Sexual contact influences orientation to plant attractant in Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae)

Authors: DICKENS, JOSEPH

Submitted to: Naturwissenschaften
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/3/2007
Publication Date: 6/12/2007
Citation: Dickens, J.C. 2007. Sexual contact influences orientation to plant attractant in Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae). Naturwissenschaften, DOI 10.1007/S00114-007-0261-2. ON-LINE.

Interpretive Summary: The Colorado potato beetle (CPB) is a key pest of plants, such as potatoes, tomatoes and eggplant. Control of CPB has involved pesticides to which the beetle rapidly develops resistance. Novel management tools are needed to slow development of resistance and as alternative control measures. This study showed that beetle behavior in response to the plant attractant is not constant but changes depending on contact among individuals of the opposite sex. A novel mechanism is described which explains this behavior. This discovery provides scientists with important information for additional studies of factors which modulate behavioral responses of insects to host plant attractants, and should facilitate design of alternate management strategies.

Technical Abstract: Chemical signals emitted by insects and their hosts are important for sexual communication and feeding. Plant volatiles facilitate the location of suitable hosts for feeding and oviposition, and may moderate responses to sex and aggregation pheromones. While mating has been shown to moderate behavioral responses to pheromones in a number of insects, with few exceptions little is known about the effects of mating on behavioral responses of insects to plant attractants and even less is known about mechanisms involved. Here I show that mating decreases behavioral responses of the Colorado potato beetle to a host kairomone within 24 hours and attraction to the kairomone recovers only after 72 hours. This decrease in responsiveness also occurs when only contact with the opposite sex allowed; the effect is not observed with contact among individuals of the same sex. Peripheral olfactory responses to a component of the kairomone correlate with the observed behavioral responses and suggest involvement of antennal receptors in the behavioral change.