Purpuricenus axillaris

Distinguished from P. humeralis by transverse (not triangular) basal elytral markings that do not extend only to humeri, and by apical dark area not extending forward along suture to scutellum. Separated from the very similar P. paraxillaris by smaller more gracile body, weaker pronotal tubercles lacking polished apical line on median callus, obtuse rather than acute lateral pronotal angles, finer sparser basal elytral punctation, subtruncate rather than emarginate elytral apices without distinct teeth, and yellow to orange rather than orange to red-orange elytral markings.

Large, robust cerambycid beetle with velvety black elytra bearing vivid yellow to orange transverse markings covering the basal half of each elytron. Posterior margin of basal markings is more or less transverse, not oblique. Pronotum with weak discal calluses; median callus lacks a polished apical line. Lateral pronotal tubercles are small with obtuse angles. Basal elytral punctation relatively fine and sparse. Elytral apices subtruncate, angles not distinctly dentate. Smaller and more gracile than the similar P. paraxillaris.

Associated with dry, post oak woodlands and interfaces between woodland and glade habitats. Adults have been collected in fermenting bait traps placed along upwind edges between dry post oak woodland and dolomite glades.

Eastern North America; recorded from Ontario, Canada and United States. Historical literature records may include misidentifications with P. paraxillaris.

Adults active from early June through mid-September based on bait trap collections in Missouri. Peak activity period not precisely determined.

Larvae feed on hickory (Carya species). Adult feeding habits not documented.

• Carya - larval hostPreferred larval host; based on reared specimens

Complete metamorphosis with wood-boring larval stage in hickory. Specific details of egg laying, larval development duration, pupation, and adult longevity not documented.

Strongly attracted to fermenting baits including molasses/beer mixtures and red wine. Readily falls into open-top bait buckets rather than perching on trap surfaces. Diurnal habits inferred from related species but not directly confirmed.

Wood-boring beetle whose larvae develop in living or recently dead hickory trees. Role in nutrient cycling through dead wood decomposition. Specific ecological interactions not documented.

Collected by entomologists using fermenting bait traps for survey and study. No documented economic importance as pest or beneficial species. Subject of taxonomic study that helped clarify species boundaries in the genus.

• Purpuricenus paraxillarisVery similar sympatric species distinguished by larger more robust body, stronger pronotal tubercles with polished apical line on median callus, acute lateral pronotal angles, coarser denser basal elytral punctation, emarginate elytral apices with distinct teeth, and orange to red-orange elytral markings. Uses oak and chestnut rather than hickory as larval host.
• Purpuricenus humeralisDistinguished by triangular basal elytral markings covering only humeri rather than entire basal half, and apical dark area extending forward along suture to scutellum.

Historically confused with P. paraxillaris, with many literature references to P. axillaris actually referring to the undescribed species. The two species were not recognized as distinct until 2000, after examination of large series from bait trapping revealed consistent morphological differences.

• Cerambycidae
• longhorned beetle
• wood-borer
• hickory
• fermenting bait
• North America

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• Catalogue of Life
• A Silver Anniversary | Beetles In The Bush
• Disteniidae | Beetles In The Bush