Plum sawfly

Once again, most of my plum crop has been badly affected by plum sawfly.  In my Garden Expert book it recommends spraying something called Thiacloprid, but apart from it being a chore to spray a big tree, I'd rather try something more eco-friendly.  My neighbour advises picking up the windfall plums as soon as possible and disposing of them,  I've also read that you should disturb the soil around the base of the tree in spring and leave the birds to pick off the larvae, but on one side of the tree base  are chippings. 

Would putting grease bands on the trunk in autumn be effective against this pest?  I hope so, as it would be the easiest solution for me.