Euthoracaphis Takahashi

Chen, Jing, Fang, Yan & Qiao, Gexia, 2009, Euthoracaphis Takahashi (Hemiptera: Aphididae: Hormaphidinae), a generic account, description of a new species from China, and a key to species, Zootaxa 2284, pp. 30-40 : 31

Euthoracaphis Takahashi

Thoracaphis (Euthoracaphis) Takahashi, 1938: 14 . Type species: Thoracaphis umbellulariae Essig, 1932 ; by original designation.

Euthoracaphis Takahashi : Takahashi, 1959: 8; Ghosh & Raychaudhuri, 1973: 156; Raychaudhuri, Ghosh, Pal & Ghosh, 1980: 373; Ghosh, 1988: 137; Noordam, 1991: 162; Blackman & Eastop, 1994: 690; Remaudière & Remaudière, 1997: 186; Blackman & Eastop, 2006: 1160.

Diagnosis. Body flat, oval. In apterae, prosoma consists of fused head, thorax and abdominal segment I, dorsum of prosoma divided by sutures into a large median and two lateral areas; abdominal segments II–VII fused and distinctly separated from prosoma and abdominal segment VIII. In apterae, dorsum with scattered sculpture or pustules; dorsal setae long, fine, sparse or numerous, submarginal setae on abdominal tergites II– VII arranged in pairs; abdominal tergite VIII with 2 or 4 setae. Antennae in apterae short, 3-segmented; in alatae 5-segmented, with annular secondary rhinaria. Rostrum short and stout, ultimate rostral segment longer than second hind tarsal segment, without secondary setae. Legs normal, tibial setae long and fine; tarsi 2- segmented, claws normal, first tarsal chaetotaxy: 3, 3, 2 or 3, 3, 3; dorsoapical setae on second tarsal segment expanded at apex. Siphunculi small, pore-like. Cauda constricted at base and distinctly knobbed, with a few setae. Anal plate bilobed. Fore wings with pterostigma a little dusky, vein sometimes distinctly bordered brownish, media once branched; hind wings with 2 obliques.

Distribution. China, India, Indonesia, Japan and North America.

Host plants. Lauraceae : Cinnamomum burmannii , C. camphora , C. camphoratum , C. iners , C. japonicum , C. pedunculatum , C. verum , Machilus yunnanensis , Sassafras variifolium and Umbellularia californica . But E. longisetosa from northeast India feeds on Senecio sp. (Compositae).

Comments. This genus is characterized by the unique division of the prosoma in apterae. Most species infest host plants in Lauraceae , except E. longisetosa on Compositae. E. umbellulariae was reported to be anholocyclic in California ( Blackman & Eastop, 1994), but life cycles of other species are unknown. All species of this genus occur in subtropical or tropical regions.

Euthoracaphis is closely related to Nipponaphis and Thoracaphis in several characteristics, such as body flat, consisting of three parts: prosoma, fused abdominal segments II–VII and separated abdominal segment VIII; dorsum with scattered sculpture or pustules ( Takahashi, 1959; Ghosh & Raychaudhuri, 1973; Blackman & Eastop, 1994). However, the dorsum of the prosoma is divided into several areas in Euthoracaphis apterae. This is a unique genus within Nipponaphidini , and its relationships to other genera and its systematic position need further study.