Evolutionary insights: enhancing pest distribution forecasts in a changing climate

Climate change is predicted to alter pest spatial distribution including important species such as corn earworm (Helicoverpa zea). Projecting the changes in distribution will be vital to guiding plans for scouting and pest managements strategies. Poleward expansion of insect pests will endanger crop production throughout the US. As pests expand poleward, they will be exposed to novel thermal regimes which are colder than those in their native range. Pests’ ability to overwinter is impacted by their tolerance to low winter temperatures, a trait that is known to show variability over a latitudinal gradient and over time due to adaptation.

This study introduces a biologically informed approach to incorporating evolutionary rates into pest distribution forecasts; these models typically only included fixed assumptions of insect thermal physiology. We aim to bridge the current pitfalls of existing modeling approaches by dynamically decreasing the lower lethal limit. First, we approximate the rate of cold adaptation for the northerly population of corn earworm. Then this rate of adaptation is incorporated into models to display how considering insects' ability to rapidly evolve will enhance to predictive capabilities of such forecasts.

Our study leverages available persistence and distribution data to predict the rate of evolution and the future distribution. Incorporating this rate into updates for existing pest distribution models may have benefits beyond improving model accuracy. Incorporating the revised distribution models into pest forecasts will improve the accuracy of these models. Accurate pest forecasts will improve pest management and sustainability resulting in better crop protection.