Mayflies
Benthic Macroinvertebrates
Sensitive Benthos
Moderately Tolerant Benthos
Pollution Tolerant Benthos
Metamorphosis:
incomplete (see our life cycle page for more information)
Nymphs:
three distinct cerci (tails), occasionally two; cerci may be fuzzy or thread-like, but never paddle or fan-like; color varies from green, brown, gray, but usually black; total length up to 1 inch.
Reproduction:
female deposits eggs on top of water where they drift to the bottom; some species crawl under water and attach eggs to submerged objects.
Adults:
resemble nymphs, but usually possess two pair of long, lacy wings folded upright; adults usually have only two cerci.
Food:
consists of small plant and animal debris, such as algae, diatoms, and plankton; preyed upon by fish and play an important role in the food chain.
Scientific Name:
Class: Insecta
Order: Ephemeroptera
Indicator Role:
mayflies display a varied tolerance to pollution, but are generally considered cleaner water benthos.
Information Source:
McDonald, B., W. Borden, J. Lathrop.1990. Citizen Stream Monitoring: A Manual for Illinois. Illinois Department of Energy and Natural Resources, ILENR/RE-WR-90/18. Springfield, Illinois.
Other Links:
- View our draft taxonomic key on the mayfly family Baetidae (29pp, 4.2MB About PDF)
- Representatives of Mayfly Families (Ephemeroptera) - New York Department of Environmental Conservation
- Mayflies - Aquatic Insect Interactive Verification Program - Chironomidae Research Group, University of Minnesota
- Ephemeroptera of Michigan The University of Michigan
- The McKenzie Page - mayflies
- Entomology: A Guide to the Freshwater Food Sources of British Columbia's Game Fish - mayflies
- Texas A & M Extension Entomology - Mayflies
- Ephemeroptera in Freshwater Benthic Ecology and Aquatic Entomology Homepage S.M. Mandaville from the Soil & Water Conservation Society of MetroHalifax
- Tree of Life - Ephemeroptera
For more pictures, see our photo library on mayflies.