nightfly's picture

Green-eyed Horsefly

Observed: 11th July 2013 By: nightflynightfly’s reputation in Invertebratesnightfly’s reputation in Invertebratesnightfly’s reputation in Invertebratesnightfly’s reputation in Invertebratesnightfly’s reputation in Invertebrates
Species interactions

No interactions present.


nightfly's picture

Thanks for the ID Martin,

Thanks for the ID Martin, however it managed it, this insect is carrying a lot of sand like sediment. It looks like it has had a dust bath.


Eskling's picture

Similar one tried...

... to bite me at Glenveagh a couple of days ago. Didn't get a pic but those green eyes were the most noticeable feature. Scary beast! (The clegs did get me though!)

nightfly's picture

Hi Philip, Theres a thought,

Hi Philip,

Theres a thought, I havent been at Glenveagh since starting to look at insects. Hope you saw some good stuff. Saw 3 lizards today on the hill but only one got its photo taken.

I would have put this down as a cleg of sorts? Is a true cleg one particular species?


Eskling's picture


I think of a cleg as the one that usually gets you in the countryside, ie, Haematopota pluvialis. They are described as horse flies too but are not the really big ones.

The walk along the upper part of the lake at Glenveagh was not pleasant in the heat. Beautiful scenery, yes, but there were so many clegs and larger horse flies that you just couldn't stand still for more than a few seconds!

Glad the lizards were out for you, I didn't see any at Glenveagh but I expect they are there somewhere.


Martin Harvey's picture


These flies belong to family Tabanidae, in which there are 30 species on the British list. In the book on this group by Stubbs and Drake, it says "There are various names for this well-known family but horseflies and clegs are among the most frequently used".

When Alan Stubbs invented English names for the individual species, he confined "Cleg" to genus Haematopota, with variations on this for the five species in the genus, e.g. H, pluvialis is "Notch-horned Cleg" and H. crassicornis is "Black-horned Cleg".

Most of the other English species names use "Horsefly" except for genus Chrysops, which Alan has called Deerflies, based on American usage.

So there isn't one true cleg, and in practice I guess these names are applied rather inconsistently to a range of largish biting flies.

Entomologist and biological recorder

nightfly's picture

Thanks Martin, So there are

Thanks Martin,

So there are many biting beasts being refered to as Clegs.

When they do give you that nasty bite, is their intention simply to access your blood? Its a wonder any animal tolerates them but maybe they just cant shed them from all parts of their body?