572 Agricultural Experiment Station, Ithaca, N. Y. 



ten in 1872, states that the insects were very common and de- 

 structive in the Routh, where the worms made their appearance 

 during April and May, in the latitude of Mobile and New Or- 

 leans. In 1877, the caterj)illars appeared in large numbers in the 

 orchards in the vicinity of Lockport, N. Y. Professor Comstock 

 investigated this outbreak and found that much damage had 

 been done in many apple and })ear orchards. In the case of 

 one young pear orchard, he counted the Avhole number of pears 

 on several trees and found that 45 per cent, of them had been 

 injured by the caterpillars. It was noted that this orchard was 

 adjoining a forest from which the insects may have spread. It is 

 a curious fact that although these green fruit worms were so 

 numerous in 1877, they seem not to have attracted attention 

 again anywhere in New York state until 1896, nineteen years 

 later. In 1888, quite a number of apples were found apparently 

 injured by these caterpillars in Maine. 



The adult insects — the moths — are not uncommon in Canada 

 and the northern and eastern portions of the United States; and 

 the insects have been recorded as injurious in the South and as 

 far west as Nevada. Collectors report the moths as common in, 

 and we have this year received the caterpillars from, several 

 widely separated localities in New York state. Thus, these fruit- 

 eating caterpillars are very generally distributed throughout 

 Canada and the United States. 



Their Life History. 



The green fruit worms do most of their damage to the young 

 fruits in May, but some of them continue working until nearly 

 the middle of June. During the first week in June most of the 

 caterpillars get their full growth and then burrow into the soil 

 beneath the trees to a depth of from an inch to three inches. 

 Here they roll and twist their bodies about until a smooth earthen 

 cell is formed. Most of them then spin about themselves a very 

 thin silken cocoon; some spin no cocoon. Within the cocoon or 

 the earthen cell, the caterpillar soon undergoes a wonderful 

 transformation which results in what is known as the pupa of the 

 insect. One of these dark brown, lifeless-looking pupfe is 

 shown, natural size, at c, plate 2, and enlarged on the same 



