The Rhopalosomatidae of Florida

The Rhopalosomatidae is a parasitic wasp family with only 34 described species in 4 genera in the world (Townes 1977). As far as is known, members of this family are external parasites of crickets (Gryllidae). Three species in 3 genera are found in Florida. Olixon banksii (Brues) is a brachypterous insect that runs around swiftly in leaf litter or on sand. The other 2 Floridian species are fully winged. The family itself is of uncertain phylogenetic position with the latest study (Brothers 1975) relating the group with the spider wasps (Pompilidae ). This family of aculeate wasps can be recognized by the upcurved female sting, upcurved spine of the male clasper, mesopleuron lacking a median transverse groove, and the mesostemum with a pair of plates on its hind edge that partially covers the bases of the midcoxae. The femora and tibiae lack bristles, and the female tarsi are expanded. Also, the antennal flagellomeres have distinctive bristles on the apex of each segment (except Olixon) .