Isogenoides hansoni nymphs are predators, and feed on both plant debris, and other aquatic insects.

   Isogenoides hansoni never seem to be present in large numbers, nor is it a major player in the scheme of things. Unless you happen to be fishing a riffle during an egg laying flight, remember an insect is never important until you don't have an imitation that matches it in your fly box. I. hansoni seem to be in abundance, but you may encounter an isolated spinner flight of a few dozen or so over a riffle.

   A few nymphs of various sizes may be present in any given riffle through out the season, thus fishing a nymph imitation that matches I. hansoni in a variety of sizes can be productive.