Eucapnopsis brevicauda
(Claassen, 1924)
short-tailed snowfly
Eucapnopsis brevicauda is a in the Capniidae, commonly known as the short-tailed snowfly. It has a transpacific distribution spanning North America and eastern Asia, with confirmed records from Canada, the United States, Mongolia, Russia, and South Korea. emerge during late winter to spring and are typically found in association with cold, running water in sub-montane stream . The was previously misidentified as E. quattuorsegmentata in Korean records.
Pronunciation
How to pronounce Eucapnopsis brevicauda: /ˌjuːkæpˈnɒpsɪs ˌbrɛvɪˈkɔːdə/
These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.
Identification
Distinguished from the Japanese E. quattuorsegmentata by possessing more than four cercal segments (5 cercomeres versus 4). The combination of small size, grey coloration, weak , and specific male genitalic structures (high, rounded main ; large elliptical vesicle) separates it from other Eucapnopsis . In Korea, previously misidentified as E. quattuorsegmentata.
Appearance
Small, delicate, with weak and general grey coloration. Males: forewings 4.0–4.4 mm, body length 3.4–3.6 mm. Females: forewings 4.2–4.6 mm, body length 3.6–4.0 mm. composed of 5 nearly cylindrical cercomeres with elongated segments. Male IX not raised; vesicle large and elliptical; main high and rounded in lateral view. Female subgenital plate pale without dark markings, lacking posteromedial lobe.
Habitat
Sub-montane streams with cold, running water. Associated with lotic freshwater environments in forested mountain regions.
Distribution
Transpacific distribution: Canada (Alberta, British Columbia), United States (Alaska, Arizona), Mongolia, Russia (Russian Far East), and South Korea (Mt. Sobaeksan, Satancheon Stream in Sanasa valley, Mt. Odaesan, Mt. Bangtaesan). No confirmed records from North Korea. Rare in South Korea compared to .
Seasonality
period March to May (late winter through spring).
Life Cycle
Winter stonefly with in late winter to spring. Nymphal stages presumably occur in cold stream waters, though specific details are not documented.
Behavior
have been collected by sweeping vegetation and using . As with other winter stoneflies, likely active during cold periods when most other insects are inactive.
Similar Taxa
- Eucapnopsis quattuorsegmentataJapanese with which E. brevicauda was previously confused; distinguished by having only 4 cercal segments versus 5 in E. brevicauda
- Eucapnopsis koreensisSouth Korean that is widespread and common in the region where E. brevicauda is rare; distinguished by genitalic and subgenital plate
- Eucapnopsis jirisanaSouth Korean apparently confined to the Jiri Mountains; distinguished by morphological features of male and female genitalia
Misconceptions
Previously misidentified as Eucapnopsis quattuorsegmentata in Korean faunistic records; this error was corrected by recent taxonomic revision.
More Details
Taxonomic history
Originally described as Capnia brevicauda by Claassen in 1924, later transferred to Eucapnopsis. The epithet 'brevicauda' (short-tailed) refers to the relatively short compared to some relatives, though it has more segments than E. quattuorsegmentata.
Korean records
In South Korea, known from only a few localities despite extensive collecting, suggesting genuine rarity rather than under-sampling. The appears to have a disjunct distribution with the main in North America and a peripheral population in East Asia.