Crested-hammertail
Guides
Efferia costalis
Crested Hammertail
Efferia costalis is a species of robber fly (Asilidae) described by Williston in 1885. The species is known by the common name "Crested Hammertail." As a member of the genus Efferia, it belongs to a diverse group of predatory flies commonly found in North America. The species has been documented through limited observations, with only 3 records reported on iNaturalist.