|Otalora Luna, Fernando|
Submitted to: Entomologia Experimentalis et Applicata
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 4, 2012
Publication Date: January 7, 2011
Citation: Otalora Luna, F., Dickens, J.C. 2011. Emissive color preferences and temporal alteration of walking performance by pulsing lights in colorado potato beetle. Entomologia Experimentalis et Applicata. 138(2):93-103 DOI: 10.1111/j.1570-7458.2010.01081.x. Interpretive Summary: The Colorado potato beetle (CPB) is a serious pest of potatoes and other solanaceous crops in North America, Europe and Asia. As CPB rapidly develops resistance to pesticides aimed at its control, alternative methods of management are desperately needed. While recently discovered chemical attractants for CPB offer potential for inclusion in management strategies, knowledge of visual behavior of CPB could greatly enhance the efficacy of the chemical attractants. We demonstrate conclusively for the first time true color vision in CPB. Specific wavelengths of light perceived as white, ultraviolet, blue, green, yellow, green, and red were attractive to CPB, while infrared was unattractive. Yellow and green were preferred over all other colors in choice tests. Continuous light was preferred over pulsed light; pulsed light while attractive, elicited walking patterns characteristic of local search. This research will be used by behaviorists and neurobiologists to further investigate receptors and mechanisms used by adult of CPB and perhaps other insects, as well as entomologists developing management strategies for CPB control.
Technical Abstract: The Colorado potato beetle (CPB) Leptinotarsa decemlineata (Say 1824) is a diurnal insect that strongly relies on vision to guide its walk. In the present study, we investigated the orientation behavior of nondiapausing walking CPB in response to emissive colors produced by light emitting diodes (LEDs), in a dual-choice arena adapted to a servosphere. Our results demonstrate that CPBs show a positive phototactic behavior when stimulated with different light wavelengths; they preferred to orient towards white (420 - 775 nm), ultraviolet (351nm), blue (472nm), green (570nm), yellow (585nm), orange (590nm) and red (660nm) than towards darkness when both alternatives were offered, but no orientation responses were elicited by infrared (940 nm) wavelength. Both males and females preferred yellow and green over the rest of the colored lights, but did not show any particular preference between both colors correlating with their preference for wavelengths reflected by vegetation. Male CPB preferred white over either red or ultraviolet. Female CPB preferred ultraviolet and blue over red. Both sexes preferred continuous over pulsed yellow light. CPB turned at higher angles and performed more tortuous walks in complete darkness and when infrared versus darkness were offered compared with the rest of the colors. CPB subjected to pulsed light showed a temporal alteration of their walking performance by walking less, slower, and turning at a higher rate. The results are discussed with regard to the role of photic stimuli in orientation to host plants and conspecifics, and avoidance of predation. The information provided may serve for the improvement of traps and development of alternate control strategies for the CPB.