Dendroctonus jeffreyi

Jeffrey pine forests; occurs in coniferous forests dominated by its host tree Pinus jeffreyi, from southwestern Oregon through California to western Nevada and Baja California. Found at elevations ranging from approximately 6,200 feet to over 8,000 feet in the Sierra Nevada.

Western North America: southwestern Oregon, California (Sierra Nevada, San Bernardino Mountains), western Nevada, and Baja California. GBIF records confirm presence in Middle America and North America.

Phloem of Jeffrey pine (Pinus jeffreyi); adults and larvae feed on the inner bark and phloem tissue of host trees.

• Pinus jeffreyi - obligate hostMonophagous; sole host tree species
• Ophiostoma clavigerum - mutualistMycangial fungus transported by beetle; vectored to host trees and contributes to tree mortality

Eggs laid under bark of host trees; larvae develop in phloem galleries; pupation occurs in gallery chambers; adults emerge to colonize new hosts. Development timing varies with temperature; may produce multiple generations in favorable conditions.

Adults bore into bark to establish egg galleries; mass attack behavior during outbreaks; males produce pheromones including (+) and (−)-frontalin and (+)-exo-brevicomin; females produce 1-heptanol as principal pheromone component; both sexes attracted to 1-heptanol plus host resin component heptane; possesses mycangia for fungal transport.

Primary pest of Jeffrey pine; causes significant tree mortality during outbreaks; vector for Ophiostoma clavigerum fungus; contributes to forest succession and fuel load dynamics; alters forest composition and structure through selective mortality of dominant conifer.

Major forest pest causing economic losses through timber mortality; management through sanitation cutting and removal of infested trees; subject of pheromone research for monitoring and potential control; fire hazard concerns due to standing dead trees following outbreaks.

• Dendroctonus ponderosaeMountain pine beetle; similar size and morphology; distinguished by host preference (primarily Pinus ponderosa and other pine species), different pheromone chemistry, and geographic overlap in some areas
• Dendroctonus frontalisSouthern pine beetle; similar gallery patterns and life history; distinguished by geographic range (eastern North America), host preferences for southern pines, and pheromone composition
• Dendroctonus brevicomisWestern pine beetle; similar morphology and biology; distinguished by host preference for Pinus ponderosa and different pheromone components

• bark beetle
• forest pest
• Jeffrey pine
• monophagous
• mycangial fungus
• pheromone
• phloem feeder
• western North America
• Scolytinae
• tree mortality
• outbreak dynamics
• semiochemicals
• vector
• symbiosis

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Publications | Entomology Research Museum
• The Day That The Beetles Invaded the Bohart | Bug Squad
• Trees of Lake Tahoe – The Pines | Beetles In The Bush
• Southern Pine Beetle: How a Fellow Species May Help in Host Location
• Managing Southern Pine Beetle Infestations in a Changing Forest Environment
• Eastern Larch Beetle Outbreak Keeps Going When Winter's Not So Cold
• Identification of Semiochemicals Associated with Jeffrey Pine Beetle, Dendroctonus jeffreyi
• Allozyme diversity and gene flow in the bark beetle, Dendroctonus jeffreyi (Coleoptera: Scolytidae)
• Allozyme diversity and gene flow in Ophiostoma clavigerum (Ophiostomatales: Ophiostomataceae), the mycangial fungus of the Jeffrey pine beetle, Dendroctonus jeffreyi (Coleoptera: Scolytidae)