Increased Pheromone Production in Wild Tobacco Budworm (Lepidoptera: Noctuidae) Exposed to Host Plants and Host Chemicals

Abstract

Compared with the laboratory colony females, 1st-generation feral (wild F1) females of the tobacco budworm, Heliothis virescens (F.), produced little sex pheromone unless exposed to a host plant. Pheromone production in wild F1 females was induced by both cotton, Gossypium hirsutum 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 F1 females, oxidized α+β-4,8,13-duvatriene-1,3-diols (oxy-DVT-diols), α-4,8,13-duvatriene-1,3-diol (α-DVT-diol), (13E)-labda-13-ene-8α,15-diol (labdenediol), and the corn silk extract evoked high pheromone production. Pheromone production may require host plant-based signals to assure that a suitable host is available for oviposition by the female, once it is mated.