Helophilus trivittatus
In 3 days ~20% in a week ~40%
Helophilus trivittatus is a species of Palearctic hoverfly. The scientific genus name is composed of the parts helos (ἕλος, gr.), meaning "marsh" and philos (φίλος, gr.) meaning "friend". The species name is composed by "tri" (lat.), meaning "three" and "vitta" (lat.) meaning "band". This name refer to the preference of these insects for moist areas and to the fact that they carry three stripes on the breast shield.
For terms see Morphology of Diptera Helophilus trivittatus has a wing length of 10.25–12.25 millimetres (0.404–0.482 in). The eyes are separated in both sexes, in the male a little less than in the female. The antennae are black, Face shows a wide yellow longitudinal stripe, with at most a central reddish-brown stripe. On the thorax four narrow pale yellow stripes alternate with three larger dark brown stripes. The drawing of the flattened abdomen is reminiscent of a wasp.
The drawing of the third and fourth segments of the abdomen is different in the two sexes. In the male, only the third segment carries a pale yellow to gray arc line. In the female, such a curve is found on the fourth and the fifth tergite. Tergites 2 and 3 have pale... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Kiskunság National Park | 🇭🇺 Hungary | |
| 2 | Wadden Sea National Park | 🇩🇪 Germany | |
| 3 | Białowieża National Park | 🇵🇱 Poland | |
| 4 | Fertő-Hanság National Park | 🇭🇺 Hungary | |
| 5 | Camargue | 🇫🇷 France | |
| 6 | Bavarian Forest National Park | 🇩🇪 Germany |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Warsaw | 🇵🇱 Poland | |
| 2 | Helsinki | 🇫🇮 Finland | |
| 3 | Hamburg | 🇩🇪 Germany | |
| 4 | Amsterdam | 🇳🇱 Netherlands | |
| 5 | Rotterdam [The Hague] | 🇳🇱 Netherlands | |
| 6 | Munich | 🇩🇪 Germany | |
| 7 | Copenhagen | 🇩🇰 Denmark | |
| 8 | Budapest | 🇭🇺 Hungary | |
| 9 | Berlin | 🇩🇪 Germany | |
| 10 | Brussels | 🇧🇪 Belgium |
With luck
About 10% of wildlife watchers report a Trivittate Marsh Fly sighting in Amsterdam on a given day, based on 13 verified sightings from GBIF citizen-science data. It is the 88th most-seen of the 234 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 40%, if each day is a fresh chance.
June to September
In those months about 10% of wildlife watchers report a Trivittate Marsh Fly in Amsterdam on a given day, against under 5% in October to May, the lowest months.
Between 11 am and 2 pm
Across all the parks we cover, that three-hour window holds the most Trivittate Marsh Fly sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
Among the best
Of the 22 cities where we can rate Trivittate Marsh Fly sightings, Amsterdam ranks 4th at about 10%, level with the leaders once rounded. The best odds are in Warsaw (Poland, about 10%), Helsinki (Finland, about 10%) and Hamburg (Germany, about 10%).
GBIF citizen-science records
It is estimated from how often the Trivittate Marsh Fly is recorded against all the insects logged in Amsterdam (13 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.
