During the period September 2006 to June 2007, a long stretch of hawthorn hedge on both sides of the A137, close to Rookery Farm, Tattingstone (TM 127374) has looked brown and dead. On closer examination the hedges proved to be completely defoliated and among the branches were lots of silken nests. Taking a nest home to look at more closely, it was found to contain a community of Brown tail moth caterpillars. They were identified using A Field Guide to Caterpillars of Butterflies and Moths in Europe by D.J. Carter and B. Hargreaves (Collins 1986). Each caterpillar had a blackish body, covered with tufts of short, greyish-brown hairs arising from small warts. A bright orange-red line was visible down the back either side of which was a row of tufts of very short white hairs. Segments 9 and 10 had a raised, red spot in the middle of the back. The field guide also informed me that its habitat is hedgerows, parks and gardens.

Great care was taken when examining the larvae. The larval hairs can cause prolonged irritation and a rash if they come into contact with the skin. The eggs are laid on twigs in August and hatch in three weeks, when the larvae begin spinning their nests.

The following spring they recommence feeding and spin a succession of nests as the food is exhausted. In June, when fully grown, the larvae disperse and pupate in silken cocoons spun among the twigs. Moths emerge in July.