Residents of the British capital should beware of getting too close to caterpillars of the oak processionary moths that are infesting the city and its surrounding areas, the British Forestry Commission has warned.

The caterpillars are covered with tiny white hairs that contain a protein which causes skin rashes, eye and throat irritations, dizziness and even respiratory problems in some people.

The commission said in an information brochure that they can also pose a hazard to the oak trees in which they normally nest, as they eat the leaves. In large numbers, they can potentially strip a tree bare, making them susceptible to other threats.

People are being warned not to touch or approach nests or caterpillars themselves, or to allow children and animals to do so.

The common name of the moth comes both from its usual nesting place and its larvae's habit of moving about in lines made up of several animals.

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Unwelcome immigrants

Since shortly after the caterpillars emerged from egg plaques in mid-April, officials have been spraying pesticides in affected areas in London and neighboring counties in an attempt to eliminate the infestation, the commission said.

The moths, which are native to southern Europe, were accidentally introduced to the United Kingdom in 2005.

The pest has been moving northward over the past two decades, possibly as a result of global warming, and now has established populations in northern countries such as Germany, Belgium and the Netherlands.

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