vine weevil

The only effective treatment is a pathogenic nematode, either heterorbabditis megidis or steinernema carpocapsae. They should be watered into the compost late in summer, while the soil is warm and moist, but before the grubs have grown large enough to cause serious damage. The adult vine weevil doesn't cause too much damage, it's the grubs in the roots that kill the plant. Don't know how fond she is of her Acer, but it might be simpler to ditch it, remove and dispose of the compost outside of the garden somehow, clean and sterilise the pot and start again. Though where there's been an infestation already, they may already be present in other containers or shrub roots.

You can use a chemical treatment if you are so inclined Provado Vine Weevil Killer. Read the instructions first as some plants do not like the stuff.
She can wash the tree roots bare and replant in fresh new compost as long as the tree is given a lot of TLC afterwards. You can buy compost with Vine weevil killing granules in it, but they only last for a short time.
To help prevent reinfestation, put a circle of plastic with a few tiny holes in it, round the tree trunk where it enters the soil and then cover that with at least 2 inches of gravel or grit. The adult lays the eggs where the stem enters the soil and will not do so if it cannot find the soil.

i have resorted to washing all the roots and checking for tunnels in the larger roots and then repotting. I then put grit on the top of the compost and keep fingers crossed.

thanks for your replies i will pass all info on at work tomorow.everyone asks me for the answers just because i love gardening but its a good job i have you guys to help so thanks.