Trout are rising feverishly all around us as we stare hopelessly into a box of neatly organized dry flies.

There have been no willing participants as our caddis, drake, and stonefly imitations have drifted on by without an ounce of attention given by the fish.  It’s frustrating, and our flies or tippet often shoulder blame, but the truth is sometimes the fault lies with our identification of the bugs fish are feeding on.

It’s much easier said than done, but a great tip to catch trout feeding on dries is to watch the way in which they are feeding.  Are there violent splashes as the fish attack bugs?  Is it a gentle sipping trout that looks calm and innocent?  Perhaps there is no rhyme or reason at all, which can still yield clues. Or maybe the only clues we need are present by the bugs themselves!

Watch The Bugs

Different types of bugs will have different mannerisms as they hatch and go through their life stages. Most mayflies will sit perfectly still on the water to dry their wings before flying off into the bushes to mate. The poetic scene of tiny bugs dotting the water surface and gently gliding with the current often an indication of mayflies, and can thus alert anglers to use those imitations.

If the bugs are erratically moving about with not true rhyme or reason, the insect in question is probably a caddis. Seeing insects skating on the surface moving upstream and downstream with no sense of direction should make us reach right for an Elk Hair Caddis.

Watch The Fish

After watching the bugs, the next stop is to observe the trout!

If fish are slashing about the surface with wreckless intent, caddis flies are most likely the bug of choice.  A hatched caddis moves through the water column with greater speed than other insects, which results in trout “tracking” and attacking the bugs heading towards the surface.

During a spinner fall (one of the more underrated life cycles to imitate) the fish might lazily take their time while eating their insect supper.  After all, the spinners are dead or dying so there is little rush to get a meal before the bug flies away. Focus efforts during a spinner fall on back eddies and slower pools.  The dead insects will congregate in these spots resulting in a trout smorgasbord that can produce great results.

Inspect The Bugs

Aside from watching how the fish feed, each individual bug can physically quite different from one another.  A mayfly will have a pair of upright wings while a stoneflies wing cover the body of the insect almost like a cape.  A spinner has splayed out wings that go almost perpendicular to the trouts body.

Those small differences can make all the difference in the world to an observant angler trying to capitalize on a short hatch window. By catching one and inspecting the physical characteristics, it’s probably to get some insight into what type of bug you’re dealing with and thus what fly to use.

  • Note the size and color of a hatching insect. Those two factors dictate fly choice.
  • There could be multiple bugs hatching at the same time!  Try to discern which one is being keyed on the most by trout.
  • Once the main hatch wanes, get ready for the spinner action that’s quick to ensue.
  • When fishing a local stream, notice the weather patterns and water flow during a hatch.  Odds are the hatch will recur on similar days during that brief window.

This is why you’ll often see anglers jumping in the air trying to catch insects flying around the stream.  Information that can be gained from close inspection of a hatching bug can do tremendous things for the fly fisher, as can careful observation of the the manner in which the fish are eating. Use these proven tips to identify the bugs, and enjoy more productive fishing!