Long-term landscape dynamics of an agricultural pest (Aphis glycines) at multiple spatial scales

Soybean aphids (Aphis glycines) are invasive, non-native crop pests. Their range and damage to crops may increase with warmer winters and increased plant stress due to changing  precipitation patterns. Soybean aphid feeding causes dramatic effects on soybeans. Plants have been observed to have lower yield, lower photosynthetic rates and stunted growth.  However, lower photosynthetic rates can be detected even when there is no sign of visible damage. We are interested in how soybean physiological processes are affected by aphid feeding. We are also interested in understanding plant stress due to climate change, as previous research has shown that CO2 does not offset effects of temperature change as much as previously thought due to interactions with temperature and precipitation.

Our objectives are to quantify links between landscape structure, insect food web structure, plant stress, and farmers’ yields in soybean fields across Wisconsin. These data will ultimately be incorporated into an improved Agro-IBIS modeling tool, which examines the interactions between the atmosphere and biosphere, uses field data to train remotely sensed imagery to detect data patterns across the growing region, and uses newly developed model to evaluate the impacts of food and fuel production in Wisconsin and across the Midwest.  Study sites were chosen to represent a wide range of agricultural and natural habitat, as well as climatic conditions.

This poster shows the results of an analysis of ten years of mid-season soybean aphid population counts across Wisconsin, as a function of both land use land cover (LULC) and biophysical (temperate, precipitation) metrics.  Populations varied widely between years. The direction of correlation between LULC and biophysical variables and aphid populations also varied between years and across spatial scales. This information is critical, as it informs best practices for managing an economically important crop pest. Moreover, it furthers our understanding of the intersections between pest populations, plant responses, and biophysical factors that will be altered due to future climate change.