Kate, I'm guessing you mean the daddy-long-legs spider, Pholcus phalangioides, since harvestmen do not make webs. Pholcus is renowned for its aggressive behaviour, its long powerful fangs and its supposedly very toxic venom. It regularly attacks and eats other spiders, often those much bigger than itself. Despite the vine weevil's tough carapace, it does not surprise me that Pholcus should make short work of it.