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Family Rhopalosomatidae - Rhopalosomatid Wasps

Rhopalosomatidae parasitoid & cricket Gelis - correction Olixon - from hardwood swamp - Olixon melinsula ID request: Olixon banksii? - Olixon ? Cricket with parasite Cricket with parasite Rhopalosoma nearcticum - female Wasp - Olixon banksii
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
Family Rhopalosomatidae (Rhopalosomatid Wasps)
5 spp. in 3 genera in our area; 74 spp. in 4 extant genera worldwide (plus 3 spp. in 2 extinct genera)(1)(2)(3)
Forewing 4.2-17 mm(1)
diagnosis in(1); key to genera in(1)
Olixon banksii: adult images (web archive)
In NA, mostly se. US (north to NY-ON-MN, west to KS-TX); globally, primarily tropical(1), none extant in the Palaeartic (3 extinct)
Cretolixon: 1 extinct species known from Burmese amber (Myanmar: Cenomanian age, Late Cretaceous)
Eorhopalosoma: 2 extinct species known from Burmese amber (Myanmar: Cenomanian age, Late Cretaceous)
Liosphex: 14 spp., one so. US to Brazil and one Oriental (Philippines, Indonesia)
Rhopalosoma: 18 spp., New World (e. US to Argentina)
Olixon: 29 spp., Africa, Australia, Americas (s. Canada to Brazil)
Paniscomima: 13 spp., Palaeotropical
usually found during the summer
ectoparasitoids of cricket nymphs(2)(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, Netelia)
Print References
Townes H.K. (1977) A revision of the Rhopalosomatidae. Contributions of the American Entomological Institute 15(1), 34 pp.