Field, semi‐field and greenhouse testing of HOOK SWD, a SPLAT‐based attract‐and‐kill formulation to manage spotted‐wing drosophila

Abstract

Native to Southeast Asia, the spotted‐wing drosophila (Drosophila suzukii) has become a major pest of small fruit crops in the Americas and Europe because females can oviposit in ripening fruit. Currently, D. suzukii management relies heavily on chemical control; thus, more sustainable approaches like attract‐and‐kill need to be evaluated to reduce insecticide use. In previous studies, HOOK SWD, an attract‐and‐kill product that combines attractants, phagostimulants and an insecticide (spinosad), showed promise for D. suzukii control; still, little is known about its performance under field conditions and under varying pest and host‐fruit densities, as well as its residual activity. Here, we evaluated the efficacy of HOOK SWD when applied in commercial blueberry farms, when deployed in semifield cages under different D. suzukii adult and fruit densities and when aged for 30 days in the greenhouse. Results from field experiments showed that HOOK SWD could reduce fruit infestation in blueberry farms; however, its efficacy varied in space and time. Semifield cage studies revealed that relatively high densities of both D. suzukii adults and fruit can reduce the effectiveness of HOOK SWD, which might explain the variation in its efficacy in the field. Ageing HOOK SWD in a greenhouse for at least 30 days yielded no significant decrease in insecticidal activity. Altogether, these studies show that HOOK SWD can potentially suppress D. suzukii populations in the field, but it should be used as part of an integrated pest management program instead of a stand‐alone control tool, especially under high pest and fruit densities.

Comparison of multimodal attract-and-kill formulations for managing Drosophila suzukii: Behavioral and lethal effects

“…Identifying a superior A&K tactic will likely increase the adoption of behavior-based strategies for managing the invasive D. suzukii and reduce insecticide use in small fruit crops. HOOK SWD has been the most tested SPLAT-based A&K formulation against D. suzukii [13][14][15][16]. HOOK SWD applications have shown promise in reducing D. suzukii populations in blueberry and raspberry fields when deployed as a part of an IPM program [14,16].…”

“…HOOK SWD has been the most tested SPLAT-based A&K formulation against D. suzukii [13][14][15][16]. HOOK SWD applications have shown promise in reducing D. suzukii populations in blueberry and raspberry fields when deployed as a part of an IPM program [14,16]. Our study compared the attractiveness of two SPLAT-based ACTTRA SWD formulations-OR1, which has the same attractant blend as in HOOK SWD, and TD, which contains a newly developed attractive blend.…”

“…These multimodal formulations consist of a blend of olfactory attractants, a red dye for adult D. suzukii visual attraction, and sugars as phagostimulants. A SPLAT-based A&K formulation similar to ACTTRA SWD named HOOK SWD has previously been tested for efficacy in managing D. suzukii in small fruit crops [13][14][15][16]. HOOK SWD contains ACTTRA SWD OR1 (henceforth OR1) as an attractive blend and technical-grade insecticide spinosad as the killing agent.…”

“…These results suggest the potential of HOOK SWD, i.e., an OR1-based A&K formulation, as a behavior-based strategy for D. suzukii management in small fruit crops. However, the field efficacy of HOOK SWD can be variable in time and space [16]; thus, new, more effective A&K formulations need to be identified.…”

Novel Lactone-Based Insecticides and Drosophila suzukii Management: Synthesis, Potential Action Mechanisms and Selectivity for Non-Target Parasitoids

“…A possible alternative to foliar spraying is the use of toxic baits or low-volume, reduced-risk sprays in conjunction with feeding attractants [ 8 , 9 ]. However, although the use of these devices can substantially reduce the amount of insecticide applied, the efficiency can be strongly influenced by factors such as the high density of insects, unharvested fruits, and other alternative host fruits in the field, in addition to the physiological aspects (e.g., reproductive maturity, age, mating status) of insects [ 10 , 11 ].…”