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Diabrotica Virgifera

Answer

[holding answer 19 November 2007]: Diabrotica virgifera, the western corn rootworm (WCR), is a serious pest that is listed in EC plant health legislation.Investigations into the origins of the populations of WCR found in the south-east of England are very difficult because the means by which it was introduced are unclear. There is circumstantial evidence to suggest that WCR is spread by aircraft since outbreaks have been closely associated with airports throughout Europe. However, to date, no studies have been carried out on the presence of potentially invasive insects on aircraft.A study is being carried out to assess the feasibility of using DMA genetic markers to identify entry pathways of invasive pests such as WCR. The results are due to be published soon. However, they indicate that the cases in the UK have been introduced from at least two sources, linked to populations in the USA and eastern Europe. Other published studies have also suggested at least three independent introductions of this pest into Europe from North America during the past two decades.Crop rotation is the most effective means of controlling WCR and enforced rotation of maize crops is required under statutory notice in infected areas of the UK, in line with the EU legislation. A range of alternative management options for the control or eradication of WCR have been used in areas where the pest occurs, including foliar insecticide treatments for use against adult beetles. Unfortunately, there are no effective methods of spraying such insecticides in the UK, since aerial application is not possible around airports and high clearance sprayers are not generally available. Insecticide seed treatments may exert a limited degree of control against larvae in the soil but will not eradicate the pest. Since the pathway for entry of WCR remains unidentified and hence uncontrolled, the possibility of further introductions remains high. Public consultation has been completed to determine future policy regarding this pest, taking account of EU legislation and recent survey results, and the outcome will be published shortly.

Secondary information

Type

Written question

Reference

164681; 467 c758-9W

Session

2007-08

Subjects

Pest control Maize

Link

View this Written question on www.publications.parliament.uk