Didea fasciata
In 3 days ~10% in a week ~20%
Didea fasciata is a Holarctic species of hoverfly. External images For terms see Morphology of Diptera Wing length 8·25– 11 mm. Halteres with yellow knob. Face yellow, at most the tip of the central knob dark. The male genitalia are figured by Vockeroth (1969). The Larva is described and figured by Heiss (1938).
Palaearctic and Nearctic. Fennoscandia South to Spain; Italy and Greece. Ireland eastwards through Russia and the Russian Far East to the Pacific coast. North America from British Columbia South to New Mexico and East to New York. Oriental region to North India and Formosa
Habitat: Deciduous and coniferous forest, tracksides, clearings. Flowers visited include white umbellifers, Arbutus unedo, Chaerophyllum, Crataegus, Galium, Hedera, Hypochoeris, Polygonum cuspidatum, Rubus fruticosus, Rubus idaeus, Sambucus, Urtica dioica, Viburnum opulus.
The flight period is May to September. The aphid feeding larvae are arboreal, on both conifers and deciduous trees. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Birmingham | 🇬🇧 United Kingdom | |
| 2 | London | 🇬🇧 United Kingdom |
Rare
Under 5% of wildlife watchers report a Didea fasciata sighting in London on a given day, based on 8 verified sightings from GBIF citizen-science data. It is the 1153rd most-seen of the 1504 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.
Any time of year
In every month with enough records, under 5% of wildlife watchers report a Didea fasciata in London on a given day, so our monthly data shows no clear season.
Among the best
Of the 2 cities where we can rate Didea fasciata sightings, London ranks 2nd at under 5%, level with the leaders once rounded. The best odds are in Birmingham (United Kingdom, under 5%).
Same family: Syrphidae
The closest relatives of the Didea fasciata that you can see in London (family Syrphidae, Hover Flies) are Yellow-Haired Sun Fly (about 40%), Marmalade Hover Fly (about 30%) and Hornet Mimic Hover Fly (about 30%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Didea fasciata is recorded against all the insects logged in London (8 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.
