What's That Bug? does not endorse extermination

Subject: Large wasp like fly
Location: West Cumbria , UK
June 30, 2016 6:25 am
A large flying insect landed on our balcony and I would like to know what it is. We live in Cumbria, UK and it’s the first time I’ve ever seen one of these before. I attach a couple of photos and it measures about an inch long. Can anyone identify this bug please?
Signature: P & K

Male Dark Giant Horse Fly

Male Dark Giant Horse Fly

Dear P & K,
This is a Horse Fly in the family Tabanidae and the large eyes with no space between them indicates this is a male Horse Fly.  It looks very much like this female Horse Fly from our archives, and we suspect they are the same species.  We believe we have correctly identified your species as the Dark Giant Horse Fly, Tabanus sudeticus, thanks to images on Influential Points where it states:  “The dark giant horsefly is distributed widely in northern Europe into Russia. In Britain it mainly lives in boggy areas in the north and west, although it is also quite common in the New Forest.”  A species page on Influential Points states:  “The dark giant horsefly flies in July and August and commonly feeds on the blood of cattle and ponies. In Europe …
Tabanus sudeticus flies from the end of June and through July and August. Krčmar (2005)  reports that it reaches its maximum abundance in third week of July. In Britain it mainly lives in boggy areas in the north and west, although it is also quite common in the New Forest. Tabanus sudeticus is distributed widely in northern Europe into Russia.”  Additionally, the site states:  “Tabanus sudeticus is anautogenous – it must first take a blood meal before it can lay eggs (Krčmar & Maríc, 2007 ). The dark giant horsefly undoubtedly prefers feeding on horses, cattle and deer, but it will bite man if available, as many have found to their cost. It makes a deep hum when flying around a host, but this stops abruptly just before it settles.”  If it is any consolation, only female Horse Flies are blood sucking biters.  Male Horse Flies take nectar.  BioPix has some excellent images of the Dark Giant Horse Fly.

Male Dark Giant Horse Fly

Male Dark Giant Horse Fly

What's That Bug? does not endorse extermination
Location: West Cumbria, UK

2 Responses to Male Dark Giant Horse Fly from the UK

  1. Saighdear says:

    It’s taken me a while to track this down! It’s what bit me on the Leg today in the garden. Visiting a non-stock farm and Garden plants – bare ground and inspecting some fruit bushes. NOT a wasp, Bee, or Horsefly…. and none of the rest as are commonly offered as common UK Biting insects. Bumble & Honey Bees are busy so knew it wasn’t them. Continued to harass me – thought it was protecting a Nest in the ground, etc. Weather cool today but Clear sky with cool breeze at Sea-Level N of Inverness today. The Foto fairly confirms what I saw – = like a LARGE Bluebottle with Striped Abdomen and Wings as you see.

  2. Holly Dean says:

    I have just had one of these huge things land in my garden. I am really allergic to horse fly bites and have never seen one this big. I am sure its a female too!
    We are in leafy (boggy) Bedford Town and I am really surprised to see it here.
    I know we have smaller ones in the forests around here but this is a huge surprise – I am keeping it under a glass until I can pluck up the courage to set it free.

Leave a Reply

Your email address will not be published. Required fields are marked *