Location: Fruit and Tree Nut ResearchTitle: Combined application of entomopathogenic nematodes and fungi against fruit flies, Bactrocera zonata and B. dorsalis (Diptera: Tephritidae):laboratory cups to field study
|WAKIL, WAQAS - University Of Agriculture - Pakistan|
|MUHAMMAD, USMAN - University Of Agriculture - Pakistan|
|PINERO, JAIME - University Of Agriculture - Pakistan|
|WU, SHAOHUI - University Of Georgia|
|TOEWS, MICHAEL - University Of Georgia|
|Shapiro Ilan, David|
Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/30/2022
Publication Date: 6/17/2022
Citation: Wakil, W., Muhammad, U., Pinero, J., Wu, S., Toews, M., Shapiro Ilan, D.I. 2022. Combined application of entomopathogenic nematodes and fungi against fruit flies, Bactrocera zonata and B. dorsalis (Diptera: Tephritidae):laboratory cups to field study. Pest Management Science. Vol 78, 2779-2791. http://dx.doi.org/10.1002/ps.6899.
Interpretive Summary: The peach fruit fly, Bactrocera zonata, and the Oriental fruit fly, B. dorsalis (Diptera: Tephritidae), are economically important fruit fly species in various regions of the world. We evaluated the effects of separate and combined applications of the entomopathogenic fungi (EPF ) Beauveria bassiana (WG-18), Metarhizium anisopliae (WG-02) and the entomopathogenic nematodes (EPNs) Heterorhabditis bacteriophora (VS strain) and Steinernema carpocapsae (ALL strain) against various developmental stages, i.e. larvae, pupae and pharate adults, of B. zonata and B. dorsalis under laboratory (small cup and potted soil bioassays), greenhouse and field cage conditions. Combined applications of EPF and EPNs produced greater mortality of larvae, pupae, and pharate adults of B. zonata and B. dorsalis compared to individual treatments under all conditions. Against both species at various stages and conditions, the combination of B. bassiana and H. bacteriophora consistently exerted the strongest effects but was not different from the combined application of B. bassiana and S. carpocapsae; M. anisopliae applied with S. carpocapsae was least effective in all combinations. In the small cup bioassay, synergistic interactions were detected between B. bassiana and H. bacteriophora applied against larvae and pharate adults of both fly species, between B. bassiana and S. carpocapsae against larvae of both species and pharate adults of B. zonata, and between M. anisopliae and H. bacteriophora against B. zonata larvae. Other combined treatments resulted in additive effects, especially against fly pupae. In the potted soil bioassay, there were only additive interactions in all combinations against different stages of both flies. The third-instar was the most susceptible stage, compared to the pharate adult and pupal stages. Additive interactions between EPNs and EPF were detected in the greenhouse against 3rd instars and pupae, and under field conditions against 3rd instars of both fly species. Our results indicate particular combinations of entomopathogenic fungi and nematodes could be deployed in integrated pest management of tephritid fruit flies in orchard agro-ecosystems of Pakistan.
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. Entomopathogenic nematodes are small round worms that kill insects and are also used as bioinsecticides. Both of these agents (the nematodes and fungi) have been shown to control fruit flies. In this study we investigated if there may be advantages in combining nematodes and fungi with the idea that the combination may produce higher levels of efficacy in fruit fly control. We combined various species of nematodes and fungi and compared the outcome to the organisms applied alone. A particular combination of nematode and fungus (Heterorhabditis bacteriophora and Beauveria bassiana) was the most virulent combination. The combined nematode plus fungus was synergisitc (greater than the some of parts) in killing the targeted fruit flies in laboratory tests. Thus, we discovered that some combinations of insect-killing nematodes and fungi have high potential for sustainable fruit fly management.