It seems like I have an infestation of Japanese beetle grubs, does anyone know how I eradicate these pests?
Where are you Gillian, in the US? Japanese beetle hasn't reached the shores of the UK in any significant numbers so most here won't have any experience with it.
Im not in the US im in the Uk. I have come across a significant amount of white grubs which look very like the Japanese Beetle they have decimated my strawberries and burrowed into the tuber roots the roots look like rust. If not the Japanese beetle do you have any suggestions to what it might be?
I don't know how big they are but cockchafer grubs may be something to look at.
vine weevil? A photo might help
It sounds like dreaded Vine weevil larvae. Do they curl-up into a C shape?
Here are some images of Vine weevil grubs:
If it is those, and because it it is an edible crop, your only safe choice is nematodes, which are safe to use on food crops. Google "Nemasys Vine Weevil Killer". When I get a bad infestation, I turn all of the soil out of the pots or containers onto a large sheet of weed membrane or tarpaulin and let the birds pick over it, and they have a feast!
Unfortunately, it is probably too late to save your plants but a dose of nematodes in all of your pots and containers will protect any new plants you grow.
Thanks Bob , yes that looks like the pests.
Thanks for the advice I will follow it up.