Spatial and Temporal Genetic Analyses Show High Gene Flow Among European Corn Borer (Lepidoptera: Crambidae) Populations Across the Central U.S. Corn Belt

Abstract

European corn borer, Ostrinia nubilalis (Hübner), adults were sampled at 13 sites along two perpendicular 720-km transects intersecting in central Iowa and for the following two generations at four of the same sites separated by 240 km in the cardinal directions. More than 50 moths from each sample location and time were genotyped at eight microsatellite loci. Spatial analyses indicated that there is no spatial genetic structuring between European corn borer populations sampled 720 km apart at the extremes of the transects and no pattern of genetic isolation by distance at that geographic scale. Although these results suggest high gene flow over the spatial scale tested, it is possible that populations have not had time to diverge since the central Corn Belt was invaded by this insect approximately 60 yr ago. However, temporal analyses of genetic changes in single locations over time suggest that the rate of migration is indeed very high. The results of this study suggest that the geographic dimensions of European corn borer populations are quite large, indicating that monitoring for resistance to transgenic Bt corn at widely separated distances is justified, at least in the central Corn Belt. High gene flow further implies that resistance to Bt corn may be slow to evolve, but once it does develop, it may spread geographically with such speed that mitigation strategies will have to be implemented quickly to be effective.

Biological invasions in agricultural settings: Insights from evolutionary biology and population genetics

“…It originated in Central Asia, and was first introduced into Europe during the Ancient history. Europe then acted as a secondary source for world colonization by the pathogen over the last 500 years; the European corn borer, Ostrinia nubilalis first invaded Europe, establishing a bridgehead from which it was subsequently introduced into North America [72,73]; the Colorado beetle, Leptinotarsa decemlineata first invaded the United States. It was then introduced into Europe [69]; Box 2.…”

Population genetic history of the dreissenid mussel invasions: expansion patterns across North America

“…First, most introductions are founded by only a few individuals that represent only a small part of native variation, and subsequent bottlenecks and Allee effects may further reduce it (DeWalt and Hamrick 2004;Grapputo et al 2005;Griffen and Drake 2008). Second, introduction and spread likely lead to high gene flow that homogenizes population genetic structure (Viard et al 2006;Kim et al 2009). Lastly, a recent introduction may lack sufficient time for local adaptation or drift to generate local population genetic structure via stochastic processes in the new range (Maron et al 2004;Whitney and Gabler 2008).…”

Genetic hitchhiking and resistance evolution to transgenic Bt toxins: insights from the African stalk borer Busseola fusca (Noctuidae)

“…Extensive gene flow is commonly observed in pest populations (e.g., Daly and Gregg, 1985;Korman et al 1993;Bourguet et al, 2000;Endersby et al, 2007;Kim et al, 2009) and may promote rapid diffusion of resistance alleles across space (e.g., Peck et al, 1999;Bourguet et al, 2000).…”