背景:Alphabaculovirus是鳞翅目特异性毒力病原体,感染多种害虫,包括Spodoptera复合物.由于其环境持久性低,Alphabaculovirus作为生物杀虫剂的传统用途包括重复治疗的高速率喷雾应用。几种非生物和生物因素可以促进其分散,促进它们在农业生态系统中的持久性。在生物因素中,捕食性节肢动物在捕食受感染的个体后可以通过排泄来分散病毒。因此,这项研究的重点是促进捕食者摄入NPV处理的饮食,以及后来将昆虫宿主暴露于被捕食者排泄物污染的叶片表面。研究的病毒-宿主-捕食者系统是斜纹夜蛾核多角体病毒(SpliNPV),斜纹夜蛾(Boisduval)和黑斑夜蛾(Reuter)。在饲喂处理过的饮食(蔗糖溶液和Ephestiakuehniella卵)后,在实验室条件下评估了N.tenuis粪便的感染潜力和SpliNPV的保留时间。
结果:在第一个感染周期中,通过N.tenuis排泄的S.littoris幼虫的死亡率低于阳性对照(喷雾应用),以及宿主死亡的延迟。在第二个感染周期中,两种SpliNPV治疗的饮食均引发100%死亡率.两种饮食都允许SpliNPV的传播,与E.kuehniella卵相比,通过蔗糖溶液排泄更快。SpliNPV保留在N.tenuis消化道中,并且在两种饮食中至少排泄9天后都是可行的。
结论:这项研究证明了捕食者N.tenuis作为杆状病毒接种剂的潜力,代表了一种新的选择,随着大量的应用,可能有助于改善虫害管理策略。本文受版权保护。保留所有权利。
BACKGROUND: Alphabaculoviruses are Lepidoptera-specific virulent pathogens that infect numerous pests, including the Spodoptera complex. Due to their low environmental persistence, the traditional use of Alphabaculoviruses as
bioinsecticides consist in high-rate spray applications with repeated treatments. Several abiotic and biotic factors can foster its dispersion, promoting their persistence in the agroecosystem. Amongst biotic factors, predatory arthropods can disperse the viruses by excretion after preying on infected individuals. Therefore, this study focused on promoting predator\'s ingestion of nucleopolyhedrovirus (NPV)-treated diets, and the later exposition of the insect host to leaf surfaces contaminated with predator excreta. The virus-host-predator system studied was Spodoptera littoralis nucleopolyhedrovirus (SpliNPV), Spodoptera littoralis (Boisduval) and Nesidiocoris tenuis (Reuter). The infective potential of N. tenuis feces and the retention time of SpliNPV were assessed under laboratory conditions after feeding on treated diets (sucrose solution and Ephestia kuehniella eggs).
RESULTS: Mortality of S. littoralis larvae was lower via N. tenuis excretion than in positive control (spray application) in the first infection cycle, together with a delay in host death. In the second infection cycle, both SpliNPV-treated diets triggered 100% mortality. Both diets allowed the transmission of SpliNPV, with a faster excretion via sucrose solution compared to E. kuehniella eggs. SpliNPV remained in N. tenuis digestive tract and was viable after excretion at least for 9 days for both diets.
CONCLUSIONS: This study demonstrated the potential of the predator N. tenuis as inoculative agent of baculoviruses, representing a new alternative that, along with inundative applications, might contribute to improve pest management strategies. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.