INTERACTION OF PINK BOLLWORM (LEPIDOPTERA: GELECHIIDAE) POPULATION LEVELS IN PHEROMONE TRAPS AND WEATHER FACTORS

Abstract

Pink bollworm (Pectinophora gossypiella) is a destructive pest of agricultural crops especially cotton crop in Pakistan. It has ability to form rosette flowers, bolls and makes them unable to open. Thus it deteriorates cotton seed quality which has significant impact on yield reduction. Increasing trend of insecticides has resulted in insecticide resistance, environmental pollution and risks of human health. Integrated pest management has key role to reduce negative impacts. Besides of several other components, pheromone traps are best monitoring and mass capturing tool for bollworms in agricultural crops. The study was conducted to check relation of pink bollworm mass trapping in pheromone traps relating to environmental factors during three years study 2018 to 2020. Results indicated that pink bollworm has two peak activity periods during study years. Standard weeks (SW) 11 to 15 and 31-35 were highly active while SW 20 to 26 was inactive periods of pink bollworm. Adult moth population captures in pheromone traps was 3.14, 4.41 and 6.75/ trap during 2018, 2019 and 2020, respectively. Highest peaks were 11.12, 11.85, 15.94 /trap with maximum, minimum, average temperatures, relative humidity and rainfall of 29.43: 36.59: 35.28°C, 11.31: 21.36: 22.80°C, 20.37: 28.96: 29.04°C, 54.66: 61.23:58. 36% and 0.00, 0.00, 0.00 mm, during 2018, 2019 and 2020, respectively. Temperature 20- 30°C had significant impacts to speed activities of pink bollworm. Minimum (r= -0.165, -0.144, -0.582) and maximum (r= -0.078, -0.045, -0.192) temperatures had negative and non- significant correlation with population in pheromone traps while average temperature had positive and significant correlation (r= 0.112, 0.290, 0.486) during study years. Average temperature had maximum impact of 20.9 (0.01), 20.7 (0.03) and 9.3 (0.07) % on population variability during 2018, 2019 and 2020, respectively. Population trends of pink bollworm had shown increasing trends during the subsequent years. Pheromone traps proved best monitoring tool of pink bollworm to integrate into integrated pest management strategy.