Page 538 - The Book of Caterpillars: A Life-Size Guide to Six Hundred Species From Around the World

MOTH CATERPILLARS

FAMILY Notodontidae
DISTRIBUTION Europe into Asia
HABITAT Woodlands, parks, and gardens
HOST PLANTS Mostly oak (Quercus spp.); also others, including beech
(Fagus spp.), birch (Betula spp.), Hazel (Corylus avellana),
and sweet chestnut (Castanea spp.)
NOTE Caterpillar that has thousands of detachable hairs with
a hazardous irritant
CONSERVATION STATUS Not evaluated

ADULT WINGSPAN

1–1⅜ in (25–35 mm)
CATERPILLAR LENGTH
1 ⁄ in (30 mm)
THAUMETOPOEA PROCESSIONEA
OAK PROCESSIONARY
536
(LINNAEUS, 1758)

Female Oak Processionary moths lay their eggs in rows on twigs
and branches. The eggs overwinter, and the caterpillars emerge
in April. The larvae are gregarious and spin communal silk nests
under branches and on trunks, leaving trails of white silk. They
also defoliate much of their host tree, making it more vulnerable
to disease. As they develop through each instar, the caterpillars
molt and pupate within the nest, giving it a brown appearance.
The adult moths are on the wing from May to September.

These caterpillars are named after their habit of walking in nose-
to-tail processions along branches and on the ground. Their
hairs contain thaumetopoein, an intensely irritating compound,
The Oak Processionary caterpillar is gray brown which can cause rashes and allergic reactions in people who
with a dark head, a single dark dorsal stripe, and come into contact with them. Airborne hairs and even hairs on
a white lateral line. Clumps of long, white hairs

arise from red tubercles. In addition, the body the ground retain their irritant e ect. Where infestations are
is covered in thousands of shorter hairs that
contain an irritant. reported, public authorities take immediate action by spraying
trees and, in rare cases, burning infested areas.

Actual size