Efficacy of Microbial and IGR-based Biopesticides Against Brinjal Shoot and Fruit Borer, Leucinodes orbonalis (Guen.)

Master's Thesis from the year 2015 in the subject Biology - Zoology, grade: 4.00, , course: Entomology, language: English, abstract: In the present study, efficacy of some microbial and IGR-based biopesticides against the infestation of brinjal shoot and fruit borer (BSFB), Leucinodes orbonalis (Guen) was evaluated in the Entomology Field Laboratory, Bangladesh Agricultural University (BAU), Mymensingh during January to July 2014. Biopesticides were applied either individually or in some selected combinations and their efficacy was evaluated on different parameters viz. percent shoot infestation, percent fruit infestation, infested and marketable fruit yield (t/ha). It was found that all the treatments significantly reduced percent shoot and fruit infestation and significantly increased marketable fruit yield. The best result was found in case of combined treatment buprofezin + emamectin benzoate treated plots (70.75% shoot and 63.99% fruit protection over control; highest marketable fruit yield of 9.94 t/ha) whereas the least protection was obtained from buprofezin (1 ml/L) treated plots (17.87% shoot and 15.66% fruit protection over control; lowest marketable fruit yield of 6.05 t/ha). In the laboratory, different concentrations of buprofezin was applied through topical, potato-dip and combined (topical + potato-dip) methods on the 2nd instar larvae of BSFB and then mortality, weight reduction or cuticular changes were observed at 3 HAT (hours after treatment), 3 and 7 DAT (days after treatment). No mortality or weight reduction was observed at 3 HAT. The significant level of mortality and weight reduction was observed at 3 DAT in all applying methods but the maximum mortality and weight reduction was found at 7 DAT. It was also observed that potato-dip method was highly effective than topical method regarding mortality and weight reduction. Cuticular abnormalities were found when larvae were treated with higher concentrations of buprofezin in comparison with that in the water-treated control. Moreover, larval mortality and weight reduction were clearly dose-dependent.