REMARKS ON THE BAG-WORM THYRIDOPTERYX 

 EPHEMER^FORMIS. 



By C. V. RILEY. 

 (Read April 13, 1883.) 



Having been asked by members of the Society quite frequently 

 of late to explain the facts in relation to the common bag-worm, 

 and as the facts are somewhat puzzling to the uninitiated, I have 

 thought it of sufficient interest to state them. 



FIG. i. THYRIDOPTERYX EPHEMER^EFORMIS : a, larva; b, male chrysalis; 

 c, female moth; d, male moth; <?, follicle and puparium cut open to show eggs; 

 /, full grown larva with bag ; g, young larvae with their conical upright coverings ; 

 all natural size. 



The bags, as they hang from the trees at the present time, and 

 as illustrated by these specimens which I now exhibit, will be found 

 to consist of very strong silk, and, while a large proportion of them 

 contain little or nothing, many of them have within a brown shell, 

 known as the puparium, and containing a large number of soft, 

 yellowish eggs, interspersed with fulvous down. In a few days 

 these eggs will hatch, the young worms from them will crawl out 

 of the bags and disperse over the tree, covering themselves with 



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