Waterboatmen

This year, for the first time, we have lots of waterboatmen living in/on our pond.Yesterday the weather was sunny enough for me to be able to get an OK picture of them without having to get the tripod out.
I thought it would be a nice idea to learn more about these little creatures, but then I entered a world of confusion. There are apparently lesser waterboatmen which do not bite, but which do not swim upside down. This is obviously not true of my friends (not sure about the biting though), these therefore looked as though they may be ‘backswimmers’ – never heard of them, but they are apparently all over the US (unlike myself – that would be a stupid idea). I then trawled around the web a bit more and found a bit more info on the BBC website. This looks as though it is a Greater Waterboatman (or backswimmer); notonecta glauca , they live in ponds and canals, are quite predatory and eat tadpoles (they are out of luck in my pond) and the larvae of diving beetles (these seem to be in shorter supply this year, I may now know the reason why). They are also known to bite, their saliva is toxic and they are not related to the lesser waterboatman. I am not sure how I feel about these now, I am a little concerned about my diving beetles and tadpoles to be.