rock worm n
1 = caseworm n. West Cf rock bait n, rock-roller n 1
1889 Amer. Angler (Ed. Harris) 15.274 MT, Their catch last Sunday afternoon in Rocky Cañon Creek, about four miles from here [=Bozeman], consisted of fifty-four trout. . . The bait being used now is fresh beef and rock worms. 1901 Adams Co. Free Press (Corning IA) 15 June 1/4 csMT, [Letter:] Each member of the family has his own fishing tackle and fly and we have learned the meaning of “rock-worms” which are most tempting to the wary trout. 1928 Anaconda Std. (MT) 7 Jan 9/4, [Advt:] Rockworms for sale. 1948 Baumann Old Man Crow’s Boy 49 ID, We turned over the rocks in the stream-bottom to get the bugs and worms on which they fed: periwinkles, which we called “rock-worms” on account of the little cases or houses which they made out of rock particles and cemented about themselves. 1976 Albuquerque Jrl. (NM) 8 Feb sec F 11/1, The trout were picking rockworms off the rocks on the bottom of the stream, barely sucking them up, not seriously feeding. 2000 NADS Letters CO (as of 1950s), My father called the little worms you described, who wrapped themselves in sand grains “rock worms.” He is a Colorado native, age 92. He didn’t mention that they might be used as bait. I had found some near a creek bank, and asked him what they were. 2001 DARE File—Internet CA, The rock worm is a generic term for the ubiquitous uncased Rhyacophila and Hydropsyche caddis larvae. 2011 in 2020 DARE File—Internet West, Green Rock Worm or Green Sedge—All caddis in this group belong to a single genus, Rhyacophila, of the family Rhyacophilidae. 2016 Sacramento Bee (CA) 30 Dec sec B 1/5, The stomach contents of a fish caught and kept a few years past included salmon eggs, green rock worms (caddis pupa) and alevins.
2 = hellgrammite n 1.
2000 Atlanta Jrl.–Constitution (GA) 7 Sept sec HG 5 (Internet) cwGA, [Letter:] The picture . . is not a stonefly but a dobsonfly. . . I fish with what I call a “rock worm” in the Flint River, which is the larva stage of the dobsonfly. 2009 in 2020 DARE File—Internet cwGA, Me and My Grandfather use to get penniwinkles from under leaves in a branch or creek and get hellgramites (Rock Worms) under rocks with grass on them mainly in the river. Penniwinkles don’t have pinchers on them if I can remember right.