THE GOLD-TAILED MOTH. 
271 
■ 
Most caterpillars wage war singly on the foliage, and though 
they do much damage, their ravages are conducted in a desul- 
tory manner. The Small Ermines, however, band themselves 
together in hosts, and march like disciplined armies to the 
attack, invading a district and completely devastating it before 
i they proceed to another. 
They live in large tents, placed among the branches of some 
tree, and composed of silken threads, which are loosely crossed 
and recrossed in various directions. From this centre the 
caterpillars issue in vast numbers, each individual spinning a 
strong silken thread as it proceeds, which acts as a guide to the 
nest, just as the fabled clue led through the intricacies of 
Rosamond’s bower. When once these caterpillars have taken 
possession of a tree, they are sure to strip it of its leaves as 
completely as if the foliage had been plucked out by hand. It 
is a very curious sight to watch the systematic manner in which 
these troublesome insects set about their work, how they send 
out pioneers which lead the way to new branches, either by 
crawling up to them or by lowering themselves to them by 
means of their silken life-lines, and how soon they are followed 
by their ever-hungry companions. 
Another well-known British insect which constructs social 
habitations is the. Gold-tailed Moth ( Porthesia chrysorrhoea), 
a familiar and beautiful insect, with wings of soft downy 
plumage, and snowy-white in colour, and a tuft of yellow hair 
at the end of the tail. The perfect insect may often be seen 
sticking on the trunks of trees in gardens, waiting until the 
evening, when it will fly off to its labours. 
When the moth has laid its eggs, it plucks off the beautiful 
yellow tuft at the end of the tail, and with it forms a roof over 
the pile of eggs, laying the hairs so artificially as to make a 
perfect thatch. When the larvae are hatched, they retain their 
sociability, and spin for themselves a common domicile. This 
house is very remarkable. Viewed on the exterior, it is seen 
to be a bag-like structure of whitish silk, rather strong and 
tough, but very yielding. 
One of these nests, which I found in Wiltshire, is now before 
