Oak procession spinner inconspicuous danger

Health risk from oak processionary spinners

07/16/2012

Caterpillars cause allergic reactions. The larvae of oak processionary moths carry tiny stinging hairs on their skin, which can lead to massive health impairments on contact. In the course of the warmer climates, the animals have also spread in Germany.

Oak Processionary Moth: Inconspicuous but dangerous
With the growing spread of the oak processionary moths, the number of people who had to be treated for contact with the poisonous hairs has increased significantly in recent years. Since the tiny hairs are often barely perceptible to the naked eye, retain their toxic effects long after the caterpillars have ended and can also be transported over long distances with the wind, many affected persons are in contact with the burning hairs of the oak processionary moths when the symptoms appear not even aware. In case of apparently unfounded allergic reactions of the skin, respiratory complaints and inflammation of the eyes after a stay in the countryside, but should also be thought of the hairy caterpillars.

Spread of the oak procession spinners by climate change
For years, the oak processionary spinners in Germany are spreading more and more. Preferably, the caterpillars of the rather inconspicuous moth infest all oak species, but other trees, such as beech, are by no means safe from the caterpillars of the animals. The oak processionary spinners occur throughout Europe, but are increasingly observed in dry and warm climates. „So it can be assumed that in addition to the forest structure the „climatic conditions are decisive“ For the spread of the oak processionary spinners, the head of the Forest Protection Department at the LFE said. Katrin Moller. For around two decades, an increased occurrence of oak processionary spinners has been observed in Germany.

The adult moths of the oak processionary fly from late June to September, especially during dusk and night. During this time, the females lay their eggs in the crowns of the trees, so the statement in the recently published information brochure of the Landeskompetenzzentrum Forst Eberswalde (LFE) in Brandenburg. Accordingly, a single female of the oak processionary moth lays up to 300 eggs within a few days. In May of next year, the larvae hatch and begin to eat the leaves of the infested trees. The appetite of the caterpillars knows little limits and so the animals can eat whole trees bald. According to LFE consumed „a caterpillar averages seven to eight oak leaves throughout its development.“

Burnt hairs of the caterpillar pose a health risk
The growth of caterpillars begins with food intake. This includes six stages, meaning that the animals shed their skin six times in total. From the third instar, the caterpillars begin to produce more focal hair, which are provided with tiny barbs and the nettle poison thaumetopoein. „The number and length of the burning hair increase with each skinning“, so the information of the LFE. As the caterpillars of the oak processionary moths rest until the third instar, they begin to spin their conspicuous, widely visible nests, where hundreds of animals gather. The webs remain in existence for years after they have been abandoned and, for a long time, are a health risk that should not be underestimated due to the presence of the burning hair.

Nettle poison of the burning hair causes partially life-threatening reactions
When skin contact with the burning hairs of the oak processionary spinners usually arises relatively soon a strong itchy skin rash, the so-called caterpillar dermatitis. The nettle venom leads to the typical nettle fever symptoms with formation of red wheals at the site of the skin contact. If the hair reaches the lungs, severe respiratory irritation and inflammatory reactions in the lungs are threatened. The stinging hair sometimes gets into the eye and trigger local inflammation. At worst, stinging hair can cause asthma or even a potentially life-threatening allergic shock in people with stress. „ The sensitivity and reaction intensity of the affected persons increases with the number of individual contacts“, so the message in the information brochure of the LFE. In addition to the symptoms mentioned, according to the experts of the provincial competence center also threaten „General ailments like fever or dizziness.“

Burning hair of the oak procession spinners an invisible danger
Last year, the professional association of German dermatologists had already warned of the health risks caused by the growing distribution of the oak processionary moths. The skin and respiratory symptoms, however, are „not allergic, but a pseudoallergic reaction caused by the poison“, stressed Reinhard Leitz from the professional association of German dermatologists in the then press release. According to the experts, all people show the above symptoms, not just sensitive allergic people. However, at the „people are more severe reactions“, the expert continues. Dr. According to Leitz, sufferers are often unaware of what causes the intense itchy rash and visible symptoms. Because the burning hairs are barely visible and can be transported over long distances (a few hundred meters) with the wind. U

To alleviate acute symptoms, Dr. Leitz „Cortisone as a cream for the itchy pustules or an injection in difficulty breathing fast and effective effect“ demonstrate. In addition, help „Antihistaminka curb the discomfort“, the dermatologist continues. If there is evidence of an anaphylactic shock, urgently call an ambulance. Since even animals such as horses or dogs are endangered by the hair of the caterpillars, it is important to ensure that they are sufficiently far away from the nests.

Faces of the oak processionary moths should be reported to the responsible local authorities, who then order removal of the caterpillar nests if health hazards exist. Because „It is also a risk for children and adults in parks, swimming pools and in schoolyards“, so the hint of the LFE. (Fp)

Read about oak processionary moths:
Strong spread of oak processionary spinners
Oak tree procession spinner a health hazard
Caterpillars cause a major alarm
Spread of poisonous caterpillars a health risk

Image: Caterpillar dermatitis caused by oak processionary spinner Photo: Daniel Ullrich.