Learn The Fly Fishing Basics and How to Fly Fish!

Fly Fishing Entomology Basics

Fly fishing entomology. Sounds pretty intimidating doesn’t it? It doesn’t have to be. To simplify this, fly fishing entomology is the study of insects and being able to identify all of those bugs you see on the water. I know what you’re thinking though, that is way to simple to be all it’s about. I’ll admit that that is a very simplified version of what fly fishing entomology really is, but there are only a few key items to keep in mind to help you catch more fish on the water. And if you want a more in-depth, full-featured introduction to entomology, be sure to check out the full fly fishing course on entomology. In the meantime, let’s get started.

brown trout - fly fishing entomology

Fly Fishing Entomology Basics

If you want to take your fly fishing to the next level, you need an understanding of basic fly fishing entomology (the study of insects) and how it applies to fly selection. This will cover the basic bugs found in typical trout waters and help you understand how to catch more fish with this knowledge and what flies to use.

You may be having thoughts of high school biology courses with topics of genus, species, and families, or more specifically the biological classification order. While that is part of entomology, applying it to fly fishing really only involves learning the basic families or orders of insects, and not every single species out there.

An easy example many people may be familiar with is the Parachute Adams dry fly. In reality, there is no “Adams” insect. Instead, it is meant to imitate a wide variety of mayflies and not a specific species. See, it’s already getting simpler.

Orders aka Categories

To start off, let’s dig into orders, or more simply categories of insects as this is one of the prime ways to begin in fly fishing entomology. Orders are just a fancy and scientific way of saying categories of insects. Nearly all of the fly patterns we use as fly fisherman imitate orders of insects. That means that instead of 10,000 or so insect species to know, we only need to focus on about 8 simple categories to help you identify insects on the water and then the stage of those insects, but we’ll get to the stage in a minute.

Those 8 categories are:

  • Midgesflies-by-stage-diagram-1 - fly fishing entomology
  • Mayflies
  • Caddis
  • Stoneflies
  • Terrestrials
  • Scuds & Sowbugs
  • Annelids (Worms)
  • Damselflies, Dragonflies and Water boatman

Stages or the Insect Lifecycle

Stages of an insect simply refer to their current stage within what is more commonly known as the insect lifecycle.  Insects go through different stages of development throughout their short lives. These different developmental stages are also known as a metamorphosis (that one sounds familiar from biology class). Most insects that are important to us as anglers go through four distinct stages that we need to know. These are a larva (nymph), emerger, adult (dry), and spinner stage. You can refer to these insect stages more simply as nymph, pupa, emerger, dry, and spinner. These should look somewhat familiar if you’ve purchased flies at any time. They often correlate to the fly patterns we use when out on the water.

Most insects have these stages, but some of them have an extra pupa stage. However, only some of those stages actually apply to trout feeding behavior. I know, the point was to simplify fly fishing entomology and not make it more complicated. For now keep in mind that entomology is a complicated subject, but you only need to focus on the few key points, not the entire subject. If you wanted to dive deeper into the subject, you’d need a fly fishing course on entomology for that and it is a great idea if you’re ready to take your fly fishing to the next level.


Fly Fishing Entomology Basics – List of Insects

Updated list of insects coming soon…stay tuned!

Final Thoughts on Fly Fishing Entomology

By breaking it down into these categories, you can see that fly fishing entomology isn’t all that overwhelming. That breakdown of insects will cover approximately 99% of all the insects you’d need in your fly box. Granted, when you head to your local fly shop you’ll see a wide variety of variations of each of these categories, but that’s all the more reason to fill up those fly boxes.

When searching out flies to fill your boxes with though, you can take these categories and break them down to general flies that will cover many of the insects in that category. Remember theParachute Adams dry fly example from earlier? That fly imitates a wide variety of mayflies and can replace multiple different variations of flies in your box. Some fish may be more picky and require a more precise fly pattern, but many times those general imitations work wonders on the water.

Take a look at the previous articles on Three Main Types of Flies for Trout and the  Top 5 Summertime Stream Flies for ideas of some of the flies to look for to fill up your fly boxes that match these categories. You can also check out The Catch and The Hatch for some great fly fishing information, more information on fly fishing entomology, and loads of fly patterns to fill your box with.

Understanding the basics of fly fishing entomology and beginning to learn how to match that hatch, whether it’s above or below the waters surface, is a surefire way to improve your fly fishing, help you learn the fly fishing basics, and help you catch more fish while on the water.

Want to Learn More?

Mayfly Nymph Identification - Fly Fishing Entomology Course

Want to learn more about fly fishing entomology? Be sure to check out the new Fly Fishing Course on Entomology. I’ve partnered with The Catch and The Hatch to bring you this amazing resource. It will help you learn to identify the insects you encounter on the water and then put that knowledge to use in selecting the perfect fly to help you catch more fish. Check it out today!

Find Out More 

About Clint Losee

Clint Losee is an avid fly angler of 30+ years, web developer, and Utah Landscape & Nature Photographer. You can connect with him on Instagram, Facebook, or Twitter. Curious about some of the gear he uses? Check out the new Amazon store.