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Pine Bark Beetles in Georgia Identification, Prevention and Control WHAT ARE PINE BARK BEETLES?

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Pine Bark Beetles in Georgia Identification, Prevention and Control WHAT ARE PINE BARK BEETLES? Pine Bark Beetles in Georgia Identification, Prevention and Control WHAT ARE PINE BARK BEETLES? The southern pine beetle (SPB), black turpentine beetle (BTB), and the lps engraver beetles are native pests in our valuable southern pine forests. Gener- ally these pests attack stressed (drought, flooded, over-crowded) or damaged trees (lightning strikes, fire, logging damage), but SPB can aggressively at- tack healthy trees under the right conditions. Across the southern U.S., millions of dollars are lost annu- ally to these pine bark beetles. The southern pine Forest Service, Bugwood.org USDA Photo by: Erich G. Vallery, beetle causes more damage to southern forests than Southern Pine Beetle all other pests combined. Dendroctonus frontalis Photo by: David T. Almquist, University of Florida , Bugwood.org T. Photo by: David Black Turpentine Beetle Dendroctonus terebrans Photo by: Erich G. Vallery, USDA Forest Service, Bugwood.org USDA Photo by: Erich G. Vallery, lps Engraver Beetles lps avulsus, lps grandicollis, lps calligraphus note hollowed out rear end HOW TO RECOGNIZE BARK BEETLE ATTACKS Pines attacked by bark beetles display several distinctive characteristics. Tree crowns fading from green to yellow to red. Pitch tubes on the trunks and galleries under the bark. Large pitch tubes, up to 1 inch or more in diam- eter, from black turpentine beetle attacks on trees damaged during harvesting. Photo by: Herbert A. ‘Joe’ Pase III, Texas Forest Service , Bugwood.org Texas Pase III, A. ‘Joe’ Photo by: Herbert Photo by: Peter L. Lorio, Jr., USDA Forest Service , Bugwood.org USDA Photo by: Peter L. Lorio, Jr., In expanding infestations of southern pine beetle, three stages of attack can be distinguished: Stage 1 with green foliage, soft pitch Photo by: Ronald F. Billings, Texas Forest Service , Bugwood.org Texas Billings, Photo by: Ronald F. Forest Service , Bugwood.org Texas Billings, Photo by: Ronald F. tubes in the bark crevices and no bark beetle galleries under the bark; Stage 2 with fading yellow-green crowns and ‘S’ shaped Southern pine beetle galleries Pitch tubes on infested galleries under the bark; Stage 3 with red crowns, or without foli- under the bark have a distinc- trees are common in both age, and with small, circular exit holes in the bark. tive ‘S’-shape with frass and southern pine beetle and boring dust in the gallery. Stage 1 Stage 2 Stage 3 Photo by: Ronald F. Billings, Texas Forest Service , Bugwood.org Texas Billings, Photo by: Ronald F. Photo by: Ronald F. Billings, Texas Forest Service , Bugwood.org Texas Billings, Photo by: Ronald F. lps beetle attacks. Southern pine beetles and lps lps beetle galleries have beetles carry blue stain fungi a ‘Y’ or ‘H’-shaped pattern on their bodies and introduce that are free from boring it into the tree during their at- dust and frass, the larval tack. The fungus clogs water galleries extending out from conductive tissues in the tree, the main gallery are filled hastening its death. Blue stain with frass and boring dust reduces the value of salvaged produced by the larva. trees. Black turpentine beetles do not carry the blue stain fungus and can be controlled with insecticide treatments. WHAT FORESTS ARE MOST SUSCEPTIBLE TO A BARK BEETLE ATTACK? Pine stands that are overstocked, those growing on poor sites or that have been damaged by fire, wind, lightning, drought, or during harvesting may be at risk and the amount of damage is based on the condition of the stand. Photo from: Stephen F. Austin State University Archive, Bugwood.org Austin State University Photo from: Stephen F. Pine struck by lightning are highly susceptible to pine bark Photo by: Scott Roberts, Mississippi State University , Bugwood.org beetle attacks and are often the initial point of an infestation. Overstocked high density stand begin to slow in growth and become more susceptible to pine bark beetle damage. Over- stocking leads to reduced crown size, slower radial growth, FOREST MANAGEMENT TO REDUCE and overall decline in tree and stand vigor. BARK BEETLE INFESTATIONS Landowners can actively manage their pine forests to reduce risk to bark beetle infestations by addressing these issues: • Protect from wildfire by establishing fire breaks and through the use of prescribed fire to reduce fuel loads and competition. • Thin overstocked stands with pre-commercial or commercial thinning operations. • Use Forestry Best Management Practices to reduce stand damage during harvest operations. • Conduct prompt salvage of damaged and diseased trees when possible. • Direct control measures can be used when SPB outbreaks occur using the Cut-and –leave method and establishing buffer strips on large outbreaks. • Monitor stand health throughout the year to detect potential or Photo by: David Moorhead, UGA, Bugwood.org developing problems. Contact a professional forester for advice. Damage to residual trees or to roots and soil during harvesting • No chemical treatments are registered for forest stands; for can increase risk of pine bark beetle attacks. ornamental trees threatened by bark beetles, contact your county Cooperative Extension office and see the Georgia Pest Management Handbook for possible treatments. Developed by David Moorhead, Chuck Bargeron, Kris Irwin, Gail Lutowski, Chip Bates, and James Johnson University of Georgia Center for Invasive Species and Ecosystem Health Warnell School of Forestry and Natural Resources College of Agricultural and Environmental Sciences Funding provided by Georgia Forestry Commission and U.S. Forest Service – Revised December 2011.
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