Key to the genera of Trogaspidiini of Japan

1. Male: head with ocelli; flagellum 11 segmented; alate........................................................ 2 - Female: head without ocelli; flagellum 10 segmented; apterous................................................. 4 2. Scutellum with median tubercle or impunctate line; penis valves asymmetrical..................................... 3 - Scutellum without median carina, tooth, tubercle or impunctate line; penis valves symmetrical.......... Petersenidia Lelej 3. Scutellum with median tubercle; metacoxa flattened with dense very short erect pale setae............ Eotrogaspidia Lelej - Scutellum with median impunctate line; metacoxa evenly convex with sparse long recumbent pale setae Neotrogaspidia Lelej 4. Lateral margins of mesosoma divergent posteriorly, widest at propodeum; procoxa ventrally with rounded tubercle; pygidial area rugose basally and micro-granulose or polished apically................................................... 5

- Propodeal width equal to pronotal width; procoxa without tubercle; pygidial are unsculptured, polished... Petersenidia Lelej

5. Distance between setal spots on T2 0.3 times as spot diameter................................... Eotrogaspidia Lelej

- Distance between setal spots on T2 1.0–2.0 times as spot diameter.............................. Neotrogaspidia Lelej