THE LEAF ROLLERS AND THE LEAF MINERS 307 



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it begins in a single leaf; but in its 

 later stages, it fastens together two or 

 three of the terminal leaflets in order 

 to gain more pasturage The Httle 

 silken tent ropes which hold the folded 

 leaves are well worth study with a lens. 

 They are made of himdreds of threads 

 of the finest silk, woven from a gland 

 opening near the lower lip of the 

 caterpillar. The rope is always larger 

 where it is attached to the leaf than 

 at the center, because the caterpillar crisscrosses the threads in 

 order to make the attachment to the leaf larger and firmer. Unroll 

 a tent carefully, and you may see the fastenings used in an earHer 

 stage, and may even find the first turned-down edge of the leaf. 

 However, the center of a leaf roller's habitation is usually very 

 much eaten, for the whole reason for making its little house 

 is that the soft-bodied caterpillar may eat its fill, completely 

 hidden from the eyes of birds or other creatures. When it first 

 hatches from the egg, it feeds for a short time, usually on the under 

 side of the leaf; but when still so small that we can barely see 

 it with the naked eye, it somehow manages to fold over itself 

 one edge of the leaf and peg it down. The problem of how so small 

 a creatvire is able to pull over and fold down or to make in a roll 

 a stiff leaf is hard to solve. I, myself, believe, it is done by making 

 many threads, each a little more taut than the last. I have 

 watched several species working, and the leaf comes slowly to- 

 gether as the caterpillar stretches its head and sways back and forth 

 hundreds of times, fastening the silk first to one side and then to 

 the other. Some observers believe that the caterpillar throws 

 its weight upon the silk, in order to pull the leaf together; bat 

 in the case of the sumac leaf-roller, I am siu"e this is not true, as 

 I have watched the process again and again vmder a lens, and 

 coiild detect no signs of this method. Many of the caterpillars 

 which make rolls, change to small moths knowii as Tortricids. 

 This is a very large family, containing a vast nimiber of species 

 and not all of the members are leaf-rollers. These little moths 

 have the front wings rather wide and more or less rectangular. 

 The names of these moths end with "ana;" the one that rolls 



