[lulurose]

Last year my lawn was damaged by what I thought were Chafer grubs however earlier this summer I saw alot of beetles on the lawn & have identified them as Japanese Beetles which produce the root eating grubs. I haven't been able to find any substance in Ireland to eradicate these beetles. Any advice would be appreciated.

[Good guy]

Hi lulu rose. I've just noticed your post - maybe I missed it because I was away on holiday.
I know nothing about the Japanese beetles you mention but if they behave similarly to chafer grubs you can probably treat them the same way.
Simply applying a chemical may well kill off the grubs, but something else (perhaps worse!) will take their place - nature abhors a vacuum, as they say.
It is natural to find some level of pest such as these, in any situation. The trick is to ensure that they don't get out of hand. This can best be done by ensuring that the grass in your lawn is healthy ( see lawn care postings) and encouraging natural predators to keep pests within acceptable limits. Jackdaws, rooks and other birds find chafer grubs tasty, apparently.
I've read that one way of reducing an infestation is to cover the wet lawn with, for example, black plastic, overnight: in the morning, turn it back and you will find the grubs accessible on the surface. I haven't tried this myself because I haven't needed to.