The flatheaded apple tree borer is especially destructive of 
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 Australian-pine borer, Chrysobothris tranquebarica (Gmel- 
in), also commonly known as the mangrove borer, occurs in south- 
ern Florida and breeds in living mangrove and Casuarina trees. 
The adult is greenish-bronze in color 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 orna- 
mental or windbreak trees is often severe. The removal and de- 
struction 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 flowing pitch to coagulate into large pitch masses 
(fig. 49). Older larvae feed in the wood. The winter is spent in 
the larval stage. In the spring of the third year, the larva con- 
structs 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. 
F-519916 
FIGURE 49.—Pitch mass on red 
pine caused by feeding of the 
larva of Chrysobothris orono. 
