
–	Longest hairs on ANT III 10-13 μm, 0.4-0.5 × BD III. Hairs on ABD TERG 8 are 12-30 μm, 0.5-1.2 × BD III	…..Semiaphis anthrisci
10	ABD TERG 8 with a backwardly-projecting process, sometimes reduced but always bearing a pair of hairs	…..Cavariella (6 species; use couplets 2-14 of key to apterae on Angelica)
–	No supracaudal process. SIPH cylindrical or tapering	…..11
11	Cauda helmet-shaped, not longer than its basal width in dorsal view, and usually bearing 5 hairs. Head and often also ABD TERG 8, or 7 and 8, with spinal tubercles (STu)	…..12
–	Cauda tongue- or finger-shaped, much longer than its basal width. STu absent from head and rarely present on ABD TERG	…..16
12	Longest hair on ANT III 40-50 μm long, 2.3-2.7 × BD III. Pronotum with a pair of pleural hairs (lateral to the spinal pair)	…..Dysaphis deltoidei
–	Longest hair on ANT III 4-15 μm long, 0.2-0.9 × BD III. Pronotum without pleural hairs	…..13
13	SIPH 0.19-0.34 mm, 1.9-3.2 × cauda	…..14
–	SIPH 0.15-0.19 mm, 1.6-2.1 × cauda	…..15
14	SIPH 2.7-3.2 × cauda	…..Dysaphis peucedani*
–	SIPH 1.9-2.5 × cauda	…..Dysaphis apiifolia
15	All apterae to some extent alatiform with ANT III-IV (-V) bearing secondary rhinaria. Arms of mesothoracic furca separate	…..Dysaphis uralensis
–	Apterae without secondary rhinaria. Arms of mesothoracic furca united at bases	…..Dysaphis oreoselini
16	Head, ANT, tibiae, SIPH and cauda all entirely black. (Large, spindle-shaped aphid)	…..Acyrthosiphon nigripes ssp. peucedani
–	At least ANT and tibiae have pale sections	……17
17	ANT tubercles weakly developed, head without spicules. SIPH dark	…..18
–	ANT tubercles well developed, head with or without spicules. SIPH pale or dusky	…..go to key to polyphagous aphids, starting at couplet 5
18	ABD TERG 1 and 7 without marginal tubercles (MTu). SIPH clavate, 0.9-1.4 × cauda	…..19
–	ABD TERG 1 and 7 always with MTu. SIPH cylindrical/tapering, 1-3 × cauda	…..20
19	Prosternal sclerite 1.36-2.6 × wider than long, often convex posteriorly. SIPH 1.05-1.4 × cauda. (Al. often with sec. rhinaria on ANT V)	…..Hyadaphis foeniculi
–	Prosternal sclerite 2.2-3.6 × wider than long, with posterior margin often straight. SIPH 0.85-1.2 × cauda. (Al. rarely with sec. rhinaria on ANT V)	…..Hyadaphis passerinii
20	Cauda with 11-19 hairs	…..21
–	Cauda with 4-8 hairs	…..22
21	ABD TERG 2-4, as well as 1 and 7, with well-developed MTu. Longest hair on ANT III 0.3-0.6 × BD III. Cauda with 12-15 hairs	…..Aphis grosmannae
–	ABD TERG 2-4 only irregularly with small MTu. Longest hair on ANT III 0.80-2.2 × BD III. Cauda with 11-19 hairs	…..Aphis fabae
22	Cauda paler than SIPH, with 4-8 hairs. Longest hair on ANT III 0.4-0.8 × BD III. MTu on ABD TERG 1 and 7 small, less than half diameter of SIPH at midlength	…..Aphis gossypii
–	Cauda as dark as SIPH. Longest hair on ANT III 0.2-0.5 × BD III. MTu on ABD TERG 1 and 7 large, more than 0.5 × diameter of SIPH at midlength	…..23
23	ABD TERG 2-4 as well as 1 and 7 regularly with MTu. SIPH 1.7-3.0 × cauda	…..Aphis peucedani
–	ABD TERG 2-4 without or only irregularly with MTu. SIPH 1.0-1.7 × cauda	…..Aphis schilderi

*Phaca* see Astragalus	Fabaceae
*Phaca frigida* = Astragalus frigidus

*Phacelia*	Hydrophyllaceae
*Phacelia circinata* = Ph. secunda
*Ph. hastata*	Pleotrichophorus amsinckii
*Ph. heterophylla*	Aphis phaceliae; Myzus ascalonicus
*Ph. nemoralis*	Abstrusomyzus phloxae; [Amphorophora sp., Oregon (see aphidtrek.org)]; Aphis phaceliae; Myzus ornatus
*Ph. secunda*	[“Nectarophora” sp. (Cockerell 1903, 17)]
*Ph. sericea*	Brachycaudus helichrysi
*Ph. tanacetifolia*	Aphis fabae; Myzus persicae
*Phacelia* spp.	[Ericaphis sp., Idaho (see aphidtrek.org)]; Illinoia phacelia; Macrosiphum euphorbiae

Key to apterae on Phacelia:-

1	Dorsal body (including front of head and ANT I –II) bearing numerous hairs with fan-shaped or capitate apices, and arising from tuberculate bases. R IV+V extremely long, thin and tapering, 1.75-2.0 × HT II	……Pleotrichophorus amsinckii
–	Dorsal body hairs not fan-shaped or capitate, R IV+V not very long and thin	…..2
2	Spindle-shaped aphid with ANT much longer than BL, and ANT PT/BASE more than 7. SIPH pale, c.2.5 × cauda, cylindrical or slightly swollen on distal part, with some indistinct subapical reticulation. R IV+V 1.6-1.8 × HT II and bearing 23-32 accessory hairs	…..Illinoia phacelia
–	Without that combination of characters	…..3
3	ANT tubercles weakly developed, and ABD TERG 1 and 7 with marginal tubercles (MTu). R IV+V 1.5-1.6 × HT II, longer than cauda and bearing 4-5 hairs	…..Aphis phaceliae
–	Without that combination of characters; i.e. if ANT tubercles are weakly developed and ABD TERG 1 and 7 have MTu then R IV+V is relatively shorter and bears only 2 accessory hairs	…..go to key to polyphagous aphids

*Phacelurus*	Poaceae
*Phacelurus speciosus*	Sipha elegans, maydis

Use key to apterae on Poaceae under Digitaria.

*Phaeomeria* see Etlingera	Zingiberaceae
*Phaeomeria speciosa* = Etlingera elatior

*Phagnalon*	Asteraceae
*Phagnalon rupestre*	Brachycaudus helichrysi; Macrosiphum euphorbiae; Myzus persicae
*Ph. saxatile*	Aphis gossypii, spiraecola; Brachycaudus helichrysi; Myzus persicae
*Ph. sordidum*	Brachycaudus helichrysi; [Macrosiphoniella helichrysi]

Use key to polyphagous aphids.

*Phaius* (or Phajus)	Orchidaceae
*Phaius albus* = Thunia alba
*Ph. grandifolius* = Ph. tankervilleae
*Ph. tankervilleae*	Aphis fabae group (Brazil); Cerataphis orchidearum

Use key to aphids on orchids under Cymbidium.

*Phalacroloma* see Erigeron	Asteraceae
*Phalacroloma septentrionale* = Erigeron strigosus var. septentrionalis

*Phalaenopsis*	Orchidaceae
*Phalaenopsis* sp.	Cerataphis orchidearum

*Phalaris* (including Phalaroides)	Poaceae
*Phalaris amethystina*	Metopolophium dirhodum; Sitobion avenae
*Ph. aquatica*	Diuraphis noxia; Metopolophium dirhodum; Rhopalosiphum maidis, padi; Schizaphis hypersiphonata; Sitobion avenae, fragariae
*Ph. arundinacea* (incl. var. picta)	Anoecia major; Atheroides serrulatus; Diuraphis noxia; Forda formicaria; Geoica lucifuga, setulosa; Hyalopterus pruni; Metopolophium dirhodum; Myzus persicae; Rhopalomyzus lonicerae, poae; Rhopalosiphum maidis, oxyacanthae, padi; Schizaphis jaroslavi, longicaudata, graminum; Sipha elegans, glyceriae, maidis; Sitobion avenae, fragariae, graminearum; Tetraneura ulmi
*Ph. brachystachys*	Israelaphis lambersi; Metopolophium dirhodum; Rhopalosiphum padi; Sitobon avenae, fragariae
*Ph. canariensis*	Diuraphis noxia; Israelaphis lambersi; Metopolophium albidum, dirhodum; Rhopalomyzus lonicerae; Rhopalosiphum maidis, padi; Schizaphis graminum, longicaudata; Sitobion avenae
*Ph. coerulescens*	Metopolophium dirhodum; Rhopalomyzus lonicerae; Rhopalosiphum padi
*Ph. minor*	Hysteroneura setariae; Metopolophium dirhodum; Rhopalosiphum rufiabdominale; Sitobion avenae, miscanthi
*Ph. nodosa* = Ph. aquatica
*Ph. paradoxa*	Israelaphis lambersi; Rhopalosiphum maidis, padi; Sitobon avenae, fragariae
*Ph. stenoptera* = Ph. aquatica
*Ph. truncata*	Schizaphis graminum
*Ph. tuberosa* = Ph. aquatica
*Phalaris* sp.	Aphis craccivora; Sipha flava
Use key to apterae of grass-feeding aphids under Digitaria.

*Phania*	Asteraceae
*Phania matricarioides*	Aphis gossypii

Pharbitis see Ipomoea

Convolvulaceae

*Phaseolus*	Fabaceae
*Phaseolus adenanthus* = Vigna adenantha
*Ph. angularis* = Vigna angularis
*Ph. atropurpureus* = Macroptilium atropurpureum
*Ph. aureus* = Vigna radiata
*Ph. coccineus*	Acyrthosiphon pisum; [“Amphorophora ampullata” of Zirnits 1927]; Aphis craccivora, fabae, glycines, gossypii; Myzus ornatus, persicae; Smynthurodes betae
*Ph. limensis* = P. lunatus	Aphis fabae
*Ph. lunatus*	Aphis craccivora, fabae, gossypii; Microparsus brasiliensis; Smynthurodes betae
*Ph. multiflorus* = P. coccineus
*Ph. mungo* = Vigna mungo
*Ph. nanus* = P. vulgaris
*Ph. nipponensis* = Vigna angularis var. nipponensis
*Ph. radiatus* = Vigna radiata
*Ph. sublobatus* = Vigna radiata var. sublobata
*Ph. trilobus* = Vigna lobata (?)
*Ph. vulgaris*	Acyrthosiphon gossypii, pisum; Aphis [citricidus], craccivora, fabae, gossypii, lhasaensis, nasturtii; Aulacorthum solani; [Capitophorus elaeagni]; [Hyalopterus pruni]; Macrosiphum creelii, euphorbiae; [Megoura viciae]; Microparsus brasiliensis, vignaphilus; Myzus ornatus, persicae; Protaphis middletonii; Rhopalosiphoninus latysiphon; Smynthurodes betae; Therioaphis trifolii
*Phaseolus* spp.	Acyrthosiphon phaseoli; Aphis glycines; Rhopalosiphoninus latysiphon; [Semiaphis heraclei]

Key to apterae on Phaseolus and Vigna:-

(See Blackman & Eastop 2000, for an illustrated key to common aphids on cultivated Phaseolus.)

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 ring of hairs with expanded apices. ABD TERG 8 with hair-bearing backwardly directed processes. Cauda broad with a median stylus	…..Anomalosiphum indigoferae
–	SIPH without hairs. ABD TERG 8 without processes. Cauda helmet-shaped, tongue- or finger-like	…..3
3	Cauda with a constriction and a knob-like apex. Anal plate bilobed. Dorsal hairs arising from pigmented bases (if apterae then these hairs are mostly long and capitate). Fore coxae greatly enlarged. ANT PT/BASE about 1	…..Therioaphis trifolii
–	Cauda tongue-shaped, rounded or triangular in dorsal view. Anal plate entire. Body hairs are blunt or pointed, with or without pigmented bases. Fore coxae normal. ANT PT/BASE much more than 1	…..4
4	ANT tubercles weakly developed. ABD TERG 1 and 7 with marginal tubercles (MTu)	…..5
–	ANT tubercles well developed. ABD TERG 1 and 7 without MTu	…..9
5	Dorsal abdomen with an extensive solid black shield. Cauda with 4-9 hairs	…..6
–	Dorsal abdomen without an extensive solid black shield, and if with any dark markings then cauda has 10 or more hairs	…..7
6	ABD TERG 2-4 usually without MTu	…..Aphis craccivora
–	Well-developed MTu consistently present on ABD TERG 2-4 as well as 1 and 7	…..Aphis lhasaensis
7	Hind femur with all hairs shorter than basal diameter of femur. SIPH uniformly dark or slightly paler near bases, and darker than cauda which bears 4-10 hairs	…..8
–	Hind femur with at least some long fine hairs longer than its basal diameter. SIPH pale or dark, but if dark then cauda is similarly dark and may have more than 10 hairs	…..go to key to polyphagous aphids, starting at couplet 25
8	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
9	ANT I and II black, contrasting with base of III. SIPH with pale basal part and dark distal part (and often slightly clavate). (Al. with forewing veins, especially the anal vein Cu_1b, conspicuously black-bordered)	…..10
–	ANT I and II pale. SIPH entirely pale or darker only at apices; tapering, cylindrical or clavate. (Al. with forewing veins not conspicuously dark-bordered)	…..12
10	SIPH 1.1-1.5 × cauda	…..Microparsus brasiliensis
–	SIPH 1.7-2.0 × cauda	…..11
11	SIPH pale on basal 0.33-0.67 of length. HT I with medial hair (sense peg) 0.4-0.6 × length of the 2 lateral hairs. BL 1.9-2.4 mm	…..Microparsus vignaphilus
–	SIPH pale on basal 0.2-0.4 of length. HT I with medial hair 0.6-1.0 × length of the 2 lateral hairs. BL 1.1-1.9 mm	…..Microparsus puertoricensis
12	Head densely spiculose, at least ventrally, with scabrous, steep-sided ANT tubercles. ANT III with 0-2(-3) rhinaria	…..go to key to polyphagous aphids, starting at couplet 5
–	Head smooth or with sparse minute spicules, ANT tubercles smooth and broadly divergent. ANT III with (0-) 1-10 rhinaria	…..13
13	SIPH with subapical reticulation (at least 4-5 rows of closed polygonal cells)	…..14
–	SIPH without polygonal reticulation	…..15
14	ANT BASE VI 0.8-1.3 × R IV+V	…..Macrosiphum euphorbiae
–	ANT BASE VI 1.4-2.0 × R IV+V	…..Macrosiphum creelii
15	SIPH long and attenuate distally, 0.42-0.50 × BL and 2.5-3.5 × cauda	…..Acyrthosiphon gossypii
–	SIPH 0.23-0.38 × BL, and 1.2-2.3 × cauda	…..16
16	SIPH tapering gradually from base to flange, 2.0-2.3 × cauda. R IV+V about equal in length to HT II or a little longer	…..Acyrthosiphon phaseoli*
–	SIPH thin and cylindrical distally, 1.2-1.9 × cauda. R IV+V 0.6-0.95 × HT II	…..Acyrthosiphon pisum

*Phaulopsis* (including Phaylopsis)	Acanthaceae
*Ph. imbricata* ssp. poggei	Aphis gossypii
*Ph. poggei* = Ph. imbricata ssp. poggei

*Phedimus*	Crassulaceae
*Phedimus middendorfianus*	Aphis sedi
*Ph. selskianus*	Aphis sedi

*Phegopteris*	Thelypteridaceae
*Phegopteris connectilis*	Amphorophora ampullata; Macrosiphum dryopteridis
*Ph. decursive-pinnata*	Macromyzus maculata

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

*Phelipanche* see Orobanche	Orobanchaceae
*Phelipanche ramosa* = Orobanche ramosa

*Phellodendron*	Rutaceae
*Phellodendron amurense*	Aphis citricidus, fabae, odinae; [Chaitophorus pheleodendri]
*Phellodendron* sp.	Neomyzus circumflexus

Use key to polyphagous aphids.

*Phenax*	Urticaceae
*Phenax mexicanus*	Aphis spiraecola
**Ph. rugosus**	Aphis spiraecola
**Ph. sonneratii**	Aphis gossypii; Myzus persicae
*Phenax* sp.	Myzus ornatus

Use key to polyphagous aphids.

*Philadelphus*	Hydrangeaceae
*Philadelphus caucasicus* = Ph. coronarius
*Ph. coronarius*	Aphis fabae, [fabae ssp. cirsiiacanthoidis], fabae ssp. mordvilkoi, gossypii, nasturtii, spiraecola; Brachycaudus helichrysi; [Macrosiphum rosae]; Myzus persicae
*Ph. delavayi*	Aphis fabae [ssp. cirsiiacanthoidis], philadelphicola
*Ph. floribundus*	Aphis fabae
*Ph. hirsutus*	Aphis fabae
*Ph. gordonianus* see lewisii
*Ph. grandiflorus* see inodorus
*Ph. inodorus* (incl. var. grandiflorus)	Aphis fabae, spiraecola; Macrosiphum euphorbiae; Myzus persicae
*Ph. latifolius* = Ph. pubescens
*Ph. lewisii* (incl. ssp. gordonianus)	[Anoecia corni]; Aphis fabae; Aulacorthum solani; Brachycaudus helichrysi; Glendenningia philadelphi; [Illinoia spiraeae]; Macrosiphum euphorbiae; Myzus ornatus, persicae
*Ph. mexicanus*	Myzus persicae
*Ph. microphyllus*	Aphis fabae
*Ph. multiflorus* (?)	Aphis fabae; Myzus persicae
*Ph. pallidus* = Ph. coronarius
*Ph. pekinensis*	Myzus persicae
*Ph. pubescens*	Aphis fabae, philadelphicola
*Ph. satsumanus*	Myzus persicae
*Ph. satsumi*	Aulacorthum solani; Myzus philadelphi
*Ph. sericanthus*	Aphis philadelphicola
*Ph. shrenkii*	Aphis fabae [ssp. cirsiiacanthoidis], philadelphicola
*Ph. subcanus*	Aphis philadelphicola
*Ph. tenuifolius*	Aphis fabae, gossypii, philadelphicola; Rhopalosiphoninus deutzifoliae
*Ph. viminalis* (?)	Aphis fabae
*Ph. × virginalis*	Aphis fabae; Brachycaudus helichrysi; Macrosiphum euphorbiae; Myzus ornatus, persicae
*Philadelphus* spp.	Aphis [philadelphi], [viburni of Borner 1923]; Aphis (Toxoptera) citricidus; [Prociphilus americanus (as Pemphigus venafuscus)]

Key to apterae on Philadelphus:-

(Couplets 1-2 can be applied to alatae as well as apterae)

1	SIPH very markedly inflated, with diameter of swollen part 2.0-4.5 × minimum diameter of basal part. (Aptera is fundatrix, all progeny being alatae)	…..Rhopalosiphoninus deutzifoliae
–	SIPH tapering or cylindrical, or clavate but with diameter of swollen part less than 2 × minimum diameter of basal part	…..2
2	Cauda broad-based with a drawn-out conical papilliform tip, bearing 1-2 hairs on the tip and 6 hairs on the swollen basal part. SIPH clavate. (Al. with numerous sec. rhinaria scattered over entire surfaces of ANT III-V; 47-61 on III, 17-28 on IV and 3-11 on V)	…..Glendenningia philadelphi
–	Cauda helmet-, tongue- or finger-shaped, tapering from base to apex, or with rounded apex. SIPH cylindrical, tapering or slightly clavate. (Al. with sec. rhinaria much less numerous)	…..3
3	ANT, SIPH and legs (even basal parts of femora) entirely dark. Head spiculose, SIPH slightly swollen on distal part, cauda triangular	…..Myzus philadelphi
–	SIPH pale or dark, ANT and legs with at least some parts pale. Other characters not in that combination	…..4
4	Well-developed marginal tubercles (MTu) present on ABD TERG 1-5 (-6) and 7. SIPH 0.67-0.87 × cauda, much shorter that R IV+V which is 1.54-1.65 × HT II	…..Aphis philadelphicola*
–	MTu only ever regularly on ABD TERG 1 and 7, and other characters not in that combination	…..go to key to polyphagous aphids (but note that specimens running to Aphis fabae are likely to be ssp. mordvilkoi).

*Phillyrea*	Oleaceae
*Phillyrea latifolia*	Macchiatiella rhamni (?); Prociphilus oleae
*Ph. media* = P. latifolia

Key to apterae on Phillyrea:-

–	BL more than 3.0 mm. Dorsum membranous. SIPH as inconspicuous pores or absent. (Apterae are all fundatrices producing all-alate progeny on twigs, with copious wax.)	…..Prociphilus oleae
–	BL less than 2.5 mm. Dorsal abdomen with variably developed dark markings. SIPH present, pale	…..Macchiatiella rhamni of Remaudière (1959)

*Philodendron*	Araceae
*Philodendron hastatum*	Myzus ornatus
Philodendron sp.	Aphis (Toxoptera) aurantii; Pentalonia nigronervosa

Key to apterae on Philodendron:-

–	SIPH with pale basal and dark distal sections. Femora with basal 0.6 or more of length pale, contrasting with black distal section. SIPH and femora covered with irregular, transverse rows of spicules. ANT PT/BASE 5.8-8.1. (Alata with dark-bordered wing veins, with radius and costa fused for part of lengths to form a closed cell behind the pterostigma)	…..Pentalonia nigronervosa
–	Without that combination of characters	…..go to key to polyphagous aphids

*Philonotis*	Bartramiaceae
*Philonotis fontana*	[Clydesmithia canadensis]; Myzodium mimulicola; [Thecabius populimonilis]

Use key to aphids on mosses under Polytrichum.

Philotria see Elodea

Hydrocharitaceae

*Phlebodium*	Polypodiaceae
*Phlebodium aureum*	Idiopterus nephrelepidis
*Ph. pseudoaureum*	Microparsus pojanii

(Use key to fern-feeding aphids under Polypodium.)

*Phleum* (including Phalaroides)	Poaceae
*Phleum alpinum*	Forda formicaria, marginata; Rhopalosiphum padi; Schizaphis jaroslavi; Sipha maydis; Sitobion avenae
*Ph. commutatum* = Ph. alpinum
*Ph. echinatum*	Israelaphis ilharcoi
*Ph. paniculatum*	Schizaphis graminum
*Ph. phleoides*	Anoecia corni; Atheroides brevicornis; Baizongia pistaciae; Forda marginata; Geoica utricularia; Rhopalosiphum insertum, padi; Sitobion avenae, fragariae; Tetraneura ulmi
*Ph. pratense*	Anoecia corni, furcata, querci; Aulacorthum solani; Carolinaia rhois; Diuraphis muehlei, noxia, tritici; Forda marginata; Geoica utricularia; Israelaphis lambersi; Laingia psammae; Metopolophium albidum, dirhodum, festucae, tenerum; Rhopalomyzus lonicerae; Rhopalosiphum maidis, padi; Schizaphis borealis, graminum, phlei; Sipha elegans, flava, glyceriae, maydis; Sitobion akebiae, avenae, fragariae; Tetraneura akinire, ulmi, yezoense
*Phleum* spp.	[Geoica discreta Börner 1952 (utricularia* group)]* Use key to apterae of grass-feeding aphids under Digitaria.

*Phlogacanthus*	Acanthaceae
*Phlogacanthus thyrsiflorus* (?)	Aphis (Toxoptera) aurantii

*Phlojodicarpus*	Apiaceae
*Phlojodicarpus sibiricus*	Aphis phlojodicarpi
*Ph. villosus*	Aphis phlojodicarpi

*Phlomis*	Lamiaceae
*Phlomis agraria*	Brachycaudus cerasicola
*Ph. bracteosa*	Cryptomyzus taoi
*Ph. canescens*	Cryptomyzus tadzhikistanica
*Ph. fruticosa*	Myzus persicae
*Ph. macrophylla*	Macrosiphum euphorbiae
*Ph. maximowiczii*	Aphis gossypii
*Ph. nepetifolia* = Leonotis nepetifolia
*Ph. olivieri*	Cryptomyzus behboudii
*Ph. oreophila*	Brachycaudus cerasicola; [Cryptomyzus transiliensis]
*Ph. regelii*	Aphis gossypii; Brachycaudus [cardui], cerasicola
*Ph. salicifolia*	Aphis gossypii; Cryptomyzus sairamugamicus
*Ph. tuberosa*	Aphis fabae, gossypii, origani; Aulacorthum solani; Brachycaudus cerasicola; Macrosiphum euphorbiae
*Ph. viscosa*	Brachycaudus cerasicola; Cryptomyzus ribis
*Phlomis* sp.	Roepkea marchali

Key to apterae on Phlomis:-

1	Dorsal hairs long with thick bases and knobbed apices	…..2
–	Dorsal hairs long or short without knobbed apices	…..5
2	R IV+V extremely long and narrow, as long as or longer than SIPH	…..Cryptomyzus behboudii
–	R IV+V less than half as long as SIPH	…..3
3	R IV+V 1.8-2.0 × HT II	…..Cryptomyzus sairamugamicus*
–	R IV+V 1.3-1.5 × HT II	…..4
4	SIPH more-or-less cylindrical, with little trace of swelling; thinner than hind tibia for most of length. SIPH 2.2-3.1 × cauda	…..Cryptomyzus ribis
–	SIPH with distinctly swollen section on distal part, with maximum diameter 1.2-1.6 × minimum diameter on proximal half, the swollen part being distinctly thicker than hind tibia. SIPH 3.6-5.0 × cauda	…..Cryptomyzus taoi
5	Hairs on ANT and dorsal side of tibiae long, stiff, erect, maximally 100-110 μm, more than 2 × BD III. ANT PT/BASE more than 7. SIPH clavate, c.2 × cauda	…..Cryptomyzus tadzhikistanica*
–	Hairs shorter or not stiff and erect, ANT PT/BASE less than 7. SIPH various	…..6
6	Cauda semicircular to helmet-shaped, shorter than its basal width in dorsal view. Dorsum often with an extensive black sclerotic shield	…..7
–	Cauda finger-like, much longer than its basal width. Dorsum without an extensive black sclerotic shield	…..8
7	SIPH shorter than R IV+V, lightly imbricated, without spicules. Dorsal cuticle not spiculose	…..Brachycaudus cerasicola
–	SIPH longer than R IV+V, with transverse rows of spicules. Dorsal cuticle spiculose	…..Roepkea marchali
8	ALL the following apply: ANT tubercles weakly developed. SIPH wholly dusky/dark, but Cauda paler. ABD TERG 1 and 7 with well-developed marginal tubercles (MTu), those on 7 having basal diameter more than 0.5 × thickness of SIPH at midlength. ABD TERG 8 (or 7 and 8) with thin dusky or dark crossbands, and abdomen usually with dark intersegmental muscle plates. ANT PT/BASE 1.8-2.6	…..Aphis origani
–	Without that combination of characters	…..go to key to polyphagous aphids

*Phlox*	Polemoniaceae
*Phlox douglasii*	Myzus ascalonicus
*Ph. drummondii*	Aphis gossypii; Aulacorthum solani; Macrosiphum euphorbiae; Myzus persicae
*Ph. paniculata*	Aphis fabae; Myzus ascalonicus, persicae
*Ph. subulata*	Abstrusomyzus phloxae; Myzus ascalonicus
*Phlox* sp.	Aphis triglochinis

Key to apterae on Phlox:-

–	ANT PT/BASE 1.1-1.73. SIPH pale and 0.7-1.3 × cauda	…..Aphis triglochinis
–	ANT PT/BASE more than 1.8. SIPH pale or dark, if pale then more than 1.5 × cauda	…..go to key to polyphagous aphids

*Phoebe*	Lauraceae
*Phoebe bournei*	Longistigma xizangensis; Machilaphis machili
*Ph. elongata*	Aphis (Toxoptera) aurantii
*Ph. lanceolata*	Aiceona retipennis
*Ph. porphyria* = Ocotea porphyria
*Ph. sheareri*	[Aiceona sp.]; Machilaphis machili
*Ph. zhennan*	Longistigma xizangensis
*Phoebe* ssp.	Aiceona actinodaphnis; [Microunguis depressa]; [Neothoracaphis saramaoensis]; Nipponaphis machili; Sinomegoura citricola, photiniae; Sinonipponaphis formosana; [Thoracaphis kashifoliae]

Key to species on Phoebe:-

1	Aptera of normal aphid form, with well-developed legs and 6-segmented antennae. Alata with circular secondary rhinaria	…..2
–	Aptera aleyrodiform with reduced legs, very short 3- or 4-segmented antennae and variably fused head, thorax and anterior abdominal tergites. Antenna of alata with annular secondary rhinaria	…..8
2	ANT PT/BASE more than 3. SIPH tubular, black, cauda tongue- or finger-shaped	…..3
–	ANT PT/BASE less than 0.5. SIPH as slightly raised pores or hairy cones. Cauda broadly rounded	…..5
3	Antennal tubercles weakly developed. SIPH imbricated, tapering without any trace of swelling. Stridulatory apparatus present	…..Aphis (Toxoptera) aurantii
–	Antennal tubercles well developed, with inner faces divergent. SIPH almost smooth, slightly swollen. No stridulatory apparatus	…..4
4	SIPH 1.0-1.3 × cauda which is pale, with thin pointed apex, and bears 10-18 hairs. Head spiculose over entire ventral surface	…..Sinomegoura photiniae
–	SIPH 0.8-1.0 × cauda which is dark with blunt apex and bears 17-24 hairs. Head spiculose only on ventral side of ANT tubercles	…..Sinomegoura citricola
5	BL more than 6 mm. Forewing of alata with pterostigma extending almost to wing-tip	…..Longistigma xizangensis
–	BL 2-3 mm. Forewing of alata with a normal pterostigma	…..6
6	Body hairs inconspicuous, apterae with compound eyes. SIPH as pores ringed with a few hairs	…..Machilaphis machili
–	Long-haired aphid, apterae with eyes of only 3 facets. SIPH as hairy cones	…..7
7	R IV+V 0.52-0.70 × HT II. ANT PT/BASE 0.30-0.45	…..Aiceona retipennis
–	R IV+V longer than HT II. ANT PT/BASE 0.5 or more	…..Aiceona actinodaphnis
8	Dorsal cuticle of aptera smooth, densely covered with short, thorn-like, broad-based, hair-like processes	…..Sinonipponaphis formosana*
–	Dorsal cuticle of aptera either smooth or with pustulate ornamentation; hairs fine and of variable length, no thorn-like processes	…..Nipponaphis machili

*Phoenix* Date Palms	Arecaceae
Phoenix dactylifera	Cerataphis brasiliensis; Schizaphis rotundiventris

(Or use key to aphids on palms under Calamus)

–	Body dorsoventrally flattened, with a crenulate margin due to a continuous row of wax glands. Head with a pair of forwardly directed frontal horns. Siphunculi poriform	…..Cerataphis brasiliensis
–	Body of typical aphid form, without wax glands or frontal horns. Siphunculi tubular	…..Schizaphis rotundiventris

*Phormium*	Phormiaceae
*Phormium tenax*	Aulacorthum solani

*Photinia* (including Heteromeles, Stranvaesia)	Rosaceae
*Photinia arbutifolia* (= Heteromeles salicifolia)	Aphis gossypii, pomi; Myzus persicae; Prociphilus caryae arbutifoliae; [Wahlgreniella nervata]
*Ph. arguta*	Nippolachnus bengalensis
*Ph. beauverdiana*	Aphis gossypii
*Ph. davidiana* (= Stranvaesia davidiana)	Aphis stranvaesiae, [Aphis sp. (Leonard, 1972: 164)]; Illinoia spiraeae
*Ph. × fraseri*	Aphis gossypii, pomi; Brachycaudus helichrysi; Ericaphis gentneri; Macrosiphum euphorbiae; [Phorodon humuli]
*Ph. glabra*	Aphis aurantii, gossypii, spiraecola; Hyalomyzus eriobotryae; Sinomegoura citricola, photiniae
*Ph. integrifolia*	Aphis spiraecola; Prociphilus sp. “A” (A.K. Ghosh et al., 1970b); [Rhopalosiphum padi]; Sinomegoura citricola, photiniae
*Ph. japonica* = Eriobotrya japonica
*Ph. melanocarpa*	Aphis fabae, pomi
*Ph. niitakayamensis* see Ph. davidiana
*Ph. notoniana* = Ph. integrifolia
*Ph. prunifolia*	Aphis pomi, spiraecola
*Ph. serratifolia*	Aphis gossypii, spiraecola; Myzus ornatus, persicae
*Ph. serrulata* = Ph. serratifolia
*Ph. variabilis* = Ph. villosa
*Ph. villosa* (incl. vars laevis, zollingeri)	Aphis citricidus, gossypii, pomi, spiraecola; [Eriosoma lanigerum]; Melanaphis bambusae; [Miyazakia ranunculi]; [Ovatus malisuctus]; Prociphilus ushikoroshi; [Rhopalosiphum padi]; Sinomegoura photiniae
*Photinia* sp.	[Greenidea photiniphaga]

Key to species on Photinia (including Heteromeles, Stranvaesia) :-

1	ANT PT/BASE less than 0.5. Cauda bluntly rounded	…..2
–	ANT PT/BASE more than 1. Cauda tongue- or finger-like	…..4
2	Body and appendages with numerous long, fine hairs. SIPH pores large, on hairy cones. No evident wax glands	…..Nippolachnus bengalensis
–	Body and appendages with sparse, short hairs. SIPH pores indistinct or absent. Wax glands evident	…..3
3	Spring migrant alatae with secondary rhinaria distributed ANT III 20-31, IV 4-9, V 0-6, VI 0	…..Prociphilus caryae arbutifoliae
–	Spring migrant alatae with secondary rhinaria distributed ANT III 10-14, IV 4-7, V 1-4, VI 0-1	…..Prociphilus ushikoroshi
–	Spring migrant alatae with secondary rhinaria distributed ANT III 35-36, IV 9-10, V 10-11, VI 0-2	…..Prociphilus sp. “A” (A.K. Ghosh et al., 1970b)
4	Antennal tubercles weakly developed. SIPH dark, conical truncate or tapering without a trace of swelling	…..5
–	Antennal tubercles well developed, their inner faces divergent or convergent in dorsal view. SIPH pale or dark, often slightly swollen, especially on inner sides	…..10
5	SIPH short and conical; in aptera less than twice as long as their basal widths	…..6
–	SIPH more than twice as long as their basal widths	…..7
6	Cauda rounded, about as long as its basal width. R IV+V long, more than twice as long as width at base	…..Brachycaudus helichrysi
–	Cauda clearly longer than its width at base. R IV+V short; in alata (emigrant) shorter that its basal width	…..Melanaphis bambusae
7	Hind tibiae entirely dark	…..Aphis stranvaesiae
–	Hind tibiae with at least the middle section paler	…..8
8	Dorsal abdomen without any dark markings. SIPH and cauda both black, cauda usually having a midlength constriction and bearing 7-19 hairs. Stridulatory apparatus absent	…..9
–	Without that combination of characters	…..go to key to polyphagous aphids, couplet 14
9	Marginal tubercles (MTu) present on ABD TERG 2-4. Cauda with 10-19 hairs (rarely less than 13). R IV+V more than 0.13 mm	…..Aphis pomi
–	MTu absent from ABD TERG 2-4. Cauda with 7-15 hairs (rarely more than 12). R IV+V less than 0.125 mm	…..Aphis spiraecola
10	SIPH dark, almost smooth, less than 1.5 × cauda, which bears 10-24 hairs	…..11
–	SIPH pale, or dusky only at apices, imbricated, more than 1.5 × cauda, which bears 4-12 hairs	…..12
11	SIPH 1.0-1.3 × cauda which is pale, with thin pointed apex, and bears 10-18 hairs. Head spiculose over entire ventral surface	…..Sinomegoura photiniae
–	SIPH 0.8-1.0 × cauda which is dark with blunt apex and bears 17-24 hairs. Head spiculose only on ventral side of ANT tubercles	…..Sinomegoura citricola
12	Head densely spiculose with scabrous, convergent ANT tubercles. SIPH clavate, 2.5-2.7 × cauda. R IV+V 1.5-1.8 × HT II. (Alata with very numerous rhinaria on ANT III, IV and V)	…..Hyalomyzus eriobotryae
–	Without that combination of characters (if head is scabrous with convergent ANT tubercles then SIPH and/or R IV+V are relatively shorter)	…..13
13	SIPH with a subapical zone of polygonal reticulation. Alata without a black dorsal abdominal patch	…..14
–	SIPH without any polygonal reticulation (sometimes with a few transverse interconnected striae near apex). Alata with a black dorsal abdominal patch	…..15
14	SIPH swollen on distal half to a maximum of 1.2-1.4 × minimum width basad. Longest hairs on ANT III 0.3-0.4 × BD III	…..Illinoia spiraeae
–	SIPH tapering/cylindrical (sometimes with distal reticulated zone constricted). Longest hairs on ANT III 0.6-1.0 × BD III	…..Macrosiphum euphorbiae
15	ANT III of aptera with one or more small rhinaria near base. ANT PT/BASE ratio is 5 or more	…..Ericaphis gentneri
–	ANT III of aptera without rhinaria. ANT PT/BASE less than 4.5	…..16
16	Dorsal abdomen of aptera with an intersegmental pattern of dark ornamentation (fig. 121J). ANT PT/BASE less than 2.5. SIPH tapering, with a shallow S-curve, and coarsely imbricated	…..Myzus ornatus
–	Dorsal abdomen of aptera without dark ornamentation. ANT PT/BASE more than 2.5. SIPH are slightly swollen on distal half, and moderately imbricated	…..Myzus persicae

*Phragmanthera*	Loranthaceae
*Phagmanthera regularis*	Aphis gossypii; Sitobion asirum

Key to apterae on Phragmanthera:-

–	SIPH entirely dark, without subapical polygonal reticulation. ABD TERG 1 and 7 with marginal tubercles (MTu)	…..Aphis gossypii
–	SIPH pale or dusky, darker towards apices, with subapical polygonal reticulation. ABD TERG 1 and 7 without MTu	…..Sitobion asirum

*Phragmipedium*	Orchidaceae
*Phragmipedium vittatum*	Cerataphis orchidearum

*Phragmites*	Poaceae
*Phragmites australis* (incl. var. stenophylla)	Brachysiphoniella montana; [Ceratoglyphina phragmitidisucta]; Ceratovacuna nekoashi; Davatchiaphis persica; Hyalopterus amygdali, arundiniformis, pruni; Laingia psammae; Melanaphis bambusae, donacis, elizabethae, sorghi; Metopolophium dirhodum; Mordvilkoiella skorkini; Rhopalosiphum maidis, nymphaeae, padi, rufiabdominale; Schizaphis graminum, hypersiphonata, [scirpi]; Sipha glyceriae, maydis; Sitobion avenae, miscanthi; Tetraneura africana, brachytricha, triangula
*Ph. communis* = Ph. australis
*Ph. karka*	Hyalopterus amygdali, pruni; Melanaphis bambusae, donacis
*Ph. longivalvis* = Ph. australis
*Ph. mauritianus*	Hyalopterus pruni; Rhopalosiphum maidis, padi
*Ph. prostratus* = Ph. karka
*Phragmites* sp.	[Ceratovacuna nekoashi]

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

*Phrodus*	Solanaceae
*Phrodus microphyllus*	Eucarazzia elegans

*Phryma*	Phrymaceae
*Phryma leptostachya*	Cavariella salicicola

*Phuopsis*	Rubiaceae
*Phuopsis stylosa*	Rhopalosiphoninus staphyleae

*Phygelius*	Scrophulariaceae
*Phygelius aequalis*	[Cavariella aegopodii]

*Phyla*	Verbenaceae
*Phyla dulcis* = P. scaberrima
P. nodiflora	Aphis craccivora, gossypii
P. scaberrima	Aulacorthum solani; Neomyzus circumflexus

Use key to polyphagous aphids.

*Phyllanthus*	Euphorbiaceae
*Ph. acidus*	Schoutedenia ralumensis
*Ph. billardierei*	Aphis eugeniae
*Ph. discoideus* = Margaritaria discoidea
*Ph. emblica*	[Anomalosiphum tiomanensis]; Antimacrosiphum bullacaudatum; Aphis eugeniae; [Chuansicallis chengtuensis]; Schoutedenia emblica, ralumensis; Sitobion phyllanthi, takahashii
*Ph. floribundus* = Ph. muellerianus
*Ph. hamiltonianus*	Schoutedenia ralumensis
*Ph. leptocladus*	Sitobion takahashii
*Ph. maderaspatensis*	Aphis gossypii; Sitobion ?mimosae, phyllanthi
*Ph. muellerianus*	Aphis gossypii; Schoutedenia ralumensis; Sitobion africanum
*Ph. myrtifolius*	Aphis eugeniae
*Ph. niruri*	Schoutedenia ralumensis; Sitobion takahashii
*Ph. odontodenius*	Aphis gossypii
*Ph. reticulatus*	Aphis eugeniae, gossypii; Schoutedenia ralumensis; Sitobion phyllanthi, takahashii
*Ph. urinaria*	Sitobion ?mimosae
*Phyllanthus* sp.	[Anomalosiphum indigoferae]; Aphis craccivora; Eonaphis phyllanthi; Macrosiphum euphorbiae; Myzus ornatus, persicae; [Quednaucallis nigropunctata]; [Tinocallis nigropunctata]

Key to aphids on Phyllanthus:-

1	At least ABD TERG 7 with a pair of large, backwardly-pointed processes. Antenna are 5-segmented. Aptera with reduced eyes	…..2
–	ABD TERG 7 without large processes. Antenna 6-segmented. Aptera with well-developed, multifacetted eyes	…..4
2	Head, thorax and ABD TERG 1-7 all with paired spinal processes, and large marginal processes also present on at least ABD TERG 5 and 7. ANT PT/BASE more than 1	…..Eonaphis phyllanthi
–	Large processes on ABD TERG 7 only. ANT PT/BASE less than 1	…..3
3	R IV+V shorter than PT. ANT PT/BASE more than 0.5	…..Schoutedenia ralumensis
–	R IV+V longer than PT. ANT PT/BASE usually less than 0.5	…..Schoutedenia emblica
4	SIPH with a subapical zone of polygonal reticulation (if this is very short, then SIPH are constricted at apex and have a very small flange)	…..5
–	SIPH without any subapical polygonal reticulation	…..go to key to polyphagous aphids
5	Hairs on ANT III maximally more than 0.5× diameter of ANT III at midpoint	…..Macrosiphum euphorbiae
–	Hairs on ANT III very short, maximally less than 0.5× diameter of ANT III at midpoint	…..6
6	SIPH constricted at apex, with slight subapical swelling; only 0.18-0.27× BL. ANT PT/BASE 3.0-4.2	…..Sitobion phyllanthi
–	SIPH not constricted at apex, and usually more than 0.27× BL. ANT PT/BASE 4.2-7.4	…..7
7	R IV+V 0.65-0.80× HT II. PT 1.4-2.0× ANT III	…..Sitobion ?mimosae
–	R IV+V 0.85-1.15 × HT II. PT 1.0-1.4 × ANT III	……8
8	Cauda with a distinct constriction one third from base. ANT III with 1 small secondary rhinarium near base	…..Antimacrosiphum bullacaudatum*
–	Cauda not so distinctly constricted. ANT III with 1-3 secondary rhinaria near base	…..9
9	Marginal abdominal tubercles absent. Dorsal abdomen of aptera unpigmented. Cauda pale	…..Sitobion takahashii
–	Marginal tubercles variably present on ABD TERG 3-5. Dorsal abdomen of aptera often with dark transverse bands. Cauda dusky	…..Sitobion africanum group

Phyllitis see Asplenium

Aspleniaceae

*Phyllocactus*	Cactaceae
*Phyllocactus ackermannii* = Disocactus ackermannii

*Phyllodoce* see Bryanthus	Ericaceae
*Phyllodoce* sp.	[Illinoia sp. (Idaho, USA; aphidtrek.org)];

Phyllostachys

Poaceae

Phyllostachys seems to have a much smaller aphid fauna than other genera of bamboos, but it may nevertheless be worthwhile to consult the keys to Arundinaria and Bambusa for specimens that do not fit the species keyed here:-

*Phyllostachys angusta*	Ceratovacuna multiglandula
*Ph. aurea*	Paracolopha morrisoni; Takecallis arundinariae, taiwanus
*Ph. aureosulcata*	Paracolopha morrisoni
*Ph. bambusoides*	[Cerataphis bambusifoliae]; Melanaphis bambusae, [sacchari]; Paracolopha morrisoni; Rhopalosiphum padi; Takecallis arundicolens, arundinariae, sasae, taiwanus
*Ph. decora* = Ph. mannii
*Ph. dulcis*	Takecallis arundinariae, taiwanus
*Ph. edulis*	Astegopteryx bambusae; [Ceratovacuna japonica, silvestrii]; [Chaitoregma tattakana]; Melanaphis bambusae, [sacchari]; Pseudoregma bambucicola; Takecallis taiwanus
*Ph. formosana* = Ph. aurea
*Ph. heteroclada*	[Chucallis bambusicola]
*Ph. iridescens*	Takecallis arundinariae
*Ph. makinoi*	Melanaphis bambusae; Phyllaphoides bambusicola; Takecallis taiwanus
*Ph. mannii*	Takecallis arundinariae, taiwanus
*Ph. nigra*	Melanaphis bambusae; Paracolopha morrisoni; [Pseudoregma panicola]; Takecallis taiwanus
*Ph. nigripes* = Ph. nigra
*Ph. pubescens* = Ph. edulis
*Ph. reticulata* = Ph. bambusoides
*Ph. sulphurea*	Glyphinaphis bambusae; Melanaphis bambusae; Takecallis arundinariae, taiwanus
*Ph. viridiglaucescens*	Takecallis arundinariae
*Ph. viridis* = Ph. sulphurea
*Ph. vivax*	Melanaphis bambusae; Paracolopha morrisoni
*Phyllostachys* spp.	Astegopteryx minuta; Ceratoglyphina bambusae; Kaochiaoja sikkimensis; [Pseudoregma alexanderi]; [Swirskiaphis bambuciepula Zhang & Zhang 2000]

Key to aphids on Phyllostachys:-

1	Antenna of aptera much less than 0.5× BL, and alata with very narrow annular rhinaria extending more than half way around segment	…..2
–	Antenna of aptera more than 0.5× BL or, if only alatae are present, these have antennae bearing circular or oval secondary rhinaria	…..6
2	Aptera without frontal horns	…..3
–	Aptera with frontal horns	…..4
3	Aptera (on roots) with antennae very short, hardly longer than the elongate R IV+V. Tarsi 1-segmented. Body hairs fine	…..Paracolopha morrisoni
–	Aptera (on leaves) with antennae short, but much longer than short R IV+V. Tarsi 2-segmented. Body hairs thick and spine-like	…..Glyphinaphis bambusae
4	Cauda and anal plate rounded. Frontal horns of aptera longer than ANT I + II	…..Ceratoglyphina bambusae
–	Cauda knobbed, anal plate bilobed. Frontal horns not longer than ANT I + II	…..5
5	SIPH pores placed on shallow cones encircled by long fine hairs. Aptera with wax pore plates if present usually arranged in longitudinal marginal rows, and those on head with only a few facets	…..Astegopteryx spp.; see Bambusa key
–	SIPH pores on very small pigmented cones without a ring of fine hairs. Wax pore plates of aptera not arranged in longitudinal marginal rows, and those on head with numerous facets	…..Ceratovacuna multiglandula*
6	Cauda tongue-like, without a constriction, anal plate entire. ANT PT/BASE more than 4. Antenna of alata with round secondary rhinaria	…..7
–	Cauda knobbed, anal plate bilobed. ANT PT/BASE about Antenna of alata with transversely oval secondary rhinaria	…..8
7	SIPH short, similar in length to cauda	…..Melanaphis bambusae
–	SIPH more than 2.5 × longer than cauda–	…..Kaochiaoja sikkimensis
8	Eyes without ocular tubercles. SIPH cones very flat, mammiform	…..Phyllaphoides bambusicola
–	Eyes with ocular tubercles. SIPH cones truncate	…..Takecallis spp. (for separation see couplets 6-11 of key to aphids on Arundinaria)

*Phyllostylon*	Ulmaceae
Phyllostylon brasiliense	Aphis spiraecola

*Phymatosorus*	Polypodiaceae
*Ph. scolopendria*	Micromyzella filicis

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

*Physalis*	Solanaceae
*Physalis alkekengi* (incl. vars franchetii and bunyardii)	Aphis fabae, gossypii; [Macrosiphoniella physaliae Shinji (nomen dubium)]; Macrosiphum euphorbiae; Myzus persicae
*Ph. angulata*	Aphis gossypii; Macrosiphum euphorbiae; Rhopalosiphoninus latysiphon
*Ph. floridana* = Ph. pubescens
*Ph. lagascae*	Aphis gossypii
*Ph. longifolia* = Ph. virginiana var. sonorae
*Ph. micrantha* = Ph. lagascae
*Ph. peruviana*	Aphis gossypii; Aulacorthum solani; Macrosiphum euphorbiae; Myzus persicae
*Ph. pruinosa*	Macrosiphum euphorbiae
*Ph. pubescens*	Aphis gossypii; Aulacorthum solani; Macrosiphum euphorbiae; Myzus persicae; Neomyzus circumflexus; Rhopalosiphoninus latysiphon
*Ph. subglabrata*	Macrosiphum euphorbiae
*Ph. turbinata* = Ph. pubescens	Aphis gossypii
*Ph. virginiana* (incl. var. sonorae)	Aphis fabae, nasturtii; Macrosiphum euphorbiae; Myzus persicae
*Ph. viscosa*	Macrosiphum euphorbiae
*Physalis* sp.	[Uroleucon illini]

Use key to polyphagous aphids.

*Physianthus* see Araujia	Apocynaceae
*Physianthus albens* = Araujia sericifera

*Physocarpus* (including Opulaster)	Rosaceae
*Physocarpus capitatus*	Aphis neilliae; Illinoia corylina; Utamphorophora humboldti
*Ph. malvaceus* = Opulaster malvaceus
*Ph. opulifolius* = Opulaster opulifolius
*Ph. ramaleyi*	Aphis neilliae

Key to apterae on Physocarpus and Opulaster:-

1	ANT tubercles well developed. SIPH mainly pale, slightly clavate. Cauda pale	…..2
–	ANT tubercles weakly developed. SIPH and cauda uniformly dark	…..3
2	SIPH with subapical polygonal reticulation, distal to swollen part. ANT tubercles with smooth, divergent inner faces. R IV+V 1.3-1.5 × HT II, and bearing c.14-16 accessory hairs. First tarsal segments with 5 hairs	…..Illinoia corylina
–	SIPH without polygonal reticulation. ANT tubercles steep-sided, somewhat scabrous. R IV+V 0.7-0.9 × HT II, with 2-3 accessory hairs. First tarsal segments with 3 hairs	…..Utamphorophora humboldti
3	ANT hairs long and fine, the longest on ANT III 2.3-3.5 × BD III. ABD TERG 8 with a dark cross-band bearing 6-8 hairs. Cauda short, tapering from a broad base to a rounded apex	…..Aphis neilliae
–	Without that combination of characters	…..go to key to polyphagous aphids, starting at couplet 22 (but specimens running to Aphis spiraecola might be A. pomi; for separation of these two species see couplet 15 of key to apterae on Spiraea

*Physocaulis*	Apiaceae
*Physocaulis nodosus*	Aphis fabae; Aulacorthum solani; Cavariella aegopodii; Dysaphis physocaulis

Key to apterae on Physocaulis:-

1	ABD TERG 8 with a backwardly-directed supracaudal process. ANT PT/BASE about 1	…..Cavariella aegopodii
–	No supracaudal process. ANT PT/BASE more than 2	…..2
2	Cauda helmet-shaped, a little shorter than its basal width	…..Dysaphis physocaulis
–	Cauda distinctly longer than its basal width	…..go to key to polyphagous aphids

*Physostegia*	Lamiaceae
*Physostegia virginiana*	Cryptomyzus taoi
*Physostegia* spp.	Aphis egomae; Aulacorthum solani; Macrosiphum euphorbiae

Key to apterae on Physostegia:-

1	Dorsal hairs long and thick with knobbed apices. SIPH distinctly clavate, and 3.6-5.0 × cauda	…..Cryptomyzus taoi
–	Dorsal hairs short or pointed. SIPH not clavate, less than 2.5 × cauda	…..2
2	SIPH black. ANT 5-segmented	…..Aphis egomae
–	Without that combination of characters	…..go to key to polyphagous aphids

*Phyteuma*	Campanulaceae
*Phyteuma* sp.	Aphis fabae

*Phytolacca*	Phytolaccaceae
*Phytolacca americana*	Aphis fabae, gossypii, spiraecola; Aulacorthum solani; Macrosiphum euphorbiae
*Ph. decandra* = Ph. americana
*Ph. dioica*	Aphis (Toxoptera) aurantii
*Ph. esculenta*	Aulacorthum phytolaccae
*Phytolacca* sp.	Myzus ornatus

Key to apterae on Phytolacca:-

–	Dorsum wholly dark sclerotic. Head spiculose. ANT III with 9-13 rhinaria. Longest hairs on ANT III 1.2-1.6 × BD III. R IV+V 1.3-1.4 × HT II	…..Aulacorthum phytolaccae
–	Without that combination of characters	…..go to key to polyphagous aphids