Importance. - Pine colaspis beetles are commonly found throughout the southeast, but are more prevalent in the Gulf states. They prefer slash pine but have been found on other southern pines, baldcypress, and ornamental spruce. Pine colaspis beetles are not serious forest pests. However, feeding damage caused by large beetle populations can cause a spectacular browning effect.
Identifying the Insect. - Adults are elongate-oval, convex, and rusty yellow or brown with green reflections. These moderate sized beetles are about 1/4 inch (6 mm) long. Full grown larvae are sparsely covered with short hairs. Small clusters of longer hairs occur at the lower outer edges of each body segment.
Identifying the Injury. - Adult beetles chew the edges of needles, producing irregular, sawlike edges that turn brown. Later the entire needle may die, causing the whole tree to become brown as though scorched by fire. Occasionally, only the tips of the needles show signs of injury. Trees 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.
Biology. - There is only one generation per year. Eggs are laid on herbaceous undergrowth during the summer. Larvae emerge, feed on roots of grasses and other vegetation, and overwinter in this stage. The larvae pupate in the spring; adults emerge in early summer.
Control. - Under forest conditions, no control measures are recommended. On ornamentals and shade trees, insecticides can be used to prevent unsightly damage.