The Diptera Medetera aldrichii Wheeler (Dolichopodidae) and Lonchaea furnissi McAlpine (Lonchaeidae) Associated with the Douglas-fir Beetle in Western Oregon and Washington

Abstract

Preliminary studies on the association of the Douglas-fir beetle with species of Diptera found in windthrown Douglas-firs were conducted in 1962 and 1963. These studies revealed that larvae of Medetera aldrichii Wheeler preyed upon larvae and pupae bur only rarely on teneral adults of the Douglas-fir beetle whereas larvae of Lonchaea furnissi McAlpine did not kill the bark beetle in any stage. Adults of M. aldrichii lived up to i weeks at 70° F. on granary mites, and L. furnissi adults survived for more than 3 weeks on honey and Metrecal. Seasonal and daily emergence patterns from naturally infested Douglas-firs are presented and the effects of temperature and light on emergence and flight are discussed.