You can buy nematodes that you mix with water and apply with a watering can, but their use is temperature dependent, so you may have missed the boat this year. Check out the Nemesys range, find the one for leatherjackets and read the info before ordering. Otherwise, the old sheet of plastic trick - spread it out at the end of the day, then lift first thing in the morning - grubs should be present beneath and you can either pick them off or let the birds have them if you have any around.

just kick the bikers out your garden and hey wont leave there jackets behing lol . only messing i couldnt help myself . you got to have a laugh x .