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Family Rhopalosomatidae - Rhopalosomatid Wasps

Rhopalosomatidae parasitoid larva & cricket Rhopalosomatidae, 5th instar larva Rhopalosoma nearcticum - female Some kind of wasp - Rhopalosoma nearcticum Gelis from hardwood swamp - Olixon melinsula ID request: Olixon banksii? - Olixon Parasite on Cricket Rhopalosoma, presumably nearcticum, for confirmation. - Rhopalosoma nearcticum
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Hymenoptera (Ants, Bees, Wasps and Sawflies)
No Taxon (Aculeata - Ants, Bees and Stinging Wasps)
Superfamily Vespoidea (Yellowjackets and Hornets, Paper Wasps; Potter, Mason and Pollen Wasps and allies)
Family Rhopalosomatidae (Rhopalosomatid Wasps)
3 spp. in 3 genera in our area(1); ca. 40 spp. in 4 extant genera worldwide(2)
Forewing 4.2-17 mm(2)
diagnosis in(2); key to genera in(2)
Olixon banksii: adult images
In NA, mostly se. US (north to NY-ON-MN, west to KS-TX); globally, primarily tropical(2), none in the Palaeartic
Liosphex: 2 spp., one so. US to Brazil and one Oriental (Philippines, Indonesia)
Rhopalosoma: 17 spp., New World (e. US to Argentina)
Olixon: 8 spp., Africa, Australia, Americas (s. Canada to Brazil)
Paniscomima: 10 spp., Palaeotropical
usually found during the summer
ectoparasitoids of cricket nymphs(1) (usual hosts seem to be in the subfamily Hapithinae); it is not known whether adults feed
Life Cycle
rarely encountered, probably active at night
See Also
Olixon banksii may be mistaken for a velvet ant or a bethylid
Rhopalosoma nearcticum is very similar to some ichneumonids (Ophioninae)
Print References
Townes H.K. (1977) A revision of the Rhopalosomatidae. Contributions of the American Entomological Institute 15(1), 34 pp.