Colaspis beetles are found throughout the Southeast, but are more common
in the Gulf states. They seem to prefer slash pine but have been found
on many of the southern pines. The pine colaspis beetle is not a serious
forest pest but feeding damage caused by large populations occasionally
produces a spectacular browning effect of the needles similar to that
caused by fire.
[Illustration: Adult pine colaspis beetle feeding damage on pine.]
The adult beetles chew the edges of needles to produce an irregular,
saw-like edge which turns brown. Occasionally only the tips of the
needles show signs of the infestation. Later, however, the entire needle
may die, causing the whole tree to become brown as though scorched by
fire. Trees that have been attacked do not die, and little or no growth
loss results. Attacks usually occur in early summer; by late summer the
trees appear green and healthy again. This pest is sporadic in its
occurrence and may not develop again in the same area for several years.
The adult female lays her eggs in the soil during the summer. Larvae
hatch and feed on roots of grasses and other vegetation, and overwinter
in this stage. The larvae pupate in the spring; adults emerge in early
summer to feed. There is only one generation a year.
Under forest conditions, no control measures are recommended for the
pine colaspis beetle. On ornamentals and shade trees, insecticides can
be used to prevent unsightly damage.