Dendroctonus terebrans

Distinguished from other Dendroctonus species by its larger size (5–8 mm vs. 2–4 mm for most congeners), attack location on the lower bole and stumps rather than upper trunk, and less destructive impact on host trees. The gallery pattern—initially horizontal then turning vertically downward, often extending below ground level—differs from the more complex patterns of D. frontalis. Pitch tubes at the base of the trunk are pinkish from resin mixed with wood dust. Distinguished from D. valens (red turpentine beetle) by geographic range; the two species overlap very little, with D. terebrans primarily in the eastern coastal plain and D. valens more widespread inland.

Pine forests, particularly in the coastal plain. Attacks living pine trees near the base of the trunk (lower few feet) and freshly cut pine stumps. Strongly attracted to volatile chemicals from freshly cut pine stumps and stressed trees. Often found in association with trees simultaneously attacked by Ips spp. (engraver beetles) and Dendroctonus frontalis.

Native to eastern United States. Range extends from New Hampshire south through the coastal plain to Florida, and westward to Texas and Missouri. Attacks both native pines and exotic pine species.

In Florida, breeding occurs year-round with up to three overlapping generations. Activity peaks vary by region but generally coincide with warmer months when flight and reproduction are optimal.

Adults and larvae feed on phloem tissue of pine trees (Pinus spp.). Larvae tunnel through surface layers of sapwood, creating galleries packed with frass.

• Pinus spp. - hostBoth native and exotic pine species; specifically noted for loblolly pine (P. taeda)
• Leptographium terebrantis - symbiontBlue-stain fungus vectored by the beetle; weak pathogen that contributes to tree mortality in combination with beetle damage
• Leptographium serpens - symbiontAdditional blue-stain fungus associate

Females initiate attacks by tunneling into bark, overcoming resin defenses to create pinkish pitch tubes at entry sites. After successful entry, females excavate galleries—initially horizontal, then vertically downward, often below ground level—for approximately two weeks. Males join females, and females lay about 100 eggs along one side of the gallery. Eggs hatch in 10–14 days. Larvae fan out and feed side by side through sapwood surface layers, creating frass-packed galleries. Upon completing development, larvae tunnel individually to create pupation chambers. Adults emerge, disperse, and seek new hosts. In Florida, three overlapping generations occur annually with year-round breeding.

Exhibits mass attack behavior facilitated by aggregation pheromones. Females are pioneering attackers that release frontalin and trans-verbenol to attract males and additional females. Males produce endo-brevicomin, exo-brevicomin, and myrtenol. The species responds synergistically to host resin monoterpenes (α-pinene, β-pinene) combined with pheromones. Produces semiochemicals that attract the southern pine beetle (D. frontalis), potentially acting as a kairomone source for this more destructive congener. Can vector blue-stain fungi to host trees, contributing to tree mortality beyond direct feeding damage.

Primary bark beetle of pine forests that contributes to tree mortality and forest disturbance dynamics. Acts as a pioneer species that may facilitate attack by more aggressive bark beetles through semiochemical signaling. Vectors blue-stain fungi (Leptographium spp.) that further compromise tree health. Provides habitat and food resources for predators including the introduced European beetle Rhizophagus grandis, which is attracted to larval frass and has been investigated for biological control.

Economic pest of pine forestry, though less destructive than D. frontalis. Damage is concentrated in the lower bole and stumps, reducing timber value. Management typically focuses on removing stressed trees and fresh stumps that attract beetles. Biological control using Rhizophagus grandis was investigated with releases in Louisiana in 1988. Semiochemical-based monitoring and management approaches have been developed. Firewood from infested trees can spread the pest to new areas.

• Dendroctonus frontalisShares hosts and geographic range; distinguished by smaller size, upper trunk attack location, more destructive mass attacks, and more complex gallery patterns. D. terebrans produces semiochemicals that attract D. frontalis, potentially facilitating its attacks.
• Dendroctonus valensSimilar size and common name (red turpentine beetle); distinguished by more widespread distribution in eastern North America with minimal range overlap, and reddish coloration. Gallery patterns are similar.
• Dendroctonus rhizophagusMexican bark beetle with similar gallery patterns on pine; distinguished by geographic restriction to Mexico and different pheromone chemistry.
• Ips spp.Engraver beetles often found attacking same trees; distinguished by smaller size, different gallery patterns (Y- or H-shaped), and attack of upper trunk and branches rather than base.

• bark beetle
• forest pest
• pine
• Scolytinae
• pheromone
• blue-stain fungus
• vector
• aggregation pheromone
• kairomone
• biological control

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• The Day That The Beetles Invaded the Bohart | Bug Squad
• Publications | Entomology Research Museum
• 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
• Pheromone Treatment Puts Up the "No Vacancy" Sign for Douglas-Fir Beetles
• Pathogenicity of Blue-Stain Fungi Associated with Dendroctonus terebrans
• Leptographium terebrantis sp. nov. associated with dendroctonus terebrans in loblolly pine
• Kairomonal‐pheromonal system in the black turpentine beetle, Dendroctonus terebrans (Ol.)1
• Antennal olfactory responses of black turpentine beetle,Dendroctonus terebrans (Olivier), to bark beetle pheromones and host terpenes
• Potential for a minor pine bark beetle pest, Dendroctonus terebrans (Coleoptera: Curculionidae: Scolytinae), to mediate host location by a major pine killer, Dendroctonus frontalis
• Correction to: Electrophysiological and behavioral responses Dendroctonus frontalis and D. terebrans (Coleoptera: Curculionidae) to resin odors of host pines (Pinus spp.)
• Electrophysiological and behavioral responses Dendroctonus frontalis and D. terebrans (Coleoptera: Curculionidae) to resin odors of host pines (Pinus spp.)