ARS | Publication request: Multimodal stimulation of the Colorado potato beetle: Prevalence of visual over olfactory cues

Submitted to: PLoS One
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 17, 2011
Publication Date: June 10, 2011
Citation: Otalora Luna, F., Dickens, J.C. 2011. Multimodal stimulation of the Colorado potato beetle: Prevalence of visual over olfactory cues. PLoS One. 6(6): e20990.

Interpretive Summary: The Colorado potato beetle (CPB) is one of the most important pests in Eurasia and North America. CPB lives in association with potato crop or other solanaceous plants where feeding and oviposition occur. As with many other plant feeding insects, CPB relies mainly on vision and smell to find food and mates. While recently discovered smells, such as the male-produced pheromone and plant odors, and visual cues for CPB offer potential for inclusion in management strategies, there is scant knowledge about how these cues interact on CPB behavior. We report that CPB orientation to its pheromone was completely abolished by the presentation of an attractive visual cue. Unexpectedly, preference for the visual cue was not enhanced by the pheromone. Although the biological significance of the strong prevalence of vision is not completely clear, this aspect of behavior appears to be a key to understanding the host-finding process of CPB and perhaps other insects. This research will be used by behaviorists and neurobiologists to further investigate receptors and mechanisms used by insects, as well as entomologists developing management strategies for CPB and other pests.

Technical Abstract: Orientation of insects to host plants and conspecifics is the result of detection and integration of chemical and physical cues present in the environment. Sensory organs have evolved to be sensitive to important signals, providing neural input for higher order processing and behavioral output. Here we report experiments to determine decisions made by Colorado potato beetle (CPB), Leptinotarsa decemlineata, in response to isolated stimuli and multimodal combinations of signals on a locomotion compensator. Our results show that in complete darkness pheromonal stimulation increases attraction behavior of CPB as measured in oriented displacement and walking speed, but when offered a choice between the photic stimulus and the pheromone, the photic stimulus prevails. Moreover, no preference was observed for the photic stimulus alone versus the photic stimulus in combination with the pheromone. Although, the biological significance of the strong prevalence of the photic stimulus over the chemical pheromonal stimulus is not completely clear, this aspect of behavior appears to be a key to elucidating the importance of multimodal stimulation in the host-finding process of CPB, and perhaps other phytophagous insects.