Hybothoracaphis, Chen, Jing, Jiang, Liyun & Qiao, Gexia, 2016

Chen, Jing, Jiang, Liyun & Qiao, Gexia, 2016, Hybothoracaphis, a new genus of Nipponaphidini (Hemiptera, Aphididae, Hormaphidinae) from China and its phylogenetic placement based on multiple genes, Zootaxa 4170 (2), pp. 375-383 : 382-383

Key to Hybothoracaphis gen. nov. and allied genera (based on apterous viviparous females)

1. Antennae small, unsegmented; body with a conspicuous median dorsal ridge; central axis of dorsal prosoma with clusters of irregular-shaped pustules, located before and behind the muscle attachment plates; on Quercus (Fagaceae) ; China......................................................................................... Hybothoracaphis gen. nov.

- Antennae 3- or 4-segmented; body without a conspicuous median dorsal ridge; central axis of dorsal prosoma without pustule clusters.............................................................................................. 2

2. Dorsum of prosoma divided by sutures into a large median and two lateral areas; on Lauraceae and Senecio (Compositae) ; China, India, Indonesia, Japan, North America. ..................................... Euthoracaphis Takahashi, 1938

- Dorsum of prosoma never divided into regions.............................................................. 3

3. Abdominal tergite VIII always with 2 setae, rarely with 4 setae; densely scattered pustules on prosoma appear double rimmed; on Distylium (Hamamelidaceae) and Fagaceae ; China, India, Indonesia, Japan.......... Metanipponaphis Takahashi, 1959

- Abdominal tergite VIII usually with 4–8 setae, if sometimes with 2 setae then pustules never double rimmed.............4

4. Dorsal setae on prosoma long, rather thick and stout, arising from conspicuous bases, sometimes mixed with smaller and finer setae; on Distylium (Hamamelidaceae), Lauraceae , and Fagaceae ; China, India, Indonesia, Japan, Malaysia, Nepal, Thailand......................................................................... Schizoneuraphis van der Goot, 1917

- Dorsal setae on prosoma fine, if thick then never as above..................................................... 5

5. Prosoma completely separated from abdominal segments II–VII; dorsum of prosoma with numerous fine setae; on Castanopsis (Fagaceae); China, Japan................................................... Neonipponaphis Takahashi, 1962

- Prosoma distinctly or indistinctly separated from abdominal segments II–VII; dorsum of prosoma not bearing so many setae as above............................................................................................... 6

6. Dorsum of prosoma almost smooth, variably corrugated, or covered with pustules; margin of prosoma sometimes radially striped, palisade-like, or with a polygonal reticulated band; abdominal tergite VIII with 2–4 setae; on Quercus (Fagaceae) and Lindera (Lauraceae) ; China, India, Indonesia, Japan, Malaysia, Thailand, Turkey.......... Thoracaphis van der Goot, 1917

- Dorsum of prosoma densely covered with pustules; margin of prosoma never with a striped or polygonal reticulated band; abdominal tergite VIII with 4–8 setae; on Distylium (Hamamelidaceae), Fagaceae , Lauraceae , and Moraceae ; China, India, Indonesia, Japan, Korea.......................................................... Nipponaphis Pergande, 1906