Department of Entomology, University of Agriculture Faisalabad, Punjab, Pakistan.
Department of Entomology, University of Georgia, Tifton, GA, USA.
J Econ Entomol. 2020 Dec 9;113(6):2627-2633. doi: 10.1093/jee/toaa209.
The objectives of this study were to quantify the virulence of four entomopathogenic fungal species to pupae of Rhagoletis pomonella (Walsh) (Diptera: Tephritidae) and to determine the potential to combine entomopathogenic fungi (EPFs) and entomopathogenic nematodes (EPNs) for biological control of this pest. The four species of EPFs included Beauveria bassiana (strain GHA), Metarhizium brunneum (strain F52), Isaria javanica (wf GA17), and Isaria fumosorosea (Apopka 97 strain). In laboratory assays, all fungi reduced adult emergence but there were no differences between fungal species. Isaria javanica and M. brunneum were examined further in a EPFs and EPNs bioassay that also included the EPNs Steinernema carpocapsae (ALL strain) and S. riobrave (355 strain). All nematodes and fungi were applied either alone or in combination (fungus + nematode). There were no differences between species within the same entomopathogen group (fungi and nematodes). However, the treatment with S. riobrave resulted in lower R. pomonella emergence than either fungal species. The combination of S. riobrave and I. javanica resulted in the lowest R. pomonella emergence (3%) at fourth-week interval, which was significantly lower than any of the single-agent applications, yet virulence of the other three combination treatments was not different from their respective nematode treatments applied alone. Additive interactions were detected for all fungus-nematode combinations. This study suggests that application of entomopathogenic nematodes and fungi could be an effective option to suppress R. pomonella populations.
本研究的目的是量化四种昆虫病原真菌对苹果实蝇（Rhagoletis pomonella（Walsh））蛹的毒力，并确定将昆虫病原真菌（EPFs）和昆虫病原线虫（EPNs）相结合用于该害虫生物防治的潜力。四种 EPF 包括球孢白僵菌（GHA 株）、绿僵菌（F52 株）、淡紫拟青霉（wf GA17）和玫烟色棒束孢（Apopka 97 株）。在实验室测定中，所有真菌都降低了成虫的羽化率，但真菌种类之间没有差异。在包括 EPNs 斯氏线虫（ALL 株）和 S. riobrave（355 株）的 EPFs 和 EPNs 生测中，进一步研究了淡紫拟青霉和绿僵菌。所有线虫和真菌单独或组合（真菌+线虫）施用。在同一昆虫病原物组（真菌和线虫）内，不同种之间没有差异。然而，S. riobrave 的处理导致苹果实蝇羽化率低于任何一种真菌。S. riobrave 和 I. javanica 的组合在第四周间隔时导致苹果实蝇羽化率最低（3%），显著低于任何单剂处理，但其他三种组合处理的毒力与单独施用相应的线虫处理没有差异。所有真菌-线虫组合都检测到了相加作用。本研究表明，应用昆虫病原线虫和真菌可能是抑制苹果实蝇种群的有效选择。
