Bothersome Beetles Benefit From Storm

Just when we thought the icestorm of 1996 had melted into just a memory, now we’re seeing its legacy lives on. As predicted nearly two years ago, dead and dying pine trees are beginning to dot our yards and forests. The injuries sustained by many of the pines during that November week were nothing short of engraved invitations to the pine bark beetles.

Seeking out injured and weak trees, the pine engraver beetle (IPS), the Western pine beetle and the red turpentine beetle quickly set up housekeeping in our ponderosa pines. Some time between early spring and midsummer 1997, the adults laid their eggs under the tree’s bark. The larvae, once hatched, began eating the soft tissue of the cambium.

Their feverish feeding resulted in a series of tunnels and galleries that interrupted the movement of water and nutrients within the trees. If that wasn’t crippling enough, the beetles left behind a blue stain fungus that clogged the water transport system, leaving the trees incapable of getting water to their needles.

All that internal damage is now starting to show.

The first of these villains, the engraver beetle, is a tiny 1/8- to 3/16-inch-long dark brown to black beetle. If you look closely at its back end, you will quickly notice a distinguishing mark: the ragged end looks as if something took a bite out of it.

Engraver beetles usually attack the tops of trees in the spring and early summer, forming galleries in a Y or H shape under the bark. As they dine, they send out signals to all their kin announcing the opening of the grandest five-star accommodations this side of the Rockies.

The Western pine beetle is also a very small beetle - dark brown to black and a little less than 1/4-inch long. They attack the trunks of weak trees that are 6 inches in diameter or more. The larvae are present most of the year, creating galleries of all different configurations - horizontal, vertical, crisscross and serpentine.

Western pine beetles usually attack in early or late summer. We can easily detect the presence of this insect on young pines by the tiny, pinhead-size emergence holes.

It is a bit more difficult to spot these holes on old, craggy bark.

The turpentine beetle is the larger of the group - averaging about 1/4-inch in size and sporting a red-brown coloration. Their presence can quickly be identified by large, red pitch tubes located around the bottom 3 feet of the tree.

Turpentines attack trees from spring to midsummer. Their larvae feed from June through October, creating fan-shape galleries that can extend below the soil line.

It’s all well and good to become acquainted with these intruders, but the question is, what can we do about them? The prognosis is not good.

Once the pine beetles enter a tree, there is nothing that can be done to remove them.

Carbaryl can be applied as a protective measure, but it will do nothing if the larvae have already set up shop.

Bark beetles have a difficult time infesting healthy trees, although if the insect populations are high, these, too, are fair game. Following are suggestions for trying to maintain healthy trees in our landscape:

Although ponderosa pines are drought-tolerant, they still benefit from deep watering.

Always remove diseased or injured trees.

Thin out dense stands of trees to reduce water and nutrient competition.

Remove infested trees during the dormant season or before the beetles emerge.

Take care of all downed trees and their branches immediately after felling the trees. Sap from the cuts will attract the beetles.

Piled branches are one of the worst culprits. Wood that is going to be used as firewood should be stacked and covered with plastic. The ends of the plastic should be secured to the ground to prevent beetles from leaving.

The heat under the plastic will help kill the beetles and their larvae.

I wish I could be more encouraging, but with this year’s long spell of heat, dry winds and beetle populations, I am afraid the worst isn’t over for our pines.

On the positive side, downed pines may open areas to sun, create new vistas and the opportunity for more interesting planting of trees and shrubs. And just think - no more raking pine needles.

But at this moment, all these positives are of little consolation as I look across the field at an age-old pine. This giant with a girth of about 3 feet stood as a sentry for nearly a century.

If it could tell stories, we may hear of owls and hawks that nested on its branches, storms it endured and the vast changes it saw in the landscape. Now it stands brown and dying, riddled with beetles.

Change is difficult, but it’s all part of the cycle of life.