The oak processionary moth has been spreading for several years, particularly in the forests in the district of Nordsachen and in the Dresden Elbe Valley. In these regions, the butterfly species benefits from the warm, dry weather, said Renke Coordes from Sachsenforst. Even the late frosts in April had no relevant impact on the population. The oak processionary moth is sufficiently cold-tolerant in the egg stage in winter and in the caterpillar stage in spring. Only cold spells lasting several days in conjunction with a lack of food due to leaves that have not yet sprouted or are dead would damage the insects.
Coordes assumes a steady but relatively slow spread due to the planned forest conversion. The oak processionary moth mainly needs oak species to develop. As a result of the forest conversion, the proportion of native pedunculate and sessile oaks in particular as potential food trees for the caterpillars will increase in the future. "However, as older trees are preferred for colonization and the native oak species need many decades to develop, the food supply will not improve abruptly."
