EVALUATION OF THE EFFECTIVENESS OF DRUGS AGAINST PESTS (NOCTUIDAE, LEPIDOPTERA) ON BEAN CROPS IN THE SOUTH-EAST OF KAZAKHSTAN

Abstract

This article evaluates the biological efficacy of chemical and biological insecticides against noctuid moths (Noctuidae, Lepidoptera) in bean fields in southeastern Kazakhstan. Field experiments were conducted from 2018 to 2021 at the plots of the Saimasai LLP training center. The study examined larvae and adults of Helicoverpa armigera and Autographa gamma on bean cultivar Inzhu. The experiment was arranged in randomized blocks with four replications; each plot covered 25-50 m². Treatments included an untreated control; Actellic 500 EC (pirimiphos-methyl, 500 g/L) at 1 L/ha, Decis Standard (deltamethrin, 100 g/L), and Vertimec (abamectin, 18 g/L); and the biological insecticides Actarofit 1.8 (Streptomyces avermitilis) at 3 L/ha and Bitoxibacillin (Bacillus thuringiensis var. thuringiensis) at 1.2 L/ha. Treatments were applied during active larval development, primarily at the budding and flowering stages of bean. Pest abundance was assessed before treatment and 3, 7, and 14 days after application. Larvae and adults were counted by visually inspecting plants and generative organs, sweep-net sampling with 10-20 sweeps per sample, and laboratory examination with a binocular microscope. Results were expressed as individuals per 100 plants. Biological efficacy was calculated relative to the control using Abbott’s formula, separately for larvae and adults. Fourteen days after treatment, larval abundance decreased by 82.7–86.3% and adult abundance by 76.6-82.9%. Decis Standard showed the highest efficacy against larvae (86.3%), whereas Vertimec produced the greatest reduction in adults (82.9%). Among the biological insecticides, Actarofit 1.8 reduced larval and adult abundance by 83.7% and 81.1%, respectively. The average efficacy of chemical and biological insecticides was 84.8% and 82.6% against larvae and 81.5% and 78.6% against adults, respectively. These findings support including biological insecticides in integrated bean protection systems to reduce pesticide pressure and the risk of insecticide resistance.