Brachypalpus valgus
In 3 days ~10% in a week ~20%
Brachypalpus valgus is a species of hoverfly found in Europe. External images Brachypalpus are medium-sized (wing length 8.5-10.75 mm.) blackish flies with clouded wings. In Brachypalpus valgus the thorax and scutellum are unstriped and aeneous black. The abdominal tergites are shining black with red lateral colour at base of abdomen. Hairs on the body surface are sand brown. Hind trochanters with a posterior process. Hind tibiae slightly curved.
The larva is illustrated by Rotheray (1993). Superficially resembles a honey bee. Brachypalpus valgus is a Palearctic species with a limited distribution in Europe South Fennoscandia to the Pyrenees then Ireland east through central Europe and northern Italy to Yugoslavia and European parts of Russia.
Occurs in wooded areas (over-mature Fagus and Quercus forest with senile trees and fallen, rotting timber) where it is a bioindicator. The "short-tailed" larvae have been found in the rotten wood of trees, and under the bark. Males have a rapid, zigzag flight over the trunks of fallen tree. They fly with a high-pitched buzz. The female can be found investigating fallen trees.... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|
More parks will be added in future updates.
Rare
Under 5% of wildlife watchers report a Brachypalpus valgus sighting in Vienna on a given day, based on 15 verified sightings from GBIF citizen-science data. It is the 760th most-seen of the 1406 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.
March and April
In those months about 10% of wildlife watchers report a Brachypalpus valgus in Vienna on a given day, against under 5% in May to February, the lowest months.
Among the best
Of the 2 cities where we can rate Brachypalpus valgus sightings, Vienna ranks 2nd at under 5%, level with the leaders once rounded. The best odds are in Warsaw (Poland, under 5%).
Same family: Syrphidae
The closest relatives of the Brachypalpus valgus that you can see in Vienna (family Syrphidae, Hover Flies) are Marmalade Hover Fly (about 20%), Hornet Mimic Hover Fly (about 10%) and Common Drone Fly (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Brachypalpus valgus is recorded against all the insects logged in Vienna (15 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.
