SPECIES ID / Invertebrates

True Flies

Net Winged Midges

Pxwíqs

  • 27 species in North America
Phylum: Arthropoda
Class: Insecta
Order: Diptera
Family: Blephariceridae

Identification Tips:

Larvae
• Body blackish and flattened, top to bottom
• 6 suckers in row down centre of underside of body
• Move like an inchworm

Pupae
• Glued tightly to rock, usually in crevice or depression

Life History:

Larvae
• Found primarily in cool, fast-flowing, mountain streams
• Cling to large stones and rock outcrops in fast water or waterfalls
• Often aggregate in groups of up to 100
• Scrape algae and detritus off of rocks

• Adult females lay eggs on rocks exposed at low water levels
• Eggs hatch when water levels rise to submerge them
• Adults emerge from pupae when water levels fall again

POLLUTION TOLERANCE
Very Sensitive Somewhat Sensitive Facultative Somewhat Tolerant Very Tolerant
Most        

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Primary Information Source:
Voshell, J. Reese. 2002. A Guide to Common Freshwater Invertebrates of North America. McDonald and Woodward Publishing Company. Blacksburg, Virginia.