Oak procession spinner a health hazard

Oak procession moth especially dangerous for allergy sufferers

The caterpillars of the oak procession moths are on their way again. The warm weather conditions of the past few weeks have favored the growth of the caterpillars, so that the animals, which are particularly dangerous for allergy sufferers, are currently multiplying massively, warn the health authorities across Germany.

The fine hairs of the oak processionary moth can trigger violent allergic reactions upon skin contact or inhalation, so that the massive spread of the pests not only poses a danger to oak trees, the leaves of which almost completely destroy the voracious caterpillars, but also to humans. Allergy sufferers in particular should be careful, because there is a risk of violent allergic reactions with itching for weeks or even anaphylactic shocks.

Violent toxic reactions on contact with the caterpillars The caterpillars of the oak procession moths settle down in the so-called webs in the trees and eat their way through the foliage. The animals protect themselves from possible attackers with fine, poisonous hairs, but these stinging hairs can trigger violent allergic reactions in humans. So-called caterpillar dermatitis threatens in direct skin contact with the hairs. The thaumetopoein contained in the stinging hairs of the caterpillars triggers painful toxic reactions on the skin. In windy conditions, the fine stinging hairs of the caterpillars can also be spread through the air and not only come into contact with the skin, but also penetrate deeply into the respiratory tract, where they can also trigger allergic reactions and even asthmatic attacks.

Stinging hairs of oak procession moths are accumulated in the environment In order to stop the spread of oak procession moths in the cities, several cities such as Frankfurt (am Main) have decided to use organic insecticides to control the pests. In the coming week, helicopters are to spray a good 150 hectares of city forest with the biological insecticide, and there is also a control from the ground, the environmental agency in Frankfurt explained. But the health hazard does not only come from the caterpillars, but also from the webs. After pupation of the caterpillars, these contain the old larval skins and have a high concentration of stinging hair for a long time. According to the experts, old webs represent a permanent source of danger and because the caterpillar hairs have a long shelf life, they are accumulated in the area over the years - with corresponding negative effects for allergy sufferers. (fp)

Image: Caterpillar dermatitis (lepidopterism) caused by Oak Processionary (Thaumetopoea processionea), Photo: Daniel Ullrich. License: released in the GFDL and CC-by-sa-2.0-de by Daniel Ullrich.

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