SYSTEMATIC TREATMENT OF APHID GENERA
(in alphabetical order)
One species in China with Phorodon-like processes on the antennal tubercles, strongly wrinkled tergum, clavate siphunculi and a characteristically-shaped cauda.
Ferusaphis xanthinae Zhang, Chen, Zhong & Li Apterae are leaf green; BL 1.8-1.9 mm. On young shoots and undersides of leaves of Rosa xanthina in Gansu Province, China (G. Zhang 1999).
Two North American species on Seriphidium with the typical stilletto-shaped R IV+V of aphids feeding Anthemideae, and related to Epameibaphis, Pseudoepameibaphis and the palaearctic genus Coloradoa, but with reduced siphunculi. Smith (1937) reviewed the genus.
Flabellomicrosiphum knowltoni Smith Apterae are dull slate grey to pinkish or greenish, overlaid with pale hairs giving it a frosted appearance (see aphidtrek.org); BL 0.9-1.5 mm. On Seriphidium tridentata in western USA. Monoecious holocyclic; oviparae have been collected in Utah in October (BMNH collection, leg. G.F. Knowlton.
Flabellomicrosiphum tridentatae (Wilson) Plate 15e (Fig.12d) Apterae are pale green, appearing frosted dorsally due to the numerous pale fan-shaped hairs (see aphidtrek.org); BL 0.9-1.5 mm. On leaves and flower stems of Seriphidium tridentata in western USA.
Two species in China forming branched flower-like galls on Rhus, the emigrant alatae having annular rhinaria with ciliate rims. In Blackman & Eastop (1994) the species were placed in Nurudea, but there are clear morphological and biological differences now supported by molecular data (Yang et al. 2010, Ren et al. 2019) and the genus is here reinstated.
Floraphis choui Xiang Galls produced on the leaflets of Rhus potaninii in China (Shaanxi) are branched, the branches thicker and rounded at apices, sometimes developing dark red spots (Xiang 1980). BL of emigrant alata c.1.1 mm. Other morphs and life cycle are unknown.
Floraphis meitanensis Tsai & Tang Galls produced on the leaflets of Rhus pujabensis var. sinica in China (Kweichow) are rosy red, somewhat flattened, branched from base, maximum diameter up to 10 cm (Tsai & Tang 1946; and see fig. 4j in C. Zhang et al. 2008). Alatae emerging from the gall in autumn have black head, pale green prothorax, dusky pterothorax and pale yellowish abdomen; BL c.1.1 mm. Other morphs and life cycle are unknown. [Alatae reported to be this species were collected from a plant identified as a Rhus sp. in Turkey (Aslan & Uygun 2005, as Nurudea meitanensis), but were subsequently determined as Baizongia pistaceae, the host being presumably misidentified (Barjadze 2011a).]
A genus for one phylloxerid which has apterae with fine hairs and alatae with a round distal rhinarium, found on oak roots in southern Europe.
Foaiella danesii Grassi & Foà Apterae are greenish yellow, pear-shaped, with broad head and thorax and tapered abdomen; BL 0.5-1.5 mm. Alatae have a pale yellow head and a yellow costal margin and pterostigma in the forewing. On roots of Quercus robur, which become tuberose. Holocyclic, producing apterous and alate sexuparae in August-October. The sexuales lay overwintering eggs on the roots, and possibly also in bark crevices on the trunk (Grassi et al. 1912). Recorded from Italy, Crimea and Transcaucasia (Börner & Heinze 1957).
An Old World genus of 10 or more species with host alternation in the Mediterranean region and south-west Asia between Pistacia spp. (or, in one case, Toona ciliata) and roots of Poaceae. Galls on Pistacia are formed by folding and rolling the leaf margins. The fundatrix of most species initially forms a small temporary gall (e.g. fig. 126F), usually near the apex of the leaf, from which the fundatrigeniae emerge to induce the definitive leaf-edge galls. Alatae emerging from these galls have 6-segmented antennae, unlike those produced on the secondary hosts which always have 5-segmented antennae. The holocycle takes two years. Anholocyclic populations of several species occur outside the range of Pistacia on roots of grasses and cereals, and several species are only known from their secondary hosts. Both F. formicaria and F. marginata have been introduced into North America. For accounts of the gall generations see Davatchi (1958), Roberti (1939, 1983) and Nieto Nafría et al. (2002a). The morphology and histology of the galls was compared with that of other Fordini by Álvarez et al. (2016). Accounts are available of root‑living morphs by Mordvilko (1935) and Remaudière (1999); from north-west, central and southern Europe (Heie 1980b, Zwölfer 1958, Roberti 1983, Nieto Nafría et al. 2002a), India (Chakrabarti, Maity, and Bhattacharya 1982, A.K. Ghosh 1984) and China (G. Zhang et al. 1999c). Ortiz-Rivas et al. (2009) studied phylogenetic relationships of Iberian species with other genera of Fordini.
Forda formicaria von Heyden Forming half-moon-shaped ("semilunarius") galls on Pistacia terebinthus and P. palaestina in the Mediterranean region and south-west Asia. There are also records from P. atlantica, P. khinjuk and P. mutica. The leaf lamina on one side is deflected down and then rolled upwards to form a crescentic sac (fig. 126G), yellowish when mature, the opening closed by a curtain of fine hairs (Davatchi 1958). Álvarez et al. (2009) studied the histology of the galls. Roberti (1983) gave a full description of all generations on Pistacia. Valentyuk (1985) described a method of rearing F. formicaria on galls on P. mutica. Emigrant alatae (BL 1.8-2.4 mm (fig. 81J), with black head and thorax and green-yellow abdomen) emerge in September-November and fly to found colonies on roots of Poaceae. Apterous exules are off‑white to dull yellow (often with a darker medio‑dorsal stripe) or various shades of dark green or bluish green (see influential points/gallery); BL 1.9-3.3 mm. They occur on roots of numerous grasses and cereals (including Agropyron, Agrostis, Bromus, Cynodon, Dactylis, Deschampsia, Festuca, Hordeum, Lolium, Poa, Secale and Triticum), and sometimes on Cyperaceae (Carex, Cyperus), attended by ants, or in ants' nests. Anholocyclic populations, often overwintering in ants' nests, occur on grass roots in northern Europe, Siberia, Central Asia and North America. Börner (1952) recognised several different forms on the roots of grasses in central Europe, and sexuparae vary greatly in abdominal chaetotaxy; it seems possible that at least three taxa are confused under the name formicaria (see also Remaudière 1999). Ivens et al. (2012a,b) used microsatellite DNA analysis to investigate clonal diversity of root-feeding populations in the Netherlands. 2n = 18-23; karyotype variation was discussed by Blackman (1987).
Forda hirsuta Mordvilko (?=mordvilkoi Börner) Plate 6e Galls are formed by upward rolling of the leaf edge of Pistacia spp. (atlantica, khinjuk, mutica, terebinthus, vera). They are short, sausage- or pocket-shaped lobes, swollen and carmine red when mature, often side-by-side along both edges of a leaf (Mordvilko 1935, as follicularia, and Wertheim 1955, as mordvilkoi) Emigrant alatae (BL 1.5-2.3 mm, fig. 81M) leave the galls in August-October to colonise roots of many and various Poaceae (including Agropyron, Bambusa, Cynodon, Elymus, Heteropogon, Hordeum, Poa, Triticum). They have also been found on Cyperus (BMNH collection, Iran, leg. V.F. Eastop). Apterous exules are straw‑coloured to orange, dorsally highly domed, and invariably ant-attended; BL 1.7-3.2 mm. The holocycle occurs in south-west and central Asia, and Pakistan (Naumann-Etienne & Remaudière 1995); presumed anholocyclic populations on grass roots occur also in Portugal (van Harten 1975), and in Russia as far north as Leningrad (Mordvilko 1935), and across to east Siberia (Pashchenko 1988a). Fet (1979) studied the ecology of gall populations on P. vera in Turkmenistan. The synonymy of F. hirsuta is complex; if Szelegiewicz (1982) was correct in his opinion that pawlowae Mordvilko (= dactylidis Börner) is the secondary host form of mordvilkoi Börner, and if mordvilkoi is a synonym of hirsuta (Davatchi 1958), then this would make the valid name for this taxon pawlowae Mordvilko. However, the name hirsuta is retained here pending further studies of the life cycle. 2n=18 (Blackman 1987).
Forda hirsutissima Remaudière Apterae are pale; BL (one specimen) 2.4 mm. On root of Triticum sp. in Turkey (Remaudière 1999).
Forda kaussarii Davatchi & Remaudiere Galls on Pistacia khinjuk are formed by upward folding of the leaf margin. They are flattened on the upper side, convex with leaf veins forming slight ridges beneath; colour green becoming reddish or yellowish especially on underside at maturity. Emigrant alatae (BL 2.1-2.4 mm) leave the galls in August-October. Only the gall generations are known, from Iran (Davatchi & Remaudiere 1957, Davatchi 1958). This is possibly the primary host form of F. orientalis (see below).
Forda longicornis Remaudière & Leclant Apterae are creamy white; BL 2.3-3.4 mm. On roots of unidentified grasses and in ants’ nests. In France, Spain and Portugal. The life cycle is unknown; alate sexuparae were collected in April (Remaudière 1999).
Forda marginata Koch Galls are formed by upward rolling of the leaf margins of Pistacia spp. (terebinthus, palaestina) into an elongate spindle shape, yellowish or pale green in colour. Álvarez et al. (2009) studied the histology of the galls. Roberti (1983) fully described the gall generations and their phenology in Italy, and Chakrabarti (1987) described the life cycle in north-west India. Emigrant alatae (BL 1.5-2.1 mm, fig. 81K) leave the galls in September-November to found colonies on roots of numerous species of Poaceae including Agropyron, Agrostis, Avena, Bromus, Dactylis, Festuca, Hordeum, Lolium, Poa, Secale, and Triticum. Apterous exules are brownish yellow or greenish yellow, body highly domed dorsally; BL 1.6‑3.1 mm. Holocyclic populations occur in southern Europe, the Middle East and north-west India. Anholocyclic populations on grass roots and overwintering in ants’ nests occur in northern and central Europe, Siberia, Central Asia, India, China and North America. Ivens et al. (2012a,b) used microsatellite DNA analysis to investigate clonal diversity of root-feeding populations in the Netherlands. The morphological variation shown by anholocyclic populations suggests that they may correspond to a group of closely related species, but the taxonomy will only be clarified by further studies of primary host‑plant relationships. Karyotype variation was studied by Blackman (1987); 2n=17-20 (soma) or 25-40 (germ line cells).
Forda orientalis George Apterae are yellowish white to citron yellow, very much arched dorsally (see aphids of Karnataka website); BL c. 3.5 mm. They occur in ant attended colonies on roots of Poaceae (including Botriochloa, Oryza, Pennisetum, Puccinellia, Saccharum, Sorghum, Stipa, Triticum) in Israel, Iran, Kazahkstan (Kadyrbekov 2004b), India (David 1969), Pakistan, and east Siberia (Mordvilko 1935, as F. ussuriensis). The sexual phase has not been established. Aphids forming brick-red pouch galls on the margins of the leaves of Toona ciliata in Uttar Pradesh, India were identified as this species (A.K. Ghosh et al. 1981). However, the inhabitants of these galls have not been described, and on re-examination A.K. Ghosh (1984b, p.381) considered the alatae from them to belong to a different, unidentified Forda species. F. kaussarii on P. khinjuk has also been suggested as the possible primary host form of F. orientalis (Eastop & Hille Ris Lambers 1976). Two species of Forda described from Triticum in China, F. auralenta Zhang & Qiao and F. multicoma Zhang (in Zhang & Qiao 1998d) are possible synonyms.
Forda pawlowae Mordvilko Apterae are pale yellow, body domed, with brownish appendages; 1.6-2.8 mm. On roots of Dactylis glomerata and Bromus spp. in central and eastern Europe (Zwölfer 1958, as F. dactylidis) and also recorded from other genera of grasses in central Asia (see Holman 2009, Kadyrbekov 2017a). Ant-attended. Anholocyclic, but possibly with a sexual phase and galls on Pistacia in south-west Asia, if F. mordvilkoi is a synonym (Szelegiewicz 1982).
Forda riccobonii (de Stefani) Pouch galls are formed on the leaves of Pistacia atlantica; many of these may be clustered around the edge of a leaflet so that it completely loses its shape. Emigrant alatae (BL 1.9-2.1 mm, fig. 81L) emerge in September-November and found colonies on roots of Poaceae, including Botrichloa sp. and Dicanthium sp. In Mediterranean area and south-west Asia. Populations on grass roots are recorded from India (Chakrabarti et al. 1982), but the appearance of apterous exules in life is not recorded; BL 1.7-3.0 mm. The ecology of populations galling P. atlantica in northern Israel was studied by Martinez (2009), and the histology of the galls was studied by Álvarez et al. (2016). This species is included in the key to aphids on Pistacia on the basis of specimens from P. atlantica in Morocco (BMNH collection, leg. Baille) and Malta (BMNH collection, leg. unknown); alatae from allegedly similar galls in Israel (leg. E. Swirski) were much more like F. hirsuta. 2n=18 in somatic cells and 30 in germ line (Blackman 1987).
Forda sichangensis Remaudiere & Tao Galls on Pistacia sinensis, formed by rolling the leaf edge upward, are elongate, crescentic in form, and may extend to the mid-rib; yellowish green, becoming reddish yellow when mature (Tao 1947; as Pemphigella marginata). Emigrant alatae, collected in May in China, have blackish-brown head, thorax and appendages contrasting with yellowish white abdomen; BL about 2.5 mm. Their embryos have very numerous hairs on antennae and legs (Davatchi 1958). On P. sinensis in China, and on this host and P. khinjuk in Pakistan (Naumann-Etienne & Remaudière 1995). In Pakistan the alatae emerged from the galls from the end of July until September. Other morphs and secondary host are unknown.
One species associated with Magnoliaceae in east Asia. The alatae have antennae with peculiar, reticulate rhinaria, and hind wings with the two oblique veins united basally as in other Pemphigini. This geneus was formerly placed in Fordini, but the position of the sensillum near the base of the second tarsal segments (placed further from the base and slightly laterally) shows that it belongs in the tribe Pemphigini, and this has been confirmed by molecular studies (H. Zhang & Qiao 2007b). Consequently if there is a sexual phase then it is likely to be on Populus.
Formosaphis micheliae Takahashi Apterae are pale brown, covered with cottony wax; BL c. 2 mm. On bark of stem and branches of Michelia spp. and Magnolia spp. in Japan, China and Taiwan (Takahashi 1963); also reported from Magnolia spp. in West Bengal (Raychaudhuri et al. 1980), and (as vagrants?) from Buchanania latifolia in Manipur, India (Raha et al. 1977). The life cycle is unknown; possibly this species is entirely anholocyclic. 2n=10, with structural heterozygosity (Blackman 1986).
Six rather large North American species living on roots of Salicaceae, closely allied to Plocamaphis but more hairy and with siphunculi much reduced or absent, probably as a result of their subterranean habit. The wing venation of the alatae seems to vary remarkably within species. Biology has been little studied. Richards (1966) reviewed the species (in Plocamaphis).
Fullawaya bradleyi (Richards) Apterae are light brown with a pink tinge, or flesh-coloured, with dark appendages; BL 3.7-4.3 mm. On subterranean parts of stems of an unidentified Salix sp. in Ontario, Canada (Richards 1966). Other morphs and life cycle are unknown.
Fullawaya braggii (Gillete & Palmer) (fig. 106H) Apterae are yellowish brown with blackish lateral areas or wholly dark brown to almost black, with a dusting of wax powder along intersegmental lines; BL 2.5-3.0 mm. Alatae usually have the media once-branched. Holocyclic on roots of an unidentified Salix sp. in Colorado, USA (see MacGillivray 1963). Oviparae occur in September-November, apterous males in October-November (Palmer 1952).
Fullawaya bulbosa (Richards) Apterae are light brown, pale pink or flesh-coloured, with dark appendages; BL 3.8-4.2 mm. On subterranean parts of stems of an unidentified Salix sp. in British Columbia, Canada (Richards 1966). Only apterous and alate viviparae have been described and the life cycle is unknown.
Fullawaya ontarioensis (Richards) Colour of apterae in life is unknown; BL 4.5-5.0 mm. On roots of Populus tremuloides in Ontario Canada, and also recorded from Colorado USA (Smith & Parron 1978). Other morphs and life cycle are not known.
Fullawaya saliciradicis Essig Apterae have dark brown head and thorax and yellow-brown to blackish abdomen, with a dusting of fine wax powder; BL 2.1-3.5 mm. Alatae generally have a twice-branched media. Holocyclic on roots of Salix spp. (laevigata, longifolia). Widely distributed in North America. Oviparae occur in October-November (Palmer 1952). Possibly F. braggii is a synonym, as suggested by MacGillivray (1963) and Richards (1966).
Fullawaya terricola (Hottes & Frison) (fig. 106G) Apterae are mainly reddish brown, with dark appendages; BL 2.5-3.1 mm. Alatae usually have a twice-branched media in the forewing (Hottes & Frison 1931). On roots of unidentified Salix sp(p). in USA (Illinois, Pennsylvania, Utah). Sexuales and life cycle are not known.