The More Important Apple Insects. 71 
ROUNDHEADED, APPLE-TREE BORER.” 
The roundheaded apple-tree borer, which is now widely distributed through- 
out the eastern half of the United States, is the most important of the apple- 
tree borers and is responsi- 
ble for the killing of many 
young trees. The injury is 
caused by the larve or 
borers (fig. 144) feeding 
upon the inner bark and 
wood, several of which may 
often be found in the same 
tree. Infested trees may be 
detected by the reddish cast- 
ings which are forced out 
through small holes near 
the base of the tree (fig. 
145), and often there will be 
small oval holes in the trunk 
some 8 or 10 inches from 
the ground from which the adult has already escaped (fig. 146). The more im- 
portant food plants include the apple, quince, pear, serviceberry, wild crab, 
and mountain ash. 
The winter is passed in the larva stage within the burrow near the base of 
the tree, though the larve that are to transform in the spring to the adult 
stage are to be found in the pupal chamber. The larva, when mature, measures 
about an inch in length, is legless, and has a broad thorax with a relatively 
small dark head. The pupa (fig. 147) is yellowish white, with small spines 
on its back. Pupation occurs about the blooming 
time of the apple; and later, through further 
transformation, the adult (fig. 146) appears. The 
beetle measures about three-fourths of an inch in 
length, has long antennz, and the wing covers are 
light brown with two longitudinal white stripes, 
which also are found on the thorax and head. 
When ready to issue during late spring and early 
summer, the beetle cuts its way through the bark, 
leaving an exit hole as described. After emerg- 
ence it spends considerable time among the 
branches of the trees, where it feeds to a certain 
extent upon the bark and also on the midribs and 
stems of the leaves. The females (fig. 148) 
usually begin to oviposit within a week or 10 
days after emergence. The rusty brown eggs, 
about one-eighth of an inch in length (fig. 149), 
are laid in small cuts made by the beetle with its 
jaws on the trunk near the base of the tree. Usu- 
Fig. 142.—Adult periodical cicada. 
Enlarged. 
ois EB Study ress 
Fig. 143.—Snowy tree cricket, 
female, and section of twig 
showing egg and egg punc- 
ture. Enlarged. 
usually cut their way into the sapwood, where the winter is passed. 
spring the feeding is resumed, the larvee penetrating the solid wood. 
ally two or three eggs are deposited by a beetle 
at one time on the same tree. Upon hatching the 
larve burrow into the inner bark and feed 
thereon until late in the season, when they 
In the 
Some 
individuals have a life cycle of 2 years, while others have one of 3 years. 
59 Saperda candida Fabricius. 
