[Note: This was formerly treated as a variant at rock worm.]
= caseworm n; also used as a mass noun.
1953 Asheville Citizen–Times (NC) 23 Aug sec B 5/6, Known to fishermen as “stick bait” or “rock bait,” the larval [sic] of the caddis fly lives in the water of streams and lakes for a year and is an important source of fish food. 1966 Courier–Jrl. (Louisville KY) 19 June sec B 10/4, Then there are the well-known “rock bait” or “stick bait” of the trout fishermen. These are the larvae of caddis flies and are named for the very unusual shelters which they construct. 1966–69 DARE (Qu. P6, . . Kinds of worms . . used for bait) Inf GA72, Rock bait—same as sandstoodle; build nests in sand; (Qu. P13, . . Ways of fishing . . besides the ordinary hook and line) Inf NC37, Rock bait. 1991 Charlotte Observer (NC) 7 Apr Catawba Valley sec 29/2, Most trout fishermen use a fly rod or a spinning rod. Popular live baits include . . caddis fly larvae (”stickbait” and “rockbait”).