Stomoxys calcitrans
In 3 days ~10% in a week ~20%
Stomoxys calcitrans is known by the common names stable fly, barn fly, biting house fly, dog fly, and power mower fly. Unlike most members of the family Muscidae, Stomoxys calcitrans ('sharp mouth' + 'kicking') and others of its genus suck blood from mammals. Now found worldwide, the species is considered to be of Eurasian or African origin.
The stable fly resembles the common housefly (Musca domestica), though smaller, and on closer examination has a slightly wider and spotted abdomen. Adults are generally about 6–8 mm (1⁄4–5⁄16 inch) in length and a lighter color than the housefly. Unlike the housefly, where the mouth part is adapted for sponging, the stable fly mouth parts have biting structures. An additional distinction from M. domestica is in the aristae, which bear a single, superior row of hairs in S. calcitrans instead of two opposing rows.
As its name suggests, the stable fly is abundant in and around where cattle are kept. Its maggots are often seen in the rotting manure near cattle and poultry. It also occurs in coastal areas where larvae may inhabit masses of decaying aquatic vegetation deposited ashore.
The earliest... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Point Pelee National Park | 🇨🇦 Canada | |
| 2 | Great Smoky Mountains National Park | 🇺🇸 United States | |
| 3 | Wadden Sea National Park | 🇩🇪 Germany |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Quito | 🇪🇨 Ecuador | |
| 2 | San Luis Potosí | 🇲🇽 México | |
| 3 | Boston | 🇺🇸 United States | |
| 4 | Lima | 🇵🇪 Peru | |
| 5 | Porto | 🇵🇹 Portugal | |
| 6 | Lisbon | 🇵🇹 Portugal | |
| 7 | Baltimore | 🇺🇸 United States | |
| 8 | Auckland | 🇳🇿 New Zealand | |
| 9 | New York City | 🇺🇸 United States | |
| 10 | Sacramento | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Stable Fly sighting in São Paulo on a given day, based on 6 verified sightings from GBIF citizen-science data. It is the 672nd most-seen of the 832 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 Stable Fly in São Paulo on a given day, so our monthly data shows no clear season.
Between 1 and 4 pm
Across all the parks we cover, that three-hour window holds the most Stable Fly sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
16th of 25
Of the 25 cities where we can rate Stable Fly sightings, São Paulo ranks 16th at under 5%. The best odds are in Quito (Ecuador, about 10%), San Luis Potosí (México, about 10%) and Boston (United States, under 5%).
Same order: Diptera
The closest relatives of the Stable Fly that you can see in São Paulo (order Diptera, Flies) are Bathroom Moth Fly (about 10%), Black Soldier Fly (about 10%) and Toxomerus virgulatus (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Stable Fly is recorded against all the insects logged in São Paulo (6 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.
