Biosecurity

Toxic Caterpillars Invading Parts of London, Officials Warn

British forestry officials are warning parts of London about an invasion of caterpillars whose long white hairs can trigger allergic reactions in humans that include skin and eye irritation, difficulty breathing and even anaphylactic shock.

Caterpillars of the oak processionary moth were spotted emerging from eggs in mid-April, according to the Forestry Commission, which oversees forests in England and Scotland.

The caterpillars’ hairs, which can be released as a defense mechanism or carried by the wind, contain thaumetopoein, an irritating protein, the commission said. Those who are allergic can become sick.

“At best, you can get contact dermatitis. At worst, you can die,” said Jason J. Dombroskie, manager of the Cornell University Insect Collection and coordinator of the Insect Diagnostic Lab in Ithaca, N.Y. “You can go into anaphylactic shock and have your airways close up. The airborne hairs set up a whole different ballgame.”