As you can see there is debate over the removal of the wire cages. We also agree with what you read from Colorado State and suggest removing the wire cage as well, if possible. While the spaces between the wires are quite large, eventually the roots that grow through them will grow in circumference and be girdled by the wire. This may not be for many years down the road, but could lead to stress later on in the plants life.

As far as applying insecticides, it is not recommended to apply any pesticides if there is no real threat of a pest. The tree species you have listed are not species that are frequently bothered by borers so I would not recommend treating for them. The best control of pests is done through proper watering, fertilization, pruning, and general care to keep the plants from being stressed. Healthy plants are less susceptible to pest problems.

Avoid wounding the trunk by keeping lawn mowers and string trimmers away. This can be done by maintaining an area at least 6 feet in diameter, weed and grass free with about 1 to 2 inches of mulch; keep mulch several inches away from the base of the tree.

For more information about planting and care of trees in the landscape see our fact sheets - HLA-6414 Planting Trees and Shrubs, HLA-6415 Training Young Shade and Ornamental Trees, and HLA-6412 Fertilizing Shade and Ornamental Trees and Shrubs.