Eristalis pertinax
In 3 days ~30% in a week ~60%
Eristalis pertinax is a hoverfly in the family Syrphidae. It was first described by Giovanni Antonio Scopoli in 1763 and is found in Asia and Europe. Like Eristalis tenax, the larvae of E. pertinax are rat-tailed maggots living in drainage ditches, pools around manure piles, sewage, and similar places containing water with high organic load and low oxygen concentration.
Wing length is 8.25–12.75 mm. Antennomere 3 brown-black. Arista plumose to tip. Tarsi 1 and 2 entirely yellow. Wing with diffusely bordered darkened median band and pterostigma four times as long as wide. Dimorphic (males with triangular abdomen, females with squarish abdomen).
The male genitalia are figured by Hippa et al. (2001). The larva is figured by Hartley (1961). Palaearctic: Fennoscandia south to Iberia and the Mediterranean basin. Ireland, east through Europe to Turkey and European Russia, east to the Urals.
The habitat is wetland, forest, alluvial forest, fen, farmland, suburban gardens and parks. The flight period is February to November. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Cairngorms National Park | 🇬🇧 United Kingdom | |
| 2 | Triglav National Park | 🇸🇮 Slovenia | |
| 3 | Snowdonia National Park | 🇬🇧 United Kingdom | |
| 4 | Aigüestortes National Park | 🇪🇸 Spain | |
| 5 | Bavarian Forest National Park | 🇩🇪 Germany | |
| 6 | Hohe Tauern National Park | 🇦🇹 Austria | |
| 7 | Pyrénées National Park | 🇫🇷 France | |
| 8 | Ordesa y Monte Perdido National Park | 🇪🇸 Spain | |
| 9 | Monfragüe National Park | 🇪🇸 Spain | |
| 10 | Tatra National Park | 🇸🇰 Slovakia | |
| 11 | Białowieża National Park | 🇵🇱 Poland | |
| 12 | Sierra Nevada National Park | 🇪🇸 Spain | |
| 13 | Mercantour National Park | 🇫🇷 France | |
| 14 | Wadden Sea National Park | 🇩🇪 Germany | |
| 15 | Cévennes National Park | 🇫🇷 France | |
| 16 | Sierra de Guadarrama National Park | 🇪🇸 Spain |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Birmingham | 🇬🇧 United Kingdom | |
| 2 | Manchester | 🇬🇧 United Kingdom | |
| 3 | Liverpool | 🇬🇧 United Kingdom | |
| 4 | London | 🇬🇧 United Kingdom | |
| 5 | Leeds | 🇬🇧 United Kingdom | |
| 6 | Brussels | 🇧🇪 Belgium | |
| 7 | Amsterdam | 🇳🇱 Netherlands | |
| 8 | Rotterdam [The Hague] | 🇳🇱 Netherlands | |
| 9 | Dublin | 🇮🇪 Ireland | |
| 10 | Izmir | 🇹🇷 Turkey |
With luck
About 10% of wildlife watchers report a Tapered Drone Fly sighting in Rotterdam [The Hague] on a given day, based on 52 verified sightings from GBIF citizen-science data. It is the 26th most-seen of the 355 insects we can rate there. Over three days the chance rises to about 30%, and over a week to about 60%, if each day is a fresh chance.
April
In that month about 30% of wildlife watchers report a Tapered Drone Fly in Rotterdam [The Hague] on a given day, against under 5% in October to February, the lowest months. That is one of Rotterdam [The Hague]'s driest months, with about 40 mm of rain against 85 mm in August.
Between 11 am and 2 pm
Across all the parks we cover, that three-hour window holds the most Tapered Drone 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.
8th of 36
Of the 36 cities where we can rate Tapered Drone Fly sightings, Rotterdam [The Hague] ranks 8th at about 10%. The best odds are in Birmingham (United Kingdom, about 30%), Manchester (United Kingdom, about 30%) and Liverpool (United Kingdom, about 30%).
Same genus: Eristalis
The closest relatives of the Tapered Drone Fly that you can see in Rotterdam [The Hague] (genus Eristalis, Drone Flies) are Common Drone Fly (about 20%), Orange-Spined Drone Fly (about 10%) and Eurasian Drone Fly (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Tapered Drone Fly is recorded against all the insects logged in Rotterdam [The Hague] (52 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.
