Learning to Identify Insects Anywhere, Anytime

Mastering the Bugs for Fly Selection

Most anglers open their fly box, look aimlessly at the hundreds (maybe more) of dollars of flies and make their fly selection based on their past experiences or whatever “looks good” in their box.  “I did good on that one last year, guess I’ll try it out.” When is the last time you heard a guide say that?

You don’t, and it’s because they first ask the question, what are the trout eating today?  Once they have a strong, educated decision, they select the fly and begin to catch loads of fish.  The knowledge that helps them select the right fly faster and more accurately is fly fishing entomology.  We covered this topic with a great story as we outlined the 3 steps to mastering fly selection, and it’s a good read if you haven’t read it yet.

This article will help you understand the orders, stages, sizes, colors, seasonal and time of day behaviors of all insects you will need to identify on the river in order to catch trout. This is the first step in perfecting your fly selection skills.

Before we begin on the list however, let’s understand what orders and stages exist with trout insects.

Orders aka Insect Categories

Let’s learn quickly what we mean by orders and stages, then we’ll show the list of insects by order, category, size and color.

Orders are just a fancy and scientific way of saying a category of insect.  Remember in highschool biology when they taught Kingdom, Phylum, Class, ORDER, Family, Genus, Species? Of course you don’t, who listens in highschool biology? You should have listened though cause it relates to fly fishing!

All you really need to know is that as fly fishermen, nearly all of our fly patterns we use imitate orders of insects, not the specific species.  Aside from some mayflies (Hex, Green Drakes, BWO, etc) and some stoneflies (salmonflies, yellow sallies etc), we keep it simple and only focus on the categories.

This is great news for all of us, because instead of having to remember 10,000 insect species, we just need to understand 13 categories.  If you can identify the order of the insect, you’re more than 50% of the way to selecting the right fly.

Stages aka Insect Lifecycles

Stages of an insect simply refer to their current stage within an insect lifecycle.  Insects go through complete and incomplete metamorphsis.  Complete metamorphisis includes a pupa stage while incomplete skips that step and gets on with the story.

Most insects that you need to know for trout fishing go through a larva (nymph), emerger, adult (dry), and spinner stage. We refer to these plainly as nymph, pupa, emerger, dry, spinner when fly fishing and they often correlate to fly patterns.

Not all insects have these stages, and some have an extra pupa stage, and only some of those stages apply to trout feeding behavior…We know it gets a bit complicated, but for now hold on to the fact that this provides a list for you to digest, not the entire subject.  You’d need a fly fishing entomology course for that and is a great idea if you’re ready to take your fly fishing to the next level.

Let’s simplify and give you a framework you can use to start learning your bugs.  In it you will see all the major insect orders (categories), the stages of importance to the angler, and common hook sizes and colors you’ll want to imitate them with.  Book mark this page and refer to it often.  On the river, at the tying bench, whenever you need to match the bug or need help remembering what to expect on the river for what time of year.

The Complete List of Insects for Fly Fishermen

Midges

• Stages: Nymph, Pupa, Emerger, Dry
• Sizes: #14-26
• Colors: Any Color Imaginable (Black, Olive, Red, Purple are my favorites)
• Seasons: All Stages, Year Round
• Time of Day: All Day, Later in Day When Colder
• Most Important Late Fall – Early Spring

---

Mayflies

• Stages: Nymph, Emerger, Dry, Spinner
• Sizes: #6-26
• Colors: Any Color Imaginable
• Seasons: All Stages, Year Round, Mostly Spring, Summer and Fall (BWO in Winter Only).  Nymphs are year round importance all times of day.
• Time of Day: Morning to Mid Day and Evening to Dusk

---

Caddis

• Stages: Nymph, Pupa, Emerger, Dry
• Sizes: #10-20
• Colors: Blacks, Browns, Olives, Oranges, Tans
• Seasons: Late Spring to Late Fall – All Stages
• Time of Day: All Day with Mid Morning and Late Evening Most Important

---

Stoneflies

• Stages: Nymph, Dry
• Sizes: #6-16
• Colors: Blacks, Browns, Oranges, Yellows, Olives, Tans
• Seasons: Early Spring (Skwalas), Rest are Late Spring to Mid Fall
• Time of Day: Mid Morning to Dark

---

Scuds

• Stages: Nymph
• Sizes: #12-18
• Colors: Greys, Pinks, Oranges, Olives, Blues, Whites, Two-Tones
• Seasons: Year round, late fall to early spring most important
• Time of Day: All day with importance on early morning

---

Sowbugs

• Stages: Nymph
• Sizes: #12-18
• Colors: Greys, Pinks, Oranges, Olives, Blues, Whites, Two-Tones
• Seasons: Year round, late fall to early spring most important
• Time of Day: All day with importance on early morning
•  

---

Annelids (Worms)

• Stages: Nymph
• Sizes: #8-16
• Colors: Reds, Pinks, Browns, Tans, Purples
• Seasons: Year round, Anytime water rises or gets off color
• Time of Day: All day, Anytime

---

Damsels

• Stages: Nymph, Dry
• Sizes: #8-16
• Colors: Blues, Tans, Olives
• Seasons: Late spring to Mid Fall (Before Frost)
• Time of Day: All day with importance on early morning and late evening

---

Dragonflies

• Stages: Nymph, Dry
• Sizes: #6-14
• Colors: Reds, Blacks, Tans, Olives, Blues
• Seasons: Late spring to Mid Fall (Before Frost)
• Time of Day: All day with importance on early morning and late evening

---

Water Boatman

• Stages: Nymph, Dry
• Sizes: #10-16
• Colors: Blacks, Olives, Tans, Browns
• Seasons: Late spring to Mid Fall (Before Frost), Hatch late fall
• Time of Day: All day with importance on early morning and late evening
•  

---

Hoppers

• Stages: Dry
• Sizes: #6-16
• Colors: Browns, Olives, Pinks, Purples, Tans, Reds, Yellows
• Seasons: Mid Summer to Mid Fall (Before Frost)
• Time of Day: All day with importance after noon to evening
•  

---

Ants

• Stages: Dry
• Sizes: #14-20
• Colors: Blacks, Reds, Browns, Tans
• Seasons: Late spring to Mid Fall (Before Frost)
• Time of Day: All day with importance on early morning and late evening
•  

---

Beetles

• Stages: Dry
• Sizes: #12-18
• Colors: Blacks, Olives, Browns, Purples, Blues
• Seasons: Late spring to Mid Fall (Before Frost)
• Time of Day: All day with importance on early morning and late evening

---

When you break it all down to these categories, it doesn’t look that overwhelming.  Contained within this list is 99% of all the insects you’ll need in your fly box including their basic seasonal and time of day behaviors.  Doesn’t look like much but when you begin adding up all the variations, it’s no wonder why we all have 15 fly boxes and still complain to our spouses we don’t have enough flies!

This information is an excellent guide to helping you stock your box, 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.  Memorize these stages, sizes, colors, seasons and time of day and you will be well on your way to preparing your fly box correctly.

---

Want to Learn More?

As you can see, this is just the tip of the iceberg when it comes to learning about fly selection and entomology. We have a comprehensive online entomology course for $199 that you should check out. Just scroll down if you really want to get a complete understanding of fly fishing entomology.  If you need a cheat sheet, this article is perfect for you, but if you really want to master fly selection, a detailed course is really going to take your fishing to the next level.

Read More