Evaluating natural compounds as potential insecticides against three economically important pests, Bemisia tabaci (Hemiptera: Aleyrodidae), Frankliniella occidentalis (Thysanoptera: Thripidae), and Myzus persicae (Hemiptera: Aphididae), on greenhouse sweet peppers

Abstract

Sweet pepper (Capsicum annuum L.) is one of the major export crops in the Republic of Korea. Currently, synthetic insecticides are frequently used to control major greenhouse pests including Bemisia tabaci (Hemiptera: Aleyrodidae), Myzus persicae (Hemiptera: Aphididae), and Frankliniella occidentalis (Thysanoptera: Thripidae) in Korea. However, the repeated use of chemicals has caused insecticide resistance to be developed by pests. Therefore, there is a growing demand to develop biopesticides that have high insecticidal effects but little adverse impacts to crops and nontarget organisms. In this study, three natural compounds were investigated for insecticidal effects against three pests, B. tabaci, M. persicae, and F. occidentalis, and nontarget effects to a pollinator, Bombus terrestris (Hymenoptera: Apidae) in laboratory. The three natural compounds, named JP503, G.sol (R), and NO40, were an extract from Perilla frutescens var. crispa with phytoncide essential oil from pine tree, a commercialized disinfectant solution, and a type of nitric oxide in aqueous solution. Among these compounds, JP503 showed high and acute insecticidal effects on all of the three pests causing 100% mortality in 3 h. In addition, this compound resulted in the same level of acute lethality to the pollinator. Moreover, JP503 caused significant leaf damage when applied to sweet pepper plants in greenhouse conditions. The results indicate that the candidate compound would have limited potential for wide application to cash crop such as sweet peppers. Therefore, it is recommended that JP503 be used only in a site-specific manner such as applications to trap crops, barrier crops, or wild hosts adjacent to cash crop fields.