1920 J General Notes. old 



intention of destroying it, was empty of caterpillars, and usually had a 

 large round hole through the web. At this time the caterpillars were 

 still very small, less than half an inch long, and the nests were only a few 

 inches across. The majority of people do not notice these nests until 

 the caterpillars are full-grown, and their depredations on surrounding 

 foliage begin to be extensive. For that reason many were of the opinion 

 that there were none in the spring of 1917, and I have heard it stated that 

 a fungus disease destroyed them in 1916. My observations go to show 

 that they were still abundant early in 1917 and that they disappeared 

 that year when only half -grown. A fungus disease may have had some- 

 thing to do with it, but a large part of the credit, according to my observa- 

 tions, goes to birds, at least in the vicinity of Norwalk. 



It is generally known that this caterpillar is immune from the attacks 

 of all birds but the Cuckoo because of its long hairs. It is my opinion 

 that when the caterpillars are small, and the hairs decidedly shorter, 

 that birds can eat them in case of necessity. The spring of 1917 was late 

 and cold. After the middle of May came the great flight of warblers, 

 thrushes and other insectivorous birds. Their arrival was coincident 

 with the disappearance of the tent-caterpillars. Other insect life was 

 scarce, and many birds died from cold or starvation. I actually observed 

 a Parula Warbler (Compsothlypis americana usneae) and a Yellow-breasted 

 Chat (Icteria v. virens) in the act of eating these caterpillars. The numer- 

 ous empty nests with holes in them, such as a bird would make with its 

 beak, were abundant evidence that what I had seen twice had taken place 

 many times. How effectually the birds did their work was shown by 

 the fact that only a single nest was observed in 1918 and none in 1919. — 

 Aretas A. Saunders, South Norwalk, Conn. 



