AUTHOR=Li Xin-lian , Zhang Jing-jing , Li Dou-dou , Cai Xin-yan , Qi Yi-xiang , Lu Yong-yue 

TITLE=Toxicity of Beauveria bassiana to Bactrocera dorsalis and effects on its natural predators

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1362089

DOI=10.3389/fmicb.2024.1362089

ISSN=1664-302X

ABSTRACT=<p>Entomopathogenic fungi (EPF) are economical and environmentally friendly, forming an essential part of integrated pest management strategies. We screened six strains of <italic>Beauveria bassiana</italic> (B1–B6) (Hypocreales: Cordycipitaceae), of which B4 was the most virulent to <italic>Bactrocera dorsalis</italic> (Hendel) (Diptera: Tephritidae). We further assessed the biological characteristics of strain B4 and the environmental factors influencing its ability to infect <italic>B. dorsalis</italic>. We also evaluated the effects of B4 on two of the natural predators of <italic>B. dorsalis</italic>. We found that strain B4 was the most virulent to 3rd instar larvae, pupae, and adult <italic>B. dorsalis</italic>, causing mortality rates of 52.67, 61.33, and 90.67%, respectively. B4 was not toxic to <italic>B. dorsalis</italic> eggs. The optimum B4 effects on <italic>B. dorsalis</italic> were achieved at a relative humidity of 91–100% and a temperature of 25°C. Among the six insecticides commonly used for <italic>B. dorsalis</italic> control, 1.8% abamectin emulsifiable concentrate had the strongest inhibitory effect on B4 strain germination. B4 spraying affected both natural enemies (<italic>Amblyseius cucumeris</italic> and <italic>Anastatus japonicus</italic>), reducing the number of <italic>A. cucumeris</italic> and killing <italic>A. japonicus</italic> adults. We found a valuable strain of EPF (B4) that is virulent against many life stages of <italic>B. dorsalis</italic> and has great potential for the biological control of <italic>B. dorsalis</italic>. We also provide an important theoretical and practical base for developing a potential fungicide to control <italic>B. dorsalis</italic>.</p>