Effects of UV-A exposures on longevity and reproduction in Helicoverpa armigera, and on the development of its F1 generation

Helicoverpa armigera adults display a conspicuous positive phototactic behavior to light stimuli, and are especially sensitive to ultraviolet (UV) light. The effects of UV-A (longwave) exposures on adult longevity and reproduction in H. armigera were investigated, as well as the development of the F1 generation. Paired adults were exposed to UV-A for various time periods (0, 1, 5 and 9 h/day), until the end of adult life. The results showed that adult longevity decreased with increasing exposure time for both sexes, and a significant decrease was observed after exposure for 5 and 9 h/day. Fecundity increased when adults were exposed for 1 and 5 h/day, and a significant difference was observed in the 5 h/day group. Oviposition rates of females in all treatments were significantly higher than in the control. Exposure to UV-A for longer periods (5 and 9 h/day) caused a decline in cumulative survival of F1 immature stages, but no significant differences were found in egg hatch, pupation and eclosion. The developmental periods of F1 larvae were significantly prolonged after exposure to UV-A for 5 and 9 h/day. UV-A radiation had no significant effects on F1 pupal period.