First off, they bite.
The Hellgrammite is a nasty aquatic inset that lives in the North Yuba. They are not as common as the Big Three: Caddis, Mayfly, and Stonefly, but they are in there and the fish know it. They can be confused with a large stonefly at first. If you see a couple of big pinchers coming off the head- it’s a hellgrammite.
The hellgrammite is a big meal for a hungry trout. If you’re after the big fish, this is your key to success. A dark brown Wolly Bugger with crystal flash is a pretty close imitation. Dead drift these in deeper pools where there is some structure for larger fish to hide.
The hellgrammite can live as an aquatic for one to three year before becoming an adult. Their presence is a good indicator of a clean and healthy river.
The adult of this is the Dobson Fly is a large flying insect- the look like giant moths with large pincers. These can be found around porch lights in the Summer months.
