昆虫病原线虫对红火蚁的致病力及田间防控效果

Pathogenicity of entomopathogenic nematodes to red imported fire ant,Solenopsis invicta Buren and the control efficacy in the field

红火蚁Solenopsis invicta Buren是一种国际重大外来入侵生物,严重危害农林生产、生命健康、公共安全和生态环境。本研究在室内条件下测定了小卷蛾斯氏线虫Steinernema carpocapsae All品系、长尾斯氏线虫S.longicaudum X-7品系和芫菁夜蛾斯氏线虫S.feltiae SN品系对红火蚁的致病力,并筛选出高致病力品系及其对红火蚁的田间防控效果。结果表明,不同昆虫病原线虫对红火蚁不同虫态的致病力存在显著差异。3种线虫对红火蚁幼虫具有较高的致病力,处理3 d后,幼虫的累计校正致死率均为100%。3种线虫对工蚁的致病力均较弱,处理10 d后的校正死亡率均小于30%。与芫菁夜蛾斯氏线虫SN品系相比,长尾斯氏线虫X-7品系和小卷蛾斯氏线虫All品系对蛹和生殖蚁具有较强的致病能力,10 d后累计校正死亡率均达到90%以上。田间试验表明,施用小卷蛾斯氏线虫All品系对红火蚁工蚁的防控效果最高可达63.7%,且不会增加红火蚁的迁巢风险。综上所述,小卷蛾斯氏线虫All品系和长尾斯氏线虫X-7品系为红火蚁的高致病品系,田间施用小卷蛾斯氏线虫All品系对红火蚁工蚁具有显著的控制作用,可推荐用于红火蚁的生物防治。

The red imported fire ant(Solenopsis invicta Buren)is one of the most destructive invasive pests,which seriously endangers agricultural and forestry production,life and health,public safety,and ecological environment.In this study,efficacy of three entomopathogenic nematodes,Steinernema carpocapsae All,S.longicaudum X-7 and S.feltiae SN,were evaluated against S.invicta in laboratory.Moreover,the control efficacy of the selected entomopathogenic nematodes with high pathogenicity on workers in the field was investigated.The results showed that the pathogenicity of different entomopathogenic nematodes to different stages of S.invicta was significantly different.Three nematodes had high pathogenicity to S.invicta larvae,with the corrected cumulative mortality 100%three days after inoculation.The pathogenicity of the three nematodes to workers was relatively low,with the corrected cumulative mortality less than 30%ten days after inoculation.Compared with S.feltiae SN,S.carpocapsae All and S.longicaudum X-7 had stronger pathogenicity to pupae and alates,with the corrected cumulative mortality more than 90%ten days after inoculation.The field experiment showed that the control efficacy of S.carpocapsae All on the workers was up to 63.7%,and it did not increase the development of new satellite mounds.The results indicated that S.carpocapsae All and S.longicaudum X-7 were entomopathogenic nematodes with high pathogenicity.In addition,S.carpocapsae All had high control efficacy against workers of S.invicta in the field,which could be used in S.invicta biological control.