Multiple Transatlantic Introductions of the Western Corn Rootworm

Abstract

The invasion of Europe by the western corn rootworm, North America's most destructive corn pest, is ongoing and represents a serious threat to European agriculture. Because this pest was initially introduced in Central Europe, it was believed that subsequent outbreaks in Western Europe originated from this area. Using model-based Bayesian analyses of the genetic variability of the western corn rootworm, we demonstrate that this belief is false: There have been at least three independent introductions from North America during the past two decades. This result raises questions about changing circumstances that have enabled a sudden burst of transatlantic introductions.

Influence of drought on plant performance through changes in belowground tritrophic interactions

“…WCR is among the most damaging maize pests and causes costs of up to 2 billion US$ per year in the United States alone (Mitchel, 2011). It is invasive in Europe (Miller et al., 2005; Wesseler & Fall, 2010), and current climate models predict that its range will expand as temperatures increase (Hemerik, Busstra, & Mols, 2004). Low soil moisture has been shown to reduce WCR survival and mobility at early developmental stages (Macdonald & Ellis, 1990; Spencer, Hibbard, Moeser, & Onstad, 2009).…”

Transatlantic invasion routes and adaptive potential in North American populations of the invasive glossy buckthorn,Frangula alnus

“…As is the case for most studies examining routes of invasion (e.g. Miller et al, 2005;Clavero and Garcia-Berthou, 2006), we assume that the sampled populations are genetically and/or geographically close to the true source populations. The distance-based DAPC assignment is preferred over Bayesian assignment software such as GENECLASS 2 (Piry et al, 2004) because the latter assumes Hardy-Weinberg equilibrium.…”

A Core Set of Microsatellite Markers for Western Corn Rootworm (Coleoptera: Chrysomelidae) Population Genetics Studies

“…The western corn rootworm, Diabrotica virgifera virgifera LeConte, causes huge economic losses annually in the United States (Metcalf 1983, Sappington et al 2006 and is now responsible for increasing damage in Europe as it continues to expand its range after its initial detection in the early 1990s (Barč ić et al 2003, Hemerik et al 2004, Miller et al 2005. In addition, this pest is becoming more difÞcult to manage in parts of its range in North America because of the development of resistance to chemical insecticides (Meinke et al 1998, Wright et al 2000 and to crop rotation (Levine et al 2002).…”

“…Diabrotica microsatellite markers have been developed by three collaborating laboratories (Kim and Sappington 2005b, Kim et al 2008, Waits and Stolz 2008. Several of these markers have been successfully used to assess genetic structure of both natural populations (Kim and Sappington 2005a, Miller et al 2006, 2007, Kim et al 2008) and laboratory colonies (Kim et al 2007) of D. v. virgifera, and to identify routes of invasion in Europe (Miller et al 2005).…”

“…Moreover, common use of a core set of markers allows direct sharing of D. v. virgifera genotype datasets across laboratories, thereby reducing unnecessary duplicate genotyping of overlapping populations. For example, the Agricultural Research Service provided raw microsatellite genotype data from U.S. populations analyzed for one study (Kim and Sappington 2005b) to the French team using the same markers to analyze invasion routes of D. v. virgifera in Europe (Miller et al 2005), thus saving the latter signiÞcant resources and time to the beneÞt of all.…”