Like slugs, root weevils are nocturnal creatures. To catch them chewing on your plants, you will have to go out at night with a flashlight. In fact, some gardeners do just that. They put on rubber gloves, grab a bucket and a flashlight, and go patroling the garden, picking weevils off their rhodies.
Personally, I'm not a fan of picking bugs off of anything at any time of day. I'm also not a fan of using pesticides. So what are the alternatives?
One, do nothing. Root weevils will not kill your rhododendrons. The worst that will happen is that you will have a lot of notched leaves.
Two, do something to prevent the weevils from climbing up the branches of the plant. Root weevils can't fly. The only way they can reach the leaves is to walk up the branches. Try coating the base of the plant with something sticky like Tanglefoot. The weevils can't get past that sticky barrier and your leaves will be safe from harm.
Three, plant rhododendrons that root weevils don't like. They won't bother any rhodie with fuzz, or indumentum, under the leaves, such as members of the Rh. yakushimanum family.
Need more ideas on ways to de-bug your garden? Check out Eartheasy's article on natural garden pest control.
