How do you deter itchy grubs?

I came across this sprawling mass of itchy grubs on a pathway beside Clarkson Drive, leading to a line-like rope across the path.  They love our deck, and anyone who leaves a towel or togs there winds up with hives. Does anyone know of natural ways to get rid of them? Send us an email or add to the discussion on: www.facebook.com/RainbowBeachCommunityNews