Efficacy of metarhizium anisopliae and beauveria bassiana as biological control agents of African Rice Gall Midge (AfRGM), Orseolia oryzivora Harris & Gagné

AbstractAfrican rice gall midge (AfRGM), Orseolia oryzivora (Diptera: Cecidomyiidae) is a significant pest of rainfed and lowland rice that causes about 25% to 100% yield loss. The effectiveness of chemical insecticides has been compromised due to insecticide resistance and concerns over their environmental impact, which necessitated an alternative approach that is safe and more sustainable. The study aimed to determine the effectiveness of Entomopathogenic fungi (EPF), Metarhizium anisopliae and Beauveria bassiana in controlling AfRGM on four popular rice cultivars under screenhouse conditions at AfricaRice/IITA, Ibadan, Nigeria. The experiment was laid out in a 4 x 3 factorial fitted in a completely randomized design (CRD) in three replications. Results showed that although both fungi significantly reduced AfRGM tiller infestation, the degree of reduction varied with the specific fungus and rice variety grown. Beauveria bassiana exhibited better control of AfRGM on FARO 37 and FARO 44 varieties, while M. anisopliae was more effective on FARO 66 and FARO 67 varieties. Tiller infestation had a significant negative correlation with grain yield (r= − 0.87, R2 = 77). The study also indicated that the two fungi strains had no harmful effect on the chlorophyll content and positively influenced agronomic traits and grain yield.Keywords: Entomopathogenic fungiMetarhizium anisopliaeBeauvaria bassianaAfRGMricetiller infestation AcknowledgementsThe authors gratefully appreciate Dr Douro Kpindou for providing the EPF isolates from IITA laboratory, Benin Republic and Mr. Adebayo Kehinde for technical assistance.Disclosure statementNo potential conflict of interest was reported by the author(s).Data availability statementData will be made available on request.