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Nerax group

Robber fly - Efferia aestuans - female Robber Fly...but what kind - Efferia robber fly - Efferia aestuans - female robber fly - Efferia aestuans Efferia? - Efferia aestuans - male Efferia aestuans - male Robber Fly eating another of the same species - Efferia aestuans - female Efferia? - Efferia aestuans - female
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Diptera (Flies)
No Taxon (Orthorrhapha)
Superfamily Asiloidea
Family Asilidae (Robber Flies)
Subfamily Asilinae
Genus Efferia
No Taxon Nerax group
Synonyms and other taxonomic changes
=Nerax Hull 1962
13 spp. in our area, 65 total(1)
The following information is based on the modified Key to Eastern Species: (2) For info on the listed reference terms see the wing diagrams here.
1) - Furcation of third vein opposite or beyond base of second posterior cell;
18) - Posterior branch of third vein (R5) curved backward at tip, meeting the costa at or beyond apex of wing = (Nerax/aestuans group)

Efferia aestuans
Efferia tabescens