The influence of male hairpencil composition during female mate selection in Helicoverpa zea
LE3 .A278 2015
Bachelor of Science
Helicoverpa zea Boddie (Lepidoptera: Noctuidae: Heliothinae) is a global pest species responsible for multibillion dollar crop losses annually. Chemical communication is essential for the success of this species and reproduction. During courtship, males of other Heliothine species produce species-specific compound blends referred to as hairpencil compounds. It is assumed male H. zea produce similar hairpencil blends that elicit common responses. In other Heliothine species hairpencil compounds elicit specific responses in conspecifics; females become more quiescent and therefore receptive to courting males and competing males are inhibited from approach. This study investigated the potential role of hairpencil blends of H. zea as a mechanism of sexual selection by females. In addition, growth of progeny was investigated to determine if optimal mate selection translated into increased survivorship. Mate choice bioassays were conducted to observe female-to-male and male-to-male interactions during courtship. Hairpencil blends of successful and unsuccessful males exhibited several compounds common in other Heliothine species. Additional compounds remain unidentified but were present in all males. Significant differences were not evident between hairpencil compound composition between successful and unsuccessful groups. The survivorship of progeny varied considerably between mated couples. However, the rate of larval growth was consistent. The potential that males exhibit unique hairpencil blends that honestly advertise their fitness and therefore translates into potential progeny survivorship remains inconclusive.
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