Estimation and Availability of Male Moths in Cotton Ecosystems Using Pheromone Trap Monitoring

Abstract

Aims of Study: A two-year field experiments (Kharif 2023 and 2024) were conducted across MCRS, NAU, Surat and RCRS, NAU, Bharuch to monitor the seasonal activity and abundance of major lepidopteran pests through pheromone traps in both Bt (protected and unprotected) and non-Bt (protected and unprotected) cotton varieties. Results: Results indicated that PBW activity peaked from the 41st to 52nd SMW, with significantly higher male moth catches in non-Bt cotton (Suraj) compared to Bt hybrids (G. Cot. Hy. 8 BG II), particularly under unprotected conditions. ABW showed peak activity between the 43rd and 48th SMW, again with higher catches in non-Bt plots. SBW recorded consistently low incidence, whereas LEC exhibited sustained trap catches from the 36th to 49th SMW. Correlation analyses revealed that PBW and LEC activities were positively associated with maximum temperature and sunshine hours, while negatively correlated with humidity, rainfall, wind speed and number of rainy days. These findings suggest that dry and warm conditions promote pest activity, with non-Bt cotton being more susceptible. Male moth availability of key cotton pests pink bollworm (PBW), American bollworm (ABW), spotted bollworm (SBW) and leaf-eating caterpillar (LEC) was estimated using peak pheromone trap catch data from kharif 2024–25, assuming 5% of cotton farmers in Gujarat and India adopted the recommended 5 traps/ha. Estimated male moth populations during peak periods were 1507.71, 719.10, 11.72 and 1127.23 lakh in Gujarat and 7215.19, 3441.25, 56.09 and 5394.40 lakh across India for PBW, ABW, SBW and LEC, respectively.