|BOITEAU, GILES - Agriculture And Agri-Food Canada|
|VINCENT, CHARLES - Agriculture And Agri-Food Canada|
|COLPITTS, BRUCE - University Of New Brunswick|
|MACKINLEY, PAMELA - Agriculture And Agri-Food Canada|
|LEE, DOO-HYUNG - US Department Of Agriculture (USDA)|
Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/9/2014
Publication Date: 5/19/2014
Citation: Boiteau, G., Vincent, C., Leskey, T.C., Colpitts, B., Mackinley, P., Lee, D. 2014. Impact of host plant connectivity, crop border and patch size on adult Colorado potato beetle retention. PLoS One. DOI: 10.1371/0095717.
Interpretive Summary: Harmonic radar technology offers a means to track the movements of insects in agricultural production. We used Colorado Potato Beetle (CPB), a key pest of potato production, to demonstrate that harmonic radar can be used to track retention of CPB in potato plots surrounded by different non-host barriers including bare ground, timothy grass and woodlands; all non-host barriers served to limit dispersal by walking. There was no difference in terms of CPB retention in small vs. large potato batches. However, because adult CPB walk as well as fly, manipulating border types, i.e. non-host barriers, and crop plot size likely will not provide behavioral means to manipulate their management.
Technical Abstract: Tagged Colorado potato beetles (CPB), Leptinotarsa decemlineata (Say), were released on potato plants, Solanum tuberosum L., and tracked using a portable harmonic radar system to determine the impact of host plant spatial distribution on the tendency of the pest to remain on the colonized host plant or patch. Results confirmed the long residency time on the host plant and showed that close connection of the plant to neighboring plants hastened dispersal between plants. Tracking walking CPB for over 6 h in small potato plots revealed that all types of mixed borders tested (potato/bare ground, potato/timothy and potato/woodland) acted as a strong barrier and retained beetles within the patch. In another experiment in potato patches surrounded by bare ground borders, tracked walking CPB displayed similar behavior for up to four days. The distribution of turning angles in the CPB walking paths was not uniform and corresponded to beetles following the edge rows of potato patches in response to the crop border barrier or reversing their direction as they reached the end of a row and therefore, a border. Patch size had no or little effect on beetle retention in the patch. The relative distribution of counts of tagged beetles detected among small (16 m2), medium (64 m2) and large size (256 m2) patches of potato four days after initial release remained similar to that of numbers released. Even though mixed crop borders were a strong barrier to walking CPB emigrating from potato patches, the departure rate of beetles over time was high. Results suggest that the effect of mixed borders is largely limited to dispersal by walking and does not apply to beetles leaving host patches by flight. The manipulation of crop borders and patch size seem to have limited potential for the management of CPB emigrating from potato fields.