Canopy spray deposition and related mortality impacts of commonly used insecticides on Drosophila suzukii Matsumura (Diptera: Drosophilidae) populations in blueberry

Abstract

BACKGROUND Insecticide applications in blueberry production systems play a crucial role in the control of Drosophila suzukii populations. Here, quantitative spray deposition patterns were obtained under replicated field experiments in blueberry during two field seasons with three sprayers, i.e. cannon, electrostatic, and air‐blast. Seven insecticides were tested (at 6 hours using a Potter spray tower) to determine the mortality data for adult D. suzukii. Spray deposition and mortality data for adult D. suzukii were used to create model simulations for insect populations. Model simulations included field deposition rates of sprayers and insecticide mortality as factors. Simulations were applied in different combinations with five applications over a 6‐week period. RESULTS Relative deposition rates for the cannon sprayer were elevated in the upper zones of the canopy, whereas for the air‐blast sprayer, deposition was greater in the bottom zones. Electrostatic spray deposition was relatively uniform within the six canopy zones. Clear trends in D. suzukii laboratory mortality were found with lowest to highest mortality recorded for phosmet, spinetoram, spinosad, malathion, cyantraniliprole, zeta‐cypermethrin, and methomyl respectively. Maximum D. suzukii population impacts, as shown by model outputs, were observed with air‐blast sprayers together with zeta‐cypermethrin. CONCLUSION The electrostatic sprayer had the least variable canopy deposition among the three types of spray equipment, and the air‐blast sprayer had the highest overall deposition rates. This study provides new hypotheses that can be used for field verification with these spray technologies and insecticides as key factors. © 2019 Society of Chemical Industry

Behavioral manipulation of Drosophila suzukii for pest control: high attraction to yeast enhances insecticide efficacy when applied on leaves

“…Developing strategies of targeted insecticide application is timely with respect to current advance of precision technology in viticulture. [63][64][65] Overall, our data suggest high efficacy of our novel yeastinsecticide formulations and application methods targeting specifically green-plant leaves rather than the whole plant with consumable fruit. Our data show that H. uvarum-based attract-andkill is compatible with different kinds of insecticides, facilitating resistance management by rotating products with different modes of action.…”

“…Optimized, a reduced spray coverage could result in excluding the fruit from insecticide application and thus minimize pesticide residues on the harvested crop. Developing strategies of targeted insecticide application is timely with respect to current advance of precision technology in viticulture 63–65 …”

Comparing the effectiveness of different insecticide application orders for suppressing Drosophila suzukii Matsumura (Diptera: Drosophilidae) infestation: experimental and modeling approaches

“…Due to the short life cycle of D. suzukii , frequent insecticide application is necessary to manage damaging populations during the production season (Van Timmeren and Isaacs 2013, Mermer et al 2021). Chemical control is impacted by the plant canopy sometimes preventing adequate spray deposition (Mermer et al 2020). Drosophila suzukii infestations are typically higher in the center of the canopy compared to other parts, and spray coverage here can be limited by dense canopies or inadequate sprayer setups (Diepenbrock and Burrack 2017).…”

“…In addition, growers apply calendar-based insecticide application to reduce populations of D. suzukii to a level that meets market expectations (Van Timmeren and Isaacs 2013, Mermer et al 2021). The range of effective insecticides available controlling D. suzukii includes different chemical classes (mode of action) (Beers et al 2011, Van Timmeren and Isaacs 2013, Shawer et al 2018, Shaw et al 2019b, Mermer et al 2021), providing variable mortality levels against D. suzukii life stages (Mermer et al 2020). Insecticides such as zeta-cypermethrin and spinetoram were found effective on adults (Van Timmeren and Isaacs 2013, Mermer et al 2020), as well as on immature stages such as egg and larvae in blueberry and tart cherry (Wise et al 2015, Shawer et al 2018, Andika et al 2019, 2020, Mermer et al 2021).…”

Molecular and behavioral studies reveal differences in olfaction between winter and summer morphs of Drosophila suzukii

“…Current management of this invasive pest relies on frequent insecticide applications, e.g. , five to eight sprays per season in blueberry fields ( Mermer et al, 2020 ). Because of substantial dependance on insecticides, novel strategies seek to use more environmentally sustainable solutions ( Tait et al, 2021 ).…”