The More Important Apple Insects. 15° 
sues adjacent to the old. While this insect seldom produces visible castings, 
its presence nevertheless can be frequently detected by the darker and slightly 
depressed bark over the area in which the borers are feeding. The flat-headed 
borer is native to this country and is generally distributed in important fruit- 
growing regions. It feeds upon a wide variety of hosts, including the apple and 
other deciduous fruit trees as well as many forest trees. 
The winter is passed in the larva stage within a pupal chamber formed at 
the end of a gallery which extends into the wood to a depth of an inch or 
more. In the South, however, the pupal chamber is generally constructed 
between the wood and the bark. The full-grown larva measures about an inch 
in length; is legless; haS a broad, flat head, which has suggested its common 
name, and is pale yellow. The larva transforms to a yellowish pupa in the 
spring, and issues as an adult shortly after the apple blooms. The adult 
(fig. 153) is a rather flat beetle, having a dark metallic color, and measures 
about a half inch in length. The beetles are active and frequent the sunny side 
of the trees. After mating, the females search the bark for a crack or open- 
ing in which to deposit their eggs. The eggs (fig. 154) are about one- 
fiftieth of an inch long, ribbed, and yellowish. They hatch in the course of 
2 or 3 weeks and the larvee begin to gnaw their way beneath the bark, where 
they feed and develop, provided the trees are not in good health. The borer 
is unable to thrive in vigorous trees having a strong flow of sap, although 
it will Sometimes continue to live in a dwarfed condition until the tree is 
weakened by another agency, thus giving the borer a chance to grow, in which 
case the life cycle may be extended to 2 years or more instead of the normal 
1-year period. 
The most practical means of dealing with this insect is to keep the trees 
resistant by proper cultivation, fertilization, pruning, and any other orchard 
practice that will maintain the tree in an upright, thrifty, and healthy con- 
dition. When borers are found, the most satisfactory remedy known is to 
cut them out with a knife, care being taken not to injure the trees. 
SPOTTED APPLE-TREE BORER.” 
The spotted apple-tree borer is sometimes of considerable importance in cer- 
tain localities. Its injuries ame somewhat similar to those of the roundheaded 
apple-tree borer, except that it more commonly works in the upper parts of 
the trunk and branches, giving the trees an unthrifty and sickly appearance. 
When abundant it frequently kills young trees and branches of older trees. 
The presence of this insect is most readily detected by means of the sawdust- 
like castings which are pushed out of the burrows or by the cankerous appear- 
ance of the infested wood. The general habitat of this native beetle ranges from 
Canada through the New England and Middle Atlantic States westward to 
Iowa, and it has also been reported from Texas. It has attracted most atten- 
tion in parts of Michigan, Iowa, and Wisconsin. In addition to the cultivated 
apple, this insect is recorded as infesting the wild crab apple, thorn trees, and 
Juneberry. 
The winter season is spent in the larva stage within the burrow, and during 
the winter preceding its transformation to the adult the insect is to be found 
in the pupal chamber at the upper end of its gallery, usually in the heartwood 
of a branch or small trunk. The mature larve or grubs (fig. 155), are legless, 
about an inch or slightly more in length, whitish, with brownish head and black 
jaws. In the spring the grubs change to yellowish white pup, about two-thirds 
& Saperda cretata Newman. 
