Relationships Between Temperature and Life History Parameters of Trichomalopsis sarcophagae (Hymenoptera: Pteromalidae)

Abstract

The effect of temperature on the life history of the pteromalid parasitoid Trichomalopsis sarcophagae Gahan was determined to develop relationships that could be used for construction of simulation models of biological control. Immature developmental rates were not influenced by parasitoid sex or host species, and increased in a linear fashion with temperatures in the range of 15 to 30°C. Development was limited at 33°C. Immature development required 197 degree-days above 12.4°C. Immature survival was lowest at 15 and 33°C, and highest in the range of 22 to 26°C. Host species did not influence the relationship between temperature and immature survival, although fewer progeny were produced in pupae of the stable fly, Stomoxys calcitrans (L.), compared with the house fly, Musca domestica (L.). Sex ratio of emerging parasitoids was 79% female at 15°C, and 62–69% female at 20–30°C. Stable fly pupae yielded 64% females compared with 73% females from house fly pupae. House fly pupae yielded 8.2 progeny per pupa compared with 4.6 progeny per stable fly pupa. Median female longevity declined from 15–18 d at 15°C to 4–5 d at 33°C. Time to 50% oviposition ranged from 8–11 d at 15°C to <2 d at 33°C. Lifetime progeny production was lowest at 15 and 33°C, and >70 progeny per female at 25°C. The net reproductive rate was <1 female per female at 15 and 33°C and >38 female per female at 25°C. Mean generation time decreased from 89 d at 15°C to <12 d at 33°C. The intrinsic rate of increase was ≤0 female per female per day at 15 and 33°C, but >0.22 female per female per day at 25°C. T. sarcophagae appears better adapted to cooler temperatures than many other pteromalids, and may prove to be a useful biological control agent for filth flies in northern areas.