A weevil, one of several on Cock's-foot on a roadside verge.
Curculio glandium feeds on acorns as a larva. I can't find any information on what, if anything, the adults eat but I think it is fairly unlikely to have been eating the Cock's-foot. These weevils are often found sitting on a wide range of other plants underneath, or in the vicinity of oaks. Personally I'd be tempted to remove the relationship link from this one as I suspect it was just sitting on the grass because it has to be sitting somewhere!
Entomologist and biological recorder
Lat/Lng: 51.3678, 0.0149
OS grid ref: TQ403651