A female hornet mimic hoverfly - one of the species we'd like you to look out for
At a glance
Flies can play an important role as pollinators. Record sightings of flies, with a focus on 14 species.
Type of activity: Outdoors
Who can take part? Everyone
When? 1 June - 18 Sept 2022
Where? Around the UK
How long will it take? About two minutes per observation
Join our fly-spotting team this summer and improve our understanding of how some of these species, important as pollinators, are faring in the UK.
With their cute fuzzy stripes, bees get all of the love when it comes to protecting insects. But flies also play a huge role in biodiversity, including helping to pollinate an estimated 72% of crops.
Unfortunately, there hasn’t been close to as much scientific attention on pollinating flies, so we just don’t know enough about them. Without knowing what species are important and where they can be found, we can’t do what is needed to protect them to support nature or agriculture.
On top of that, several fly species have recently arrived in the UK due to warming climates, and we need to keep track of their spread.
By using the iNaturalist app to take photos of flies you see in your local area, you can improve our knowledge of their populations and geographic spread.
In partnership with
How to take part
We’re asking you to spend a short time outdoors looking for and photographing flies in window boxes, gardens, parks or other safe urban areas.
There are 14 species of fly that we are particularly interested in, see the list below for more on these. But if you find other species, or you aren’t sure what you’ve photographed, that’s fine too.
- Download app. You can download the free iNaturalist app onto your smartphone, either from the Google Play store for Android phones or the Apple App store for iPhones.
If you’d rather use your camera and a browser, then you can sign up on the iNaturalistUK website, then upload your photos later.
- Register for the project. Create an iNaturalist account and join the Fly Finder project. Please note: it's important to join the project so that your results can be counted by us and that you can see other people's entries.
- See it. Find a fly between 1 June - 18 Sept 2022. Please see the list below for the 14 species we are particularly interested in. For some top tips on finding and photographing flies successfully see the section below.
- Snap it. Take a picture of the creature you've found.
To help our team of fly scientists with identification, get a few photos at different angles if possible: especially a top down and a side on shot. - Record it. Record what you find by uploading a picture onto the iNaturalist app or at iNaturalistUK.
- Log your location. Please note: it's important that you log the location of where you saw the fly. If you take the photo through the iNaturalist app, please ensure that your phone location information is turned on.
If you upload a picture later onto the app from your phone's photo gallery, or upload via a web browser, then you may have to add the location manually.
Tips on taking photos of flies and other winged insects
Finding flies is all about getting out in nature and being mindful and patient.
- Don't go chasing after flies, wait for them to come to you. The best approach is to choose a patch of flowers or foliage that seems to be attracting insects and settle down to watch, eventually one will land in front of you.
- Different insects move and behave differently, if you sit and watch for a while you will get to know their flight patterns, as well as which flowers they like to land on. You can time your photo just right.
- Flies are slower in the morning when they haven't warmed up yet so this can be a good time of day to see and photograph them.
- Move slowly. Flies will stay in the same spot for longer if you don’t startle them or cast your shadow over them.
- Rather than zoom in, creep as close as you can without scaring the fly off. You can crop the photo later to enlarge the image. It’s too hard to hold your phone steady to keep it in focus when you zoom.
- Take photos in burst mode and move your phone or camera slowly around to get photos at different angles.
- You might have to practice a bit but don’t be disheartened if your first photos are less than perfect: you'll be an expert insect photographer in no time!
Fly species to look out for and record
There are over 7,000 species of fly in the UK. For Fly Flinder, our scientists have selected 14 species they are particulary interested in. These include some common ones that you will frequently see on flowers, as well as new arrivals to the UK and species that are expanding their geographic range.
If you'd like to print out the list of flies, you can download them as a single sheet (PDF 421KB).
Marmalade hoverfly
Marmalade hoverfly (Episyrphus balteatus) - a very common species in most gardens across the country whose numbers are boosted in summer by an influx from mainland Europe.
Size: 10mm See more examples on iNaturalist
Batman hoverfly
Batman hoverfly (Myathropa florea) - one of the most distinctive species, with markings that look like the Batman logo on its thorax (the middle section of its body). They are part of the tribe whose larvae are 'rat-tailed maggots', which live in muddy water and use their long extendable tail as a breathing snorkel.
Size: 12mm See more examples on iNaturalist
Hornet mimic hoverfly
Hornet mimic hoverfly (Volucella zonaria) - a large and beautiful hoverfly that has spread across the country in the last 20 years and we would like to know how far north it has reached. Similar in size and colour to a European hornet.
Size: 20mm See more examples on iNaturalist
Broad centurion
Broad centurion (Chloromyia formosa) - a lovely metallic green & blue soldier-fly with a broad, flat abdomen (the rear section of its body). The larvae of soldier flies usually live in damp habitats but the larvae of this species live in humus-rich soil where they eat the decaying organic matter.
Size: 10mm See more examples on iNaturalist
Locust fly
Locust fly (Stomorhina lunata) this unusual blow fly has moved into the UK from mainland Europe and can now be found as far north as Scotland. It was once thought to only attack the eggs of locusts but its presence in the UK where we don't have any locusts suggests that they will attack other large grasshoppers as well.
They would be easy to confuse with hoverflies, with their big eyes and orange striped abdomen (the rear section of its body), but the sloping face and sleek appearance mark them out as something a bit different.
Size: 12mm See more examples on iNaturalist
(Image: © Amanhuy Duque y Andrea Castro, CC BY-NC via iNaturalist)
Hedgehog flies
Hedgehog flies (Tachina fera and Nowickia ferox) - these are very common, bristly parasite flies whose larvae attack the larvae of moths.
Tachina fera (left image, with browny-orange legs and antennae) is fairly common across the whole of the country but Nowickia ferox (right image, with black legs and antennae) has in the past been found mainly in the southern half but we'd like to know how far north it has spread.
Size: Both 15 mm See more examples on iNaturalist: T. fera and N. ferox
Parasite flies
Parasite flies (Eriothrix rufomaculata and Mintho rufiventris) - Eriothrix rufomaculata (left image) is actually one of the commonest flies you will see on flowers in mid-summer, however it was only in recent years that someone worked out which host it attacks when they reared some out of fresh turf. It turned out that they attack the soil-dwelling larvae of grass moths.
Mintho rufiventris (right image) looks superficially similar but it has two broad black stripes on the thorax (the middle section of its body) and a slightly flattened abdomen (the rear section).
Size: Both 10 mm See more examples on iNaturalist: E. rufomaculata and M. rufiventris
Phasia hemiptera
Phasia hemiptera - this extraordinary looking fly with broad, coloured wings is a regular visitor to gardens, favouring tall nectar-rich flowers such as hemp agrimony, buddleia and the carrot family. The larvae attack large plant bugs such as shieldbugs.
Females of this species have plain, transparent wings and so can be easily confused for hoverflies.
Size: 13mm See more examples on iNaturalist
Ladybird fly
Ladybird fly (Gymnosoma rotundatum) - this very distinctive species is another one whose larvae attack plant bugs.
It used to be restricted in range to a small area south-west of London but in recent years, for reasons we don't fully understand, it has spread north and east into The Thames Valley, London and Kent at a rapid rate. We are very interested to see how far this species has travelled across the country.
Size: 8mm See more examples on iNaturalist
Four-banded beegrabber
Four-banded beegrabber (Conops quadrifasciatus) - a wasp mimic with black and yellow abdomen (the rear section of its body), widespread in the UK. Its larvae feed on adults of the red-tailed bumblebee.
Size: 12mm See more examples on iNaturalist
(Image: © garethwilson, CC BY-NC via iNaturalist)
Waisted beegrabber
Waisted beegrabber (Physocephala rufipes) - another wasp mimic, mostly dark with narrow pale bands on the abdomen (the rear section of its body), the wings darkened along the leading edge. A slender species with the abdomen much narrowed at the base. Its larvae feed on adults of several species of bumble bees.
In the UK it is mostly confined to England and Wales.
Size: 15mm See more examples on iNaturalist
(Image: © Gerrit Öhm, CC BY-NC via iNaturalist)
Ferruginous beegrabber
Ferruginous beegrabber (Sicus ferrugineus) - this is less slender than the previous two beegrabber species and has short antennae, the body is largely reddish brown and the head is extensively pale yellow. Its larvae feed on adult bumble bees. This species is widely distributed in the UK
Size: 13mm See more examples on iNaturalist
Other projects that help track UK pollinators
If you've enjoyed taking part in Fly Finder, why not help with other UK monitoring schemes?
The UK Pollinator Monitoring Scheme examines which pollinators are active in different parts of the country and what flowers they are visiting. Beginners or people with limited time can take part with a quick 10-minute count. While the more advanced level gives a volunteer a 1km plot to survey, whcih is visited four times a year.
The Garden Butterfly Survey: run by Butterfly Conservation, is a great excuse to sit in your garden at least once a month on a sunny day and spot the butterflies that fly past, while contributing to critical research.
Read more about flies
-
BiodiversityThe compelling case for why flies are actually fabulous
Did you know that there are more species of fly in the UK than there are mammals on the planet? And they perform some pretty important jobs.
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British wildlifeSeven insect heroes of pollination
Pollination is not just the work of honeybees. Meet some of the buzzing, bold and beautiful insects carrying out this critical task.
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British wildlifeMeet the bee-fly: the cute bee mimic with a dark side
They look like bees and pollinate flowers, but these fluffy flies have a gruesome teenage stage that makes them one of the most fascinating species in your local park or garden.
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What on Earth?Flies are saving your chocolate cravings
Bees' pollinating prowess often overshadows many of the insects working just as hard as them.
Funding
We thank all funders to the Urban Nature Project campaign so far, including those who wish to remain anonymous, for their generous support. We recognise the following funders for their exceptional contributions to the campaign:
