For me the best bit about this fabulous hot and sunny weather is that it really brings out the insects! A couple of days ago I was in the wet meadows at Parke and saw this very large horsefly quartering the grassland. I managed to net the insect first time and successfully transferred it to a pot so I could inspect it more closely. I brought it back to the office and put it in the fridge for half an hour to calm it down. I was then able to take the following photographs.
This species is Tabanus sudeticus or the Dark Giant Horsefly – this is a female (you can tell the sex of the adults by looking at the gap between the eyes: gap = female and no gap = male. This individual is 25mm long! This is as large as horseflies get anywhere in the world including the tropics. The orange antennae and black bands on the abdomen are diagnostic of this species.
Here is a frontal view – the long ‘dagger’ under the antennae are the mouth parts. Horseflies as we all know suck blood from animals such as cattle and horses. It should be noted that it is only the females that drink blood and they only do so when they are preparing to lay their eggs. The rest of the time they feed on nectar from flowers.
Last year I was in Scotland and the Lake District and on both occasions I found Dark Giant Horseflies – here are some photos I took from the National Trust’s property Aira Force.
In case you are thinking of having nightmares – these giant horseflies don’t like human blood and instead specialise on horses and cattle. Other horseflies – particularly the clegs and the gadfly do bite humans but are much smaller – nevertheless the bites are painful and irritating so watch out! Clegs have skinny red eyes and gadflies have shiny green eyes in case you are wondering ….
You will, I am sure also be pleased to hear I released the animal back into the wilds of Parke after I had finished photographing it – maybe you will come across it too.