Great Diving Beetle

I am sorry this is such an awful photograph, but it was really lively by the time I got to get any shots.
This Great Diving Beetle was trapped in a spider's web beside my moth trap this morning when I came to see what moths were sitting on the wall around it. Luckily the spider must have thought better of attempting to take such prey and was nowhere to be seen! 
The Great Diving Beetle Dytiscus marginalis is a large and voracious predator of ponds and slow-moving waterways. It can often be spotted coming to the surface to replenish the air supply it stores beneath it's wing cases which allows it to dive for it's prey.
This one is a male, with specially adapted front feet with little suction pads to allow it to hold onto the female and it's prey.
They can also fly well, which explains why this one was found by my moth trap!