_ 
The More Important Apple Insects. “7 
of an inch in length (fig. 156). Later the adult beetle gnaws its way through the 
bark and escapes through the small roundish exit hole (fig. 157) which has a 
diameter of about one-fourth of an inch. The female 
beetles (fig. 15S) are approximately two-thirds of an inch 
or more in length, while those of the other sex are some- 
what smaller. The brownish beetles have white sides and 
are most easily distinguished from the roundheaded apple- 
tree borer by the two white spots on each wing-cover and 
the white stripe on each side of the thorax. The beetles 
feed upon the tender bark of twigs, on leaf petioles, and 
also to a slight extent upon the leaves (fig. 159). The 
creamy white eggs (fig. 160), which soon become brownish, 
are inserted between the bark and the wood (fig. 161). 
Upon hatching the larva commences to gnaw out its bur- 
row, and if two larve hatch from eggs placed in the same 
repository they usually feed in opposite directions, result- 
Fic. 160.—Egg of 
é b spotted applc-tree 
ing in a more or less complete girdling of the branch. By borer, Enlarged. 
the end of the first season, or early in the next, the larva 
usually tunnels into the heartwood, and in the 
case of a borer with a 2-year cycle completes its 
pupal chamber at the close of the second season. 
The general life cycle varies from 2 to 4 years, de- 
pending on latitude and other conditions, with 
perhaps 38 years as the common period over most 
of the area of its distribution. 
In all probability many of the beetles. are killed 
previous to oviposition by means of the poison 
sprays employed against the codling moth and 
other chewing insects. In infested trees the larval 
tunnels can best be located~by searching for the 
sawdust castings or the infested wood, as indi- 
cated by its cankerous appearance. The borers 
when found should be killed with a knife, wire, or 
other suitable tool. Where branches are heavily 
infested they should be pruned off and destroyed. 
As a further aid in reducing injury. it is advis- 
able to cut down all of the wild host plants grow- 
ing in the neighborhood of the orchard, thereby 
destroying natural breeding grounds. 
APPLE CROTCH-BORER.™ 
The apple crotch-borer is of comparatively 
minor importance, although if searched for it 
may frequently be found in the roughened 
erotches of apple trees (fig. 162) or in bark 
wounds caused by other borers, by diseases, im- 
Fic. 161.—Chain of punctures 
of spotted apple-tree borer ae ; 
in apple bark accompanying plements, etc. The injury is caused by the larvze 
oviposition scar. Eggs were (fig. 163), which feed in the inner bark or occ¢a- 
deposited at broad place 
; sionally make shallow burrows into the sapwood. 
about center of chain. 
Their presence results in slight injury to the 
tree, except in instances of severe infestation, when the affected part may 
be killed or in extreme cases the tree itself may die. The same trees 
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6&8 Aegeria pyri Harris; also known as the pear borer. 
