Toxoptera Koch, 1856

Qiao, Gexia, Wang, Jianfeng & Zhang, Guangxue, 2008, Toxoptera Koch (Hemiptera: Aphididae), a generic account, description of a new species from China, and keys to species, Zootaxa 1746, pp. 1-14 : 2-3

Genus Toxoptera Koch, 1856

Toxoptera Koch, 1856: 253 . Type species: Toxoptera aurantii Koch, 1856 = Aphis aurantii Boyer de Fonscolombe,

1841:178, by original designation. Arimakia Matsumura, 1917: 363 . Ceylonia Buckton, 1891: 35 . Paratoxoptera Blanchard, 1944: 15–62 . Toxoptera Koch : Wu, 1935:149; Shinji, 1941: 149,167; Cottier, 1953: 165; Eastop, 1979: 388; Raychaudhuri, 1980: 74;

Zhang & Zhong, 1983: 237; Stroyan, 1984: 42; Ghosh, 1986: 30; Remaudière & Remaudière, 1997: 58; Tao, 1961:

257; 1999: 92; Zhang, 1999: 326; Blackman & Eastop, 2006:1318.

Diagnosis. Dorsum of head smooth or finely granulated, lateral frontal tubercles indistinct; median frontal tubercle undeveloped or indistinct. Antennae 6-segmented, shorter to slightly longer than body; processus terminalis more than 2 times base of last antennal segment; antennal hairs acute, acuminate or with slightly blunt apices. Rostrum extends to hind coxae; ultimate rostral segment normal, 1.2–1.9 times as long as second hind tarsal segment, with 2–4 long fine accessory hairs. Mesosternal furca with separated arms. Abdominal dorsum in apterae pale or dusky with polygonal reticulations, and with large post-siphuncular sclerotic, and some dark patches marginally, besides a dark band on each of tergites VII–VIII; in alatae pale with segmentally arranged spino-pleural patches, with large post-siphuncular patch and transverse bars on tergites VII–VIII; dorsal hairs of body with acute apices, with or without sclerotized patches at hair-base; tubercles at hair-base indistinct or developed. The postero-ventral sides of abdominal segments V–VII with developed spinulate ridges. Legs normal; hind tibiae with some peg-like stridulatory spines. First tarsal chaetotaxy: 3, 3, 3 or 3, 3, 2. Fore wings with media once or twice-branched and hind wings with two oblique veins. Siphunculi brown to dark brown, weakly to strongly imbricate, with apical flange; longer or shorter than cauda. Cauda tapering, slightly constricted in middle; bearing 10–46 long hairs. Anal plate with 12–40 hairs.

Comments. The small aphid genus Toxoptera Koch is a member of the tribe Aphidini and is characterized by the unusual presence of a stridulatory mechanism, comprising peg-like modified hairs on the hind tibiae and roughened postero-ventral cuticle on the abdomen ( Martin, 1991). These aphids feed on vigorously growing shoots of a variety of mostly woody dicotyledonous plants and are usually ant-attended. Three species, T. aurantii , T. citricidus and T. odinae , are widespread and well-known agricultural pests of woody and crop plants, and are recorded from many families of host plant. The type species is extensively distributed in tropical, subtropical and most warm temperate regions of the world, and is regarded as native to south-east Asia ( Martin, 1989, 1991).

Among five species hitherto recognised, the name T. celtis (Shinji) was accepted by Eastop and Hille Ris Lambers (1976) and Remaudière and Remaudière (1997), but is possibly synonymous with T. aurantii ( Martin, 1991) . We have not seen specimens of this species, so we can not comment on its validity.

Another species, T. schlingeri Tao , described from Ficus (Moraceae) in Hong Kong, had been placed in synonymy with T. aurantii by Raychaudhuri (1980), but Martin (1989) thought a future opportunity to study the numbers and distribution of antennal rhinaria in greater numbers of alatae may suggest this synonymy to be erroneous. In this research, we checked all specimens of T. schlingeri from the Natural History Museum, London, U.K., and the Zoological Museum, Institute of Zoology, Chinese Academy of Sciences, Beijing, China, and find that the species differs from T. aurantii as follows: in apterous viviparous females: length of marginal hairs on abdominal tergite I longer than widest diameter of antennal segment III ( aurantii : shorter than or as long as); in alate viviparous females: secondary rhinaria on antennal segments III–V, each with 7– 17 (most 11–16), 1–6 (most 4–6), and 0–2, respectively ( aurantii : on antennal segment III–V, each with 2–10, 0–3, and 0). To host plants, the species mainly infest on members of the Moraceae . According to the above descriptions, T. schlingeri and T. aurantii in morphology have some difference. But, T. aurantii occurs on many host plants, and if enough material will be examined, it is very likely that we would find the overlap of characters between T. aurantii and T. schlingeri . So, the validity of T. schlingeri as a valid species, needs further check specimens and study thoroughly. In the paper, the species still is regarded as a synonymy of T. aurantii .