White-stockinged Black Fly

Simulium venustum

General Status Rank: 
Secure
Common Name: 
White-stockinged Black Fly
Scientific Name: 
Simulium venustum
Naming References: 
B170
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Taxonomy
Group: 
Fly (Blackfly)
Kingdom: 
Animalia
Phylum: 
Arthropoda
Class: 
Insecta
Order: 
Diptera
Family: 
Simuliidae
References: 
B170
General Biology

Longevity

This species is univoltine, however some stenothermal streams produce 2 or more generations (or cohorts) per year. Eggs can overwinter in the sediments of dry streambeds.
References: 
B170

Economic/Human Considerations

Attracted to carbon dioxide and sweat in humans. Biting typically occurs after walking on the skin for 2-5 seconds.
Habitat
One of the most common blackflies in North America. Immature stages are found in a wide variety of streams and small rivers from the mountains to the coastal plain, but are encountered most frequently in rocky woodland streams. Larvae and pupae are able to tolerate a broad range of physical and chemical conditions and currents. The tendancy of females to feed increases with age, with max. feeding at 7 days. Attracted to carbon dioxide and sweat in humans. Biting typically occurs after walking on the skin for 2-5 seconds.
References: 
B170
Distribution

Ecozones

Southern Arctic, Taiga Plains
References: 
B170

Distribution

3/175 x 100 = 2%
Score: 
FG
References: 
B170

Number of Occurrences

4, Reindeer Depot-Inuvik, Normand Wells, Thelon R.
Score: 
AD
References: 
B170

Area of Occupancy

Score: 
-
Population

Population Size

Widespread
References: 
B170
Threats

Threats

Larvae are hosts of mermithid nematodes, chytrid fungi, trichomycete fungi and microsporidia.
Score: 
C
References: 
B170

Intrinsic Vulnerability

Score: 
-
References: 
B170
General Status Rank
Rank: 
Secure
Status Rank Description: 
Widely distributed, but rarely collected species. Member of a cryptic species complex, likely more prevalent than suggested by few confirmed occurrences. Presumed stable.
S Rank: 
S3S4
Decision Process Description: 
Drafted by Doug Currie, Royal Ontario Museum (January 2009); Draft ranks in 2014 by Patrick Schaefer for the black flies and horse flies for the National General Status Ranking Program.
Last Updated: 
July 14, 2014

References

Ecozones

  • Adler, P.H., Currie, D.C., Wood, DM. (2004) The Black Flies (Simuliidae) of North America. Comstock Publishing Associates, Cornell University Press ENR Library - B170 Return

Habitat

  • Adler, P.H., Currie, D.C., Wood, DM. (2004) The Black Flies (Simuliidae) of North America. Comstock Publishing Associates, Cornell University Press ENR Library - B170 Return

Intrinsic Vulnerability

  • Adler, P.H., Currie, D.C., Wood, DM. (2004) The Black Flies (Simuliidae) of North America. Comstock Publishing Associates, Cornell University Press ENR Library - B170 Return

Longevity

  • Adler, P.H., Currie, D.C., Wood, DM. (2004) The Black Flies (Simuliidae) of North America. Comstock Publishing Associates, Cornell University Press ENR Library - B170 Return

Naming

  • Adler, P.H., Currie, D.C., Wood, DM. (2004) The Black Flies (Simuliidae) of North America. Comstock Publishing Associates, Cornell University Press ENR Library - B170 Return

Number of Occurrences

  • Adler, P.H., Currie, D.C., Wood, DM. (2004) The Black Flies (Simuliidae) of North America. Comstock Publishing Associates, Cornell University Press ENR Library - B170 Return

Population Size

Adler, P.H., Currie, D.C., Wood, DM. (2004) The Black Flies (Simuliidae) of North America. Comstock Publishing Associates, Cornell University Press ENR Library - B170 Return

Range Extent

  • Adler, P.H., Currie, D.C., Wood, DM. (2004) The Black Flies (Simuliidae) of North America. Comstock Publishing Associates, Cornell University Press ENR Library - B170 Return

Taxonomy

  • Adler, P.H., Currie, D.C., Wood, DM. (2004) The Black Flies (Simuliidae) of North America. Comstock Publishing Associates, Cornell University Press ENR Library - B170 Return

Threats

  • Adler, P.H., Currie, D.C., Wood, DM. (2004) The Black Flies (Simuliidae) of North America. Comstock Publishing Associates, Cornell University Press ENR Library - B170 Return