Seasonal incidence and monitoring of Helicoverpa armigera Hübner on damask rose (Rosa × damascena Herrm.) by sex pheromone traps in western Himalaya (India)

Incidence of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) and pheromone trap captures of male moths in damask rose (Rosa × damascena Herrm.) under field conditions was studied for three years. Results indicated that peak infestation of H. armigera eggs/bud reported at 19, 14 and 17th week (0.51, 0.73, 0.32 eggs/bud) in first (May), second and third year (April), respectively. Feeding holes/bud was peak at 19, 17 and 18th week (2.12, 2.16 and 1.1 holes/bud) in first, second and third year, respectively. The number of larvae/bud was higher at 19th week (0.53 larvae/bud) in the first year and was followed by the third year at 17th week (0.52 larvae/bud) as compared with second year. Similarly, the number of larvae/flower was also higher at 20th and 17th week (0.68 and 0.59 larvae/flower) in the first and third year, respectively as the compared second year. H. armigera damage on flowers was significantly positively correlated with humidity (evening) and rainfall during first year. Whereas, larva/bud and larva/flower were also significantly positively correlated with humidity (evening) and temperature (max. and min.), respectively in second year. In third year, eggs/bud was significantly positively correlated with humidity (morning). The number of H. armigera moths captured in sex pheromone traps at 30 cm above crop canopy level was significantly higher in all the three years as compared to crop canopy level and 30 cm below crop canopy level.