Fauna
Insect

Western Conifer Seed Bug

Leptoglossus occidentalis

Also known as Pine Seed Bug

Western conifer seed bugs feed on the sap and embryonic seeds of pines, firs, and spruces using piercing-sucking mouthparts. In autumn, adults frequently seek warm overwintering shelters, clustering on exterior walls and wandering into homes where their buzzing flight and leaf-like hind legs cause alarm. When threatened or crushed, they release a pungent pine-scented chemical defense from thoracic glands to deter predators.

HerbivorousForest DwellerIntroduced
Western Conifer Seed Bug reference1 / 7
(c) Holger Krisp, some rights reserved (CC BY) · cc-by
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Not EvaluatedConservation statusIUCN Red List categoriesLCNTVUENCREWEXNot Evaluated — not placed on the risk ladderRed List categories, explained →
Key facts
Diet & preyPine seed pulp, Douglas-fir cones, Spruce seed sap
Predators
  • Insectivorous birds
  • Spiders
  • Assassin bugs
ThreatsSevere winter freezes, targeted insecticide application, and predation
HabitatsConiferous forests, mixed woodlands, parks, suburban gardens, and buildings
Life span9–12 months
Classification
  1. OrderHemiptera
  2. FamilyCoreidae
  3. GenusLeptoglossus
  4. SpeciesLeptoglossus occidentalis
Range & activity
Range data is not available yet.
Safe observation
Interaction riskLow
  1. Low
  2. Moderate
  3. High
  4. Very high
Why interaction risk is low
Harmless to humans; safe to observe at a normal distance.
Responsible observation
  • Indoor Removal: Gently trap indoors with a cup and cardboard to release outside without triggering their scent defense.
  • Identification Check: Look for distinct flattened leaf-like expansions on the hind legs to separate it from stink bugs.
  • Cone Inspection: Examine immature pine or Douglas-fir cones in midsummer to spot developing reddish-brown nymphs.
Related species
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