Pyrethroid insecticides such as pyrethrum, pyrethrins, and permethrin paralyze weevils on contact. The problem is that the material must be applied directly to the beast in order to be effective. This is difficult with weevils since as soon as they see you they drop to the soil and burrow down into the dirt. There is some residual effect so that weevils returning from the dirt to the leaves can still be killed for a day or two.
To see a selection of synthetic insecticides commonly found in local garden centers to to Synthetic Insecticides