Effect of Long Term Colonization on Attractancy of Females to Wild Males: Heliothis virescens and Heliothis Hybrid Backcross (Lepidoptera: Noctuidae)

Abstract

The sexual attractancy of female Heliothis virescens (F.) which had been cultured in the laboratory for 40 generations and of hybrid and backcross females (H. subflexa ♀ X H. virescens ♂) was determined and compared with the attractancy of wild female H. virescens. In field tests, females reared (< 1 generation) from field-collected larvae were significantly (P ≤ 0.05) less attractive to wild males than were females reared in the laboratory for 40 generations (HVL-40), but the attractancy of females reared in the laboratory for 1 or 41 generations did not differ significantly. The attractancy of H. virescens females from generations 40, 41 and BC females from generations 41, 42 or 179, 180 did not differ significantly in any of five tests, except in test three, where more wild males were attracted by HVL-40 than by BC-41 females. Continuous backcrossing of the female hybrid (180 generations) did not affect the attractivity of the female to the wild males. The attractancy of lab-reared H. virescens (except for generation 40) or hybrid BC virgin females, regardless of generation, to wild H. virescens males was not significantly different from that of the synthetic female sex pheromone Z-11-Hexadecenal: Z-9-tetradecenal (14.6:1). The data indicate the attractancy of H. virescens and BC virgin females to wild males may be enhanced by continuous laboratory rearing. These findings are important in population dynamic studies in which lab-reared females are used and in determining the ratio of BC to wild H. virescens females needed to suppress a given population of H. virescens.