Southern Pine Beetle

Southern pine beetle Anthrenus flavipes, are slightly larger and rounder than the varied carpet beetle adult. Coloration and markings of the adult are highly variable, but they generally have a mottled appearance due to white and dark yellow to orange scales interspersed with black spots on their elytra.

Southern pine beetle is short-legged, stout, and about 1/8 inch long. The fore part of the head is notched, and the hind end of the body is rounded. Mature beetles are dark reddish-brown with slightly lighter wings. The egg is pearly white and just visible to the naked eye. Larvae grow to about 1/8 inch long. They are legless grubs with glossy, reddish-brown heads and wrinkled, curved bodies. The pupa is delicate, white, and shaped somewhat like the adult.

Life Cycle: Southern pine beetles are 1/8 inch long and have cylindrical, reddish-brown to black bodies. There are several overlapping generations in Kentucky each year. All stages of the life cycle (egg, larva, pupa, and adult) can be found in trees at any time. Development is faster in the summer (26 days) than during the winter (54 days). Following a period of relative inactivity in the winter, adults begin to fly again in the spring.

Females land 6 to 30 feet above the ground on mature trees and bore into the bark. There, they create galleries (shown left) in which they mate and lay eggs. The yellowish white, legless grubs feed in the inner bark, enlarging their tunnels as they grow. Mature larvae move to the outer bark and create a cell in which they pupate. New adults chew through the bark, leaving small, clearly visible, open exit holes. Adult emergence may continue for an extended period of time.

Prevention: Infestations often start on stressed and injured trees in older-aged dense stands, so cultural practices that promote healthy trees will reduce the frequency and severity of infestations. During outbreaks, avoid pruning and other activities that produce terpenes and attract dispersing beetles. If nearby trees are infested, homeowners may wish to have a pest control service apply insecticide to their uninfested trees.

The insecticide should be applied on dry bark, to the point of runoff, from at least the base of the crown down to the ground line. If Ips beetles are abundant and aggressive, then the upper stem and larger branches should also be treated. When carefully and properly applied, these insecticides dry in a few hours and pose little danger to birds, squirrels, or humans.

Control: It is very important to aerial survey for Southern Pine Beetle activity in the spring and periodically in the summer. This must be followed up by immediate ground checking. Quick action to protect a stand of trees is essential in trying to suppress the infestation. Active infestations can be halted using several cultural tactics. One is to salvage all old and new attacks, plus a buffer strip of unattacked trees in the direction the infestation was spreading.

Size of buffer strips should range between 6 to 35 meters, depending on the number of fresh attacked trees present. Another option, for pre-commercial sized timber or hard to get to areas is to cut the timber down and leave it at the site. These trees should be felled toward the center of the infestation. The brood in the felled trees will not survive very well under the bark due to solar heating at the forest floor.