Some alternatives to the chemical control of Spodoptera exigua (Hubner, 1808) in black-eyed pea

Abstract

Spodoptera exigua (Hubner), is a destructive pest in different parts of the world. In this study, the effects of indoxacarb, chlorpyrifos, deltamethrin, hexaflumuron, matrin, and Bacillus thuringiensis var. kurstaki)Bt), were evaluated against S. exigua in a complete randomized block design under field conditions. Four replications were considered for each treatment. The qualitative and quantitative damages of the pest were estimated based on plant growth characteristics. The experiments were carried out in 2016 and 2017 in a pea field in Khuzestan province, Iran. Sampling of S. exigua population was conducted 1 day before treatment (DBT) and 1, 3, 5, 7 and 10 days after treatment (DAT). The results showed that indoxacarb significantly reduced oviposition in S. exigua. Chlorpyrifos and indoxacarb significantly affected larval survival shortly after treatment. However, no significant difference was observed in larval mortality among treatments 10 DAT and all were effective against larvae. The results also showed that the maximum bean pods were observed in chlorpyrifos and indoxacarb treatments, respectively. There were the most seeds in each pod in matrin, indoxacarb, chlorpyrifos and deltamethrin treatments. According to the results, Bt and matrin were effective insecticides against S. exigua larvae and can be recommended as an alternative to chemical pesticides.