Weevils may damage plants in pots and/or in containers- young weevils damage roots. Adult weevils damage leaves.

But weevils will certainly damage plants grown in open fields, not just containers. Whoever gave you that information was incorrect, Ian. Was it the same person who told you that all beetles are carnivorous? ;-)

The weevil family (Curculionidae) is a large and diverse one, with many different hosts, habitats, and feeding habits, depending on the species. Find and identify the insect at work, then you can learn about what it does and how to manage it. As rhizo implied, whoever is giving you information about beetles and weevils clearly does not know their stuff. :)