43 



In about a week the beetles bore out from their burrows. The result 

 iw that the bark is loosened and sometimes the tree girdled. When 

 they attack peach there is a great exudation of sap and a consequent 

 weakening of the tree. There are two and probably three broods a 

 year, but as they start at different times the broods become mixed. It 

 attacks all kinds of fruit trees, and prefers trees that are dying, 

 diseased, or weakened by other insects, but healthy trees are not 

 exempt. 



THE APPLE TWIG-BOREE. 

 (Amphicerus bicaudatus Say— fig. 41. ) 

 In the fall and winter the adults of this insect bore into twigs of 

 apple and other fruits, as indicated in fig. 41, ^. Cutting back from 

 this hole one will find this borer in the adult state— a cylindrical brown 

 beetle about one-third of an inch long. These holes are their hiber- 

 nating quarters. In the spring the insect works in grape canes, caus- 

 ing the withering of new shoots, as indicated at fig. 41,/. In the 

 spring the beetles emerge and insert their eggs in diseased or dying 

 twigs of grape, maple, or other plants; the larva bores through the 

 center of the twig until fall, when it pupates. The beetle issues in late 

 fall, and there is but one brood a year. It attacks chiefly appie, pear, 

 peach, plum, and grape. 



ACARINA (MITES). 



The mites are not insects, although related to them. They are rec- 

 ognized by lacking the distinction between the head and thorax and 

 by the absence of antennfe. There are usually four pairs of legs, 

 but in the pear-leaf blister-mite and its allies there are but two pairs. 

 Besides the pear-leaf blister-mite, which is treated below, there are 

 often found upon fruit trees in winter numbers of tiny, roundish, red 

 eggs. These belong to a mite known as the clover mite {Bryoiia pra- 

 tensis Gar.). They rarel}' do damage to fruit trees in the East, but 

 feed on clover and similar plants. 



THE PEAR-LEAF BLISTER-MITE. 



( Eriophyes pyri Scheut. ) 



This is a microscopic mite about one one-hundred and fiftieth of an 

 inch long, with a slender body provided with two pairs of legs near 

 the head end. Although each mite is so small as to do little damage 

 of itself, it may become the parent of a vast assemblage capable of 

 doing a great amount of injury. During the winter the mites remain 

 hidden between the bud scales. Early in spring the mites move to 

 the young unfolding leaves, eat through the under surface, and feed 

 on the interior substance of the leaf. Here the mites increase a thou- 

 sandfold. Some of these mites move out to form new galls, until a 



