Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes

Upcoming Events

Photos of insects and people from the 2022 BugGuide gathering in New Mexico, July 20-24

National Moth Week was July 23-31, 2022! See moth submissions.

Photos of insects and people from the Spring 2021 gathering in Louisiana, April 28-May 2

Photos of insects and people from the 2019 gathering in Louisiana, July 25-27

Photos of insects and people from the 2018 gathering in Virginia, July 27-29

Photos of insects and people from the 2015 gathering in Wisconsin, July 10-12

Previous events


Genus Efferia

robber - Efferia albibarbis - male Robber Fly - Efferia - female Robber Fly - Efferia Efferia pogonias? - Efferia pogonias - female Efferia pogonias? - Efferia Robber Fly - Efferia aestuans Robber Fly 20mm - Efferia - male Asilidae - Efferia
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
Synonyms and other taxonomic changes
Treated here broadly; species-groups used in the guide are sometimes recognized as separate genera Albibarbefferia, Aridefferia, Carinefferia, Nerax, Pogonioefferia, Tuberculefferia, e.g. in(1)
Explanation of Names
Efferia Coquillett 1893
from Latin efferus 'wild, savage'
~110 spp. in our area, 185 total(1)
more or less average in size, 15 to 25-30 mm(2)
Key to eastern spp.(3), key to others(4).
in our area, the vast majority are restricted to sw. US, with some widely western spp. and just two widespread spp.; Nerax predominantly southeastern(1)
Internet References