Pine processionary caterpillar

What you see

Unmistakable: hairy orange-brown caterpillars marching in single-file nose-to-tail processions, from big silky white tent-nests high in pine trees.

Damage

Silvery-white candy-floss nests in pine branches in winter. Needles stripped brown. Long single-file processions crossing the ground from late winter into spring.

Lifecycle on this coast

One generation a year. Nests form over winter, and the caterpillars descend in a procession in late winter or early spring to pupate in the soil.

When to act

This is a health matter, not a crop one. Treat any nest or procession near the house as needing action.

Months: January, February, March, November, December

Plants it bothers

Pine

Natural enemies

Great tit, Hoopoe, Bat

Remedies

Pheromone traps, Bacillus thuringiensis (Bt)

The thing people get wrong

DANGER TO DOGS AND CHILDREN. The hairs carry a protein that causes severe reactions - a dog that noses or licks a caterpillar can lose part of its tongue to necrosis, and this is a genuine veterinary emergency. Never let a dog near a procession or a fallen nest, never handle them or break a nest open by hand, and keep well upwind: the airborne hairs alone cause rashes and eye irritation.