Abstract Dryinus sinicus Olmi (Hymenoptera: Dryinidae) is an important nymphal parasitoid of the spotted lanternfly, Lycorma delicatula White (Hemiptera: Fulgoridae), in its native range in China. As part of evaluations of this parasitoid as a biological control agent for invasive L. delicatula in the United States, this study evaluated its immature developmental morphology and reproductive potential. Adult D. sinicus exhibits sexual dimorphism; females possess a chelate protarsus. Larvae are ectoparasitic, with the head partially embedded in the host’s coelom and the body protruding between 2 sclerites, covered by the larval exuviae (thylacium). The larva develops through 5 instars before crawling out to pupate in a silken cocoon, killing its host in the process. Dryinus sinicus is highly synovigenic (ovigeny index: 0.0843), with females emerging with 15.6 ± 2.2 mature oocytes and ready for oviposition. Host feeding and oviposition likely prompt egg production. At 20 °C, adult females lived 61.3 ± 9.9 d, parasitized 137.2 ± 34.9 nymphs, laid 175.8 ± 46.1 eggs, and host-fed on 20.8 ± 3.8 nymphs during their lifetime. Self-superparasitism occurred frequently in the laboratory setting, and multiple offspring occasionally developed from a single host. The lifetime fecundity and predation of D. sinicus were positively correlated with longevity. In the laboratory trials, D. sinicus more effectively parasitized and host-fed upon first than second instars and killed approximately 7 times more nymphs through parasitism than through host feeding. Overall, D. sinicus demonstrates high fecundity and strong potential as a biological control agent for L. delicatula.
Wang et al. (Tue,) studied this question.