Hexagenia limbata
In 3 days ~10% in a week ~30%
Hexagenia limbata, the giant mayfly, is a species of mayfly in the family Ephemeridae. It is native to North America where it is distributed widely near lakes and slow-moving rivers. The larvae, known as nymphs, are aquatic and burrow in mud and the adult insects have brief lives. They are often referred to as fish flies around the Great Lakes as they tend to cause the areas around water to smell like rotten fish.
It's also called the golden mayfly, big Michigan mayfly and great leadwing drake. The mature adult stage of Hexagenia limbata can be as much as 27 mm (1.1 in) long. The females tend to be slightly larger than the males but have smaller eyes. The forewings are long and membranous while the hind wings are much smaller and have dark margins. The tip of the abdomen bears two long cerci or tails. When the insect is at rest, the wings are folded vertically above the back. The color and body markings are somewhat variable but this insect is usually some shade of yellow, pale brown or white.
Hexagenia limbata is the most widely distributed mayfly in North America. It is known from most of Canada and all the states in the United States... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Detroit | 🇺🇸 United States | |
| 2 | Minneapolis [Saint Paul] | 🇺🇸 United States | |
| 3 | Montreal | 🇨🇦 Canada |
No species of the same family or order lives in Detroit, so these are its closest relatives here: other insects.
Rare
Under 5% of wildlife watchers report a Giant Mayfly sighting in Detroit on a given day, based on 7 verified sightings from GBIF citizen-science data. It is the 192nd most-seen of the 268 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.
June and July
In those months about 10% of wildlife watchers report a Giant Mayfly in Detroit on a given day, against under 5% in August to May, the lowest months.
Yes
Of the 3 cities where we can rate Giant Mayfly sightings, Detroit has the highest daily chance: under 5%. Next come Minneapolis [Saint Paul] (United States, under 5%) and Montreal (Canada, under 5%).
GBIF citizen-science records
It is estimated from how often the Giant Mayfly is recorded against all the insects logged in Detroit (7 verified sightings), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
