The best indicators of red turpentine beetle attack on pines
are: large pink-white pitch tubes on the lower bole; accumulations
of reddish brown sawdust at the base of the tree and in bark crevices;
and accumulations of cream to pink colored crystallized resin granules
at the tree base. The egg galleries under the bark are fairly wide
and linear to irregular in shape. Galleries extend downward from
the entry hole 7 cm to 1 m and may even extend into large roots.
Adults are reddish brown, cylindrically shaped beetles approximately
8 mm in length. Larvae are white, legless grubs.
The number of generations varies from 1 to 2 years in the
coldest portions of its range to 2 to 3 generations per year in
the warmest areas. Attacks are made in the lower bole of pines.
Attacks occur throughout warm weather but peak by midsummer. These
beetles often attack trees scarred by fire.
Effects: Through repeated attacks this
beetle can sometimes kill trees; however, more often it weakens
trees, predisposing them to fatal attack by other bark beetle species.
In successful attacks, a patch of bark ranging from a few square
cm to a square m or more may be killed. Red turpentine beetles frequently
colonize fire-scorched ponderosa pines.
Similar Insects and Diseases: This beetle
is distinguished from other bark beetles by the large size of the
pitch tubes, galleries and the beetle itself.