the thick inner bark. Mature larvae construct cells in the outer wood during late 
summer where they spend the winter and pupate the following spring. There is one 
generation per year (402). 
The flatheaded appletree borer is especially destructive to newly planted trees 
and trees weakened by drought, defoliation, or other adverse factors. Young trees 
are often girdled and killed; larger trees are often seriously injured through the loss 
of large patches of bark over mined areas. Maintenance of tree vigor, wrapping the 
trunk with high-grade wrapping paper or burlap when trees are planted or pruned, 
and shading the south side of newly planted trees are recommended control 
practices. 
The Australianpine borer, C. tranquebarica (Gmelin), also commonly known 
as the mangrove borer, occurs in southern Florida and breeds in living mangrove 
and horsetail casuarina trees. The adult is greenish bronze and about 12 to 17 mm 
long. Eggs are deposited in the spring under roughened areas of bark. The larvae 
feed beneath the bark until nearly full grown, and then enter the wood to construct 
pupal cells. Damage to ornamental or windbreak trees is often severe. The removal 
and destruction of infested wood during fall and winter is helpful in control. 
Chrysobothris orono Frost attacks living red and jack pines in the Lake States. 
Eggs are laid singly on the trunk. The larvae feed in the bark during the first three 
instars, excavating cells and causing pitch to coagulate into large masses (fig. 121). 
Older jiarvae feed in the wood. The winter is spent in the larval stage. In the spring 
of the third year, the larva constructs an L-shaped cell, plugged with frass and wood 
chips, where pupation occurs. This species is seldom injurious, although its injury 
may remain in the bole as a defect after the wounds have healed. 
Several other species of Chrysobothris also occur fairly commonly in eastern 
forests. Some of these and some of their more important hosts are as follows: C. 
F-519916 
Figure 121.—Pitch mass on red pine caused by feeding 
of the larvae of Chrysobothris orono. 
282 
