Listrus senilis

The species can be identified by its small size (<5 mm), gray coloration, and consistent association with yellow asteraceous flowers. Mawdsley (1999) provides a formal redescription with diagnostic characters distinguishing it from related taxa. It resembles other small dasytine melyrids but can be confirmed by reference to the MCZ type specimen.

Adults measure less than 5 mm in length. The body is small and gray in coloration. Detailed morphological descriptions are provided in Mawdsley (1999), including redescriptions of diagnostic features.

Open prairie and grassland habitats with exposed gypsum or clay soils. Associated with flowering vegetation in sunny conditions.

Great Plains of North America, from Alberta, Canada south to Texas, USA. Documented from Oklahoma (Glass Mountains, Alabaster Caverns State Park), and inferred to occur throughout the central plains based on Mawdsley (1999).

Adults active in fall (October documented). Activity period coincides with blooming of yellow-flowered asteraceous host plants.

Adults feed on pollen of yellow-flowered asteraceous plants, particularly Heterotheca stenophylla (stiffleaf false goldenaster) and Heterotheca subaxillaris.

• Heterotheca stenophylla - pollen sourcestiffleaf false goldenaster
• Heterotheca subaxillaris - pollen sourcestiffleaf false goldenaster

Adults are pollen feeders, frequently observed singly or in small aggregations (up to 4-5 individuals) on individual flowers. They are diurnal and associated with sunny conditions.

Pollen consumer on native asteraceous plants; likely contributes to pollination through incidental pollen transfer.

• Epicauta species (Meloidae)Similar gray coloration and flower-visiting behavior, but Epicauta are blister beetles (family Meloidae), typically larger, with different body shape and elytral texture. Listrus senilis is distinguished by smaller size (<5 mm vs. 10+ mm) and family-level characters of Melyridae.
• Other DasytinaeSmall gray dasytines share general appearance; precise identification requires reference to Mawdsley (1999) redescription and comparison with type material.

• pollen-feeder
• asteraceae-associate
• great-plains
• fall-active
• small-size

• BugGuide
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Meloidae Holdings | Entomology Research Museum
• Meloidae | Beetles In The Bush | Page 3