2. Management practices for major insect pests of tomato by using insecticide treated nets and their impact on natural enemies

Abstract

In many parts of the world, insect pests are a serious problem in tomato production. In tropical countries, the utilization of pest exclusive nets to protect garden crops has proven to be an effective and sustainable tool against lepidopteran insects, but not against small insects. This study evaluated the repellent effect of a 40-mesh net with a diameter of 0.9 mm treated with cypermethrin against major tomato pests (including small sucking insects). The study was conducted at the experimental farm of Sher-e-Bangla Agricultural University, Dhaka to evaluate the management practices of tomato pests using insecticide treated nets and its impact on natural enemies. BARI Tomato-1 (Manik) variety was used as the planting material. The insecticide treated nets and non-treated nets were used as treatments with a control plot without any netting. The efficacy of insecticide-treated and untreated nets was evaluated over a period of six months. In this experiment, the treatments were replicated 3 times in a completely randomized block design. The evaluation of the abundance of major insect pests and their natural enemies in tomato was carried out by collecting and counting their numbers every week for each replication. Mature tomatoes were harvested after twelve weeks of transplantation, sorted and divided into marketable and non-marketable fruits. The total number of saleable fruits and their weights were recorded. A total of 7 pest species (Aphis gossypii, Thrips tabaci, Bemisia tabaci, Haltica pyritosa, Helicoverpa armigera, Tetranychus spp. and Liriomyza trifolii) those infected tomato plants during field production were identified. The insecticides-treated nets were fruitful in protecting tomato plants from A. gossypii, B. tabaci, T. tabaci, L. trifolii and H. armigera. Compared with tomatoes harvested from unprotected tomatoes, the average marketable fruit weight of tomatoes harvested using treated nets was significantly higher. The results of this study reveal the potential of using insecticides-treated nets as a viable strategy to increase tomato yields by reducing the number of pests in crops. The netting covers can be used as an integral part of the integrated management of insect pests in tomato production.