Chow Andrew, Dunlap Christopher A, Jackson Mark A, Flores Daniel, Patt Joseph M, Sétamou Mamoudou
Citrus Center, Texas A&M University-Kingsville, Weslaco, TX 78596 (
USDA-ARS, National Center for Agricultural Utilization Research, Peoria, IL 61604 (
J Econ Entomol. 2016 Oct;109(5):1995-2005. doi: 10.1093/jee/tow164. Epub 2016 Jul 19.
Antagonistic interactions between the nymphal parasitoid, Tamarixia radiata Waterston (Hymenoptera: Eulophidae), and the ARSEF 3581 strain of the entomopathogenic fungus, Isaria fumosorosea Wize (Hypocreales: Cordycipitaceae), could disrupt biological control of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae). Three interactions were evaluated under laboratory conditions at 25 °C: 1) parasitoid survival if parasitized hosts were exposed to ARSEF 3581 blastospores before or after host mummification; 2) parasitoid survival if mummies containing larva or pupa were exposed to ARSEF 3581 hyphae; 3) parasitoid oviposition on infected hosts with visible or without visible hyphae. Topical application of blastospore formulation onto the dorsal surfaces of live nymphs parasitized with second-instar wasp larva (3 d after parasitism) reduced host mummification by 50% and parasitoid emergence by 85%. However, parasitoid emergence was not affected by topical application of blastospore formulation onto mummies that contained fourth-instar wasp larva (6 d after parasitism). Parasitoid emergence was reduced by 80% if mummies containing fourth-instar wasp larva were covered with blastospore formulation colonized by fungal hyphae. In comparison, parasitoid emergence was not affected if mummies containing wasp pupa (9 d after parasitism) were covered with formulation colonized by fungal hyphae. Female parasitoids oviposited on infected hosts without visible hyphae but not on infected hosts with visible hyphae. Our findings suggest that I. fumosorosea could detrimentally affect T. radiata, if both natural enemies are simultaneously deployed for biological control of D. citri However, temporal separation of the fungus and parasitoid could reduce antagonism and enhance control of D. citri.
若虫寄生蜂——放射潜蝇茧蜂（Tamarixia radiata Waterston，膜翅目：优茧蜂科）与昆虫病原真菌玫烟色棒束孢（Isaria fumosorosea Wize，肉座菌目：虫草科）的ARSEF 3581菌株之间的拮抗相互作用，可能会扰乱对亚洲柑橘木虱（Diaphorina citri Kuwayama，半翅目：木虱科）的生物防治。在25℃的实验室条件下评估了三种相互作用：1）若被寄生的寄主在木乃伊化之前或之后接触ARSEF 3581芽生孢子，寄生蜂的存活率；2）含有幼虫或蛹的木乃伊接触ARSEF 3581菌丝时，寄生蜂的存活率；3）寄生蜂在有可见或无可见菌丝的受感染寄主上的产卵情况。将芽生孢子制剂局部施用于被二龄黄蜂幼虫寄生的活若虫（寄生后3天）的背面，使寄主木乃伊化减少了50%，寄生蜂羽化减少了85%。然而，将芽生孢子制剂局部施用于含有四龄黄蜂幼虫的木乃伊（寄生后6天）上，对寄生蜂羽化没有影响。如果含有四龄黄蜂幼虫的木乃伊覆盖有被真菌菌丝定殖的芽生孢子制剂，寄生蜂羽化减少80%。相比之下，如果含有黄蜂蛹的木乃伊（寄生后9天）覆盖有被真菌菌丝定殖的制剂，寄生蜂羽化不受影响。雌性寄生蜂在无可见菌丝的受感染寄主上产卵，但不在有可见菌丝的受感染寄主上产卵。我们的研究结果表明，如果同时部署这两种天敌来对柑橘木虱进行生物防治，玫烟色棒束孢可能会对放射潜蝇茧蜂产生不利影响。然而，真菌和寄生蜂在时间上的分开可以减少拮抗作用，并增强对柑橘木虱的防治效果。
