The black turpentine beetle is found from New Hampshire south to
Florida, and from West Virginia to east Texas. It is a particularly
serious pest in the Gulf States where recent outbreaks have killed large
acreages of timber. Attacks have been observed on all pines native to
the Southeast, and also on red spruce.
[Illustration: Life stages of the black turpentine beetle: adult,
callow adult, pupa, larva and eggs.]
This is the largest of the southern bark beetles, varying in length from
⅕ to ⅓ of an inch, or about the size of a raisin. They are reddish-brown
to black in color. The beetle attacks fresh stumps and living trees by
boring through the bark and constructing galleries on the face of the
sapwood where eggs are laid. Fifty to 200 eggs are laid in a group. They
hatch into white larvae which feed on the inner bark. The beetle may
girdle trees when several broods occur at approximately the same height,
killing the trees. From 70 to 90 percent of the trees attacked by the
beetle die.
After the larvae complete their development, they pupate. Adult beetles
emerge and infest more pine trees. The entire life cycle takes from 2½
to 4 months, depending on temperature. In the insect’s southern range
there usually are two generations and part of a third each year. In its
northern range, the third generation does not develop; consequently the
beetle is not a serious pest there.
Weather is probably the most influential factor in regulating the
numbers of this insect. During outbreaks the removal or chemical
treatment of infested trees helps to keep losses to a minimum.
[Illustration: Close-up of black turpentine beetle pitch tubes.]