A beetle whose larvae can cause considerable damage to maize, given the right conditions, has been found at two sites in the UK, close to Heathrow Airport. The beetle, Diabrotica virgifera virgifera, which is known in its USA homeland as the Western corn rootworm, was first found in eastern Europe in 1992 and has since spread westwards, with outbreaks reported in Italy in 1998, Austria, and France in 2002 and the Netherlands in 2003.
Given the findings in France, traps were set for the pest in the UK for the first time in 2003. It is probable from the number of beetles trapped at one site that the pest has been in the UK for more than one year, and there may be other small undetected outbreaks in maize crops in the south of England.
Control measures against the pest, which affects the roots, are still under consideration but are likely to involve early controlled harvest and conversion to silage of the maize crop within the vicinity of the outbreaks and further precautions to prevent spread of the pest from the outbreak sites. Limitations on future cropping are also likely to be applied to fields where infestation has been confirmed. Searches and trapping of other maize crops in the area are being undertaken.
Discussions are currently taking place in the EU Standing Committee on Plant Health on a proposed Commission Decision on the measures to be taken to prevent the spread of Diabrotica virgifera virgifera. Defra is discussing with growers' groups how to tackle this new pest. Further information about this pest can be found on the Defra website at www.defra.gov.uk/planth/pestnote/diabrotica.htm.
