Seasonal development
and life cycle—Flatheaded Borer
Flatheaded borer females lay their eggs in bark crevices. Young larvae feed under the bark in the rapidly
growing outer wood and bore deeper into the trunk to pupate. Excavations are usually filled with a finely
powdered sawdust. Pacific flatheaded borer and alder borer have one generation a year. Oak twig girdler
takes 2 years to complete its life cycle.
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Pacific
flatheaded borer adult
Flatheaded
borer larva
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