Diseases

Stress threatens plant health, just like stress threatens human health. The recent drought years have stressed area trees, making them more susceptible to certain insect and disease problems. One pest currently rearing its ugly head is the Ips beetle and it is causing serious damage to area spruces.

These insects are small (1/8 to 3/8 inch long), red-brown to black beetles. They have a cavity on their rear end lined with tooth-like spines. Generally, the Ips beetles are not as destructive as other bark beetles such as mountain pine beetle, because they attack trees that are stressed from various environmental factors, such as drought.

Ips beetles tunnel underneath the bark of the trunk and small limbs, damaging the conductive tissue and interrupting water flow. This causes affected portions of the tree to turn off-color and die. Recently infested spruce will not be entirely killed by the initial attack as do pines after a Mountain pine beetle attack, however Ips beetles have 2-4 generations per year and the subsequent generations will reinfest lower living portions of the affected tree. The secondary attacks eventually kill the entire tree.

To prevent beetle attacks, promote vigorous plant growth. Water spruces adequately, but not excessively, including during dry fall and winter periods. Avoid root damage from compaction, digging, trenching and other mechanical injury. Newly transplanted trees as well as older, valuable specimens should be preventively sprayed with bark treatments of either carbaryl or permethrin. Two treatments per year (one in spring and one in summer) are recommended.