oak processionary caterpillars thaumetopoea processionea nest in a tree in a forest

allergy animal caterpillar caterpillars closeup crawl damage dangerous detail eikenprocessierups epidemic forest hair hairy hazard health infection infestation insect irritation larvae lepidoptera macro metamorphosis moth nature nest oak outdoor processionary processionea public rash skin thaumetopoea transformation tree voracious warning web wild wildlife