INSECTS INJURIOUS TO THE APPLE AND PEAR 563 



The larva is a footless, whitish grub a half inch long when full 

 grown with a hump-backed appearance due to the enlargement 

 of the anterior abdominal segments, which prevents the larva 

 from straightening out. The beetles injure the fruit by puncturing 

 it for feeding and for the deposition of eggs, causing it to become 

 dimpled and gnarled as does the plum curculio, and the larvae feed 

 within the fruit, mining the flesh, in which they undergo their 

 complete development. 



Control. Thickets of wild crab or hawthorn trees should be 

 destroyed wherever near an orchard, for the beetles will breed in 

 their fruit and then migrate to the orchard. Jarring as for the 

 plum curculio may be practiced on young trees, and spraying as 

 for that species will doubtless largely reduce the injury. Usually 

 this insect is not sufficiently injurious to warrant special treatment 

 where its native food-plants are not overabundant near the 

 orchard. 



The Pear Leaf Blister-mite * 



The pear leaf blister-mite has long been known as a pest of pear 

 foliage wherever the pear is grown, and has similarly affected apple 

 foliage in Europe, but only in recent years has it become a serious 

 pest of apple foliage in New York, New England, Ontario and 

 Pennsylvania. Just why it should suddenly become an apple 

 pest after having occurred in this country for years without 

 noticeably injuring it is a mystery, though dry seasons may 

 possibly be accountable for it. 



The work of the mites is recognized by reddish blisters forming 

 on the young foliage, which later turn blackish and have a corky 

 texture. Badly affected leaves drop, so that a tree is often largely 

 defoliated, and where the mites are abundant they attack the 

 young fruit. 



The mites are not true insects, as they belong to the same class 

 as the spiders, scorpions, and ticks. One of the more common 

 larger mites is the red spider of greenhouses, which affects flower- 

 ing plants, vegetable crops, and fruits of all sorts. These little 

 blister-mites are of microscopic size, only 1-100 to 1-200 inch in 

 length, so that they can be seen only with a lens, and must be 



* Eriophyes pyri Pgst. Class Arachnida. Order Acarina. Family 

 Eriophyidce, with which are associated several nearly related species with 

 similar habits. See Parrott, Hodgkiss and Schoene, Bulletins 283 and 306, 

 N. Y. Agr. Exp. Sta. 



