The Dobson fly is a large insect that can get as large as 1″ in length. Dobson flies spend most of their lives, up to 4 years, in the larval stage and they can reach lengths of almost 4 inches. While in this stage, they are called HELLGRAMMITES. The hellgrammites live under rocks in swift streams or rivers, and indeed, are the bait that is preferred by large trout.
Collecting:
Some states do not allow the collection of bait in a trout stream, so you would have to collect the hellgrammites in another river. We collect our own hellgrammites by using a garden implement known as a potato hook. The potato hook has a long handle and about 4 or 5 tines that are about 6 inches long. It resembles a garden rake, but with less tines. We look for large flat rocks in rapid flowing water that is approximately 10 inches to 20 inches deep. About 2-3 feet downstream from the rocks, have someone hold a section of window screen on the bottom of the stream, such that the water flowing down will necessarily flow thru the screen, filtering out any object in the flow. Hook the tines of the implement under the rock, pulling it up and out of the way. Then, briskly scratch the floor of the stream. After the water clears, inspect the screen for your catch, if there are hellgrammites, hold the back of the hellgrammites’ head between your index finger and thumb, not allowing their head (with pinchers!) to turn and pinch you.
Rigging:
Top start rigging them, you will want to use a swivel on your line to prevent twist when using live bait. Use a small short shank hook, perhaps #8 or #10, and insert it under the hellgrammites such that the hook point goes in one side of the hard shell behind their head and comes out the other. This will prevent them from escaping.
It may be necessary in the more swift waters, to add a small split shot about 12″ to 14″ above the hook to carry the hook to the bottom of the stream. However, if that is not necessary to reach the bottom, it is advised not to use the weight, as it is another component to get snagged on the bottom.
Fishing:
Cast the hellgrammite into any pool with a preference given to the head waters of the pool. The hellgrammite can be retrieved at a slow constant speed or it can be jiggled by steadily raising and lowering the rod tip. For shallow water, start by using a small bobber (foam or cork bobbers are preferred to plastic ones on rocky streams), 2′ – 3′ above the hook. You may then want to remove the bobber and/or add small split shot weights to the line, if the water is deeper. You will notice the hellgrammite swimming with a very graceful, artistic, and tasty to trout action.
Note: Hellgrammites can swim and crawl, and as such can easily get the hook caught under rocks, on logs, etc., causing you to lose your hook and bait, so watch them closely and keep them moving in the water. For more information on trout fishing and useful tips go to Troutu.
