Oak processionary moths are also spreading more and more in this country. The hairy pests originally come from Central and Eastern Europe, but due to climate change they already feel quite comfortable in the north. Milder winters and warmer spring weather offer them perfect living conditions and the many oak forests attract them even more. The cheeky larvae not only eat the leaves of the trees bare, but are also problematic for humans and animals and in some cases even really dangerous. It is not for nothing that many federal states undertake regular control measures and spend a large part of their budget on them. You can find out here today why the oak processionary moth is so harmful to us, how to recognize it and what to do about it.
The caterpillars are often seen in such rows as a procession
Recognize oak processionary moths
The larvae/caterpillars of the moth of the same name are actually called oak processionary moths. Unlike its successors, the moth itself is completely harmless to us humans. This one has a wingspan of about 3 cm and is camouflaged in brown-grey shades. Its head and body is covered with short hairs. It can easily be confused with other moths. The moth lives only for a few days in August and lays its eggs in the crowns of oak trees around this time. These are cleverly camouflaged with scales and secretions and spend the winter on the tree. The larvae then hatch in early/mid-May and begin their six consecutive larval cycles.
This is what lightly infested oak trees look like
They eat the leaves of the oaks and from the third life cycle, the so-called webs or nests begin to form. These serve as accommodation and protection for the caterpillars as well as for the later pupation in July/August. The caterpillars of the oak processionary moth actually move in so-called nose-to-tail processions and can thus be more easily distinguished from other caterpillars. In addition, their nests can only be seen on trees and never on walls, garden fences or other objects.
Do not confuse the oak processionary moth with other caterpillars
Why are oak processionary moths dangerous?
The dangerous secret of the caterpillars lies in their thin stinging hairs. They contain thaumetopoein, an aggressive nettle toxin. This is able to trigger strong allergic reactions, which can lead to itching and reddening of the skin, a sore throat and bronchitis to asthma or shortness of breath. The larval hairs are equipped with barbs and can therefore easily and, above all, hold on to the skin and mucous membranes of humans and animals for a long time. If these are inhaled or get into the eyes, serious consequences can be expected in many cases. In urgent situations, you should definitely consult an emergency doctor and if you have an oak processionary moth rash or an allergy, you should treat the affected parts of your body with cream containing cortisone and also take antihistamines. It is also advisable to wash yourself thoroughly and change all your clothes if you come into contact with the stinging hairs of the larvae.
The stinging hairs of the larvae can cause itchy skin rashes
Why do oak processionary moths spread?
As we have already mentioned above, higher temperatures also offer the perfect living conditions for the annoying oak processionary moths in our latitudes. In addition, the excessive use of pesticides has destroyed large numbers of their natural predators. There are hardly any factors that can stop the rapid spread of the pests. Some experts cite another reason for this, namely the increased trade in young oak trees from southern and central Europe. This is probably why many eggs of the oak processionary moth come to Germany unnoticed due to insufficient controls.
The larvae multiply rapidly and quickly become a nuisance
Oak processionary moth control – the most important methods
Although there is no official reporting obligation for these pests, you should report any infestation to the responsible authorities immediately. Or contact a professional pest controller directly. Because removing the nests and the caterpillars yourself is not a good idea. The stinging hairs are extremely breakable and can fly several hundred meters in the air. Experts are well versed in this and will remove the oak processionary moth appropriately. In most cases, this is done by mechanical methods such as suction with an industrial vacuum cleaner. Sometimes pressure washers are used and sprayed with pesticides and other insecticides. Unfortunately, the last measures are not only quite expensive, but also harmful to the environment and at the same time destroy many other species of butterflies and beneficial insects.
Vacuuming the nests is a relatively gentle method
For these reasons, scientists are also developing newer control methods that are purely biological. The most used among them are the use of the bacterium Bacillus thuringiensis and roundworms, also known as nematodes. Bacteria and worms are able to penetrate the larvae and dry out and destroy them from the inside. These are biocides that have almost no side effects. Nevertheless, one should not overdo it and not use these agents uncontrollably on a large scale, because this can also affect other useful insects.
Specialists can treat an infestation professionally and safely
It is just as environmentally friendly to support and attract the natural predators of the oak processionary moth. Wasps, predatory beetles, bats and some birds such as tits, the hoopoe or the cuckoo are among the most important of these. You can become active yourself and hang up birdhouses in the garden or in the park and grow different plant-based food sources such as nectar-rich flowers and herbs.
Tits like to feed on the eggs and larvae of the oak processionary moth
So be mindful and responsible to yourself and others. If you notice nests of the dangerous caterpillars, report them immediately and do not approach them. Above all, protect children and pets from this and get yourself checked out by a doctor, especially if you get rashes or have an allergy.
Declare war on the oak processionary moth!
So that it has fewer chances of spreading over a large area
The moth also looks quite similar to other moths
The nests are often well camouflaged
Sheep’s wool seems to drive away the larvae