43 
In about a week the beetles bore out from their burrows. The result 
is 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-BORER. 
(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, d. 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 antenne. There are usually four pairs of lees, 
but m 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 (Bryobia pra- 
tensis Gar.). They rarely do damage to fruit trees in the East, but 
feed on clover and similar plants. 
THE PEAR-LEAF BLISTER-MITE. 
( Briophyes 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 
