Insecticide Application Trends and Resistance Development <i>Leucinodes orbunalis</i> Guenee in Brinjal Shoot and Fruit Borer

A study conducted during 2021-2022 on pesticide usage history in brinjal to relate it with the development of insecticide resistance revealed that insecticide usage varied widely in studied districts. Bioassay conducted in March, 2022 on field collected population of brinjal fruit and shoot borer Leucinodes orbonalis indicated the shift in susceptibility level of the insect compared to the laboratory reared susceptible population against Indoxacarb 14.5% SC, Spinosad 45% SC and Thiodicarb 75% WP where the LD50 value was observed in a range of 0.043-0.731 μg/ μl, 0.017-0.337 μg/ μl and 0.442-16.945 μg/ μl respectively. Varying level of resistance development against thiodicarb 75%WP (31.46-38.34-fold), indoxacarb 14.5%SC (14.21-17.01-fold) and spinosad (11.00-19.82-fold) was observed as compared to susceptible iso-female colony maintained in laboratory condition.