There is a specific vine weevil pesticide on the market, Provado do one. Its designed to kill the pests in the soil.
https://www.google.co.uk/#q=vine+weevil+control+products&revid=1647535882
You can also treat the the compost with Armillatox a coal tar product. You can buy this product in odd places but it is a niche product.
He has done it! The toolmakers son has resigned!

