E. General life cycles 1. The insects usually have only one generation per year, bark beetles are the exception. These have up to 4 generations per year 2. Larvae feed until the pupate, then spend their pupal stage under the bark, emerging as adults fully formed. Round and flatheaded borers may burrow into deeper wood to pupate.
Emergence is in the early spring and usually continues through early summer.
When adults of moths emerge, they leave behind an amber colored pupil skin in the mouth of the burrow which is sufficient to identify the insect as a moth F. General control 1. Once beetles are feeding inside the bark they cannot be controlled. Dursban and Sevin are replacements and these must be used twice a year 3. Dispose of killed trees to reduce the population of insects 4. As and alternative, wood stacks can be covered with 8 mil thick clear polyethylene film sealed at the bottom.