Department of Entomology, Tamil Nadu Agricultural University, Coimbatore-641 003, Tamil Nadu (India).
The activity of Heliothis armigera Hub. moths was monitored in the cotton field by using a synthetic sex pheromone formulation, viz, a mixture of (Z)-11-hexadecenal and (Z)-9 -hexadecenal (97:3). During 1995, the pheromone at a concentration of 1 mg/septum was effective in monitoring moth catches, being 5.33/trap on LRA 5166 (summer crop), 19.67/trap on TCHB 213 (winter crop), and 15.11/trap on MCU 5 cotton cultivar (winter crop) at Karadimadai, Meenakshipuram and TNAU campus, respectively. Correlation studies between moth catches and egg and larval populations indicated a significant positive relationship with a ‘r’ value of 0.388 for eggs on 314 th day of moth catches on TCHB 213 cotton. However, it was not significant with eggs and larval populations on 7th day of moth catches on TCHB 213 and MCU 5 cotton.
