12 Bulletin 124. 



c, plate I. On May ist, Messrs. Yeomans, Walworth, N. Y., 

 wrote me that the insects had also done the same thing in their 

 orchard. It seemed hardly possible that they had finished their 

 destructive work thus early, and were preparing to undergo their 

 further transformations. Cases were detached apd examined 

 every day, and no explanation was found for the curious preceed- 

 ure until the fourth or fifth day. Then the cases began to move, 

 and at each spot where a case was fastened there remained at- 

 tached to the bark the anchor, a minute cup or button of silk, and 

 on each of these we found the cast skin of the head of the cater- 

 pillar. This meant that the cases had been fastened to the twigs 

 so that the caterpillar could shed off, undisturbed, its old skin 

 that had become too small, and could then come forth clad in a 

 new and elastic skin that had been growing under the old one. 

 All caterpillars moult or shed their skin several times ; it is the 

 way they grow. Doubtless the pistol-case-bearer moults at least 

 three or four times during its life as a caterpillar, and perhaps in 

 the way just described. Apparently the moult which occupied 

 the last four days of April, 1896, was the last one ; its occurrence 

 in the heighth of the feeding season rendered it quite conspicuous. 

 Its feediyig habits on the flowers and leaves. — Beginning on the 

 swelling buds, as described on a previous page, the case-bearers 

 continue their destructive work on the opening leaves and flowers. 

 They now feed quite difierently from the cigar-case-bearers, which 

 mined out the tissue between the two skins of the leaves. The 

 pistol-case-bearers either devour the whole leaf or all of it but the 

 lower skin and veinlets, thus skeletonizing it, as shown, natural 

 size, in figure i . The caterpillar never leaves its case, but pro- 

 jects its body out far enough to obtain a good foothold and then 

 begins to eat, holding its case at a considerable angle from the 

 leaf. The cases are thus not attached to the leaf, but move with 

 every motion of the caterpillar as it feeds. While they feed freely 

 on the leaves, they seem to show a decided preference for the 

 opening flowers ; this habit makes the insect especially destruc- 

 tive. In the upper part of figure a, plate 2, is shown a cluster of 

 flowers which has sufiered severely from the attacks of this little 

 foe. It works mostly on the petals of the flowers, but often eats 

 into the stem and soon kills it. Thousands of prospective fruits 



