Interactions betweenMeteorus pulchricornisandSpodoptera exiguaMultiple Nucleopolyhedrovirus

Abstract

Baculoviruses may interact with parasitoids in the same host. A previous study has shown that infection of larvae with Spodoptera litura nucleopolyhedrovirus (SpltNPV) was deleterious to the survival and development of Meteorus pulchricornis (Wesmael) (Hymenoptera: Braconidae). In this paper, the interactions between M. pulchricornis and Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) in Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), a permissive host of the virus and parasitoid, were investigated. The results showed that the effect of M. pulchricornis on SeMNPV and the effect of the virus on the parasitoid both depended on the concentration of the virus and the interval between viral infection and parasitism. Whether S. exigua was treated with the parasitoid and virus simultaneously or 1 day apart, the biological activities of 105, 106, and 107 OBs/mL SeMNPV were all significantly improved by M. pulchricornis. In contrast, the biological activity of 103 OBs/mL SeMNPV was significantly decreased when the host was exposed to the virus and parasitoid simultaneously. Regarding the impact of SeMNPV on M. pulchricornis, exposing the host to the parasitoid and SeMNPV with concentrations lower than 106 occlusion bodies (OBs)/mL produced no negative effects on the parasitoid. The results also showed that ingestion of SeMNPV by adult stage M. pulchricornis significantly increased the number of parasitoid offspring that successfully emerged from the host. Furthermore, M. pulchricornis was found to transmit SeMNPV among populations of S. exigua. Taken together, these findings indicate that M. pulchricornis integrated with an appropriate concentration of SeMNPV has the potential to improve the efficacy of biological control against S. exigua.

Proceedings

“…There is also no significant difference in the developmental period (egg to pupae) of parasitoids that emerged from SoNPV-treated and untreated larva. These results find support from earlier findings of Guo et al(2013) who reported that the development time of the M. pulchricornis that emerged from SeMNPV-infected S. exigua was not affected by the virus.…”

Improved effects of Helicoverpa armigera nucleopolyhedrovirus integrated with Campoletis chlorideae against H. armigera and impact of the virus on the parasitoid

“…Furthermore, the ingestion of SeMNPV OBs by parasitoids increased the number of parasitoid offspring that successfully emerged from the host. 37 By contrast, HearNPV infection prolonged the development of Microplitis mediator. 30 The results of the current study showed that HearNPV also prolonged the development time (from larvae to adults) of C. chlorideae and negatively affected C. chlorideae reproduction.…”

“…These natural enemies have also been used in combination 27 . However, not all combinations of baculoviruses and parasitoid wasps have resulted in improved pest control, which may depend on inoculum concentration 37 . In this study, the combined use of C. chlorideae with a high concentration of HearNPV OBs revealed that the mortality of H. armigera larvae infected with HearNPV and parasitized 24 h later (treatment 3, V + P) was significantly higher than that caused by HearNPV or C. chlorideae alone, whereas the mortality in treatment 4 (P + V) was not higher than that caused by parasitism alone.…”

Contribution of a parasitoid species to multiplication and transmission of a multiple nucleopolyhedrovirus in caterpillars

“…Parasitism by parasitic wasps has been demonstrated to affect NPV in caterpillars. For example, the use of Meteorus pulchricornis as a biocontrol agent improved the insecticidal effect of high‐dosage SeMNPV against beet armyworms (Guo, Fang, Zhong, & Liu, ). Furthermore, the use of Microplitis demolitor increased the lethality of the Helicoverpa armigera NPV (Murray, Monsour, Teakle, Rynne, & Bean, ).…”

“…Furthermore, the use of Microplitis demolitor increased the lethality of the Helicoverpa armigera NPV (Murray, Monsour, Teakle, Rynne, & Bean, ). Conversely, however, M. pulchricornis was shown to reduce the biological activity of low‐dosage SeMNPV (Guo et al, ). These results indicate that the effect of parasitic wasps on NPV is determined by the virus type, parasitoid species, viral dose and other factors (Escribano, Williams, Goulson, Cave, & Caballero, ; Stoianova, Hernandez, & Caballero, ).…”