Return to main tree page 
Return to Bad Insects Page

AVTreeFarm  
Insects

             

Bark Beetles

 Bark Beetles (Flitters and Fliers)

BARK BEETLES AT A GLANCE
Tunnel through and just under a tree's bark, cutting off the flow of nutrients
Target stressed or diseased trees
First symptoms: little holes in bark with gummy "sawdust" oozing out
Later, branches droop and turn yellow
Trap with white vinegar or spray with the Peppermint Soap Spray (below)

 

Life Cycle
Believe it or not, trees that are under stress from drought, disease, or other woes give off a distinctive scent. Male bark beetles home in on that aroma and fly to the scene from miles around, like bargain hunters flocking to a going-out-of-business sale. Once the boys are on the scene, they release their own scent that invites the girls to the party. They fly in, and after the usual festivities, insect-style, they lay eggs within the bark or on the ends of cut branches. When the larvae hatch, they tunnel through the cadmium (the tissue just under the bark) to pupate. Then, all grown up, they exit through holes in the bark and fly away to start the cycle all over again in other trees. Bark beetles attack many kinds of trees and shrubs, both deciduous and evergreen, but they don't bother any nonwoody plants.
There are several different species of bark beetles, but they all look pretty much the same: They're dark, shiny, hardshelled, and about the size of a grain of rice. The larvae are white, legless grubs about 1/4 inch long. They tunnel through and just under a tree's bark, cutting off the flow of nutrients. One of the most notorious of the bunch is the European elm bark beetle, which spreads the fungus that causes Dutch elm disease. If your trees have little holes in the bark with what looks like sawdust oozing out, or little projections that resemble toothpicks, think bark beetles. In more advanced cases, you may see drooping, yellowed branches or even girdled, dead trunks and limbs. Bark beetles are attracted to trees that are diseased, dead, or under stress; but once they're in the neighborhood, they sometimes attack healthy trees, too.

 
One of many types of Bark Beetle

Type of Damage: In pines, resin often oozes from the bark where beetles first attack, producing conspicuous pitch tubes. Some beetles become trapped in the pitch and die. A healthy tree produces enough pitch to prevent successful attack by many beetles, but sometimes bark beetles are able to overwhelm and kill healthy trees. This may happen to trees which are near heavily infested breeding sites. Once a bark beetle is successfully established in a tree, it emits a pheromone which attracts other beetles to the same tree. Bark beetles do not attack trees that are dead for more then a season and dried, nor dying or recently cut wood if the bark is removed. On healthy trees, bark beetles may attack individual twigs and branches that are dying from shading out or other causes. For example, some species breed only in the dead or dying twigs, branches, and limbs of pines. These bark beetles will not breed in live branches, and thus are not a progressive destructive threat to healthy parts of trees.

First Response
At the first sign of trouble, prune off infested branches and burn them if that's allowed in your neighborhood; otherwise, cut up that wood and send it off with the trash. Don't get it anywhere near the compost pile, or before you know it, you'll have bark beetles all over the place. Then, give the tree a big dose of water and fertilizer. That will help it produce pitch or sap, which will ooze out through the beetles' holes, taking grubs with it. As for any adult beetles you find scampering around on the bark, give 'em what for with my Peppermint Soap Spray (below).

Pickled Beetles
Once bark beetles have tunneled into a tree, no Bug Buster or even commercial insecticide can reach them. Fortunately, though, it's a snap to get 'em on the fly. The weapon: white vinegar. The vile villains throng to it in the same way they zero in on sick trees. (Maybe the odor is the same as a tree's distress signal.) Just set jars of  the tangy stuff among your troubled trees, and the beetles will dive right in and they won't get out alive. Note: This trick seems to work only with white distilled vinegar, not cider or any of the fancy flavored kinds.

Drink to Their Health
Drought-stricken trees are prime targets for bark beetles. To help keep your personal forest off their radar screen, make sure the big guys get enough water. Most trees can handle short rainless periods just fine, but during prolonged dry spells, they sometimes need an extra drink or two. When you deliver that water, soak the ground slowly and thoroughly from the trunk out to the far reaches of the branches (a.k.a. the drip line). Then mulch with compost or well-rotted manure to help conserve moisture.

Loosen Up
If bark beetles are targeting your trees, the reason could lie in the soil. When it's compacted, water, nutrients, and oxygen can't reach the tree's roots-leaving the poor plant as stressed out as you'd be if you couldn't get water, food, or air! To solve the problem, work organic matter, such as compost, into the soil as far down as you can without disturbing the roots. Then, reroute both foot and vehicle traffic (the prime cause of soil compaction).Install a foot path, and if that doesn't send a strong enough message, erect a barrier around the root zone.

Go Native
One of the simplest ways to prevent stress (and therefore, major problems with bark beetles and other bad guy bugs) is to choose trees that grow naturally in your area. The same applies to any other kind of plant. If you're not sure what species are native to your neck of the woods, get in touch with your local Mature Conservancy office, native plant society, or Cooperative Extension Service.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Peppermint Soap Spray
This brew is a nightmare-come-true for hard-bodied insects like beetles. The secret weapon: peppermint. It cuts right through a bug's waxy shell, so the soap can get in and work its fatal magic.
2 tbsp. of dishwashing liquid 
2 tsp. of peppermint oil 
1 gal. of warm water
Mix the dishwashing liquid and water together, then stir in the peppermint oil. Pour the solution into a hand-held sprayer, take aim, and fire! Those beetles'll never know what hit 'em!

Bark beetles are the most destructive insects in the coniferous forests of the Southwest. There are many bark beetle genera, of which the most important with respect to forest damage are Dendroctanus, Ips, and Scolytus. Adult bark beetles bore through the outer bark to the inner cambial layer, where they channel out galleries in which to lay eggs. Larvae hatch in these galleries and may excavate additional channels as they feed. As bark beetles carve out galleries, they introduce blue-stain fungi. This fungi grows in the wood, interfering with the tree's water transport system. Tree deterioration and eventual mortality result from two factors:
(1) tree girdling caused by gallery excavation, and
(2) spread of blue-stain fungi. Several species of bark beetles may attack in concert, partitioning the tree by elevation. Roundheaded pine beetle, western pine beetle, mountain pine beetle, and several species of Ips may all be found on severely infested trees.

Infested trees may be recognized at a distance by fading foliage high in the tree, initially a light green, changing to a light straw color in a few weeks, and eventually to yellowish-brown. Close inspection may show a fine reddish-brown boring dust in bark cervices and at the base of the tree. Small pitch tubes, or globules of pitch may be seen on the tree trunk. Cream to dark red pitch tubes, resin mixed with boring dust, ¼" to ½" in diameter, are an indication of a successful bark beetle attack. In some cases where the number of attacking bark beetles is not high, the tree may have sufficient resin available to eject the attacking bark beetles by extruding resin at the attack site ("pitching out"). Pitch tubes of whitish resin ¾" or more in diameter are evidence of an attack successfully resisted. Other evidence of bark beetle infestation includes galleries discovered under the bark, sapwood discolored by blue-stain fungi, woodpecker feeding holes and bark removal by woodpeckers.


Cypress Bark Beetle


Cypress bark beetle


Ips calligraphus


ips knausi


ips latidens


ips pini


mountain pine beetle


mountain beetle pine grub


 ips pinyon


 ips sixspined


 southern pine beetle


 turpentine pine Beetle


 turpentine pine Beetle view #2


 western pine beetle


 western pine beetle #2


 Western pine borer

Common Bark Beetles

Several of the most common bark beetles are listed below, along with characteristics which should help identify them. However, there are many other species that may be encountered in shade trees and wooded areas.

Ips Beetles. Bark beetles in the genus Ips are commonly called engraver beetles or simply Ips beetles. They can be distinguished from other bark beetles by the scooped-out posterior section of their bodies. Ips galleries, found in pines, have egg tunnels in the form of an H or a Y. Though capable of attacking the entire tree, Ips beetles are usually confined to the crown.

Southern Pine Beetle. One of the smaller bark beetles, the southern pine beetle is barely 3/16 inch long. Following long dry spells or poor forest management, outbreaks occur that rapidly kill large areas of pine forests. Southern pine beetles attack mainly the middle or upper part of the tree trunk. All ages and sizes of pine trees are potential hosts. Larval tunnels wind around in an unorganized pattern. Healthy, vigorous trees and proper forest management practices reduce the likelihood of outbreaks and tree losses.

Conifer Bark Beetles. A wide variety of bark beetles attack pines and other conifers. In general, they attack trees in decline and leave long meandering tunnels under the bark and small exit holes on the bark. Live trees moved and replanted are often attacked and may require an insecticide spray just after planting if the tree is moved in the spring or early summer.

Black Turpentine Beetle. This beetle is large for a bark beetle, about 1/3 inch long. It attacks pine trees at the base of the trunk, and may also breed in stumps. Black turpentine beetle grubs feed together and excavate large patches under the bark. A common characteristic of this beetleÕs attack is the presence of a glob of pitch, about 1/2 inch in diameter, at the exit hole. Sometimes there will be large numbers of white pitch globs on the dark bark.

Elm Bark Beetles. There are two species of bark beetles that attack elms. Both of them are capable of transmitting Dutch elm disease when they feed on healthy trees. The European elm bark beetle feeds in the crotches of one- to three-year-old-twigs; the native elm bark beetle feeds in the thick bark of trunks and limbs. Native elm bark beetles construct egg tunnels across the wood grain. Egg tunnels of the European elm bark beetle are parallel to the grain. Both make galleries and breed only in recently killed or dying elm wood three inches or larger in diameter.

Other common bark beetles include: the shothole borer which attacks fruit trees, wild cherry, serviceberry, and occasionally elm; the peach bark beetle in stone fruits, mountain ash, elm, and mulberry; Pityogenes spp. and Pityophthorus spp. in pines; Phloeosinus spp. in cypress and junipers; the ash bark beetle in ash; the birch bark beetle in birch, beech, wild cherry, and red gum; and the hickory bark beetle in hickory.

Control Methods

Similarities in their life cycles and in the injury they cause usually make bark beetle species determination unnecessary for making pest management decisions. Once infested, trees almost never recover and control efforts are usually futile.

Prevention (Non-chemical): Preventative measures include maintaining healthy, vigorous trees and eliminating beetle breeding sites, such as recently dead or cut trees, limbs, slash, and firewood with bark.

Treatment (Chemical): Apply residual insecticides to susceptible, but as yet uninfested trees, especially those under stress and therefore attractive to bark beetles. Treating infested materials before bark beetles emerge will kill them as they chew their exit holes. Check the Pest Management Guide in your area,  for current insecticide recommendations. Always read and follow the instructions on the pesticide label.

Complete Insect Killer For Soil & Turf

This product contains Bayer's proprietary 2-way action formula. Bayer Advanced's 2-way action controls turf pests like ants, fleas, and ticks plus soil pests like grubs in one easy step. It not only kills existing pests quickly, but also keeps on protecting for up to 3 months. Keeping the yard, lawn, and around your home free of listed nuisance pests has never been easier.

Active Ingredients:
Imidacloprid: 0.15%; Beta-Cyfluthrin: 0.05% 

When to Use:
General Surface Pests: Whenever insects are present  
White Grubs: May through July
European crane fly larvae: Apply once, when adult insects are present in large numbers

 

 

 

        Granules                 

Complete Insect Killer For Soil & Turf Granules

This product contains Bayer's proprietary 2-way action formula. Bayer Advanced's 2-way action controls turf pests like ants, fleas, and ticks plus soil pests like grubs in one easy step. It not only kills existing pests quickly, but also keeps on protecting for up to 3 months. Keeping the yard, lawn, and around your home free of listed nuisance pests has never been easier.

 

  • Kills Insects Both Above & Below Ground
  • Long-Lasting - up to 90-Day Subsurface Insect Protection

 

 Ready to spray 

Complete Insect Killer For Soil & Turf Ready-To-Spray

This product contains Bayer's proprietary 2-way action formula. Bayer Advanced's 2-way action controls turf pests like ants, fleas, and ticks plus soil pests like grubs in one easy step. It not only kills existing pests quickly, but also keeps on protecting for up to 3 months. Keeping the yard, lawn, and around your home free of listed nuisance pests has never been easier.

 

  • Fast Acting Formula Works 2 Ways for Powerful Insect Control
  • Kills Insects Both Above & Below Ground
  • Long-Lasting - up to 90-Day Subsurface Insect Protection

 

concentrate

Complete Insect Killer For Soil & Turf Concentrate

This product contains Bayer's proprietary 2-way action formula. Bayer Advanced's 2-way action controls turf pests like ants, fleas, and ticks plus soil pests like grubs in one easy step. It not only kills existing pests quickly, but also keeps on protecting for up to 3 months. Keeping the yard, lawn, and around your home free of listed nuisance pests has never been easier.

 

  • Fast Acting Formula Works 2 Ways for Powerful Insect Control
  • Kills Insects Both Above and Below Ground
  • Long-Lasting – Up to 90-Day Subsurface Insect Protection