Key to Japanese species of Hypseloecus

(Revised from Yasunaga et al. 2021)

1. Dorsum uniformly fuscous or dark brown (Figs. 1G, 2F–G).................................................... 2

- Dorsum reddish brown (Figs. 1A, C, 2C) or paler (Fig. 2A).................................................... 3

2. Base and apical 1/4 of antennomere II darkened (Fig. 2F–G); procoxa uniformly creamy white; vesica with a single median process; inhabiting cold temperate zones in mountain areas of Honshu and associated with Viscum album L........................................................................................ H. nakagawai Yasunaga & Duwal

- Antennomere II with pale basal half and darkened apical half (Fig. 1G); procoxa dark brown; vesica with two median processes (Yasunaga 2001a, fig. 9); thermophilic species inhabiting Ishigaki and Iriomote Islands of Ryukyus (host plant unknown).................................................................................... H. takahashii Yasunaga

3. Body oval; dorsum almost uniformly brownish olive (Fig. 2A); each tibia with obscure spots that are not forming annulations.......................................................................... H. fukutomii sp. nov.

- Body rounded, tumid; dorsum reddish brown or reddish chestnut brown (Figs. 1A, 2C); each tibia with dark or reddish brown annulations.......................................................................... H. tamaderai sp. nov.