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Efferia mortensoni
Portal Hammertail
Efferia mortensoni is a species of robber fly in the family Asilidae, described by Wilcox in 1966. It is known by the common name "Portal Hammertail." Like other members of the genus Efferia, this species is a predatory dipteran that likely hunts other insects. The species name suggests a connection to the Portal area in southeastern Arizona, a region well-known among entomologists for its exceptional biodiversity. Robber flies in this genus are typically active during daylight hours and are often observed perching on vegetation or the ground while hunting.