Dicerca tenebrica

Distinguished from congeners by female genitalia: reduced or absent middle tooth. Flattened head shape and specific prothoracic margin configuration (parallel at base, expanded toward middle; subparallel near elytra, wider distally) aid separation from similar Dicerca species. Size range overlaps with other large Dicerca but tends toward larger extremes in females. Coloration alone insufficient for species identification due to similarity across genus. Confirmation requires examination of female abdominal sternites or male genitalia.

Associated with woodlands and forests containing host trees. Adults found on trunks and branches of living and recently dead host trees. Larval habitat is wood of host trees, boring in sapwood and heartwood. In Alberta, occurs in mixed coniferous forests; elsewhere primarily in deciduous woodlands with Populus species.

Nearctic region. Canada: Alberta, British Columbia, and eastern provinces. United States: northeastern states and southern states. Absent from much of New England, Appalachian Mountains, Allegheny Plateau, and upper Midwest where suitable hosts are lacking.

Adults active March through November, indicating extended flight period possibly including overwintering. This year-round adult presence pattern is characteristic of the genus Dicerca.

Adults feed on poplar species, especially balsam poplar (Populus balsamifera). In Alberta, has been observed feeding on lodgepole pine (Pinus contorta), aspens (Populus spp.), jack pine (Pinus banksiana), and white spruce (Picea glauca). Larvae bore in wood of host trees; specific larval diet presumed to be phloem and wood tissues of recorded hosts.

• Populus balsamifera - primary hostespecially favored adult food source
• Populus spp. - hostaspens
• Pinus contorta - hostAlberta populations
• Pinus banksiana - hostjack pine, Alberta
• Picea glauca - hostwhite spruce, Alberta

Complete metamorphosis (holometabolous). Eggs laid in bark crevices or under bark of host trees. Larvae bore into wood, creating galleries in sapwood and heartwood. Larval development likely extends over multiple years given size and wood-boring habit typical of large Buprestidae. Pupation occurs in wood. Adults emerge through exit holes. Adults may be present year-round, with peak activity March–November; some individuals likely overwinter under bark.

Adults exhibit cryptic behavior, resting on bark where metallic coloration and surface sculpturing render them nearly invisible. Rapidly colonize wind-thrown or cut trees while wood remains hard. Adults may be active throughout year, with winter hibernation under loose bark as observed in congeners. Adults feed on host foliage or bark; specific feeding behavior not detailed beyond host association.

Primary wood-borer in living and recently dead trees of host species. Contributes to nutrient cycling through wood decomposition. Creates habitat for other organisms through gallery systems. May act as secondary pest, attacking stressed or damaged trees. Serves as prey for woodpeckers and other bark-foraging predators.

Minor forestry pest, potentially damaging to poplar plantations and ornamental trees. Value to entomologists and collectors due to large size and attractive metallic coloration. Subject of ecological study regarding cryptic coloration and host associations. No significant direct economic importance documented.

• Dicerca obscuraSimilar size and appearance; distinguished by host association (primarily persimmon and sumac) and geographic distribution (eastern U.S., absent from upper Midwest and New England). Female genitalia differ.
• Dicerca luridaSimilar cryptic habits and coloration; primarily associated with hickories (Carya) rather than poplars. Distinguished by host preference and female genitalia.
• Dicerca asperataSimilar large size and metallic appearance; surface sculpturing more rugose. Distinguished by specific elytral punctation patterns and female genitalia.

• wood-borer
• jewel beetle
• cryptic
• poplar
• conifer
• North America

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• The Marvelously Cryptic Dicerca lurida | Beetles In The Bush
• The “obscure” Dicerca | Beetles In The Bush