Eastward expansion and discovery of the soybean biotype of western corn rootworm (Diabrotica virgifera virgifera LeConte) in Canada

Abstract

The western corn rootworm (WCR), (Diabrotica virgifera virgifera LeConte), was collected in eastern Ontario and western Quebec in 2000. At Ottawa and North Gower, WCR adults were recovered using emergence traps from first-year corn and, at Ottawa, from first year soybean after corn. This constitutes an extension of the species distribution and the first report of WCR developing in soybean in Canada. Key words: Western corn rootworm, Diabrotica virgifera virgifera, distribution, corn, soybean

Oviposition site selected by the western corn rootworm (Diabrotica virgifera virgifera Leconte) in southern Ontario strip plots

“…Although rootworm feeding damage did not exceed the threshold in the first-year strips, producers who use strip cropping systems may be unable to control WCR exclusively through crop rotation alone since larvae are capable of movement through the soil. In addition, adult beetles are capable of ovipositioning in crops other than corn, Meloche and Hermans (2004) suggested that the rotationresistant variant is present in Ontario based on the capture of a limited number of beetles with emergence traps at two locations in first-year corn. Incidental egg laying in non-host crops has been observed previously under environmental stress (Boetel et al 1992).…”

“…The spread of the variant WCR in Ohio has been limited to only the western tier of counties in the state (Onstad et al 1999). Meloche and Hermans (2004) speculated that the variant has arrived in the Ottawa valley through an eastward expansion of its distribution. Our surveys conducted in southwestern Ontario since 1997 provide no conclusive evidence that the rotation resistant WCR has become established (unpublished data).…”

Adaptation and Invasiveness of Western Corn Rootworm: Intensifying Research on a Worsening Pest

“…It remains unclear how this infestation began, but frequent international flights from major airports within the United States located near large maize production areas suggest that accidental transport of adults by commercial aircraft was most likely 304 Gray et al Reconstruction of western corn rootworm, Diabrotica virgifera virgifera LeConte, range expansion from central Great Plains across North America from 1867 to 2005, based on data or reports in the literature (25,39,48,49,64,67,68,69,70,110,115,116,123 (Figure 2), with the most significant number of infested hectares in Hungary (93,000 km 2 ), Serbia and Montenegro (73,000 km 2 ), and Romania (65,000 km 2 ). Miller et al (72) determined that at least three independent incursions by the western corn rootworm across the Atlantic Ocean, rather than a single invasion, are responsible for the current European distribution of this insect pest.…”

First report of Hypsipyla grandella (Lepidoptera: Pyralidae) on African mahogany Khaya ivorensis

“…This fact has been reported in Hypsipyla robusta attacking the American mahogany Switenia macrophyla cultivated in Africa and Australia (Newton et al, 1993;Cunningham et al, 2005), Diabrotica virgifera virgifera LeConte migrating from corn to soybean (Meloche and Hermans, 2004), and Euschistus heros migrating from soybean to cotton (Azambuja et al, 2013). Further research must be encouraged concerning monitoring, pest control techniques, selection of new resistant materials and resistance management strategies, such as the use of structured refuge with susceptible materials.…”