Hi

This is my first post and first pond so please bear with me. If this is the wrong forum for my problem, I apologise.

I filled our new wildlife pond on the 3rd June 07. It has a 1mm thick rubber liner and measures 10' x 8', 2' deep the centre with 10" deep 1'3" wide shelves, a pebble drawdown beach in one corner and a 4" deep 1' wide edge zone for bog plants. I realise now it is too shady, it only receives about 4 hours sunlight a day. I'll correct this by felling some nearby tall leylandii.

THE PROBLEM: The pond was planted with oxygenators: a water violet, a starwort, 10 bunches of hornwort and also a small leaved lily. At first everything thrived especially the water violet which grew to about 2' across. However, they have since all been (or in the case of the hornwort are being) devoured by small (less than 10mm long) thin tanslucent grubs. The grubs don't swim but crawl freely over the plants and have dark heads. I consulted two pond centres and got two different opinions: one said the grubs were fungus fly larvae and the other, china mark moth caterpillars.

Can anyone help with the identification please?

Also should I let nature take its course and hope the predators arrive?

Fish are banned (unless they arrive naturally) but already the pond is occupied by numerous invertebrate species, most of which I can't identify but I have confirmed culex larvae, blood worms, an ephemerid larva, leeches, pond skaters, a flatworm, a diving beetle and many L. pereger and also a smooth newt. I also saw a southern hawker laying her eggs on the obligatory log pile.

Thank you in advance.