Brown-tail moth: the underrated stinging caterpillar
By Wespenprofis.ch · Reviewed by:Fachbewilligung Schädlingsbekämpfung VFB-S · Updated: 3 July 2026
At a glance
The brown-tail moth is a white tussock moth with a golden-brown tuft of hair at the tip of its abdomen, and its caterpillars build conspicuous silk nests in deciduous and fruit trees. The stinging hairs affect the skin in much the same way as those of processionary moths, but they are easier to spot, which lowers the risk of contact. In Switzerland, the brown-tail moth is more widespread than the processionary moth species.
How to identify the brown-tail moth
The brown-tail moth (Euproctis chrysorrhoea) is a tussock moth with pure white wings and a distinctive golden-brown tuft of hair at the tip of its abdomen, which is what gives the species its name. Its caterpillars live communally and spin dense, clearly visible silk nests in deciduous and fruit trees. These nests often stand out on bare branches as early as winter, since the caterpillars overwinter inside them. In spring the young caterpillars leave the nest and feed on fresh leaves, before pupating later on and emerging again as moths.
Why the brown-tail moth is often underestimated
Compared with the oak processionary moth, the brown-tail moth is more widespread in Switzerland and is found in a much wider range of tree species. Because its nests and caterpillars are easy to see, however, the hazard is frequently underestimated or simply overlooked, even though these caterpillars also carry stinging hairs from a certain stage of development onwards. Good visibility does reduce the risk of unnoticed contact, but it does not make the hairs themselves any less harmful. With children in particular, who are drawn to the conspicuous nests, the apparent harmlessness often leads to unnecessarily close contact.
How the stinging hairs affect you
The fine hairs of brown-tail moth caterpillars irritate the skin and mucous membranes in much the same way as the stinging hairs of the oak or pine processionary moth. On contact, you can expect a skin rash with itching as well as irritation of the eyes and airways, particularly when the hairs are stirred up by wind or garden work. Because brown-tail moth nests often hang at hand height in hedges, fruit trees or ornamental trees, they should be avoided just as much as the nests of processionary moths. The likelihood of unintentional contact rises especially in spring, when the overwintered caterpillars become active and feed on fresh shoots.
What you should do
Do not touch nests or caterpillars, and do not let children play with them. When pruning affected shrubs or trees, watch out for visible nests and stay clear of the area. If the infestation is larger, or if nests are in heavily used areas, it is worth calling in a professional (/prozessionsspinner-bekaempfung). You can read more about the effects of contact with stinging hairs in our guide on caterpillar dermatitis.
Frequently asked questions
How do I recognise the brown-tail moth?
The moth is a striking white with a golden-brown tuft of hair at the tip of its abdomen. The caterpillars live communally in dense silk nests in deciduous and fruit trees.
Is the brown-tail moth more dangerous than the oak processionary moth?
No, the risk of contact tends to be lower, because the nests and caterpillars are clearly visible and are less often touched unnoticed. The stinging hairs do, however, irritate the skin in a similar way.
How widespread is the brown-tail moth in Switzerland?
The brown-tail moth is considerably more common in Switzerland than the oak or pine processionary moth, and it can be found in many deciduous and fruit trees.