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ARS Home » Southeast Area » Byron, Georgia » Fruit and Tree Nut Research » Research » Publications at this Location » Publication #386116
Research Project: Novel Approaches for Managing Key Pests of Peach and Pecan

Location: Fruit and Tree Nut Research

Title: Evaluation of locally isolated entomopathogenic fungi against multiple life stages of Bactrocera zonata and Bactrocera dorsalis (Diptera: Tephritidae): Laboratory and Field Study

Author
item MUHAMMAD, USMAN - University Of Agriculture - Pakistan
item WAKIL, WAQAS - University Of Agriculture - Pakistan
item Shapiro Ilan, David

Submitted to: Microorganisms
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/1/2021
Publication Date: 8/24/2021
Citation: Muhammad, U., Wakil, W., Shapiro Ilan, D.I. 2021. Evaluation of locally isolated entomopathogenic fungi against multiple life stages of Bactrocera zonata and Bactrocera dorsalis (Diptera: Tephritidae): Laboratory and Field Study. Microorganisms. 9/1891. https://doi.org/10.3390/microorganisms9081791.
DOI: https://doi.org/10.3390/microorganisms9081791

Interpretive Summary: Fruit flies including Bactrocera zonata and B. dorsalis (Diptera: Tephritidae) are con-sidered major pests of orchard systems in Pakistan. This study evaluated the labora-tory virulence, sub-lethal effects, horizontal transmission, greenhouse and field-cage efficacy of locally isolated entomopathogenic fungi (EPF) against B. zonata and B. dorsalis. In virulence assays against 3rd instars and adults, all 21 EPF isolates (Beauveria bassiana and Metarhizium anisopliae) tested were pathogenic and caused varying levels of mortality to the fruit flies. Based on the initial screening, four isolates (B. bassiana WG-21 and WG-18 and M. anisopliae WG-07 and WG-02) were selected for further study. The isolate WG-18 was the most virulent against larvae and adults of B. zonata and B. dorsalis followed by WG-21, WG-02 and WG-07. In both species, adults were more susceptible than larvae to all isolates, and pupae were least susceptible. Isolates WG-18 and WG-21 caused the lowest female fecundity and fertility, lowest adult and larval survival, and longest developmental time of larvae and pupae. Fungal isolates were found to disseminate conidia from infected to healthy adults and induced sig-nificant mortality particularly from infected males to non-infected females. In greenhouse and field-cage experiments, WG-18 and WG-21 were the most effective isolates in reducing adult emergence when applied to larvae and pupae of both fruit fly species. Our results indicate that B. bassiana isolates WG-18 and WG-21 were the most lethal against multiple life stages of B. zonata and B. dorsalis and also exerted the strongest sub-lethal effects.

Technical Abstract: The oriental fruit fly, and the peach fruit fly are important pests of various fruits. Chemical insecticides are often used to control these pests. Due to environmental and regulatory concerns, alternative measures of control must be sought. Entomopathogenic (insect-killing) fungi are safe natural biopesticides. We investigated the virulence (killing ability) of 21 isolates of entomopathogenic fungi to determine which might be the best ones for controlling the oriental fruit fly, and the peach fruit fly. Laboratory, greenhouse and field tests indicated that two isolates (Beauveria bassiana isolates WG-18 and WG-21) are the most promising strains and will be explored further as potential biological control agents for these harmful fruit flies. These results enhance the potential for sustainable fruit fly management.