Numbers
a single genus, with 2 spp. in our area and 3 spp. total
(1)Size
Mature nymphs and adults approximately 15-25mm body length
Identification
Nymph: hypognathous, head nearly square in dorsal view, mouthparts exposed; forlegs short, with spinous pad at base of forecoxa, tarsal claw slender with 4-5 spinelike denticles
Range
North American species from Pacific Northwest, intermountain west (Canada), and upper Colorado Basin (southwestern Wyoming to northwestern New Mexico)
Habitat
Large rivers with silty sand bottoms
Season
Adults emerge in spring and early summer
Food
Nymphs are collector-filterers, feeding on organic particles carried by the current
Life Cycle
Probably univoltine. Adults have been collected from May through July. Early instars appear soon thereafer and, in many populations nymphal development continues through the following winter
Print References
Allen R.K., Edmunds G.F., Jr. (1976) A revision of the genus Ametropus in North America (Ephemeroptera: Ametropididae). Journal of the Kansas Entomological Society 49: 625-635.
Clifford H.F., Barton D.R. (1979) Observations on the biology of Ametropus neavei (Ephemeroptera: Ametropodidae) from a large river in northern Alberta, Canada. Canadian Entomologist 111: 855-858.
Soluk D.A., Craig D.A. (1988) Vortex feeding from pits in the sand: A unique method of suspension feeding used by a stream invertebrate. Limnology and Oceanography 33: 638-645.
