Western Conifer Seed Bug

Leptoglossus occidentalis

Seed bug

Western conifer seed bug (David Cappaert, Bugwood.org)

Seed bug

Western conifer seed bug (Steven Katovich, USDA Forest Service, Bugwood.org)

Seed bug

Western conifer seed bug nymphs (Sandy Kegley, USDA Forest Service, Bugwood.org)


  • 5/8 – 3/4 inch long
  • overall brownish color; yellow-orange upper abdomen with 5 black patches visible during flight
  • flat, leaf-like projections on hind legs
  • emit a piney odor when handled
  • similar in appearance to western leaf-footed bug; distinguished by absence of thorn-like projection extending from the head

Nesting Habits

  • develop on pines, Douglas-firs and other conifers


  • primarily seeds of pines and Douglas-fir


  • common invader of homes as individuals or in small clusters
  • seek overwintering sites indoors when cold fall weather begins (September – October)
  • major outbreaks/migrations can occur in the fall
  • resemble kissing bugs (Triatoma spp.) but pose no threat to human health

IPM Recommendations

  • Eliminate weeds in landscaping around the building.
  • Equip foundation and attic vents with tight-fitting screens during warmer months.
  • Find and seal any exterior cracks.
  • Vacuum conifer seed bugs found in- or outdoors.