Abstract:

Objective: Female adults of Sclerodermus pupariae can develop into winged or wingless morphs. However, winged females are only occasionally found in both wild and mass-reared populations. This study aims to investigate whether there are differences in the parasitic behavior and progeny development between winged and wingless female individuals, so as to provide a theoretical basis for further clarifying the necessity of inducing production of winged females in the parasitoid mass-rearing. Method: The parasitism ability, pre-oviposition period, offspring immature duration, fecundity, and male offspring proportion of winged and wingless females were measured in the laboratory conditions. Result: 1) Both winged and wingless females could complete four times of parasitism. There was no significant difference in parasitism ability between the two types of morphs of the parasitoids, but the parasitism ability decreased with the increasing parasitism times. There was no significant difference in longevities of winged and wingless females, with an average lifespan of approximately 43 days. 2) There were no significant differences in the pre-oviposition period and the offspring immature duration between winged and wingless females. 3) The total numbers of offspring and male proportions of winged and wingless females exhibited no significant differences. Winged and wingless females could produce approximately 103 and 98 progenies, respectively. Their male progeny proportions were 10.59% and 6.90%, respectively. Both winged and wingless females had the four parasitism times, and their offsprings in the first two broods were dominated by females, and the second two broods of offsprings were dominated by males. Conclusion: The parasitism and fecundity of winged females are not lost due to the development of wings, and the reproductive fitness of winged females does not decrease in comparison to the wingless individuals. Due to the strong self diffusion ability of winged females after release, more winged females produced by artificial regulations would achieve benefits for biocontrol application of this parasitoid.

Key words: wing dimorphism, parasitism ability, fecundity, developmental duration, sex ratio