Aokii group

Diagnosis. Body moderately small (3.6–4.8 mm), with significant variability in proportions and punctation of forebody; aedeagus with narrow median lobe, preapical portion with concave lateral margins, parameres narrow, not reaching apex of median lobe, middle part of median lobe with two short parallel structures and moderately long sclerotized flagellum between them.

Species included. G. aokii (Watanabe, 1972), G. sprius (Watanabe, 1990).

Distribution. Species of the aokii group are distributed in North and Central Japan: Hokkaido and Honshu islands.

Bionomics. Detailed bionomic data are unknown.

Remarks. In the narrow median lobe and the presence of a strongly sclerotized flagellum, the aokii group is somewhat similar to the plagiatus group, but it differs by having narrower apical portions of the parameres and two short parallel structures in the middle part of the median lobe. The narrow parameres and the shape of the flagellum are somewhat similar to the sinuatus group, from which it differs by a smaller body, narrower elytra, and a narrower median lobe.