Importance of color for artificial clay caterpillars as sentinel prey in maize, soybean, and prairie

Abstract

The use of artificial clay caterpillars to measure predation pressure under real field conditions is one method that has garnered recent support for quantifying ecosystem services that beneficial insects provide. Here, we focus on color and ask whether it is an important variable that should be considered in studies using clay caterpillars as sentinel prey. We deployed a total of 1920 brown, cream, green, gray, terracotta, and white clay caterpillars onto maize, soybean, and prairie plants to test if lighter colored caterpillars will be attacked and retrieved more than caterpillars with darker colors. As hypothesized, color was a significant predictor with green and terracotta caterpillars performing best, whereas brown and gray caterpillars performed the worst. Interestingly, clay caterpillars were also attacked proportionally to the number of insects in the surrounding habitat. Combined, we suggest artificial clay caterpillars could be useful for rapid ecosystem function assessments, but only when their color is considered.