Chalybion Dahlbom, 1843

Anagha, S., Girish Kumar, Puthuvayi & Hegde, Vishwanath Dattatray, 2023, A study of the genus Chalybion Dahlbom, 1843 (Hymenoptera, Sphecidae) in India, Journal of Insect Biodiversity and Systematics 9 (1), pp. 59-66 : 64

Key to Indian species of genus Chalybion Dahlbom (modified from Hensen, 1988)

1 Ventral margin of clypeus with broadly projecting median lobe, which may be weakly emarginate medially in female or bi or trilobate in male (see Fig. 2 of Hensen, 1988); petiole and legs with partly yellow markings; tarsi without plantulae.............................................................................. spinolae (Lepeletier)

— Ventral margin of clypeus with three or five teeth or lobes; petiole and legs without yellow markings; tarsi with or without pantulae. .......................................................................................................................... 2

2 Tarsi with plantulae ( Fig. 8); metapleuron with carina, which run along outer side of midcoxa and bend sharply outwards posteriorly, to end above base of hind coxa ( Fig. 6). ....................... gracile Hensen

— Tarsi without plantulae ( Fig. 17); metapleuron without angular carina. ..................................................... 3

3 Clypeus with five teeth, the median three close together, more or less fused, lateral teeth sharp and rather distant from others; sixth sternite of female flat and wide, apically broadly truncate. ....................... .................................................................................................................................................................... malignum (Kohl)

— Clypeus with three or five teeth, in latter lateral teeth not sharply pointed and not distant from median three ( Fig. 12); sixth sternite of female not markedly wide, apically rounded........ bengalense (Dahlbom)