It’s hard to imagine that an insect the size of a grain of rice could become public enemy number one in Santa Fe, but this is how many have felt about the Ips confusus, piñon bark beetle. Normally an innocuous part of the piñon-juniper ecosystem it feeds off host trees. In times of extreme drought all piñon trees are stressed and most are highly vulnerable to the bark beetle.

Northern New Mexico first showed signs of the bark beetle epidemic in the late 1990s
By 2002 Los Alamos was severely hit and by 2003 had lost more than 90% of piñon trees over ten feet tall.

While we can’t be sure when this bark beetle epidemic will end, evidence shows that epidemics usually last from three to seven years.

Latest Information

Good news! Indications are that the infestation in Northern New Mexico has slowed down. In 2004, the hardest hit areas continued to be Santa Fe, Ojo Caliente, East Mountains, Glorieta, and Pecos. The City of Santa Fe reports bark beetle populations peaked in July and October of last year.

The City of Santa Fe is monitoring insect traps to understand when the bark beetles are most active and when they go dormant. The U.S. Forest Service and the New Mexico Forestry Division have been conducting aerial surveys to track the beetle’s yearly progress.

Life history of the Bark Beetle

Adult bark beetles chew their way through the outer bark of a living tree and emit a scent to attract other beetles. Beetles infect the tree, then mate and lay eggs in galleries they construct between the bark and the wood. When the eggs hatch, the larvae feed on the nutritious soft inner bark layer or cambium. A “blue stain” fungus carried by the beetles contributes to the death of the tree by clogging water and nutrient-conducting tissues. When the cambium is damaged the tree begins to die. Larvae form into pupae that transform into callow or immature adults. Once fully mature, adult beetles leave the infected tree and start the life cycle over again.

At the height of infestation beetles can produce multiple generations each year, between the months of April and October. Bark beetles over-winter inside dead or dying trees in late fall. In early spring the hibernating beetles re-emerge and begin to spread to other living piñon trees.

Recognizing a Sick Tree

Once infestation takes place successfully, there is no way to save the tree.

To determine if a piñon has been infested with bark beetles, look for evidence of a “pitch tube,” a small hole surrounded by a buildup of sap. Other signs include small piles of sawdust around the base of the tree or in branch cross-sections, and browning of needles on the entire tree. While we would like to believe something could be done at this point to save the tree, there really is nothing that will save it.

Relative sizes of insects:

Twig Beetles and Woodborers are Here Too

Be on the lookout for the twig beetle, an insect that attacks piñon and other pines, particularly in times of drought. The twig beetle does not normally kill trees.

To see a comparison table of bark beetle and twig beetle identification click here »

  
Twig Beetle Damage

Woodborers

Roundheaded and flatheaded woodborers are secondary insect pests that attack and help decompose trees killed by the piñon bark beetle. Be aware that roundheaded borers are very destructive, tunneling deep into the wood. Fresh-cut logs left in the forest or in storage for a year can be seriously damaged. Woodborers have been reported in firewood and in vigas.

Woodborer Beetles

Other insects are also active throughout New Mexico. The State Forestry Division conducted additional insect and disease aerial surveys on approximately 1.25 million acres of state and private forestlands. The most active insects include the Western pine beetle, the Douglas fir beetle, and the Western spruce budworm.

Northern New Mexico Piñon Survey 2004 Aerial Survey Maps» (PDF)

Learn more

New Mexico Energy, Minerals and Natural Resources Department, Forestry Division, Facts Sheets-Bark Beetles »

U.S. Forest Service, Southwestern Region (R3), Forest Health: Bark Beetle Outbreak »

Colorado State University, Cooperative Extension Service, Piñon pine diseases and insects »

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