Damascena Alixelhe Pacheco, de Carvalho Vanessa Rafaela, Ribeiro Murilo Fonseca, Horta André Ballerini, Monteiro de Castro E Castro Bárbara, Zanuncio Antônio José Vinha, Wilcken Carlos Frederico, Zanuncio José Cola, Wilcken Silvia Renata Siciliano
Universidade Estadual Paulista (UNESP), Faculdade de Ciências Agronômicas, Departamento de Proteção Vegetal, Departamento de Proteção Vegetal, 18610-034, Botucatu, São Paulo, Brazil.
Departamento de Entomologia/BIOAGRO, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900 Brazil.
R Soc Open Sci. 2020 Aug 5;7(8):200282. doi: 10.1098/rsos.200282. eCollection 2020 Aug.
Entomopathogenic nematodes (EPNs) can control pests due to mutualistic association with bacteria that reproduce and kill the host from septicemia, making the environment favourable for nematode development and reproduction. The objective of this study was to identify an EPN isolate collected in eucalyptus cultivation and to determine its pathogenicity with regard to Marelli (Coleoptera: Curculionidae). Four steel-mesh traps with two seventh-instar larvae were buried 5 cm deep in the soil in a commercial plantation. After 7 days, the traps were packed in plastic bags and transported to laboratory to isolate the EPNs using White traps. The obtained nematodes were multiplied in larvae and identified by sequencing their D2/D3 expansion of the 28S rDNA region by polymerase chain reaction (PCR) and specific primers for ITS regions. was identified and inoculated into pupae at doses of 500, 1000 and 5000 infective juveniles (IJs) to determine its pathogenicity to this pest. At 8 days after inoculation, the mortality rate of the pupae was 80% with the lowest concentration and 100% with the others. The emergence of nematodes and the rapid degradation of pupae were observed in those inoculated with IJs. The pathogenicity to the pupae indicates potential for using this nematode in the integrated management of this insect.
昆虫病原线虫（EPNs）可通过与细菌的共生关系来控制害虫，这些细菌会繁殖并通过败血症杀死宿主，从而为线虫的发育和繁殖创造有利环境。本研究的目的是鉴定在桉树种植中收集到的一种EPN分离株，并确定其对马雷利象甲（鞘翅目：象甲科）的致病性。在一个商业种植园的土壤中，将四个装有两只七龄幼虫的钢丝网诱捕器埋入地下5厘米深处。7天后，将诱捕器装入塑料袋并运至实验室，使用怀特诱捕器分离EPNs。将获得的线虫在幼虫中繁殖，并通过聚合酶链反应（PCR）和ITS区域的特异性引物对其28S rDNA区域的D2/D3扩增片段进行测序来鉴定。鉴定出该线虫后，以500、1000和5000条感染性幼虫（IJs）的剂量接种到蛹中，以确定其对这种害虫的致病性。接种后8天，最低浓度组蛹的死亡率为80%，其他组为100%。在接种IJs的蛹中观察到了线虫的出现和蛹的快速降解。对蛹的致病性表明该线虫在这种昆虫的综合管理中具有应用潜力。
