a nose-to-tail procession of processionary caterpillars on tree trunk

allergic allergy animal bark caterpillar caterpillars closeup damage danger dangerous environment forest hair hairs hairy hazard health infection infestation insect invertebrate irritant irritating irritation larvae lepidoptera line macro moth natural nature oak outdoors pest poison poisonous problem procession processionary processionea queue row setae spring thaumetopoea toxic tree trees trunk venomous wildlife