Tuesday, 20 July 2010

Once bitten...

After a hectic weekend with a lot of wildlife about I am going to write about.... CLEGS!
Horseflies to some... family Tabanidae to others.... these are large insects with a particularly nasty bite [to me anyway].
I was first bitten by one in 1970 and my whole arm came up like a well stuffed sausage so, whenever they are about, I declare war.
That said, I should only kill half of them as the males tend to be vegetarian [nectar feeders].... but I'm not going to stop and ask!

When I was bitten in '70, it was able to get through an ex-US Army jacket and my workshirt [but that was probably nothing compared to a horses hide!], all four layers quite tight fitting [the army jacket was three layers thick] so if they are about I now tend to wear very loose fitting clothing which reduces the contact points... except for exposed skin.
To me the most fascinating thing about the horsefly group are the eyes... the one shown here has very clear colouring on the eyes... this varies between species. [You will notice from the eyes that this one supports Jamaica and is wearing wrap-around sunglasses!] The colour also fades away after death [I can vouch for this!!]

What allowed me to get this close was the fact that these were feeding on the bonnet of the '56 2CV. They were probably males as they seemed to be drinking the dried drips of aphid sap on the bonnet [the car was parked under our lime].
Their feeding method was to use the front feet in a sweeping motion across the surface towards their head, covering in the process about a centimetre circle.
They would then extend their proboscis and work over the small patch immediately under their head.
That completed, they moved forward about a centimetre dabbing the proboscis on the bonnet as they went.
They then stopped and repeated the 'harvesting' action.
They moved up and down the bonnet in straight lines.... turning and shuffling sideways to do a return sweep.

According to Chinery [Collins; Insects of Britain and Western Europe 1986] about 160 species occur in Europe.... the one here is most likely to be Tabanus bromius which has a very simple eye pattern [although there are a number of similar species this is the commonest (Chinery)]. The actual Cleg Fly [Haematopota pluvialis] is much smaller and unlikely to be the one that got through my jacket.


Susan said...

This is a female, and I think likely to be the Large Marsh Horsefly Tabanus autumnalis although I can't be sure from this photo.

Tim said...

Thanks Susan,
This is one of the ones harvesting spots from the lime tree on the 2CV bonnet. I'll put the other pix up on flickr tomorrow evening [Wed 28] along with the better pincertail pic and some crops onto the thorax.
The Western Spectre [female] was around again today... hunting under the eaves of the longere as per the other day. Saw it twice at about 5 hrs apart.