OBSERVATIONS ON HABITS OF FALL WEBWORM. 41 



Mr. Forbes replied that it varies too much to be expressed in aver- 

 ages. The migrants, however, seem to be more abundant in the 

 earlier generations. 



In the absence of the author, the following paper was read by Mr. 

 Osborn : 



OBSERVATIONS UPON THE MIGRATING, FEEDING, AND NESTING 

 HABITS OF THE FALL WEBWORM (HYPHANTRIA CUNEA DRU.). 



By E. W. Berger. Ph. D. (.T. II. U.). ColKinbu.^. Ohio. 



The majority of the observations upon which this paper is based 

 were made at Cedar Point, Sandusky, Ohio, during the past summer, 

 while I was at the Lake Laboratory of the Ohio State University. 

 The webs of the fall w^ebworm were abundant on all sides, and those 

 who had spent preceding summers at Cedar Point were under the 

 impression that the Avebworm was on the increase. After a few days 

 of casual observation it was decided to make a more careful study of 

 its habits and to determine if it is double brooded at that place. 

 While a few specimens pupated in the laboratory during the latter 

 part of Juh% none of them transformed into adults, and no positive 

 results were obtained in regard to a possible second brood. Acknowl- 

 edgment is due Prof. Herbert Osborn for his interest and for his gen- 

 erosity in placing valuable suggestions and facilities at my command. 



FOOD PLANTS. 



The worms were observed upon the following plants: Walnut 

 {JugJans nigra), choke-cherry {Primus vii^giniana) , common wild 

 black cherry {Primus serotina), willow {Salix sp.), elm {Ulmus 

 americarta) , boxw'ood {Cornus sp.), hackberry {Celt is ocridentalis) , 

 and wild grape {Vitis vulpina). The Avebs w^ere abundant every- 

 where upon the choke-cherry (PI. I, fig. 2) and the common wild 

 black cherry, some trees of the latter having nearly one-half of their 

 foliage destroyed. Willows were also nearly always populated with 

 a few or many broods. The few walnut trees (PI. I, fig. 1) present 

 were literall}' defoliated, and these w^ill be the subject of the next 

 topic. Elm, boxwood, and hackberry were frequently infested, but 

 never to the same extent as the previously named trees. In only 

 two instances did I observe the w^ebworm feeding upon the wild 

 grape, and then only when the grape leaves grew among the leaves of 

 willow and choke-cherry. I did not observe a single instance of the 

 worms feeding upon the poplars at the Point. This is quite at vari- 

 ance with previous observations. In Riley's bulletin upon the web- 



