Vol 104 (2007)

Journal of the Entomological Society of British Columbia

Cover Page

COVER: Efferia coulei Wilcox (Diptera: Asilidae)

This robber fly is common in May and June in BC grasslands from the Okanagan Valleynorth to the Chilcotin Plateau. It ranges south to eastern Washington. Most of the 110 North American Efferia species live in the West, where they are major invertebrate predators in aridlands; there are seven species in BC. They are easily seen and heard, buzzing about in the open, frequently perching on the ground and attacking a variety of insectsfrom beetles to damselflies. This species is about 15 mm long. The oval object on the fly’s thorax is the larva of a parasitic mite (Parasitengona).

Photograph details: Male Efferia coulei, captured at Penticton, BC in June 1982 and photographed live in a glass terrarium. Nikon F2 with 55 mm macro lens, #1 extension tube and two small strobeflashes; Kodachrome 64 film. Robert A. Cannings and M. Brent Cooke, Royal BC Museum.