The oak processionary (Thaumetopoea processionea) is a moth whose caterpillars can be found in oak forests, where they feed on oak leaves, causing significant damage. They travel in nose-to-tail processions (hence their name), often arrow-headed, with a leader followed by rows of several caterpillars abreast. They are a human irritant because of their venomous setae (hairs), which can cause skin irritation and asthma. The species was first described by Carl Linnaeus in his 1758 10th edition of
