COMMON VAPOUREK MOTH. 139 



The little ashy, dirty yellowish, or lead-coloured 

 caterpillars, spotted with black, spin web-nests, in 

 which they live in great companies, until the leafage 

 all around may be destroyed and hung with the 

 tattered remains of their successively spun webs. 



The yellowish or brownish Lackey Moths, with 

 their handsome hairy caterpillars, as much as an 

 inch and a half in length, striped on a grey ground 

 with scarlet or orange, blue, and black, give another 

 example of a common web-nest-forming caterpillar. 



These various kinds, including besides what may be 

 called those of common habits, such, that is, as moths 

 which come on the wing to the tree, and of which the 

 caterpillars, after feeding, spin up on the bark, or in 

 any convenient shelter, may be counteracted in some 

 degree by measures based on knowledge of their 

 habits. The webs of those that make nests may be 

 cut off and destroyed with the caterpillars, or (in the 

 case of the Small Ermine Moth) the chrysalids, within 

 them. Cocoons covered with eggs, as in the case of 

 the Common Vapourer Moth, may be searched for 

 and destroyed ; and, similarly, the rings of eggs of the 

 March Moth (Fig. 108), and of the Lackey Moth, 

 which resemble them in being laid in a band on 

 twigs, may be got rid of in some degree by careful 

 search, and pruning off the infested twigs where they 

 can be reached. But for the most part these and 

 various other means of prevention or remedy have 

 to be applied, not as broad measures of treatment, 

 but as special measures for each special attack, in- 

 volving necessarily special outlay. For these reasons, 

 that is, the pressing need which has long been felt of 

 having some kind of application at hand which is 

 cheap and sure in its action, and which can be bruuglU 

 to bear at once, ivhen required, on any or all sorts of 

 Moth-caterpillars together (whatever their various 

 natures or previous histories may have been), and 

 will kill the whole collection of ravaging hordes at 

 once, without damaging the leafage, the experiments 



