Report of the State Geologist. 681 



such branches as you can cut away, or do not crush. Every 

 tent found, whether on orchard or forest tree, should be 

 destroyed. 



Nearly akin to this insect is 



The Forest Tent Caterpillar. 



Clisiocampa sylvatica, Harris. 



This caterpillar, for some years past, has been destructive 

 to forest trees as well as apple orchards, yet what I have 

 previously said will equally well apply to this species, only its 

 €ggs which surround the twig in the same manner, form a com- 

 plete cylinder, holding its full size from one end to the other, 

 uniform in diameter, and cut off squarely at each end, 

 while the egg masses of the other are oval rings, rounded 

 at each end of the mass. They are a more hardy species, 

 and after having stripped one tree of its leaves, will travel 

 in troops to another, ascend, and there make their home. 

 This can easily be prevented by putting tar or printer's ink 

 about the trunks of trees not infested. The habits of this 

 insect are not the same as those of the other. While they 

 spin a thread they do not form a tent between the branches, 

 but, resting upon the smooth side of the trunk or branch, 

 their thread lies between and beneath them, so it does not 

 make much show. Thev feed nio;ht and morn, sometimes 

 in the night, and are more voracious than the former. 

 While the former appear almost every year, this species is 

 seldom plenty but a year or two at a time. They will 

 hardly be seen for three or four years, and then reappear in 

 abundance as l^efore. 



The reason for this seems to be that their natural ene- 



