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Photo for species Hexagenia_limbata
Photo Credit:
Jessica Louque, Smithers Viscient, Bugwood.org. License: Creative Commons Attribution 3.0 License (http://creativecommons.org/licenses/by/3.0/us/)

Hexagenia limbata

giant mayfly
Where is this species found?
States & Provinces: 
CA, FL, IA, KY, MI, MT, NC, ND, NE, NH, NS, NV, NY, OK, ON, OR, SC, SD, SK, TX, UT, WA, WY

Also reported in:
AL, AR, CO, CT, GA, IL, IN, ME, MN, MO, MS, OH, TN, VA, WI

Which phenophases should I observe?
Activity

Do you see...?

Active adults
One or more adults are seen moving about or at rest. Mayfly adults (imagos or spinners) are brighter in color than subadults, and have clear, glassy wings.

What is the intensity of emergence?

Slight: Less than 100 individuals are seen within the immediate observation area (approximately 5 feet in any direction).;Light: Between 100 and 500 individuals are seen within the immediate observation area (approximately 5 feet in any direction).;Moderate: Consistent coverage of surfaces is seen (ground, building walls and windows, vegetation, etc.), or small groups of individuals are seen under lights.;Heavy: Thick coverage of surfaces is seen, or very noticeable groups of individuals, including small to medium piles, are seen under lights.;Very heavy: Very thick coverage of surfaces is seen (with minimal surface area exposed), or large groups of individuals, including large piles, are seen under lights.

More...

Reproduction

Do you see...?

Mating
A male and female are seen coupled in a mating position, usually one on top of the other.

For abundance, enter the number of individual animals observed in this phenophase.

Development

Do you see...?

Active subadults
One or more subadults are seen moving about or at rest. Mayfly subadults (subimagos or duns) are duller in color than adults, and have cloudy wings with a fringe of small hairs.

What is the intensity of emergence?

Slight: Less than 100 individuals are seen within the immediate observation area (approximately 5 feet in any direction).;Light: Between 100 and 500 individuals are seen within the immediate observation area (approximately 5 feet in any direction).;Moderate: Consistent coverage of surfaces is seen (ground, building walls and windows, vegetation, etc.), or small groups of individuals are seen under lights.;Heavy: Thick coverage of surfaces is seen, or very noticeable groups of individuals, including small to medium piles, are seen under lights.;Very heavy: Very thick coverage of surfaces is seen (with minimal surface area exposed), or large groups of individuals, including large piles, are seen under lights.

Dead adults
One or more dead adults are seen, including those found on roads.

What is the intensity of death?

Slight: Less than 100 individuals are seen within the immediate observation area (approximately 5 feet in any direction).;Light: Between 100 and 500 individuals are seen within the immediate observation area (approximately 5 feet in any direction).;Moderate: Consistent coverage of surfaces is seen (ground, building walls and windows, vegetation, etc.), or small groups of individuals are seen under lights.;Heavy: Thick coverage of surfaces is seen, or very noticeable groups of individuals, including small to medium piles, are seen under lights.;Very heavy: Very thick coverage of surfaces is seen (with minimal surface area exposed), or large groups of individuals, including large piles, are seen under lights.

Method

Do you see...?

Individuals in a net
One or more individuals are seen caught in a net.

For abundance, enter the number of individual animals observed in this phenophase.