Sinodiapterna Dellacasa, 1986

Wang, Chuan-Chan, 2017, The genus Sinodiaptera Dellacasa (Coleoptera: Scarabaeidae: Aphodiinae) in Taiwan, Zootaxa 4320 (1), pp. 68-80 : 69

Genus Sinodiapterna Dellacasa, 1986

Sinodiapterna Dellacasa, 1986: 265 . Type species: Aphodius troitzkyi Jacobson, 1896 by original designation.

Description. Body length 3.0– 6.2 mm. Form: body oval in shape, convex, overall black; shiny (the S. troitzkyi species group) or dull (the S. gorodinskiyi species group). Head: clypeus with lateral dentate angles, angles reflexed, epistoma rugopunctate; frons tuberculate (the S. troitzkyi species group) or convex centrally (the S. gorodinskiyi species group); clypeofrontal suture ridged (the S. troitzkyi species group) or obsolete (the S. gorodinskiyi species group). Thorax: pronotum with (the S. gorodinskiyi species group) or without (the S. troitzkyi species group) tiny setae attached with punctures; scutellum triangularly elongate, 1/3–1/4 as long as elytra. Elytra: length of elytra subequal to head and pronotum combined, elytra with impressed punctate striae; humerus dentate (the S. gorodinskiyi species group) or rounded (the S. troitzkyi species group). Abdomen: Pygidium coarsely punctate, setose. Legs: apex of protibia truncate with tip of spur curved downwardly and inwardly in male; protrochanter with a tuft of setae, setae long in the S. troitzkyi species group, while setae in the S. gorodinskiyi species group short. Male genitalia: tip of parameres broadened in arrow shape in the S. troitzkyi species group, shape of tip simple in the S. gorodinskiyi species group.

Diagnosis. The genus Sinodiapterna can be separated from Teuchestes Mulsant, 1842 (which it has been allied by sharing the common characteristic of larger scutellum, 1/3–1/4 as long as elytra, in East Asia) by the following combination of features: clypeofrontal suture ridged or nearly obsolete (clypeofrontal suture trituberculate in Teuchestes ); clypeus with dentate angles, angles reflexed (clypeus with rounded anterior angles in Teuchestes ); pronotum coarsely punctate with mixed large and small punctures or overall densely and coarsely punctate (punctures on pronotum moderate in size, sparsely distributed in Teuchestes ); apex of protibia truncate with tip of spur curved downwardly and inwardly in male (apex of protibia obliquely prolonged with tip of spur curved outwardly in Teuchestes ).

Distribution. Eastern Siberia, Russian Far East, northeastern China, Korean Peninsula, Japan (Hokkaido through Kyushu), and Taiwan.

Remarks. The natural history of Sinodiapterna species is largely unknown, yet adults of the S. troitzkyi species group ( S. hammondi , S. songrini , and S. zeni ) are known to feed on dung (cow or sheep) ( Masumoto 1977; Dellacasa 1986; Stebnicka & Galante 1992). In the S. gorodinskiyi species group, none of the known specimens were obtained using a baited trap or had been found within dung ( S. gorodinskiyi in a soil trap and S. yushana in a flight intercept trap). Further investigations on the habits of species in this group are needed.