Key to species of Trichogrammatoidea in Brazil (male genitalia)

1. Intervolsellar process distinct but short; volsellar apex far below apex of parameres; ventral process indistinct ................................................................................... T. nana

1’. Intervolsellar process minute, indistinct or absent; volsellar apex approaching apex of parameres......................................................................................................................2

2. Volsellae divergent apically, forming an inverted V; ventral ridge long extending beyond the mid­point of the genital capsule .............................................. T. annulata

2’. Volsellae relatively parallel to one another, not divergent apically............................... 3

3 Genital capsule width less than 0.33 the length, with tapering base and broad at apex; apex of volsellae very near apex of parameres; ventral ridge extending to about 0.75 the length of genitalia; aedeagus with short apodemes, both together about 0.6 the length of hind tibia ....................................................................................... T. robusta

3’. Genital capsule width 0.35 the length, without a broad apex without tapering base; ventral ridge short, extending only half the length of genital capsule; aedeagus 0.82 the length of apodemes, together 0.52 the length of hind tibia .......................... T. bennetti