Polygraphus rufipennis

Distinguished from similar bark beetles by its restriction to spruce hosts (Picea spp.) and association with male-produced aggregation pheromone 3-methyl-3-buten-1-ol. Four-week interval between first and second brood establishment may aid in distinguishing active populations. Attack densities of 8-9 per 100 cm² on felled/severed trees versus 4.7 on standing unsevered trees provide a quantitative population indicator.

Spruce forests; breeds in the bark of spruce trees. Colonization success is higher on trees felled in shade than in full sunlight. Thinner bark at greater bole heights correlates with reduced brood survival.

Northern and mountainous areas of North America. Documented in Newfoundland, New Brunswick, Alberta, British Columbia, and Labrador in Canada. GBIF records indicate presence in North America and Africa, though African records may require verification.

Emergence begins in late May and continues for approximately 11 weeks, with 50% emergence by mid-June. Two peaks of flight activity occur: one corresponding to spring brood emergence and another to parent adult re-emergence in summer. Females respond to male frass in winter; both sexes respond consistently in spring and summer.

Phloem tissue of spruce trees (Picea spp.).

• Picea mariana - hostblack spruce; supports breeding and survival
• Picea rubens - hostred spruce; most favourable host due to thicker, more scaly bark and reduced competition
• Picea glauca - hostwhite spruce; used in laboratory rearing studies

One generation per year with spring and summer broods. Development from egg to adult takes approximately two months. All brood stages except eggs overwinter in host trees, with larvae and callow adults comprising the majority of overwintering individuals. Parent adults re-emerge four weeks after establishing first brood to establish second brood.

Males initiate host colonization and produce an aggregation pheromone in frass that attracts both sexes. Following copulation, males exhibit guarding behavior by occupying the entrance hole. Adult activity levels and brood success are influenced by bark moisture content, with drier bark causing increasingly adverse effects over time.

Phloeophagous bark beetle contributing to spruce mortality, particularly in managed forest contexts. Serves as host for associated organisms including the cylindrical bark beetle Lasconotus intricatus, which utilizes its aggregation pheromone as a host-finding kairomone. Frequently secondarily attacked by Dryocoetes affaber and Crypturgus borealis; associated predatory flies include Medetera sp.

Contributes to black spruce mortality in Newfoundland, where projected wood shortages have focused attention on bark beetle impacts. Pheromone-based communication studied for potential management applications.

• Dendroctonus rufipennisSimilar specific epithet and shared association with white spruce; distinguished by genus-level differences in morphology and pheromone chemistry
• Dryocoetes affaberSecondary attacker of P. rufipennis-infested trees; not a primary colonizer
• Crypturgus borealisSecondary attacker of P. rufipennis-infested trees; not a primary colonizer
• Lasconotus intricatusAssociated cylindrical bark beetle attracted to P. rufipennis aggregation pheromone; distinguished by family (Colydiidae) and kairomone-mediated association

• bark beetle
• spruce
• forest pest
• pheromone
• Curculionidae
• North America
• phloeophagous

• BugGuide
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Fungi associated with Dendroctonus rufipennis and Polygraphus rufipennis, and white spruce inoculation tests
• Some Relationships Between Polygraphus rufipennis (Kirby) (Coleoptera: Scolytidae) and Spruces in New Brunswick
• THE EFFECTS OF BARK MOISTURE ON POLYGRAPHUS RUFIPENNIS (COLEOPTERA: SCOLYTIDAE) ADULTS AND THEIR DEVELOPING BROODS
• Evidence for a male‐produced aggregation pheromone in the four‐eyed spruce bark beetle, Polygraphus rufipennis (Kirby) (Col., Scolytidae)
• Bionomics of the four‐eyed spruce bark beetle, Polygraphus rufipennis(Kirby) (Col., Scolytidae) in Newfoundland I. Emergence and flight patterns
• ATTRACTION OF LASCONOTUS INTRICATUS KRAUS. (COLEOPTERA: COLYDIIDAE) TO THE AGGREGATION PHEROMONE OF THE FOUR-EYED SPRUCE BARK BEETLE, POLYGRAPHUS RUFIPENNIS (KIRBY) (COLEOPTERA: SCOLYTIDAE)
• Bionomics of the four‐eyed spruce bark beetle, Polygraphus rufipennis (Kirby) (Col., Scolytidae) in Newfoundland II. Host colonization sequence