The Colorado State Forest Service recognizes the rise in beetle populations and the potential for tree loss. In The Pinery, pine trees have come under attack by two common and dangerous bark beetles. Both the IPS Beetle and the MPB (Mountain Pine Beetle) are in the area.

Beetles Carry Deadly Blue Stain Fungus.

Both the IPS and MPB beetles cause damage by boring under the bark, disturbing the natural processes of the tree. This can be a problem in itself, but the primary, lethal danger is a fungus that the beetles transport. Blue stain fungus will lead to a quick decline by clogging the tree’s vascular system. Once in a tree, blue stain fungus is untreatable. It could kill your tree in one season, and is almost certain to kill it within 3 years.

Promoting Tree Health Key to Prevention

IPS and MPB are less likely to attack healthy trees. Trees under stress or in poor health are most susceptible to attack. New transplants, trees near construction sites or roads, malnourished and improperly watered trees are prime targets for the beetles.

Proper Watering, Annual Fertilization and Pruning Keys to Tree Health.

Over-watering is one of the biggest killers of pine and spruce transplants. Too much water is as harmful as too little. Both situations will result in root die-back and possible tree loss. Mature trees might need supplemental watering in drought conditions during winter months.

Annual fertilization will help keep trees healthy. Just as well-nourished people are less likely to get sick, well-fed trees are less likely to have problems. Fertilization can be done anytime the soil isn’t frozen. If done by the homeowner, the directions on the packaging should be carefully followed. Homeowners who are not comfortable doing their own fertilizations could call professionals.

Pruning, another key part of a tree health program, might also require a professional. Whether done by the homeowner or professionals, pruning should only be done during the dormant season when beetles are not active.

Beetle populations can grow rapidly in felled trees or firewood (pine and spruce), so dead and dying trees must be removed or destroyed promptly.

Massive Beetle Populations Attack Even Healthy Trees

Even healthy trees are susceptible to attack when beetle populations reach very high numbers, as is now the case. In these situations, the best defense for your pine and spruce trees is an annual preventative insecticide spray application. Otherwise, your trees could be lost to the blue stain fungus the beetles carry, because once in the tree, blue stain fungus is untreatable.

Preventative Spraying Best Before May & June.

IPS beetles begin to fly and attack trees in mid-spring. Preventative applications of insecticide should be done no later than May. MPB begin to fly and attack trees in June or July. Preventative applications against them should be done no later than June. Spraying usually takes about 30 minutes for an average property. People and pets should be kept indoors or away for about 30 minutes after spraying is completed. Carbaryl and Permethrin are the two approved chemicals. Both of these insecticides are effective against IPS and MPB. Carbaryl has been in use for over 10 years, and is the old standard. When mixed in regular concentrations it makes a foam-like spray, and lasts about 12 months. The more modern Astro (a brand name for permethrin), though more expensive for the tree company to use, is becoming the product of choice. It is less of a threat to wildlife, pets and children, and some tests have indicated it has a longer residual effect – up to 14 months against IPS and MPB. Both are effective.

Choose Your Tree Company Carefully

Ask lots of questions, and be sure to get answers. Do they have a Certified Arborist on staff? Will they give you a written estimate? What product do they use, and when do they time the application?

Next to your home itself, your trees are the most valuable asset on your property. Protect them. Choose the most reputable and knowledgeable tree company you can find. If you’re not comfortable with the first arborist you talk with, call another. Let’s keep the pines healthy!

Article written by:
Brett Lemur & Kevin Marks
Wilhelm-Davey Tree Experts