Douglas-fir twig weevil
Cylindrocopturus furnissi
4 host plants
Last updated
Douglas-fir twig weevil larvae feed inside twig bark and shoot tips of young Douglas-fir trees, causing stunting and dieback of new growth. You will see wilted, brown shoot tips with exit holes where larvae have exited. New leaders and branch tips fail to develop normally, leaving trees misshapen. Damage is most serious on young plantations and nursery stock; established trees tolerate it better.
Prune out damaged shoots below the injury zone and remove them from the site. Maintain young trees with consistent watering and avoid stress that attracts weevils. No effective chemical control is practical in field settings. Most nurseries use cultural practices to manage populations in production. Accept that young trees will show some dieback; they usually recover and grow normally once established and mature.
Quick Reference
Cultural Controls
- Provide proper culture and minimize stress for trees, especially young ones.
- Healthy plants are more able to withstand insect feeding.
- Prune and destroy infested twigs, burning where possible.
- Hand-pick adults to control minor infestations on small trees, where practical.