284 



State Horticultural Society. 



6 g. As the larvae become larger, they continue to enlarge this case or 

 bag, and finally it becomes so heavy that it droops, and the larvae then 

 carry it around suspended from the leaves and twigs upon which they are 

 feeding or crawling. A full-grown larva is shown, natural size, carry- 

 ing its case about in Fig. 6 f. 



The appearance of the cases will differ somewhat according to the 

 plant upon which the larvae are feeding, since they use portions of the 

 leaves of that particular plant to help construct the cases. The larvae 

 never leave the cases, but are provided with little hooks on the interior 

 end of the body which holds the case and prevents its falling off, but 

 when pulled out of their cases present the appearance as shown in Fig. 

 6a. The larvae become full grown the last of July, and then fastens 



Fig. 



a, Bag-worm of Pear Tree; d, moth; e, eggs; /, worm ia bag. 



the cases securely to the twigs by means of silk threads, retire within 

 them, and there transform to' pupae. 



The adult male, as soon as it emerges from the cocoon, is a clear- 

 winged moth, about one inch across its expanded wings, with a trans- 

 parent grayish color to the wing, and a very dark body. A very good 

 illustration is shown, natural size, in Fig. 6 d. These males fly about 

 at will. The adult female is interesting on account of the fact that it 

 never leaves the cocoon, or bag. When they transform from the pupa 

 stage to an adult, they are not only entirely wingless but are also with- 

 out legs. They deposit their eggs inside of the cast pupa skin, which is 

 within the case or cocoon, and after finishing the egg-laying process, 

 wriggle their way out and drop to the ground, where they die. These 

 eggs remain in the bag over winter. An adult female is shown in Fig. 

 6 c, natural size. 



These bag-worms sometimes do considerable damage by eating the 

 leaves off of various fruit, shade and forest trees, but are usually re- 



