LETHAL AND REPELLENT EFFECTS OF SELECTED BIOPESTICIDES AGAINST BRINJAL SHOOT AND FRUIT BORER AND THEIR IMPACT ON BRINJAL PRODUCTION

ABSTRACT: The study was undertaken from June 2021 to February 2022 in the field and laboratory of the Department of Entomology, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh to assess the effect of four biopesticides (Fytomax PM, Neem oil, Spinomax SC 44.03%, and Bio-chamak 1% EW) and one conventional insecticide (Ripcord 10 EC). Investigation was carried out on the repellency and mortality effects of tested insecticides against brinjal shoot and fruit borer (BSFB) (Leucinodes orbonalis) and their impact on brinjal production. The repellency rate of adult BSFB at 24 hours after treatment (HAT)was the highest (72.2%) on Spinomax SC 44.03% while the lowest (17.7%) was on Fytomax PM. Mortality rates of the BSFB larvae at 24 and 48 HAT with Spinomax SC 44.03% were 23 to 38%, respectively which were statistically similar to that of Ripcord 10 EC (19.1% and 33.4%, respectively). Spinomax SC 44.03% revealed higher mortality rates of the larvae at 72, 96 and 120 HAT. Spinomax SC 44.03% and Ripcord 10 EC treated plants revealed statistically similar mortality and provided the highest plant height, branches and fruits per plant, fruit length, diameter and weight. Among the insecticides, Spinomax SC 44.03% showed the highest yields (15.5 t ha-1) and benefit cost ratio (3.9). The findings indicated that application of Spinomax SC 44.03% to control BSFB infestation was the best one ensuring maximum yield. 

Keywords: Leucinodes orbonalis, mortality, pesticide, Solanum melongena.