Plionoma suturalis

Distinguished from the similar Batyle suturalis by belonging to the tribe Trachyderini rather than other cerambycine tribes. Separated from the congeneric Plionoma rubens by geographic distribution and subtle morphological differences. The combination of large size, bright coloration, diurnal activity, and strict association with mesquite flowers in the southwestern U.S. and Oklahoma helps identify this species. The 2013 Oklahoma specimens were immediately recognizable to experienced collectors despite representing a significant range extension.

Large, colorful longhorned beetle with bright coloration typical of the Trachyderini tribe. Sexual dimorphism present: males and females can be distinguished, with females observed feeding on mesquite flowers. The species shares the general facies of Trachyderini members—robust body form with vivid patterning.

Mesquite chaparral and associated arid habitats. Strongly associated with honey mesquite (Prosopis glandulosa, syn. Neltuma glandulosa) trees, where adults are found on both living branches and flowers. In Oklahoma, occurs in gypsum-capped mesa landscapes with red clay soils at Gloss Mountains State Park. The habitat has been described as having a 'New Mexican' character despite being in northwestern Oklahoma.

Native to southwestern North America. Documented from Texas west to California and south into northern Mexico. The 2013 discovery in Major County, Oklahoma (Gloss Mountains State Park) represented a new state record and significant northeastern range extension—the closest previous records were from Wichita County, Texas, over 200 miles to the south. GBIF records indicate presence in Mexico (MX) and the United States (US).

Adults exhibit bimodal seasonal activity: active during spring months (May-June), absent during summer, then reappearing in fall. In the Lower Rio Grande Valley of south Texas, found on fresh-cut mesquite and huisache (Acacia farnesiana) in fall and on blossoms of fabaceous trees during spring and early summer. Oklahoma records from early June represent the northern extent of spring activity.

Adults feed on mesquite flowers (Prosopis glandulosa). In the Lower Rio Grande Valley, also observed on huisache (Acacia farnesiana) flowers. Larval diet unknown but presumably develops in woody tissue of host plants.

• Prosopis glandulosa - adult feeding; probable larval hostHoney mesquite; adults abundant on flowers and living branches
• Acacia farnesiana - adult feedingHuisache; documented in south Texas

Complete metamorphosis with bimodal adult emergence pattern. Larval development presumably occurs within woody host tissue, though specific details unreported. Adults overwinter or aestivate during summer months, with spring and fall activity peaks suggesting either two generations per year or a single generation with extended adult longevity and summer inactivity.

Diurnal (day-active) with strong attraction to flowers. Adults observed in mating pairs on mesquite trees. Highly abundant at peak activity, with collectors obtaining 'several dozen specimens' in short periods. Exhibits typical trachyderine behavior of visiting blossoms for feeding and mating. In Oklahoma, found on both living branches and flowers of mesquite, suggesting flexible adult movement within host trees.

Adults function as pollinators or pollen feeders on mesquite and related leguminous trees. As woodboring beetle larvae, presumably contribute to nutrient cycling in dead or dying woody tissue. The 2013 Oklahoma discovery highlighted the role of under-surveyed regions in understanding true species distributions.

Subject of entomological collecting interest due to bright coloration and relative scarcity in collections. The 2013 Oklahoma record was significant enough to warrant collection of voucher specimens for scientific documentation. Used as example species in studies of longhorned beetle trapping efficacy using ethanol and wine-baited jug traps.

• Batyle suturalisShares similar name and general appearance but belongs to different tribe; distinguished by tribal assignment and subtle morphological differences
• Plionoma rubensCongener with similar bright trachyderine coloration; the other U.S. species in the genus, distinguished by distribution and minor morphological features

• Trachyderini
• flower-visiting
• diurnal
• bimodal activity
• range extension
• new state record
• mesquite associate
• Oklahoma
• southwestern fauna

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• Catalogue of Life
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