Colias behrii

Edwards, 1863

Behr's sulphur, Sierra green sulfur, Sierra Sulphur

Colias behrii is a small alpine to the Sierra Nevada of California, restricted to high-elevation mostly around and above 9,000 feet. It has a wingspan of 35–42 mm and is active from July to August. The has been subject to genetic study revealing a historical range-wide bottleneck approximately 531–281 years ago, coinciding with a period of global cooling.

Colias behrii by (c) Christine Melvin, some rights reserved (CC BY), uploaded by Christine Melvin. Used under a CC-BY license.

Colias behrii01 by Colorado State University. Used under a CC BY 3.0 license.

Colias behrii female 01 ventral side ZISP by Josef Grieshuber. Used under a CC BY-SA 3.0 license.

Pronunciation

How to pronounce Colias behrii: /ˈkoʊ.li.əs ˈbɛə.raɪ/

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

Identification

Distinguished from other Colias by its restricted high-elevation distribution in the Sierra Nevada; are on wing in mid-summer (July–August) when many other alpine butterflies have completed their period. The species' alpine preference separates it from lower-elevation sulphurs such as Colias eurytheme.

Images

Habitat

Alpine meadows and high-elevation in the Sierra Nevada, mostly around and above 9,000 feet elevation.

Distribution

to California's Sierra Nevada from Tuolumne County south to Tulare County.

Seasonality

are on wing from July to August.

Diet

feed on flower nectar. Larvae feed on Vaccinium and Gentiana newberryi.

Host Associations

Vaccinium - larval plant not specified
Gentiana newberryi - larval plant

Life Cycle

stage not explicitly documented; supercooling points have been studied in comparison to Parnassius clodius, suggesting diapausing eggs with cold adaptations.

Human Relevance

Subject of research on cold and thermal ; reared in captivity for study and educational purposes. The has been featured in seminars at the Bohart Museum of Entomology.

Similar Taxa

Colias eurythemeBoth are yellow sulphur butterflies in the Colias, but C. eurytheme occurs at lower elevations in agricultural and urban areas, has multiple per year, and is a significant pest of alfalfa
Parnassius clodiusShares high-elevation and cold-adapted ; both have been studied for thermal of , though P. clodius belongs to Papilionidae and has different larval plants

More Details

Genetic history

Microsatellite data indicate a range-wide genetic bottleneck 531–281 years ago followed by rapid growth, coinciding with the Little Ice Age. This demographic event overwhelms contemporary landscape factors in shaping genetic patterns.

Conservation concern

Like other alpine , the is vulnerable to climate change; rising tree lines would eliminate its high-elevation with no higher ground available for range shift.