Red Turpentine Beetle by Carol Bell Randall US Forest Service Dendroctonus Valens Leconte (Coleoptera: Scolytidae)

January 2006 Forest Health Protection and State Forestry Organizations

4.2 Management Guide for WEB July 2010 Red Turpentine Beetle By Carol Bell Randall US Forest Service Dendroctonus valens LeConte (Coleoptera: Scolytidae)

Hosts (primarily): Red Turpentine Beetle is not  Ponderosa pine considered to be a tree killer,  Lodgepole pine but its attacks may indicate that  Monterey pine the tree is stressed and at Topics  Coulter pine increased risk of dying.

Introduction 1 Damage 2 Introduction Life History 2 The red turpentine beetle (RTB) Stressed pines are the most common is the largest (1/4 – 3/8th inch long) Assessing Damage 3 host. and most widely distributed bark Adults are attracted by the odor Natural Control 5 beetle in North America. It is a of tree pitch or resin. Adults Management: 5 common pest of forest, shade, and primarily attack freshly cut stumps Prevention park trees 8 inches or larger in or the bases of trees that are dying. diameter. It has been recorded from Freshly cut logs with thick bark may Management: 5 Pesticides at least 40 species of domestic and be attacked, but they will not foreign conifers, but is most produce large numbers of beetles. Management: 6 commonly found on ponderosa, Red turpentine beetle may be Pheromones Monterey, and Coulter pines. It is attracted to healthy trees near Other Reading 6 not considered to be a tree killer, but freshly cut logs and lumber and to its attacks may indicate that the tree stands attacked by other bark Field Guide is stressed and at increased risk of beetles. Management Guide dying. There is evidence that red Red turpentine beetle has been Index turpentine beetle can kill Monterey destructive in areas disturbed by pines. fire, logging, land clearing, or Outbreaks of this beetle have not construction. In some stands up to been extensive or severe. red 3% of pines remaining after logging Key Points turpentine beetle is most frequently have been attacked. On construction  Not usually a found in individual trees or in sites, injured trees or those adjacent tree killer groups of trees in localized areas. to fresh lumber frequently become  Usually infested. associated with damage from Red Turpentine Beetle Management other insects or diseases or 1. Prevention. Thin pine stands to maintain tree vigor. Avoid acute tree damaging trees. Salvage promptly any trees that are damaged or diseased. stress 2. Chemical pesticides. Can be used to temporarily protect  Prevent attack high-value trees during periods of drought or other by limiting stresses. predisposing 3. Pheromones. Reduce beetle populations using attractant factors -baited funnel traps.

Page 2 Back to menu Red Turpentine Beetle 4.2 Damage All serious damage by red fire, logging, or land clearing. turpentine beetle has been to pines. Injured trees, stumps, or trees near Monterey pine is the tree most fresh lumber or slash can be Seldom are healthy frequently killed and ponderosa infested and residual healthy trees trees damaged pine is the most frequently attacked. nearby may be killed. Attacks on other genera of conifers- Red turpentine beetle attack spruce, larch, true fir, and Douglas- trees wounded or stressed by fir- are infrequent and have never construction activities, like paving, led to serious losses. grading, trenching or root Seldom are healthy trees killed. smothering. Damage from red Host Range Usually trees of poor vigor or those turpentine beetle can be prevented infested with other bark beetles are by not conducting any of these In the Northern and attacked. However, populations activities within 40-50 feet of the Intermountain may build up in areas disturbed by large pines. Regions most frequently attacked: Life History  Ponderosa pine (Pinus Adult beetles initiate new attacks exceed an inch a day. Typically ponderosae) Red turpentine beetle peak one pair of beetles is found per  Lodgepole pine flight and attack activity usually gallery, but 1, 3, or 4 adult red (Pinus contorta) occur in the spring. Beetles turpentine beetles may be present. In North America the emerging from recently cut stumps most frequently and dying trees and attack trees, Egg galleries attacked: exposed roots, or freshly cut Eggs are laid in an elongate stumps. The female bores inward mass along the side of the gallery  Ponderosa pine  Monterey pine through the outer corky bark and and are partitioned off from the (Pinus radiata) inner, spongy phloem to the surface adult gallery by a wall of pitchy  Coulter pine of the wood where she is quickly borings. The egg mass may extend (Pinus coulteri) joined by a male. The pair generally from 1 to several inches along the bore downward, although at first gallery; the number of eggs in it Red Turpentine Beetle the gallery usually has a lateral or varies from a few to more than a has been found on over even slightly upward direction. hundred. A single female may 40 species of conifer including larch (Larix Where attacks are made just above deposit one or more groups of eggs sp.), spruce (Picea sp,) the ground line, the gallery may farther along the gallery, usually and white fir (Abies extend below the ground line and several inches or more below the concolor). along the larger roots. Boring may previous group. 4.2 Back to menu Red Turpentine Beetle Page 3

The parent beetles continue to feed emerge as adults. in the gallery for several weeks, and then they either bore out through New adults emerge from galleries the bark and make additional New adults move around in the A unique feature attacks or die within the gallery. gallery area for a few days to of Red Turpentine several months. In warm weather Beetle is that the small larvae feed Larval feeding they soon bore outwards through gregariously where In summer eggs hatch in 1-3 the bark and fly to new host as most other bark weeks. A unique feature of red material. Several adults may use beetle larvae turpentine beetle is that the small the same exit hole. The adult maintain separate larvae feed gregariously where as beetles are capable of flying more feeding tunnels. most other bark beetle larvae than 10 miles. maintain separate feeding tunnels. The rate of development and red turpentine beetle larvae tunnel number of generations per year are away from the adult gallery. As largely dependent upon they grow they feed more temperature. In most areas there is Attacking extensively and make an irregularly at least one generation of red adults are margined, fan shaped gallery. turpentine beetle per year. In attracted by Larvae feed side by side in an northern areas and at high the odor of irregular line, steadily moving elevations, 2 years may be required tree pitch or forward into fresh tissue. Their for a single generation. In southern resin feeding kills patches of cambium areas at low elevations, there may which may vary from a few inches be as many as three generations per to more than a foot wide. year. In the warmer parts of their Pupation range, the beetles’ flight may occur As larvae complete their feeding during intermittent warm periods in Red they scoop out bits of wood or bark the winter and new attacks may Turpentine to make separate pupation cells. occur at nearly any time of the year. Beetle The cells are located between the In the colder parts winter is passed Attacks— bark and the wood, either in the in hibernation, chiefly in the adult area of the gallery or a short stage and to a lesser extent in the  Generally start distance forward in the fresh inner larval stage. Pupae and eggs rarely near ground bark. Here the larvae pupate then overwinter. level and rarely occur above eight Assessing Red Turpentine Beetle Damage feet Signs of Attack the resin. The resin is usually white  May occur Red turpentine beetle attacks to yellow and the borings are red. over a period generally start near ground level On pines red turpentine beetle pitch of two years or more, and rarely occur above eight feet. tubes may be as large as 2 inches in especially on Attacks are often accompanied by diameter, much larger than the pitch vigorous trees. the presence of light pink to reddish tubes of other pine infesting bark  Have been brown pitch tubes around the base beetles. On other species of trees destructive in of the tree and/or white granular which produce little resin (such as areas material on the ground. fir or spruce) the pitch tubes may be disturbed by Pitch tubes vary in size, texture, small or absent, but boring dust or fire, logging, land clearing, and color depending on the kind of small pitch pellets may be found on or construction tree and the relative amounts of the ground around the base of the bark borings and frass embedded in tree.

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Red turpentine beetle attacks, reason for concern. especially on vigorous trees, may The appearance of 5 or more occur over a period of two years or new pitch tubes over a one to two Pitch masses of an inch or more in more. month period warrants a more diameter that occur Often crown fading from green careful inspection of the tree to higher on the trunk or to yellow to sorrel and red lead to determine why it is being attacked. on the branches are the discovery of red turpentine Injury, disease, or attacks by other probably due to beetle attacks. In most cases crown attacks by the fading is a direct result of bark beetles are likely causes for Sequoia Pitch Moth. associated attacks by other insects, repeated red turpentine beetle primarily bark beetles, not red attacks. A tree that exhibits turpentine beetle. symptoms of stress and has many red turpentine beetle attacks is at Evaluating Attacks high risk for mortality. Pitch tubes are the result of the In vigorous trees the flow of trees defensive reaction to red resin apparently prevents egg- turpentine beetle attack. As long as laying. Beetles may remain in these the tree continues to release resin, trees expanding their galleries pitch tubes are formed and the tree Red turpentine laterally or vertically but they is resisting attack. A few pitch tubes beetle is the seldom deposit eggs. largest (1/4-3/8th on an otherwise healthy tree or old inch long) and pitch tubes that are hard and have most widely turned yellow are generally not a distributed bark beetle in North America. When Assessing Tree Vigor Consider:

Stressed trees often exhibit crown symptoms such as:

 Needles shorter than normal.

 Poor needle retention, resulting in tufts of foliage at branch ends lion’s tail) and a thin crown that is easy to see through. Factors that may help Red Turpentine  Off-color, chlorotic foliage. Beetle by decreasing resin production—  Slow height growth, resulting in a flattened, rounded top.

The introduction or  Excessive amounts of dead or dying branches. invasion of blue stain fungi which grow in In contrast, a vigorous fast growing tree will have a the sapwood surface pointed top and a full green crown. of the gallery. Wounding can attract red turpentine beetle: Lowering of the sapwood moisture  Has there been any major wounding to the trunk or roots of content as a result of the tree? Have roots been cut? beetle feeding activity.  Have the roots been disturbed by soil compaction, sidewalks or pavement ? 4.2 Back to menu Red Turpentine Beetle Page 5 Management Considerations

Prevention The most effective way to prevent red The most effective way to and health. turpentine beetle prevent red turpentine beetle Fire damage attacks is to attacks is to maintain tree vigor Red turpentine beetle attacks maintain tree vigor and avoid practices that attract frequently occur on pines that have and avoid practices that attract beetles. been damaged by fire. beetles.

Tree disease Actions to prevent red Red turpentine beetle activity is turpentine beetle attacks often associated with tree diseases, Preventative measures can be including root diseases. If disease taken to make your property fire is present, it will be important to safe and reduce the potential for learn about the disease and how it fire damage to your trees. can be managed.  Thin— In forest situations, thinning trees to achieve wider Wounds and site factors spacing can help alleviate stress Wounding has the potential to and reduce the possibility of tree Natural Control

attract red turpentine beetle. If mortality. portions of the root system are cut There is little  Avoid damage— Damage to information or paved over, the vigor of the tree stands or individual trees should be available on the may be seriously impacted. Any minimized through improved biological or natural sudden or dramatic change in the logging, construction, and control of red soil/root environment e.g. management practices. Fresh turpentine beetle. compaction, grade changes, stumps, slow-dying trees, fire- flooding, etc. will adversely affect scorched trees, exposed roots of  Insect parasites the trees health. When building live trees, and trees with and predators have near trees special precautions need been observed compacted soil around them should destroying some to be taken to maintain the be treated or removed stages of the beetles integrity of the tree’s environment beneath the bark.  Many beetles die Pesticides in their attempts to attack healthy trees. Certain pesticide formulations Factors to consider before  Woodpeckers containing carbaryl, chlorpyrifos, choosing to use a pesticide for feed on larvae and or permethrin when applied to the this purpose: pupae.  The competition bark of a tree have been proven  Only those portions of the main for food within and effective at preventing bark beetle stem of the tree that are sprayed between broods attacks. Pesticide applied to the will be safe from bark beetle may result in lower 6-8 feet of the tree trunk can attack. reducing beetle populations. be used to prevent red turpentine  It is important to use a beetle attacks, but it must be pesticide specifically formulated None of these realized that other species of bark for use against bark beetles. All natural or biological beetles may pose a threat to the pesticides must be applied means can be tree as well. according to label instructions, and counted on to Pesticide treatments can be if the pesticide is a restricted control the beetle. useful at protecting high value material it must be applied by a trees during drought or other certified applicator or under their periods of acute stress. direct supervision.

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 Pesticides that are injected into  The use of pesticides against trees have not been proven bark beetles is best viewed as a effective against bark beetles. temporary measure for protecting The use of pesticides  One treatment in the spring trees during periods of temporary against bark beetles before bark beetle flight begins is stress. is best viewed as a temporary measure usually sufficient to protect trees  Trees that have little or no for protecting trees for the duration of the beetles’ chance of recovering from the during periods of flight. effects of chronic stress should not temporary stress.  A common mistake is to spray be treated with pesticides, as such pesticides on a tree that is already attempts to save them eventually dead or dying. fail.

Warning- remember, when using pesticides, always read and follow the label!

Baited funnel traps need to be placed Pheromones well away from host trees (over 20 Attractant pheromone baited 8 (+)-alpha-pinene, (-)-beta-pinene, yards) to avoid or 12 unit Lindgren funnel traps and (+)-3-carene. unwanted attacks. have been used to reduce local Baited funnel traps need to be populations of red turpentine placed well away from host trees beetle. The standard red turpentine (over 20 yards) to avoid unwanted beetle pheromone blend used in attacks. North America is a 1:1:1 blend of