Conifers (AKA..Pine Bark Beetles)
Ips spp. (beetle)
Their larvae are very small (3/16 in. long when mature) and white, while adults are 1/10-3/8 in. long; red brown to black, shiny with parallel sides; 3-6 spinesat ends of wings.
Tunnels or gallaries are curved, S-shaped, or inverted-Y, tortuous or straight and parallel.
Many various pines, Douglas fir, fir, and spruce are their host trees and found throughout the United States: Alaska, east, southeast, Canada, British Columbia, Quebec to Nova Scotia.
Poor site, drought, injuries, nutritional deficiencies will attract them to weakened trees.
Dieback occurs on the upper terminals and laterals branches tunneling under the bark with egg galleries with 3 or more larval mines issuing from each egg pocket.
The rapidity of development and number of generations varies with different seasons and localities. Usually 1-3 summer generations and 1 overwintering. Overwinter as adults, larvae, or pupae beneath the bark of trees killed the previous season. Attacks may be primary or secondary.