Crossidius ater

LeConte, 1861

Grizzled Long-horned Beetle

Crossidius ater is a in the , distinguished from by its uniformly black coloration without the , red, or orange markings typical of other Crossidius . It was described by John Lawrence LeConte in 1861 and occurs across the Great Basin and surrounding mountainous regions of western North America. Unlike its more -specific relatives, it utilizes multiple rabbitbrush species and shows minimal geographic variation across its range.

Pronunciation

How to pronounce Crossidius ater: /ˈkrɒsɪdiəs ˈɑːtər/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Easily distinguished from other Crossidius by its completely black coloration. Most exhibit varying amounts of , red, or orange markings on the body. Shows almost no geographic variation in appearance across its range, unlike C. coralinus and C. hirtipes which are divided into numerous geographically restricted .

Appearance

Uniformly black throughout, lacking the , red, or orange coloration present in most other Crossidius . Body form typical of the with elongated . includes longer antennae in males.

Habitat

Sagebrush and rabbitbrush chaparral in mountainous and basin regions. Associated with gray rabbitbrush (Ericameria nauseosa) and rabbitbrush (Chrysothamnus viscidiflorus) stands. Occurs in wet bottomland forests, high desert sage, and pinyon-juniper woodland .

Distribution

Western North America: Great Basin and surrounding areas including Nevada, California (eastern Sierra Nevada, Mono Basin, Owens Valley), Utah, Colorado, and north to British Columbia. Records from Pine County, Nevada; Mono County, California; and areas near Lake Tahoe.

Seasonality

active in late summer and early autumn, particularly August through October. Peak activity coincides with rabbitbrush bloom.

Diet

feed on flowers of rabbitbrush including Ericameria nauseosa (gray rabbitbrush), Chrysothamnus viscidiflorus ( rabbitbrush), Haplopappus bloomeri, H. suffruticosa, and Gutierrezia sarothrae. have been recorded from roots of Artemisia tridentata (big sagebrush).

Host Associations

Ericameria nauseosa - food sourcegray rabbitbrush
Chrysothamnus viscidiflorus - food source rabbitbrush
Haplopappus bloomeri - food source
Haplopappus suffruticosa - food source
Gutierrezia sarothrae - food source
Artemisia tridentata - larval and recorded from roots

Behavior

are , visiting flowers of multiple rabbitbrush . Often found perched on , sometimes hidden within flower clusters during cooler periods. Readily comes to blacklights. More generalized use than , utilizing multiple rabbitbrush species rather than showing strong preference for single host plants.

Ecological Role

of rabbitbrush ; larval development in roots contributes to in sagebrush .

Human Relevance

Subject of entomological interest due to distinctive all-black appearance among colorful . No known economic importance.

Similar Taxa

Crossidius coralinusSimilar size and body form, but distinguished by bright red, orange, or coral coloration with black markings; highly -specific to Ericameria nauseosa
Crossidius hirtipesSimilar size and body form, but distinguished by reddish- to dark coloration with variable elytral markings; primarily associated with Chrysothamnus viscidiflorus
Neandra brunneaSimilar dark coloration and form, but distinguished by (entire in C. ater) and different pronotal structure; belongs to archaic Parandrinae

More Details

Taxonomic stability

Unlike C. coralinus and C. hirtipes, which have been divided into numerous based on color and marking variation, C. ater shows almost no geographic variation and has not been subdivided into subspecies.

Host plant generalization

C. ater is notably less -specific than , utilizing multiple rabbitbrush (Ericameria, Chrysothamnus, Haplopappus, Gutierrezia) and even a non-rabbitbrush genus (Artemisia) for larval development.