Hexagenia limbata
In 3 days ~10% in a week ~20%
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 |
Rare
Under 5% of wildlife watchers report a Giant Mayfly sighting in Montreal on a given day, based on 9 verified sightings from GBIF citizen-science data. It is the 599th most-seen of the 926 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 20%, if each day is a fresh chance.
Any time of year
In every month with enough records, under 5% of wildlife watchers report a Giant Mayfly in Montreal on a given day, so our monthly data shows no clear season.
Among the best
Of the 3 cities where we can rate Giant Mayfly sightings, Montreal ranks 3rd at under 5%, level with the leaders once rounded. The best odds are in Detroit (United States, under 5%) and Minneapolis [Saint Paul] (United States, under 5%).
GBIF citizen-science records
It is estimated from how often the Giant Mayfly is recorded against all the insects logged in Montreal (9 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.
