ID for a beastie foud in a n Shropshire pond

[vole-woman]

Can anyone tell me what this is, please? It had a pale underbelly, and seemed to be able to walk backwards as well as forwards.

[Monkey Orchid]

I think it looks like the larva of a silver water beetle, Hydrous piceus... Maybe someone else could confirm?

This beetle is the second biggest found in British freshwater habitats, I think (the Great Diving Beetle is the biggest).

[vole-woman]

Thanks!

[Dogghound]

This is the larvae of Acilius likely A.sulcatus . Hydrophilus (great silver beetle) have very different looking larvae which are more like a large maggot.

[vole-woman]

I've just looked up the sulcatus and we did pull a few of these adult beetles out of a neighbouring pond. I never knew what they were called. My son calls them 'acorn beetles'.

[ollyk]

Originally Posted by Monkey Orchid

I think it looks like the larva of a silver water beetle, Hydrous piceus... Maybe someone else could confirm?

This beetle is the second biggest found in British freshwater habitats, I think (the Great Diving Beetle is the biggest).

You got that the wrong way round me thinks! Also, the Silver water beetle is very, very rare, only known in a handful of locations in the south I believe?

[Monkey Orchid]

Originally Posted by Dogghound

This is the larvae of Acilius likely A.sulcatus . Hydrophilus (great silver beetle) have very different looking larvae which are more like a large maggot.

Oops, my bad! Apologies. Not sure why I went off on a silver water beetle tangent. I had several different Internet tabs open and was typing in more than one page, so I got my wires crossed. Silver water beetle is indeed rare: the lesser silver water beetle is found only in Wales, Somerset and Cheshire I understand, whilst the great silver water beetle is even rarer and lives only in Somerset. And it is indeed the biggest UK water beetle (I got my wires crossed with that too - I really must stop trying to type messages on the web and eat my breakfast at the same time ).

I once helped a school in south Oxfordshire create a wildlife garden with a large pond, which attracted lots of Acilius: I remember watching the larvae swimming about and thinking what sinister-looking critters they were. The adults are quite pretty seen close-up though.