Critical Facets of European Corn Borer Adult Movement Ecology Relevant to Mitigating Field Resistance to Bt-Corn

Abstract

The European corn borer (Ostrinia nubilalis, Hübner) has been managed successfully in North America since 1996 with transgenic Bt-corn. However, field-evolved resistance to all four available insecticidal Bt proteins has been detected in four provinces of Canada since 2018. Evidence suggests resistance may be spreading and evolving independently in scattered hotspots. Evolution and spread of resistance are functions of gene flow, and therefore dispersal, so design of effective resistance management and mitigation plans must take insect movement into account. Recent advances in characterizing European corn borer movement ecology have revealed a number of surprises, chief among them that a large percentage of adults disperse from the natal field via true migratory behavior, most before mating. This undermines a number of common key assumptions about adult behavior, patterns of movement, and gene flow, and stresses the need to reassess how ecological data are interpreted and how movement in models should be parameterized. While many questions remain concerning adult European corn borer movement ecology, the information currently available is coherent enough to construct a generalized framework useful for estimating the spatial scale required to implement possible Bt-resistance prevention, remediation, and mitigation strategies, and to assess their realistic chances of success.

Impact of Chemical Insecticide Application on Beneficial Insects in Maize

“…Damage caused by these two pests can be conveniently prevented by planning appropriate crop rotation protocols, a precaution that helps to keep the pests below the economic threshold limit using traps to monitor and study adult flight and movements [7][8][9][10][11][12][13]. Both WCR and ECB are in general the main pests of maize; crop rotation is recommended to limit these two pests [12,13].…”

“…However, where the threshold limit is particularly low (i.e., sweet maize and maize for seed), ECB is limited by insecticide sprays or inundative T. brassicae releases [2]. Natural control by Trichogramma egg parasitoids is active against ECB throughout all the periods of overlapping generations of the host [11][12][13][15][16][17].…”

Continental-scale migration patterns and origin of Helicoverpa zea (Lepidoptera: Noctuidae) based on a biogeochemical marker

“…Migration is a behavioral pattern observed in animals, involving travel between habitats in search of food, improved conditions, or for reproductive purposes. It typically involves a series of physiological, morphological, and behavioral adaptations ( Johnson 1969 , Dingle 2014a , Sappington 2024 ). Unlike other forms of animal movement, such as short-range dispersal, migration is characterized by long-distance movement, usually occurs seasonally, and often involves a return journey ( Johnson 1969 , Chapman et al 2011 , Dingle 2014b , Hu et al 2016 ).…”