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Subfamily Rhyssinae

MN - Giant Ichneumons (Megarhyssa atrata) 2009061504 - Megarhyssa atrata - female long stinger? wasp - Megarhyssa macrurus - female Visitor - Megarhyssa macrurus Wasp - Megarhyssa - female No idea maybe a wasp. - Megarhyssa atrata - male Megarhyssa atrata Ichneumon Wasp_1 - Megarhyssa nortoni - female Female wasp inserting eggs in wood - Rhyssa lineolata - female
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Hymenoptera (Ants, Bees, Wasps and Sawflies)
No Taxon ("Parasitica" (parasitoid Apocrita))
Superfamily Ichneumonoidea (Braconid and Ichneumonid Wasps)
Family Ichneumonidae (Ichneumonid Wasps)
Subfamily Rhyssinae
14 spp. in 4 genera* in our area; 234 described species in 8 genera worldwide (4 Oriental)(1)(2)(3)
*Genus not yet in the guide: Epirhyssa (1 sp.: E. dietrichi, AZ)
Ovipositors may exceed 200 mm(3)
Medium to large size, very long ovipositor, cylindrical abdomen becoming dorsolaterally compressed apically, hind coxae length more than twice their width. In all but 1 species in our area (Epirhyssa dietrichi), there's a small triangular areolet.

Some Pimplinae (esp. Ephialtini) and Poemeniinae are superficially similar and cannot always be ruled out by the above traits alone. Pimplinae can be ruled out as they lack the extent of transverse ridges on the mesoscutum found in Rhyssinae. Some Pimplinae also have more of a quadrate areolet, when present. Poemeniinae can be ruled out by the presence of anterolateral grooves on T2 of the abdomen not found in Rhyssinae and/or having the apex of T8 not terminating as a polished horn as in Rhyssinae.

Worldwide except Australian(1); in the New World, the highest diversity occurs in the ne. hardwood forests, whilst in tropical countries there are only 2 genera(3)
Idiobiont ectoparasitoids of the immature wood-boring endopterygote insects, in our area usually larval woodwasps (Siricidae and Xiphydriidae), but may also develop as facultative hyperparasitoids using other woodwasp parasitoids as hosts or on virtually any endopterygote (some have even been cultured in the laboratory on entirely unnatural surrogate hosts)(3)