Horse Fly from the UK

Subject:  Unidentifed Fly
Geographic location of the bug:  Somerset, UK
Date: 06/25/2018
Time: 06:45 AM EDT
Your letter to the bugman:  This fly was in my house in Somerset, UK this morning. I am unable to identify it because it was so large. The body was 35mm long. The eyes were green matt (olive/emerald). It buzzed loudly. This is much larger than the Giant Horse Fly known in the UK. Please can you help?
How you want your letter signed:  Liz

Horse Fly

Dear Liz,
This is a female Horse Fly in the genus Tabanus.  Horse Flies often plague livestock by biting to feed on blood, but only the females bite.  We located an article on Huffington Post that states:  “
Forget giant hogweed, horseflies are the newest atrocity plaguing the nation.  People across the UK have been sharing photos of their horrendous horsefly bites – and it’s enough to put you off your dinner.  The flies, which are large, dark-coloured and 1-1.2cm in size, are often found loitering around farm animals (such as horses and cattle), ponds and other grassy areas.  Their bites cut the skin, rather than piercing it, which can be very painful.”  Your fly might be the Dark Giant Horse Fly, Tabanus sudeticus.

Thank you for your quick reply. I am very familiar with our common horse flies but this one was nothing like them in size. This one was 3.5cm (35mm) long with a much wider body and not the normal 1-1.2 cm. I have also looked up the Dark Giant Horse Fly but the recorded maximum size for that type seems to be 2.5 cm. This was definitely something you would not like to bite you. I am now wishing I had trapped it rather than letting it go!
Many thanks for getting back to me.

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