Relationships between temperature and life history parameters of Muscidifurax raptor (Hymenoptera : Pteromalidae)

The effect of temperature on the life history of Muscidifurax raptor Giraul t & Sanders was determined to develop relationships that could be used to i mprove simulation models of biological control. Immature developmental rate s were influenced by temperature and sex. Males developed faster than femal es, and the developmental rate increased with, temperature to 30 degrees C, then declined. Immature survival was lowest at 15 and 33 degrees C, and hi ghest in the range 20-25 degrees C. Sex ratio of emerging parasitoids avera ged 72 and 55% from house fly, Musca domestica (L.), and stable fly, Stomox ys calcitrans (L.), pupae and increased with temperature. Female longevity, time to median oviposition, and lifetime progeny production declined as te mperature increased. The net reproductive rate was lowest at 15 and 33 degr ees C, and greatest at 25 degrees C. Mean generation time decreased with in creasing temperature. The intrinsic rate of increase was highest at 30 degr ees C. M. raptor has a broad thermal preference which may account for its g reater relative abundance and wider seasonal abundance in Alberta compared with other species of naturally occurring parasitoids.