Migration plays an important role in the ecology of insect pests, including Helicoverpa zea , a major pest of multiple crops across the U.S. The long-standing “pied piper” hypothesis proposes that H. zea populations migrate northward each summer to exploit seasonal resources but because cannot overwinter in the lethal winter conditions, populations of this pest fail to continue to be established in higher latitudes in North America. This study investigated the natal origins and migratory connectivity of H. zea moths collected across Florida between 2017 and 2024 using stable hydrogen isotope analysis of wing tissues. Through this approach, we traced the origins of 249 individuals, revealing that most late-season moths originated locally or from southern U.S. regions. However, a distinct subset exhibited isotopic signatures indicative of long-distance migration from northern areas, including the upper Midwest and Corn Belt. Estimated flight distances for these northern migrants ranged from 1,375 to 1,725 km, with dispersal patterns showing a predominant northwest-to-southeast orientation. These findings provide evidence that H. zea populations engage in bidirectional migration. This H. zea reverse migration has critical implications for integrated pest management (IPM) and insect resistance management (IRM) to insecticides and Bt traits, considering the risk of gene flow of populations under continuous selection for resistance in both Cotton and Corn Belts.
Twaibu et al. (Fri,) studied this question.