Birch moth

The moth moth is a typical representative of the moth. As its name suggests, this butterfly belongs to the family of the Spanner (Geometroidea), which is one of the largest butterfly families in Germany with 400 species.

The birch tree stretcher is only on the road at night. The very narrow wings are drawn in black with a white ground colour. The colour of the wings imitates the bark of the birch, making the butterfly difficult to spot even during the day. The same applies to the caterpillars. They have a long, thin body shape and are light green to dark brown in colour. It’s hard to tell them from small branches.

The pine moth can be observed from the beginning of May to August. Its distribution area extends over almost the whole of Europe to Central Asia and Northern Europe. Alluvial, fragmented and mixed deciduous forests and their peripheral zones are the preferred habitats. The caterpillars of the birch stretcher can be found on many plants, e.g. English oak, weeping birch, black alder or blackthorn.

Many people may be familiar with the birch moth from biology lessons. It is considered an example of the phenomenon of “industrial melanism”. There are also dark forms of the birch trees, which are caused by an increased storage of dark colour pigments (melanin). At the time of the Industrial Revolution, British scientists observed an accumulation of these dark-coloured birch trees. It was assumed that they were better camouflaged on the black sooty birch bark and therefore had a better chance of survival than their bright relatives. However, this theory is nowadays controversial, as an increased occurrence of dark birch peepers can also be observed in clean air areas.