EFFECT OF SOME SELECTED INSECTICIDES ON BRINJAL SHOOT AND FRUIT BORER (Leudnodes othona/is Guenee) AND ARTHROPOD BIODIVERSITY IN THE BRINJAL FIELD

Abstract

Field experiment was conducted to evaluate the effect of some selected insecticides on brinjal shoot and fruit borer (BSFB) (Leucinodes orbonalis Guenee) and arthropod biodiversity in the brinjal agroecosystem at Sher-c-Bangla Agricultural University (SAU) farm during November, 2007 to April, 2008. Fifteen species of harmful arthropods under 15 families from 6 different orders were recorded in brinjal agroecosystem. Among them BSFB, jassid, aphid, white fly and epilachna beetle were found as the most common insect pcst of brinjal. Coleoptera was the most common order of plant dwelling predatory insects, which occupied 5 1.17% of the total predators. Surface dwelling arthropods caught in pitfall traps were grouped into 17 families, among them, Formicidac ranked Lop followed by Lycosidae. Six treatments comprising insecticides viz., carbosulfan 20EC. cartap 50SP, cypermethrin IOEC, chlorpyriphos 20EC, flubendiamide 24WG and an untreated control were tested. The experiment was laid out in Randomized Completely Block Design (RCBD) with 3 replications. Among the treatments carbosulfan showed the best efficacy providing more than 80% reduction of fruit infestation and gavc highest healthy fruit yield (20.29 tiha) of brinjal. Almost similar results were obtained by application of flubendiamide against brinjal shoot and fruit borer attack Carbosulihu, cypermethrin and chiorpyriphos had strong negative effect and cartap had moderate impact on the plant dwelling predaceous arthropods. Flubendiamide had minimum impact on both plant and surface dwelling predaccous arthropods in the brinjal agroccosystem.