Efficacy of commercially available predators, nematodes and fungal entomopathogens for augmentative control of Drosophila suzukii

Abstract

The recent arrival of Drosophila suzukii, an invasive pest of soft-skinned fruit with a wide host range, has resulted in increased production costs for growers and the need for additional insecticide applications each growing season. There are few effective organic insecticides for D. suzukii, and insecticide use in conventional farms may be disruptive to natural enemies, suggesting a need for effective biological control to combat D. suzukii. Commercially available natural enemies were evaluated for their potential use in augmentative releases, including: the predators Orius insidiosus and Dalotia coriaria; the entomopathogenic fungi Metarhizium anisopliae, Beauveria bassiana and Paecilomyces fumosoroseus; and the entomopathogenic nematodes Heterorhabditis bacteriophora, Steinernema feltiae and S. carpocapsae. This suite of natural enemies was chosen to target D. suzukii adults as well as larvae in hanging or dropped fruit. Of the cultured fungal strains tested, only M. anisopliae significantly decreased D. suzukii survival, but it had low residual activity and no effect on D. suzukii fecundity. O. insidiosus decreased D. suzukii survival in simple laboratory arenas but not on potted blueberries or bagged blueberry branches outdoors. D. coriaria did not decrease D. suzukii survival in infested blueberries in simple laboratory arenas. The nematodes tested showed low infection rates and were not able to affect D. suzukii survival. Although this suite of natural enemies showed limited ability to suppress D. suzukii under the tested conditions, these and related natural enemies are present as part of the endemic natural enemy community in agricultural fields, where they may contribute to D. suzukii suppression.

Invasion biology of spotted wing Drosophila (Drosophila suzukii): a global perspective and future priorities

“…For example, there has been wide participation in national natural enemy collections (e.g., Rossi Stacconi et al 2013), and assessment of candidates for augmentative releases is ongoing (e.g., Woltz et al 2015). We now turn to a broader discussion of biological control prospects for SWD, with particular emphasis on research related to foreign exploration for specialist parasitoid wasps.…”

“…Although predators and pathogens may play important roles in regulating SWD populations (see above and the preliminary surveys by Gabarra et al (2015) and Woltz et al (2015)), most efforts in examining biological control options for invaded regions have focused on hymenopteran parasitoids. We begin our discussion of the prospects for SWD biological control with a brief review of the taxonomy and biology of larval and pupal parasitoids of Drosophila.…”

Invasive Drosophila suzukii facilitates Drosophila melanogaster infestation and sour rot outbreaks in the vineyards

“…Yield losses can reach 80% on crops such as strawberries, raspberries, blueberries and cherries [2,6]. Several biocontrol solutions including predators or parasitoids, fungal entomopathogens or nematodes have been tested, but yet none was successful [7]. Conventional pesticides are effective [8] but difficult to use, as fruit infestation occurs right before harvest at a time when most chemical treatments are prohibited for consumer health reasons [3].…”

Environmentally sustainable pest control options forDrosophila suzukii

“…In an evaluation of commercially available greenhouse biocontrol agents, Cuthbertson et al. () and Woltz, Donahue, Bruck, and Lee () tested several hemipteran predators ( Orius majusculus , O. laevigatus , O. insidious and Anthocoris nemoralis ), staphylinid rove beetles ( Atheta coriaria ), and predatory mites ( Hypoaspis miles ) for their ability to control D. suzukii . These predators achieved only low to intermediate mortality (Table ) in the closed‐arena survey and had no effect on fly mortality in field trials (Cuthbertson et al., ; Woltz et al., ).…”

“…Only S . feltiae infected the larvae, and the infection rate was just 1.6–2.2% (Woltz et al., ). A recent in vitro study, in which H .…”