Review of Parathoracaphis Takahashi, 1958 with description of a new species from China (Hemiptera, Aphididae, Hormaphidinae)

Abstract The aphid genus Parathoracaphis Takahashi, 1958 is reviewed. Parathoracaphis spinapilosa sp. n., found on Quercus sp. and on an unidentified species of Fagaceae in China is described and illustrated. A generic diagnosis and a key to Parathoracaphis species are presented.


Materials and methods
Morphological description. Aphid terminology in this paper generally follows Takahashi (1958) and Ghosh (1988). The unit of measurements is millimetres (mm). In Table 1, the following abbreviations are used: Ant.IIIBD, basal diameter of antennal segment III; URS, ultimate rostral segment; BW URS, basal width of ultimate rostral segment; 2HT, second hind tarsal segment; BW Cauda, basal width of cauda.
COI sequencing. COI barcode sequence was obtained for the new species with primers LepF and LepR (Foottit et al. 2008) and has been deposited in GenBank.
Specimen depositories. The holotype and some paratypes of the new species and all examined specimens of P. manipurensis and P. setigera are deposited in the National Zoological Museum of China, Institute of Zoology, Chinese Academy of Sciences, Beijing, China (NZMC). Four paratypes of the new species and the examined specimens of P. cheni are deposited in the Natural History Museum, London, UK (NHM).
Biology. Sitting tightly on the undersides of leaves of host plant (Takahashi 1936, Blackman andEastop 1994). The life cycle is unknown. (Takahashi, 1941) Thoracaphis elongata Takahashi, 1941: 22. Parathoracaphis elongata: Takahashi 1958Ghosh and Raychaudhuri 1973 Biology. This species occurs in large numbers on the undersides of leaves of host plant (Takahashi 1941). The life cycle is unknown.

Parathoracaphis elongata
Comments. Known only from the original description. Takahashi (1941) mentioned that the dorsal prosoma of this species has 5 pairs of spine-like spinal setae, tarsi are unsegmented, and claws are absent. (Takahashi, 1950) Thoracaphis gooti Takahashi, 1950 (Takahashi 1950). The life cycle is unknown.

Parathoracaphis gooti
Comments. Known only from the original description. The figure in Takahashi (1950) indicates that the dorsal prosoma of this species has 16 pairs of spine-like submarginal setae and 5 pairs of long and fine spinal setae, a pair of submarginal setae on head dorsum located near the front end, and 2 pairs between the eyes. The original description mentioned that the antennae of P. gooti are 3-or 4-segmented, the tarsi are distinctly 2-segmented, and the claws are slender.
Comments. Takahashi (1950) mentioned that P. kayashimai was closely related to P. setigera, differing in ornamentation of dorsum and leg measurements. The key to Nipponaphidini species on Quercus and the figure of P. kayashimai in Blackman and Eastop (1994) indicate that submarginal setae on abdominal tergite VI of this species are much smaller than setae on other tergites.
Comments. Ghosh (1988) described an apterous morph on Amaranthus sp. (Amaranthaceae) as a fundatrix of P. manipurensis. However, the specimen was not collected at the type locality, no life cycle observations were conducted, and Amaranthus sp. is unlikely to be a primary host plant of Nipponaphidini species. Additionally, the presence of siphunculi suggests that it does not belong in Parathoracaphis.

Parathoracaphis setigera (Takahashi, 1932) Figs 4-7, 11
Thoracaphis setigera Takahashi, 1932 Biology. Apterae are scattered on the undersides of leaves of host plant, with a circle of thin and curved wax filaments along the margin of body and two rather long wax filaments at the hind end of body (Fig. 7). In Japan, apterae occur on undersides of leaves of Quercus throughout the year (Takahashi 1958).
Diagnosis. Body small, aleyrodiform. Dorsum of prosoma densely covered with convoluted markings medially and short folded-line shaped sculptures pleuro-marginally. Head with a pair of spine-like frontal setae. Dorsum of prosoma with four pairs of minute spinal setae and 16 pairs of spine-like submarginal setae. Antennae 3-or 4-segmented. Tarsi 2-segmented. Claws normal.
Description. Apterous viviparous females: Body oval, aleyrodiform, and strongly sclerotized (Fig. 12). Black in life, with a fringe of long and curved wax filaments, the filaments sparse at the hind end of body (Fig. 25). For morphometric data see Table 1.
Taxonomic notes. The new species resembles the type species P. setigera (Takahashi), but differs from it as follows: dorsum of prosoma densely covered with convoluted markings medially and short folded-line shaped sculptures pleuro-marginally (Figs 8,(12)(13)(14) (the latter with convoluted markings in medial and pleural area, and marginal area covered with branched linear markings radiating outwards, Figs 4, 6); head with a pair of long thick and spine-like frontal setae (Fig. 10) (in the latter: these are much shorter and finer, Fig. 11); dorsum of prosoma with 16 pairs of submarginal setae (the latter: 15 pairs, the pair on abdominal tergite V absent); head dorsum with two pairs of submarginal setae anterior to eyes, along the body margin, and a pair between eyes (Fig. 17) (the latter: all three pairs located along the body margin, Fig. 5); antennae 3-or 4-segmented (the latter: 2-segmented).
Distribution. China (Fujian and Yunnan). Host plants. Quercus sp. and unidentified Fagaceae species. Biology. Forming large colonies on the undersides of leaves of host plant (Fig. 24). The colony is attended by ants. Apterae bear long and curved wax filaments around the body (Fig. 25). The life cycle is unknown.