author(s)
Shrilakshmi RG and Udikeri SS

abstract
Roving surveys were conducted to know the incidence of pink bollworm in Bt cotton during kharif-2017-18 and 2018-19 in different agro-ecological zones of Karnataka. The level of incidence was recorded twice during the season i.e. at flowering and boll development stages. Widespread infestation of pink bollworm on Bt cotton across Karnataka was observed with a range of 20–85% in both the years. A typical pattern of progressive increase in the level of pink bollworm infestation and intensification of locular damage with the advancement of the crop season was evident. Raichur recorded highest no of larvae/50 bolls, green boll and locule damage (72.74, 58.50, 72.84% in 2017-18 and 42.78, 61.00, 62.69% in 2018-19). Relatively less damage was recorded from Mysuru with 6.48% flower damage in 2017-18 and 4.20% in 2018-19, 70.35% green boll damage in 2017-18 and 37.02 percent in 2018-19, 68.20% and 42.74% locule damage in 2017-18 and 2018-19 respectively. Least percent of flower damage recorded from Uttara Kannada i.e. 1.48%, 0.97% in 2017-18 and 2018-19 respectively, followed by Shivamogga and Chitradurga. Least locule damage was recorded from Uttara Kannada during both the years (19.96%, 12.89%), followed by Shivamogga (35.45%, 30.22%) and Chitradurga (38.50%, 30.72%). Average flower, boll and locule damage under rainfed condition was 1.46, 32.92 and 41.93% whereas, it was 4.23, 40.78 and 48.07%, under irrigated condition, respectively. None of the districts had any infestation below ETL.