Efficacy of Reduced-Risk Insecticides to Control Flower Thrips in Early-Season Blueberries and Their Effect on <i>Orius insidiosus</i>, a Natural Enemy of Flower Thrips

Abstract

Flower thrips are one of the key pests in production of southern highbush blueberries (Vaccinium corymbosum L. × V. darrowi Camp). They feed on the reproductive parts of the flower and reduce yield. Very few insecticides are available to manage thrips population. Therefore, it is necessary to evaluate pre-existing and experimental insecticides for their efficacy against thrips. There is also a high demand for reduced-risk insecticides that are less toxic to beneficial insects and the environment. In this study, a number of conventional and reduced-risk insecticides were evaluated against flower thrips on farms in Florida and Georgia and in the laboratory. The best performing insecticides were also evaluated in the laboratory for their effects on Orius insidiosus Say, which is a common thrips' predator in Florida. Assail 70WP (Acetamiprid) and SpinTor 2SC (Spinosad) were the most promising insecticides in reducing thrips numbers in the field as well as in laboratory experiments. SpinTor 2SC killed all of the thrips in laboratory arenas within 4 hours of application and showed low toxicity toward O. insidiosus. All of the compounds tested performed as well as the conventional pesticide malathion.

Evaluation of non‐target effects of OMRI‐listed insecticides for management of Drosophila suzukii Matsumura in berry crops

“…There has been increasing availability of reduced‐risk insecticides with more selectivity in fruit crops (Isaacs, Mason, Brewer, Noma, & 'Neal, ), especially in organic production (Sial et al, ). Reduced‐risk insecticides have several advantages over broad‐spectrum insecticides including shorter pre‐harvest intervals due to their lower mammalian toxicity and greater compatibility with biological control tactics due to their less harmful effects on natural enemies (Atanassov, Shearer, & Hamilton, ; Liburd, Arevalo, & Rhodes, ; Roubos, Rodriguez‐Saona, & Isaacs, ). While many selective reduced‐risk insecticides may indicate a low risk to beneficial insects, this is not always the case (Biondi, Desneux, Siscaro, & Zappalà, ).…”

“…The larvae of C. rufilabris are generalist predators that feed on aphids and whiteflies (Dean & Schuster, ), which are important pests of many crops. Orius insidiosus is an important predator of flower thrips (Liburd et al, ) and aphids (Walton & Isaacs, ) in blueberries. Aphidius colemani is a commercially available aphid parasitoid, one of several parasitoids important in regulating aphid populations in blueberry fields (Walton & Isaacs, ).…”

“…Although several studies have evaluated the toxicity of conventional and reduced‐risk insecticides to these common predators (Barbosa, Oliveira, Barros, Michaud, & Torres, ; Garzón, Medina, Amor, Viñuela, & Budia, ; Liburd et al, ; Moscardini et al, ), only few studies have evaluated the non‐target effects from organic insecticides. The goal of this present study was to determine the relative risk of different OMRI‐listed (organic) insecticides used in organic berry production to natural enemies.…”