APPLE INSECTS — BUDS AND FOLIAGE 117 



sites which prey upon it in the egg, hirval and pupal stages. 

 This control is so effective that for many years the insect is 

 rarely noticed. Then the time comes when, owing to the rarity 

 of the host, the parasites are reduced in numbers to a still 

 greater degree, and the caterpillars again have an opportunity 

 to multiply unchecked. The resultant outbreak may be very 

 serious, as was the case in New York and New England in 1897 

 and 1899. Four species of parasites have been reared from 

 the egg and over 20 from the larva and pupa. Birds and toads 

 also feed on the caterpillars to a considerable extent, and many 

 nearly full-grown larvae die of a bacterial disease. 



Means of control. 



In orchards which are well sprayed as for the codlin-moth 

 and curculio, tent-caterpillars are rarel}^ troublesome. The 

 young larvae are readily poisoned by either Paris green or 

 arsenate of lead. On peach and plum, which are not commonly 

 sprayed with an arsenical, it will pay to keep careful watch for 

 the conspicuous egg-rings while pruning. They should be re- 

 moved and burned. 



The nests may be destroyed l^y wiping out with the hands. 

 It should be done while the caterpillars are at home, which is 

 usually the case during stormy weather and in the heat of the 

 day. Burning out the nests is not to be recommended as there 

 is danger of injuring the tree ; burned areas in the bark often 

 develop cankers that may destroy the whole branch. 



The wild cherry is the favorite food-plant of this insect. 

 When growing along roadsides and fences and in other waste 

 places these trees are usually worthless and should be cut down, 

 as they serve as centers of infestation for near-by orchards. 



References 



N. Y. (Geneva) Agr. Exp. 8ta. Bull. 152, pp. 279-297. 1898. 



Conn. Agr. Exp. Sta. Bull. 131). 1902. 



N. H. Agr. Exp. Sta. Tech. Bull. 0. 1903. Parasites. 



