Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/6/2000
Publication Date: N/A
Interpretive Summary: Boll weevils are attracted to cotton plants by volatile chemical compounds (mostly terpenoids) given off by the plants. These volatile compounds are structurally somewhat similar to the pheromone compounds produced by the male boll weevils. The current study was undertaken to learn if volatile compounds in fallen leaves and other ground litter attract boll weevils to favorable overwintering sites. Boll weevils seek these sites, primarily during autumn, in which to hibernate until the following spring or summer. Our results did not unambiguously indicate that boll weevils find overwintering sites because of volatile compounds given off by ground litter. However, B-caryophllene and some other terpenoids increased the attractivity of the boll weevil sex pheromone.
Technical Abstract: Volatiles play a large role in governing the behavior of boll weevils (Anthonomus grandis Boheman). They are attracted to cotton plants, and the female is sexually attracted to the male. The attracting compounds in both instances are terpenoids. Primarily in the fall of the year, boll weevils seek hibernation sites in leaf trash where they remain until the following spring or summer. In this present study, essential oils were prepared by steam distillation from several leaf samples known to be prevalent at hibernation sites and the oils were analyzed by GLC-MS. Based on the resulting identifications, a number of mixtures were formulated and were field tested, as were the essential oils. The field tests failed to support unambiguously the premise that boll weevils select hiberation sites on the basis of leaf odor alone. However, in the presence of the sex pheromone, B-caryophyllene (P>T=0.08), a mixture of 3 sesquiterpene hydrocarbons (P>T=0.10), and a mixture of alkyl alcohols (P>T=0.15) captured more boll weevils than the pheromone alone.