The hellgrammite is the aquatic, or nymph, stage of a large flying insect called the dobsonfly (Corydalus cornuta). The nymphal stage lasts nearly three years, during which time it grows to a length of about 2 inches. The ugly-looking creature with nippers on its head end can give you a painful snip.

It lives under stones or among vegetation along lake and stream shores. During the summer, when metamorphosis occurs, it crawls ashore and, under debris such as old boards or rocks, it forms a small hollow in which it stays until “hatching” time.

Few bait dealers offer live hellgrammites. Usually, you will have to resort to one of many artificial replicas or gather your own. They can be kept in cool, damp grass for some time.

Hellgrammites are tough. They should be hooked under the collar behind the head, with the point entering at the head side. If you puncture the body cavity, the hellgrammite will die. Some who use hellgrammites for bait snip off the two prongs or hooks at the rear end of the body. The nymph uses these to grab and hold on bottom.

Hellgrammites can be fished under a bobber or by flipping or casting them and using a slow, deep retrieve. Use them for stream bass by casting them up and across and letting them tumble down. Slight tugs on the line help prevent them from clinging to the bottom.