Life table studies of the pupal parasitoid Urolepis rufipes (Hymenoptera: Pteromalidae) on the house fly Musca domestica (Diptera: Muscidae) in Denmark

Urolepis rufipes (Hymenoptera: Pteromalidae) is a newly recorded species in Denmark. It occurs in connection with livestock facilities, is a parasitoid on houseflies, and may therefore have potential as a biological fly control agent. The effects of five temperatures (15, 20, 25, 30, and 35 degreesC) on sex ratio, development time, survivorship, age-specific fecundity, net reproductive rate, intrinsic rate of natural increase (r(m)) and generation time of U. rufipes were investigated. Sex ratio was female-biased at all temperatures. Successful development occurred at all temperatures, with a minimum development time near 34 degreesC. Development time of males was significantly shorter than that of females. Immature survivorship was highest at 25 degreesC and 30 degreesC and lowest at 35 degreesC. An inverse relationship was found between longevity of adult females and temperature. The net reproductive rate (R,) was highest at 25 degreesC and 30 degreesC and lowest at 35 degreesC. The maximum r(m)-value was 0.346 d(-1) at 30 degreesC, and the minimum was 0.038 d(-1) at 15 degreesC. r(m)-values of the Danish strain were higher than those previously reported in a New York strain of U. rufipes. Generally, r(m) was higher than in most other fly pupal pteromalid parasitoids investigated, and hence U rufipes appears to be a promising control agent for houseflies.