Poecilobothrus nobilitatus
In 3 days ~10% in a week ~20%
Poecilobothrus nobilitatus or semaphore fly is a species of fly in the highly studied family Dolichopodidae. P. nobilitatus flies are popular study subjects because they are easy to recognize and are of large size. They mainly reside around ponds and wet lands, where most of their hunting and mating take place. Their mating ritual is highly studied due to their distinctive mate selection behaviors.
P. nobilitatus has been found in Austria, Belgium, Czech Republic, Denmark, France, Germany, Hungary, Ireland, Italy, Luxembourg, Netherlands, Poland, Romania, Russia, Slovakia, Spain, Sweden, Switzerland, and the UK. Many flies in the Dolichopodidae family have metallic green reflections in their cornea due to the cornea's wavelength-selective spectral reflectance. Their cornea is built like a multi-layered mirror that reduces the transmission of green light to the cornea's light receptors. This results in distinctive green iridescent eyes that many of the flies have.
The P. nobilitatus species exhibits sexual dimorphism; females and males have distinctive wing markings. Males are usually 7mm long and are smoky black on the distal half... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Wadden Sea National Park | 🇩🇪 Germany |
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Liverpool | 🇬🇧 United Kingdom | |
| 2 | Birmingham | 🇬🇧 United Kingdom | |
| 3 | London | 🇬🇧 United Kingdom | |
| 4 | Dublin | 🇮🇪 Ireland | |
| 5 | Manchester | 🇬🇧 United Kingdom | |
| 6 | Leeds | 🇬🇧 United Kingdom |
Rare
Under 5% of wildlife watchers report a Semaphore Fly sighting in Wadden Sea National Park on a given day, based on 6 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 630th most-seen of the 818 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.
June and July
In those months about 10% of wildlife watchers report a Semaphore Fly in Wadden Sea National Park on a given day, against under 5% in August to May, the lowest months.
Between 2 and 5 pm
Across all the parks we cover, that three-hour window holds the most Semaphore Fly sightings with a recorded time, and about 7 in 10 of them come between 6 am and 6 pm: it is most active around dawn and dusk.
Only Wadden Sea National Park, in our data
Wadden Sea National Park is the only park on Wallace's Line with enough records to rate Semaphore Fly sightings: under 5% of wildlife watchers there report one on a given day.
Same order: Diptera
The closest relatives of the Semaphore Fly that you can see in Wadden Sea National Park (order Diptera, Flies) are Common Drone Fly (about 20%), Marmalade Hover Fly (about 20%) and Sun Fly (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Semaphore Fly is recorded against all the insects logged in Wadden Sea National Park (6 verified sightings from 2019 to 2026), 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.
