Eristalis nemorum
In 3 days ~10% in a week ~20%
Eristalis nemorum is a species of hoverfly. It is found in the Palearctic (Fennoscandia South to Iberia, the Balkans and Italy, Ireland eastwards through Central Europe into Turkey and Russia and on into the Russian Far East, Siberia and Japan) and in the Nearctic (Quebec south to Colorado).
External images For terms, see: Morphology of Diptera. Wing length: 8.25–10.5 mm (0.325–0.413 in). All tarsi are extensively black. Body-hairs are short. Arista plumose basal half. Densely dusted face has a black shining stripe. Hind femora are black in male. Wings are hyaline with quadrate brownish pterostigma (basal to merge of vein sc with costa). Body is yellow-haired. Hind metatarsi are darkened.
The male genitalia are figured by Hippa et al. (2001). The larva is figured by Hartley (1961). The larvae are aquatic, and of the Rat-tailed maggot type. Adults are often seen visiting flowers. Flight period in the United Kingdom is from April to October, peaking around July and August. The males show a characteristic courtship display, hovering above a foraging female for minutes.
When many males are present two or more males may hover above one female.... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Snowdonia National Park | 🇬🇧 United Kingdom | |
| 2 | Bavarian Forest National Park | 🇩🇪 Germany | |
| 3 | Wadden Sea National Park | 🇩🇪 Germany | |
| 4 | Pyrénées National Park | 🇫🇷 France |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Amsterdam | 🇳🇱 Netherlands | |
| 2 | Helsinki | 🇫🇮 Finland | |
| 3 | Birmingham | 🇬🇧 United Kingdom | |
| 4 | Rotterdam [The Hague] | 🇳🇱 Netherlands | |
| 5 | Essen | 🇩🇪 Germany | |
| 6 | Leeds | 🇬🇧 United Kingdom | |
| 7 | Manchester | 🇬🇧 United Kingdom | |
| 8 | Liverpool | 🇬🇧 United Kingdom | |
| 9 | Brussels | 🇧🇪 Belgium | |
| 10 | London | 🇬🇧 United Kingdom |
Rare
Under 5% of wildlife watchers report an Orange-Spined Drone Fly sighting in Saint Petersburg on a given day, based on 11 verified sightings from GBIF citizen-science data. It is the 248th most-seen of the 448 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.
August
In that month about 10% of wildlife watchers report an Orange-Spined Drone Fly in Saint Petersburg on a given day, against under 5% in September to July, the lowest months. That is one of Saint Petersburg's wettest months, with about 100 mm of rain against 40 mm in February.
Between 11 am and 2 pm
Across all the parks we cover, that three-hour window holds the most Orange-Spined Drone Fly sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
12th of 13
Of the 13 cities where we can rate Orange-Spined Drone Fly sightings, Saint Petersburg ranks 12th at under 5%. The best odds are in Amsterdam (Netherlands, about 10%), Helsinki (Finland, about 10%) and Birmingham (United Kingdom, about 10%).
GBIF citizen-science records
It is estimated from how often the Orange-Spined Drone Fly is recorded against all the insects logged in Saint Petersburg (11 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.
