Diving beetles

[agrumpycow]

We've just discovered what we think are the first inhabitants of our pond which is a few weeks old!
They seem to be diving beetles, the largest is about 10mm long and there are several 2-3mm long. The largest is in the pic below. Can anyone tell me what type of diving beetle it is and is it a welcome inhabitant ?

[Jenny W]

Hi

Many water beetle species require examination under a microscope or hand lens to confirm I.D. so I can't say exactly, but it looks like it's probably a Dytiscidae sp.

[numeniusaqua]

It's great seeing a pond evolve from a sterile thing to looking like it's been there forever. Our is 2 years old now and also brings far more birds to our garden than our birdtable ever has - an unexpected benefit to be honest. We have magpies, collared doves, and numerous smaller birds taking a bath in the waterfall every day - at times a line builds up on the fence until the best spot is free - actual queuing!
Amongst our first few arrivals were the enormous Great Diving Beetle - whose larvae went on to kill almost every last tadpole last year! So we were fishing them out (just the great diving bettles and their aggresive larvae, which look like something from "Alien" and behave like it too!) and getting rid until the pond developed a balanced population of predators and prey. Being ambush predators, they lurk on the weed waiting for a tadpole to pass - then grab them just behind the body and eat them from the tail up -horrible as the tadpole stays alive all that time! However, it means that you can learn to spot the places they wait and catch them. Now we have loads of sticklebacks and they seem to be keeping the level in check naturaly as I'd hoped - I saw one eating a small beetle the other day (well, pulling bits off it!).
We have loads of frogspawn this year, so fingers crossed that more tadpoles make it to frogs this time.
Enjoy your pond - they are like having a little world in your garden!