Biocontrol potential of entomopathogenic nematodes and entomopathogenic fungi against the soil-dwelling stages of spotted-wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae)

Authors: THAPA, RAMBIKA - Michigan State University; USMAN, MUHAMMAD - Michigan State University; COLE, EMILE - Michigan State University; PINERO, JAIME - Michigan State University; Shapiro Ilan, David; CHUNG, YOENSUK - Michigan State University; QUINTANILLA, MARISOL - Michigan State University

Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/10/2026
Publication Date: 2/12/2026
Citation: Thapa, R., Usman, M., Cole, E., Pinero, J., Shapiro Ilan, D.I., Chung, Y., Quintanilla, M. 2026. Biocontrol potential of entomopathogenic nematodes and entomopathogenic fungi against the soil-dwelling stages of spotted-wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae). Pest Management Science. 214. https://doi.org/10.1016/j.biocontrol.2026.105986.
DOI: https://doi.org/10.1016/j.biocontrol.2026.105986

Interpretive Summary: Spotted-wing drosophila is a serious invasive pest of fruit crops such as berries and certain stone fruits. Currently, control of this important pest consists of chemical pesticide applications. However, environmental and regulatory concerns indicate the need to develop alternative methods of pest control. To address this issue, a variety of safe natural bio-insecticides were tested for their ability to kill spotted-wing drosophila. Specifically, bio-pesticide agents including several species of entomopathogenic (insect-killing) nematodes and fungi were tested for their ability to kill pupae of spotted-wing drosophila. Among the fungi, a species called Beauveria bassiana was the most effective, and a few nematode species were also effective such as Steinernema feltiae. Additionally, in some cases combinations of the Beauveria fungus and nematode species resulted in synergistic levels of fly mortality. In conclusion, we discovered that beneficial nematode and fungal biological control agents (alone or in combination) may be able to provide safe and effective control of the highly damaging pest, spotted-wing drosophila.

Technical Abstract: Spotted-wing drosophila (SWD), Drosophila suzukii, is an invasive pest of small fruits such as blueberries and raspberries, causing substantial yield losses. This study evaluated the biocontrol potential of entomopathogenic nematodes (EPNs) and entomopathogenic fungi (EPF) against the last instar larvae and pupae of D. suzukii. In the first experiment, three EPN species, Steinernema carpocapsae (ALL strain), S. feltiae (SN strain), and Heterorhabditis bacteriophora (SN strain), were applied at a rate of 50 infective juveniles (IJs) cm'². S. feltiae was the most effective, reducing adult D. suzukii emergence to 20% from larvae and 40% from pupae. A subsequent experiment tested nine EPN species, including S. carpocapsae, S. riobrave (355 strain), S. glaseri (VS strain), H. indica (HOM1 strain), H. georgiana, H. floridensis, and H. megidis (UK211 strain). Among these, S. feltiae, S. carpocapsae, and S. glaseri consistently reduced adult emergence to below 50%, with S. feltiae achieving 20% emergence at 100 IJs cm'². In a third experiment, three EPF, Beauveria bassiana, Metarhizium anisopliae, and Cordyceps fumosorosae, were evaluated. B. bassiana proved most effective, reducing D. suzukii adult emergence by more than 50% at 1 × 108 conidia mL'¹. In the final experiment, combinations of S. carpocapsae, S. feltiae, or S. glaseri with B. bassiana at both 50 and 100 IJs cm'² further reduced emergence, with the most effective treatment resulting in only 8% adult emergence. These findings demonstrate the strong potential of EPNs and EPF, individually and in combination, as biocontrol agents targeting the soil-dwelling stages of D. suzukii.