Virto Cristina, Navarro David, Tellez M Mar, Herrero Salvador, Williams Trevor, Murillo Rosa, Caballero Primitivo
Instituto de Agrobiotecnología, CSIC-Gobierno de Navarra, Mutilva 31192, Navarra, Spain; Departamento de Producción Agraria, Universidad Pública de Navarra, 31006 Pamplona, Navarra, Spain.
IFAPA, La Mojonera, 04745 Almería, Spain.
J Invertebr Pathol. 2014 Oct;122:22-7. doi: 10.1016/j.jip.2014.07.007. Epub 2014 Aug 13.
Sublethal infections by baculoviruses (Baculoviridae) are believed to be common in Lepidoptera, including Spodoptera exigua. In addition, novel RNA viruses of the family Iflaviridae have been recently identified in a laboratory population of S. exigua (S. exigua iflavirus-1: SeIV-1; S. exigua iflavirus-2: SeIV-2) that showed no overt signs of disease. We determined the prevalence of these viruses in wild populations and the prevalence of co-infection by the different viruses in shared hosts. Infection by S. exigua multiple nucleopolyhedrovirus (SeMNPV) and iflaviruses in S. exigua adults (N=130) from horticultural greenhouses in southern Spain was determined using qPCR and RT-PCR based techniques respectively. The offspring of these insects (N=200) was reared under laboratory conditions and analyzed to determine virus transmission. Overall, 54% of field-caught adults were infected by SeMNPV, 13.1% were infected by SeIV-1 and 7.7% were infected by SeIV-2. Multiple infections were also detected, with 8.4% of individuals harboring SeMNPV and one of the iflaviruses, whereas 2.3% of adults were infected by all three viruses. All the viruses were transmitted to offspring independently of whether the parental female harbored covert infections or not. Analysis of laboratory-reared insects in the adult stage revealed that SeIV-1 was significantly more prevalent than SeMNPV or SeIV-2, suggesting high transmissibility of SeIV-1. Mixed infection involving three viruses was identified in 6.5% of laboratory-reared offspring. We conclude that interspecific interactions between these viruses in co-infected individuals are to be likely frequent, both in the field, following applications of SeMNPV-based insecticides, or in laboratory colonies used for SeMNPV mass production.
杆状病毒（杆状病毒科）引起的亚致死感染被认为在包括甜菜夜蛾在内的鳞翅目中很常见。此外，最近在甜菜夜蛾的实验室种群中发现了新的艾弗病毒科RNA病毒（甜菜夜蛾艾弗病毒-1：SeIV-1；甜菜夜蛾艾弗病毒-2：SeIV-2），这些病毒并未表现出明显的疾病迹象。我们测定了这些病毒在野生种群中的流行率以及不同病毒在共同宿主中的共感染率。分别使用基于qPCR和RT-PCR的技术，测定了来自西班牙南部园艺温室的130只甜菜夜蛾成虫中甜菜夜蛾多核多角体病毒（SeMNPV）和艾弗病毒的感染情况。将这些昆虫的200只后代在实验室条件下饲养并进行分析，以确定病毒传播情况。总体而言，54%的野外捕获成虫感染了SeMNPV，13.1%感染了SeIV-1，7.7%感染了SeIV-2。还检测到多重感染，8.4%的个体同时携带SeMNPV和一种艾弗病毒，而2.3%的成虫感染了所有三种病毒。所有病毒都能传播给后代，无论亲代雌虫是否携带隐性感染。对实验室饲养的成虫阶段昆虫的分析表明，SeIV-1的流行率显著高于SeMNPV或SeIV-2，这表明SeIV-1具有高传播性。在6.5%的实验室饲养后代中发现了涉及三种病毒的混合感染。我们得出结论，无论是在田间施用基于SeMNPV的杀虫剂后，还是在用于SeMNPV大规模生产的实验室种群中，共感染个体中这些病毒之间的种间相互作用可能都很频繁。
