358 



NEW YORK STATE MUSEUM 



NOTES ON VARIOUS INSECTS 



Pyralis costalis Fabr. 



Clover-hay caterpillar 



Numerous examples of the larvae of this insect, which weie noticed in 

 detail in my nth report, p. 145-51, were brought to my office by Mr H. 

 S. Ambler, of Chatham, N. Y. They were found swarming in the 

 cow stable of Mr G: C. Herschart, North Hillsdale, April 8, having 

 probably emerged from a mow of clover nearby. It is probable that 

 their feeding place had been disturbed by the hay containing them being 

 fed to the stock, as they were only about two-thirds grown and are not 

 known to leave their food voluntarily except for pupation. 



The larvae were placed in a cage and provided with grass, on which 

 they fed readily, eating both green and dried blades. They manifested a 



gregarious habit in spinning their 

 silken larval cases in close proxi- 

 mity to one another. So marked 

 was this, that most of the larvae 

 would usually be found in about 

 one-fourth of the material in the 

 cage. The places selected for 

 their retreats rapidly became filled 

 with frass and speedily molded on 

 account of the gathering damp- 

 ness. This gregarious habit is 

 undoubtedly of benefit, as it ren- 



moth, PYRALIS costalis; 1,2, larva; 3, cocoon ; ders their food moist and more 

 4, pupa; 5, 6. moth; 7, larva within the web palatable, sincc they dislikc food 



(from Riley). ' ' -' 



containing no moisture and are 

 apparently unable to thrive when it is perfectly dry. 



April 19 a number of the larvae molted for the last time and othtrs 

 were observed casting their skins as late as May 4. A month later the 

 pretty moths began to appear, and continued to emerge from time to time 

 for about two weeks. Since Prof Webster obtained a second brood in 

 Ohio from moths emerging in June, it seems most probable that the insect 

 has normally two generations annually in this vicinity, the moths of the 

 second appearing about the middle of August, the same as in Ohio. 



1 W d 



Fig. 2 The clover-hay caterpillar and gold-fringe 



