Genus Psilotreta Banks, 1899

Type species. Psilotreta frontalis Banks, 1899

Diagnosis (adapted to the fossils and modified after Banks, 1899, Parker & Wiggins, 1987, Oláh & Johanson, 2010).Head:Ocelli absent,antennae longer than forewings, maxillary palps five-segmented, terminal segment not annulate or flexible, labial palps three-segmented. Tibial spurs: 2/4/4. Wings: Forewings longer and narrower than hindwings. Discoidal cell usually present. R 1 running separate to wing margin, not fused with Sc or R 2. Fork I often longer than fork II; fork I sessile, fork II usually petiolate, fork III usually absent, fork IV always absent; medial cell absent, M reduced, often simple or simply forked or three-forked. Crossveins sc-r, r, s, r-m and cu-a usually present, crossveins m and cu absent. In hindwings fork I longer than fork II. Male genitalia: Inferior appendages (gonocoxites) two-segmented, harpagoes originating from apex of coxopodites or originate mesally on coxopodites.

Following Oláh & Johanson (2010) genus Psilotreta includes three diagnostic species-groups: 1. Psilotreta japonica diagnostic species-group, 2. Psilotreta trimeresuri diagnosticspecies-group,3. Psilotretafrontalis diagnostic species-group. The diagnostic species groups are distinguished on the following genitalic characters: (1) the position of the harpagoes on the coxopodites; (2) the number and size of apical spines on the harpagoes; and (3) the presence or absence of phallic parameres.