Cylindrocopturus furnissi

Cylindrocopturus furnissi. (Photo courtesy of Oregon Department of Agriculture.)

Cylindrocopturus furnissi. (Photo courtesy of Oregon Department of Agriculture.)

General Pest Information

Exit holes from adult Douglas-fir twig weevil. (Photo courtesy of Oregon Department of Agriculture.)
Gallery from larval feeding. (Photo by Gary Chastagner, Washington State University.)

Exit holes from adult Douglas-fir twig weevil. (Photo courtesy of Oregon Department of Agriculture.) [Top]

Gallery from larval feeding. (Photo by Gary Chastagner, Washington State University.) [Bottom]

Pest identification

  • Adults are 2 to 3 mm (1∕10") long.
  • Bronze-colored (sometimes spotted) with long beaks
  • Larvae are legless, white, C-shaped grubs.

Biology and life cycle

  • Adults emerge between mid-June and early August but can be present throughout the year.
  • Adults feed on the inner bark of new twigs.
  • Eggs are laid in punctures in twigs and branches about a month after adult emergence.
  • Larvae bore in Douglas-fir twigs, branches, and leaders.
  • Pupation occurs in April through mid-July.
  • Larvae can be present throughout the year.
  • One generation and a partial second generation occur each year.

Management

(Photo by Gary Chastagner, Washington State University.)

(Photo by Gary Chastagner, Washington State University.)

Growing years

  • Control from July to early August, when most adults emerge; be aware that adults can be present any time. (Visit the PNW Insect Management Handbook.)
  • Maintain vigorous growth.
  • Avoid planting or replanting stress-prone sites.
  • Remove or destroy infested trees.
  • Prune out damaged branches.

At harvest

  • Identify and remove trees with damage.
  • Do not ship unhealthy, damaged trees.

Calendars

Life cycle

Life cycle calendar

  • Look for eggs: July through mid-August
  • Look for larvae: all year
  • Look for pupae: April through mid-July
  • Look for adults: all year

Management

Management calendar

  • Dead branches present: all year
  • Look for larvae actively tunneling in twigs, branches, and leaders: mid-January through the beginning of May
  • Control adults: July through August
  • Remove dead branches and trees: September through October