I live in Belgium, and I've just witnessed a weird looking wasp/fly flying around in my room. Here's a picture:

enter image description here

So, what's this? It's still in my room, just chilling there. It zooms like a wasp, and flies VERY FAST. You can see white vertical stripes on his upper body, and then golden vertical patches. I couldn't get the camera to focus, so it's not really full-hd.

[Edit (better picture)]

  • $\begingroup$ Welcome to Biology.SE. You should add a descriptive of the size (or an object for size reference on the picture). $\endgroup$ – Remi.b Jul 26 '16 at 0:48
  • $\begingroup$ I have to disagree. Horseflies are in the Tabanidae family, and I really suspect this is a hoverfly (the Syrphidae family). Please see my answer below. $\endgroup$ – Dave Gruenewald Jul 26 '16 at 16:03

This is a hoverfly! Specifically in the genus Helophilus. A lot of species of hoverflies exhibit Batesian mimicry of wasps/bees, as we see here, while they mainly feed on pollen and nectar. So please, don't worry about it trying to bite you.

As far as species go, I think it is probably a Helophilus trivittatus. I am basing that on location and a lot on the banding patterns on the thorax as well as the markings on the prominent terga. Here is a picture below for you to compare.

Helophilus trivittatus


It looks like a horse-fly

enter image description here

What is a horsfly?

Horse-flies (Tabanidae) represent a family in the order of Diptera that are distributed world-wide. They are large flies that fly quickly. Adults feed on nectar while females feed on mammals blood (including humans). When they sting, it hurts much more than a mosquito! You probably want to get rid of it before going to bed!

Wasps (Hymenoptera) vs flies

You thought about a wasp because you saw a pseudo-pattern of yellow bands on the abdomen I suppose. It is actually easy to tell it is a fly (Diptera) because (1) it has only two wings, (2) it has very big eye and (3) Hymenopterans have a thin waist while diptera don't. Another noticeable trait that should make you think of a horsefly is that it flies very fast. Note by the way that hoverflies have a very distinctive pattern of black and yellow bands but are flies and don't sting.

What species?

I don't know! But someone on this website will probably be able to find out.

  • $\begingroup$ As the OP noted, horseflies can indeed fly very fast. Actually, they are the fastest flying insect on earth! The speed of the male horsefly is attributed to Jerry Butler, an entomologist at the University of Florida, who once got a male Hybomitra to chase a plastic pellet fired from an air rifle; "Which it caught in midair and dropped," Butler says. From the speed of the pellet, he calculated the fly was going at least 90 miles per hour (145 km/h) at the beginning of female pursuit. $\endgroup$ – BioGeek Jul 26 '16 at 10:40

It's not a wasp. Wasps have a thin waist.

It's a fly, and flies can indeed be fast.

I would not bet on Tabanidae, but on Sarcophagidae instead, because your fly looks less hairy than what I'm used to for horseflies, and because of the striped pattern on the thorax, but it may well be some other family.


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