Stenaspis verticalis insignis

Distinguished from the nominate subspecies Stenaspis verticalis verticalis by geographic distribution and potentially by coloration. The specific epithet 'insignis' suggests notable or marked appearance. Adults have annulated (ringed) antennae. Males and females can be found together in mating pairs on host plants. Similar to other Stenaspis species but separable by combination of host plant association and geographic range.

Associated with Baccharis sarothroides (desert broom) in desert grassland and oak woodland ecotones. Collected in lower elevation canyons with mixed vegetation including mesquite, acacia, and desert broom. Occurs in areas with sandy or rocky soils in southwestern sky island mountain ranges.

Southwestern United States (Arizona) and Mexico. Documented from the Santa Rita Mountains in Arizona. GBIF records indicate presence in Guatemala and Honduras, suggesting broader Middle American distribution. The subspecies represents the westernmost population of the species complex.

Active during summer monsoon season. Collected in late July to early August in Arizona. Adult activity coincides with flowering of host plants and warm, humid conditions.

• Baccharis sarothroides - breeding hostAdults collected from foliage and stems; mating pairs observed on this plant

Adults are diurnal and can be found resting on host plant foliage. Mating pairs remain in copula on host plants. Beetles are apparently not attracted to ultraviolet lights, as no specimens were collected at blacklight stations despite intensive sampling in appropriate habitat. Adults are likely strong fliers based on their occurrence in open, windy canyon habitats.

• Stenaspis solitariaSympatric in Arizona; also found on Baccharis sarothroides and similar host plants. S. verticalis insignis distinguished by larger size and different antennal structure.
• Stenaspis verticalis verticalisNominate subspecies occurring further east; separable by geography and subtle morphological differences in coloration and punctuation.

• Cerambycidae
• Trachyderini
• Southwestern US
• Mexico
• desert broom associate
• diurnal
• rarely attracted to lights

• BugGuide
• GBIF taxonomy match
• iNaturalist taxon
• Catalogue of Life
• Sphecidae | Beetles In The Bush
• Erebidae | Beetles In The Bush | Page 2