Some members of the Argyopidae (Cyclosa) are exactly like small snails; others (Cyrtarachne) resemble Coccinellidae in shape and colour.
Now, Coccinellidae (ladybirds) are known to be highly distasteful to most insectivorous mammals and birds, and snails would be quite unfit food for the Pompilid or Ichneumonid larvae, so that the reason for the mimicry in these cases is also perfectly clear.
In the Philippines, a cricket (Scepastus pachyrhynchoides), has taken on the shape and coloration of a species of Apocyrtus, a hard and inedible weevil (Curculionidae); and Phoraspis, a kind of grasshopper similarly resembles ladybirds (Coccinellidae).
Amongst the orbweavers of the family Argyopidae there are species belonging to the genera Cyclosa and Cyrtophora which closely resemble small snail-like gastropods as they cling to the underside of leaves with their legs drawn up. Other members of the same family - like Araneus coccinella, and Paraplectana thorntoni- imitate beetles of the family Coccinellidae which are known to be distasteful; and certain genera of the family Salticidae (Homalattus and Rhanis) closely resemble small hard-shelled beetles.