Pine Bark Beetles

G. Keith Douce, Professor of Entomology, The University of Georgia.

Cooperative Extension Service, College of Agricultural and Environmental Sciences, The University of Georgia Bulletin 1097, October 1993, 8 pp.

How to Recognize Infestations

Bark beetle attacks can be recognized by the presence of boring dust, pitch tubes on the outside of the bark, characteristic galleries under the bark, and beetle adults and larvae in the inner bark.

The presence of "pitch tubes" on the bark of trees is one of the best ways to identify bark beetle attack. However, pitch tubes may not form on stressed trees. Instead, attacks are indicated by the presence of brown boring dust. Use a good pair of binoculars to observe the middle and upper trunk and the base of large limbs for pitch tubes, since the initial attack of some bark beetles occurs at mid-trunk height or above. Observing the change in color of tree crowns is not a good method of locating beetle attacks since it may take several weeks or longer after the initial attack for the crowns to "fade" to a light yellowish-green or red.

Identification, Biology and Management Pine bark beetles belong to the Order Coleoptera, Family Scolytidae. The important pine bark beetles in Georgia are: The black turpentine beetle (BTB), Dendroctonus terebrans (Olivier) The southern pine beetle (SPB), Dendroctonus frontalis Zimmermann, and Four species of Ips beetles: Ips avulsus (Eichhoff), Ips grandicollis (Eichhoff) and Ips calligraphus (Germar) are common in most areas of Georgia, while Ips pini (Say) attacks white pines in the mountains. The top of the abdomen (back end) on adult BTB and SPB are rounded (Figure 6). In contrast, the rear end of adult Ips beetles are concave (scooped-out in appearance) with four to six pairs of spines on either side of the concaved areas (Figure 7).
	Figure 6. Common Southern Pine Bark Beetles. T to B: Ips avulsus, Ips grandicollis, Ips calligraphus, Dendroctonus frontalis (SPB) and Dendroctonus terebrans (BTB).
Figure 7. Ips spp. pine engravers. Diagnostic Appearance of the Abdominal Concavity and Location of Spines.

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