PEMPELIA HOSTILIS. 277 



from a brown curled aspen leaf to a living green one. 

 On picking the dead leaf and nncurling it, I saw 

 exposed on its surface a silken tube, at once sugges- 

 tive of the work of a Knothorn, and this supposition 

 became almost a certaint}^ when the little grey larva, 

 after some persuasion, was prevailed on to show 

 itself. For the rest of the afternoon, I had, as may 

 be supposed, eyes for nothing but dead or dying aspen 

 leaves, and the result was two more nests. I call 

 them nests because I subsequently found that with one 

 exception, in which instance only a single larva was 

 present, the leaves were occupied by two or even three 

 larvae living together, each in its own gallery, but with 

 the galleries closely joining or even interlacing. The 

 larvae at this time were very young, and considering 

 the choice they had made (in the one case of a dead 

 leaf, in the other two of the old tenements of other 

 larvae), might readily have been overlooked ; but it 

 was quite a different matter when I found, later in the 

 month, a fourth nest containing two nearly full-grown 

 larvae. As in the others, so there was here, the 

 nucleus of two half-dead yellow leaves, but from these 

 were stretching in all directions bands of silk to the 

 adjacent fresh ones, which had been freely eaten, 

 drawing them together, and thus making a large and 

 conspicuous object. I sent Mr. Buckler two of the 

 larvae, and am greatly indebted to his kindness for the 

 description of them given above ; unfortunately, both 

 proved to be stung. Mine, when full-fed, left their 

 nests. They spun up (four of them) in rolls of paper, 

 and changed to pupae at once. Being anxious to see 

 the moth, I forced one early in the spring, and was 

 punished with a very bad cripple ; the others, left to 

 themselves, produced fine specimens in June. 



The question arises — which selects the site of the 

 nest? Does the parent moth lay her eggs on these 

 old leaves, or do the larvae wander about till they find 

 them ? In favour of the former is the fact that more 

 than one larva is generally present ; nevertheless I 



