Pine Bark Beetlesin 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

beetle causes more damage to southern forests than all other pests combined.

Southern Pine BeetleDendroctonus frontalis

Black Turpentine BeetleDendroctonus terebrans

lps Engraver Beetleslps avulsus, lps grandicollis,

lps calligraphusnote hollowed out rear end

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HOW TO RECOGNIZE BARK BEETLE ATTACKSPines 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.

Southern pine beetle galleries under the bark have a distinc-tive ‘S’-shape with frass and

boring dust in the gallery.

Pitch tubes on infested trees are common in both southern pine beetle and

Large pitch tubes, up to 1 inch or more in diam-

eter, from black turpentine beetle attacks on trees damaged during

harvesting.

In expanding infestations of southern pine beetle, three stages of attack can be distinguished: Stage 1 with green foliage, soft pitch tubes in the bark crevices and no bark beetle galleries under the bark; Stage 2 with fading yellow-green crowns and ‘S’ shaped galleries under the bark; Stage 3 with red crowns, or without foli-

age, and with small, circular exit holes in the bark.

Stage 1 Stage 2 Stage 3

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Southern pine beetles and lps beetles carry blue stain fungi on their bodies and introduce it into the tree during their at-tack. The fungus clogs water conductive tissues in the tree, hastening its death. Blue stain reduces the value of salvaged trees. Black turpentine beetles

do not carry the blue stain fungus and can be controlled with insecticide treatments.

lps beetle attacks.lps beetle galleries have

a ‘Y’ or ‘H’-shaped pattern that are free from boring dust and frass, the larval

galleries extending out from the main gallery are filled with frass and boring dust

produced by the larva.

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.

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,

and overall decline in tree and stand vigor.

Damage to residual trees or to roots and soil during harvesting can increase risk of pine bark beetle attacks.

Pine struck by lightning are highly susceptible to pine bark beetle attacks and are often the initial point of an infestation.

FOREST MANAGEMENT TO REDUCE 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 developing problems. Contact a professional forester for advice.• No chemical treatments are registered for forest stands; for ornamental trees threatened by bark beetles, contact your county Cooperative Extension office and see the Georgia Pest Management Handbook for possible treatments.

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Developed by David Moorhead, Chuck Bargeron,Kris Irwin, Gail Lutowski, Chip Bates, and James Johnson

University of GeorgiaCenter for Invasive Species and Ecosystem HealthWarnell School of Forestry and Natural ResourcesCollege of Agricultural and Environmental Sciences

Funding provided by Georgia Forestry Commissionand U.S. Forest Service – Revised December 2011