Question
Please could you advice me about the best thing to get rid of this grub, it is ruining our lawn and I have not had any luck so far.
                     I would be grateful for any advice you can give me,
                      thanks Anita.  

Answer
depends on where you live in this big world. i'm in southern NJ.
leather back grubs are a problem in the leather hide business. that is the only one i know of by that name. it is not a lawn grub problem. take a sample of the grub. seal it in a plastic bag. and take it to your local garden center for ID. if they aren't sure what it is go to another garden center that does.   integrated pest management(IPM) is the big buzz-word in pest control in the new millenium. 1st you have to ID the problem pest so you know how to best get rid of it. chemical pesticides are necessary sometimes, but sometimes they do more harm than good. usually it is not good to indiscriminately treat for bug infestations. many bugs(over 99%) are actually beneficial. ID the problem pest 1st.
hope this helps.
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good luck
rick