Oak Processionary

From Wikipedia, the free encyclopedia

iOak Processionary

Oak Processionary caterpillars in nest on oak tree trunk

Scientific classification

Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Lepidoptera
Family:	Thaumetopoeidae
Genus:	Thaumetopoea
Species:	T. processionea

Binomial name

Thaumetopoea processionea
Linnaeus, 1758

The Oak Processionary (Thaumetopoea processionea) is a moth whose caterpillars have come into conflict with humans both as pests of oak forests and because of the health hazard posed by their poisonous setae (hairs), which may cause skin irritation and asthma.

1 Distribution
2 Description
3 Public Health Problem
4 Reference
5 External links

[edit] Distribution

Oak processionary moths are widely distributed in central and southern Europe, but are occasionally found as far north as Sweden. Their range is expanding northward as a result of global warming and they have already eroded some forests in the Netherlands.

[edit] Description

The wingspan of adult stage moths is between 25 and 35 mm. Their pattern of tan, brown and white make the adults difficult to see against oak bark. Adults fly during July and August. The larvae construct communal nests of white silk from which they crawl at night in single file, head to tail in large processions to feed on foliage in the crowns of trees, later to return in the same manner.

[edit] Public Health Problem

The moths are posing an increasing threat to humans as their range is being extended by the warming European climate. The backs of older caterpillars (3rd to 6th instars) are covered with as many as 63,000 pointed defensive bristles containing an urticating toxin (thaumetopoein or closely related compounds). Even if the larvae are not handled, the setae break off readily, become airborne and can cause epidemic caterpillar dermatitis (lepidopterism), manifested as a papular rash, pruritus, conjunctivitis and, if inhaled, pharyngitis and respiratory distress including asthma or even anaphylaxis.