Tuesday, December 14, 2010
Grand Exhibit Hall (Town and Country Hotel and Convention Center)
Our changing climate will alter many aspects of our agroecosystems mediated through changes in precipitation, growing degree days, and possibly an increase in extreme events. Less obvious consequences resulting from climate change will be shifts in the habitats of many of our important pests. Pests that are primarily regulated by weather variables are more likely to see correlative shifts in habitat with changes to our climate. One such insect pest, which causes significant damage to small grains in the North America, is the Russian wheat aphid, Diuraphis noxia, (Kurdjumov). We developed a spatially-explicit habitat model for the Russian wheat aphid based on two forcing functions. These functions are correlated with two time periods during which Russian wheat aphid populations decrease. Our forcing functions are informed by spatially-explicit climate variables such as daily precipitation and average daily temperature. The first function describes the reduction in Russian wheat aphid populations that occurs during the harsh overwintering period. The second function quantifies the restriction to aphid populations during the oversummering period, where high temperatures and a lack of food resources reduce populations. By entering these two forcing functions into a Geographic Information System, a habitat map was developed across the western Great Plains. The habitat map may aid integrated pest management strategy, such as placement of resistant cultivars. Additionally, by using temperature and precipitation perturbations to current climate variables, we were able to examine the likely shift in quality habitat of the Russian wheat aphid. Our habitat-shift results will inform management strategy (e.g., improved timing of crop planting).