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Insect Pests
Pogonomyrmex: Harvester Ant is a large, red-brown, stinging ant that nests underground.
The entrance to the nest is a hole without a mound. Sometimes more than one entrance is present.
The colony kills all vegetation within one to three feet of the hole, making the entry hole
easy to find.
Eradication is difficult. One method is to pour Fire Ant and Termite insecticide down the holes until the holes fill. The colony will close the holes and go dormant for a few weeks. Weekly inspection of the area will eventually find a new hole open with fewer ants. Pour the insecticide down the hole again and repeat. The ants may try to disguise the hole by placing it under a rock or large root and by having more than one entrance. After three or more doses, the colony will die from poison and starvation. A powdered form of the insecticide blown down the hole with a bulb or bellows is also said to work well. 
Dendroctonus brevicomis LeConte: Western Pine Beetle usually
breeds in and kills overly mature, slow-growing, decadent, or diseased trees and
trees weakened by drought, lightning, fire, or mechanical injury.
It is commonly found in forests with a mid-elevation level between 2,000 and 6,000 feet
(600 to 1,800 m).
Adult beetles carry spores of a blue-staining fungus, Ceratocystis minor (Hedgcock) Hunt, in special pouch-like structures in their heads called mycangia. As the beetles chew their way through the bark, the spores of this wilt-causing fungus dislodge and begin to germinate. In trees attacked in early or midsummer, it takes only a few weeks for the fungus to invade and block the conductive vessels of the inner bark and sapwood. Once the vessels are blocked, the foliage begins to fade, first to a pale green and then to yellow. Finally, perhaps after a year, the foliage may turn red brown. This fading is the first evidence of damage to the tree that is visible at a distance. Any condition that results in excessive demand for moisture, such as tree crowding, competing vegetation, or sudden exposure to severe sunlight; or any condition that reduces the ability of the roots to supply water to the tree, such as mechanical root damage, root disease, soil compaction, or drought, can cause moisture stress and increase susceptibility to attack by the western pine beetle. |
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