Demography and Fitness of Reared from as a Biological Control Agent of .

Japanese giant silkworm (JGS), Moore, is an emerging defoliator pest of forest and fruit trees in East Asia, causing severe economic losses. To develop a cost-effective biological control program against JGS, we used eggs of the Chinese oak silkworm (COS) Guérin-Méneville as an alternative host to rear the most dominant JGS egg parasitoid Ashmead. We compared the demographic parameters and total parasitism (killing) rates of parasitizing JGS and COS eggs using an age-stage, two-sex life table method. The results showed that performed differently on these two different hosts. reared from COS eggs had a higher fecundity (369.7 eggs per female) and a longer oviposition period (35.9 days) on the COS than JGS eggs (180.9 eggs; 24.0 days). Consequently, parasitizing COS eggs had a higher intrinsic rate of increase ( = 0.1466 d), finite rate of increase (λ = 1.1579 d) and net reproductive rate ( = 284.9 offspring) than those parasitizing JGS eggs ( = 0.1419 d, λ = 1.1525 d, = 150.0 offspring). The total net parasitism rate (the number of parasitized hosts in which the parasitoids successfully developed) of parasitizing COS eggs was 284.9, significantly higher than that of parasitizing JGS eggs (150.0), while the net non-effective parasitism rate (the number of parasitized hosts in which the parasitoids failed to develop) of the former (0.0) was significantly lower than that of the latter (9.6). These results suggest that can be efficiently reared on the alternative (or factitious) COS eggs, and the reared parasitoids have a high biological control potential against the target JGS.