Demography of the leafminer parasitoid Ganaspidium utilis Beardsley (Hymenoptera: Eucoilidae) at different temperatures

Demographic parameters, reproductive pattern, and heterogeneity for the leafminer parasitoid Ganaspidium utilis Beardsley (Hymenoptera: Eucoilidae) were determined in the laboratory at 16, 27, and 32 degrees C using Liriomyza trifolii (Burgess) with "Henderson" bush lima beans as the host. Development and progeny production did not occur at 16 degrees C. Mean developmental time was significantly shorter (13.2 days) at 32 degrees C than at 27 degrees C (18.4 days). Preadult cumulative survival rates at 27 degrees C (62%) and 32 degrees C (43%) were significantly different. Male and female longevities were similar. Adult G. utilis lived a maximum of 23 days at 16 degrees C, 13 days at 27 degrees C, and 8 days at 32 degrees C. Total mean lifetime progeny production per female G. utilis ranged from 68.50 progeny at 32 degrees C to 115.10 progeny at 27 degrees C. Heaviest progeny production occurred during Days 2 and 3 of a female's life at 32 and 27 degrees C, respectively. Of the total progeny produced, the female percentage ranged from 47 at 27 degrees C to 49 at 32 degrees C. Mean generation time was 15 days at 32 degrees C and 21 days at 27 degrees C. Intrinsic rate of increase varied from 0.19 at 27 degrees C to 0.23 at 32 degrees C. In the stable age distribution, egg percentage was highest (56-58) followed by larval stage (36-37), whereas pupal and adult stages each only represented 3 to 4. Age-by-parity relations demonstrated that timing and magnitude of reproduction were influenced by temperature