This section is from the book "Commercial Gardening Vol3", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
These are the houses of the Lackey Moth caterpillars (fig. 343), which now and then occur in such plenty that they defoliate the trees over large areas. The caterpillars hatch in April from regular egg bands laid in the previous year on that year's growth of wood. When full grown they reach 1 1/2 in. in length, and are brilliantly coloured, having thin lines of orange and white, and broader lines of blue and brown, with tawny hairs. They mainly feed under the silken tents, but before they mature they spread out over the trees, and feed ravenously. Pupation takes place in a cocoon of pale silk with yellow powder amongst it, either between leaves or on the branches or fences, etc, near at hand. The rusty-brown moths hatch out in August, and vary from 1 to 1 1/2 in. across the wings, their bodies being very hairy and thick.
All egg bands should be collected in winter and burnt. The nests may be cut off with long-handled shears and destroyed, and arsenate of lead spraying will kill the larvae when free.