INCREASED PHEROMONE PRODUCTION IN WILD TOBACCO BUDWORM (LEPIDOPTERA, NOCTUIDAE) EXPOSED TO HOST PLANTS AND HOST CHEMICALS

Compared with the laboratory colony females, 1st-generation feral (wil d F-1) females of the tobacco budworm, Heliothis virescens (F.), produ ced little sex pheromone unless exposed to a host plant. Pheromone pro duction in wild F-1 females was induced by both cotton, Gossypium hirs utum L., squares and tobacco, Nicotiana tabacum L., buds. With either of the hosts, physical contact evoked a significantly higher response than did exposure to volatile compounds from these plant parts. Of the 12 tobacco chemicals and a corn, Zea mays L, silk extract tested with wild F-1 females, oxidized alpha+beta-4,8,13-duvatriene 1,3-diols (ox y-DVT-diols), alpha-4,8,13-duvatriene-1,3-diol (alpha-DVT-diol), (13E) -labda-13-ene-8 alpha,15-diol (labdenediol), and the corn silk extract evoked high pheromone production. Pheromone production may require ho st plant-based signals to assure that a suitable host is available for oviposition by the female, once it is mated.