Entomology

December 27 2022

Intro to Entomology

Blog, Education, Entomology, Trout Match the Hatch

Fly Fish Instruct wants to help you take your fly fishing to the next level. One way to increase your catching ratio is to understand basic fly fishing entomology (the study of insects) and how you can choose the correct fly to match the hatch.

At a minimum, it’s essential for an angler to know and be able to identify the four most important aquatic insect groups (orders) and their stages in and off the water. The bonus is to know when the most common genus are hatching and the behaviors of each stage.

Blog Review

Refer back to our previous blogs.

Learn more about in our “Match the Hatch” online course.

Insect Orders

We commonly refer to order as a specific group of aquatic insects. Most artificial flies are designed to imitate a particular order in a specific stage. To keep things simple, we will reference the commonly known names of an order, such as Caddis and Mayflies.

Most Common Trout Fly Orders:

- Caddis (Trichoptera order)
- Mafly (Ephemeroptera order)
- Midge (Diptera order)
- Stonefly (Plecoptera order)

Metamorphosis

Each aquatic insect group (order) goes through different stages of development throughout their lives. These stages are also known as metamorphosis, which means change. Each order will go through either complete or incomplete metamorphosis. As an angler, understanding these stages or transitions is essential. Most anglers use a basic understanding of these stages to fish by mimicking behavior. Often, these stages are referred to as nymphs/larvae, emergers, and dry flies.

Incomplete Metamorphosis (Mayflies and Stoneflies) –

3 Stages – Egg, Nymph, and Adult (Imago) Stages.

Complete Metamorphosis (Caddis and Midges) –

4 Stages – Egg, Larva, Pupa and Adult (Imago)
- Exactly like a butterfly.

Insect Stages

Larva are juvenile insects that often look worm-like.
- Complete Metamorphosis
- Fish flies in the lower part of the water column.

Larvae are also referred to as nymphs. “Nymphing” refers to the fishing technique of an artificial fly subsurface (under the water).

Nymphal Stage –
- Incomplete Metamorphosis
- Life begins when the immature nymph escapes its egg and starts to feed. The nymph will shed its exoskeleton in a process called molting. The nymphal period can vary from a few months to several years.
- Fish flies in the lower part of the water column.

Pupa –
- Complete Metamorphosis
- Life stage begins when the mature larva transforms into a pupa. The larva spins some sort of cocoon or case and enters the pupa stage.
Emergers are the stage where the nymphs or larvae rise to the surface in preparation to emerge into their adult (dry fly) form.
- Fish wet emergers in the mid-water column and dry emergers just below the surface.
Adults are the final life stage of the insect.
- Fish most dry flies on top of the water.
Spinners are the dead insects that fall to the water’s surface.
- Not all insects have a spinner stage.
  - Midges, for example, don’t have a separate spinner fly pattern.
- Fish spinners on top of the water.

Immature Characteristics

A subsurface artificial fly mimics any stage of an immature aquatic insect.

Caddis and Midges
- Aquatic Larva “worm-like”.
- Caddis are either cased or free living larva.
Mayflies and Stoneflies
- Classic insect shape with a distinct abdomen, thorax, and head segments.
- Mayflies have two or three tails.
- Stoneflies always have two tails. The gills on mayflies are on their abdomens and stoneflies have thoracic gills.

Adult Characteristics

A dry fly is the adult stage of an insect. All adult aquatic insects have the same shape but will vary in size and color.

Mayflies (order Ephemeroptera) have upright “sailboat” wings.
Caddis (order Trichoptera) have a “tent-shaped” wing.
Stoneflies (order Plecoptera) have wings that lie flat over their backs. Think of longboard.
Midges (order Diptera) as their order name suggests have only two wings (Di = 2; -ptera = wing).

Life Cycle Factors

There are several life cycle factors.

Time of Year
- Certain aquatic insects hatch annually during the same time of the year. Start to become familiar with hatch charts to know what genus hatches when.
Time of Day
- Water temperatures usually rise during the day. Many aquatic insects hatch at the same time of the day during a specific time throughout the year.
Water Temperatures
- Aquatic insects have different hatching water temperatures. Having a thermometer will you start to predict when the adult life cycle stage will happen.
Available Food
- Aquatic insects have the same 4 basic needs as fish.
  - Food, Protection from Predators, Shelter from Current and Oxygen.
- Insects need available food to survive.

Conclusion

You can familiarize yourself with the stages and individual characteristics of the four most important aquatic insect groups (0rders) Caddis, Mayflies, Midges, and Stoneflies. This will help lessen the stress of matching the hatch and being a more successful angler.

Connect Heather Hodson

Website-Featured-Image-5-Factors-To-Choose-A-Fly

December 27 2022

5 Factors When Choosing a Fly

Blog, Education, Entomology, Trout Match the Hatch

By: Heather Hodson

As a nurse, I start the day by walking into my patient’s room and assessing my patient’s status and surroundings. Is the patient awake, alert, and oriented? Do I have all the equipment in the room if something happens? This is the same with fly fishing. Look around, and assess the river. Are there any bugs flying around, are the fish feeding on these bugs? What are the fish feeding behaviors?

In previous blogs, we’ve covered the different fly types and the four types of fly categories. This blog will cover the 5 factors when choosing a fly. Take a breath because you don’t need to know the insect’s order, genus, species, or even common name to be able to choose a fly. The two most important factors are the size and silhouette of the insect.

Learn more about it in our “Match the Hatch” online course.

5 Factors When Choosing a Fly

The first rule of choosing a fly is that there are no rules. Choosing a fly is not an exact science and there will be days that some flies fish better for no apparent reason. Whenever possible you should try to determine what the fish are feeding on and choose your fly that most closely mimics the natural food. Fly selection can be broken down into 5 different factors.

Size
Shape/Profile
Color
Behavior
Habitat

Disclaimer: Many intermediate and advanced anglers would argue that behavior is more important than color.

#1 - Size

Size refers to the length of the fly. It is the number one factor when choosing a trout fly. It’s best to err on the side of smaller.

Choose a similar size (or smaller) fly to a natural insect or aquatic baitfish of what you’ve assessed.
Assessment
- Pick up rocks in the river. What size are the nymphs crawling around or attached to these rocks?
- Seine the riverbed to see what insects and aquatic baitfish are in that specific section of the river.
- Catch adult insects flying around.
- Put the insects in your fly box and match the size to your flies.
It’s important to learn the general sizes of insects.
- Caddis Size #4 – #20
- Mayflies Size #4 – #24
- Stonefly Size #2 – #16
- Midge Size #16 – #28

#2 - Shape/Profile

You’ve assessed the insect or baitfish size; now, what profile/shape or silhouette of the fly to choose? Shape/Profile plays a large role with surface flies.

Assessment –

What shape is the insect you observe in the air or the water?
What type of wings does it have? How many legs or tails?
Choose a fly that matches the shape you are mimicking.
What order (caddis, mayfly, midge, stonefly) are you matching? This is where entomology will come into play.
Adult Shapes –
- All adult aquatic insects have the same shape but will vary in size and color.
  - Caddis – Tent
  - Mayfly – Sailboat
  - Stonefly – Long Board

Immature Shapes –
- Look at the Profile of the subsurface insect or aquatic prey.
- Try to match the same body profile.

#3 - Color

If matching and using an imitative fly, choose a similar natural color. Try matching your fly with the color of the habitat.

It’s essential to recognize that the color of your fly in the water is almost always different from what it is in the air.
Look at the color of the natural insect in the water attached to a rock and match that color.
From my personal experience that many times matching the color of the hatch has helped lead to a successful evening of fishing.
- For example, during a Pale Evening Dun (PED) hatch I’ve caught more fish with a size #16 yellow parachute than a size #16 gray parachute Adams.

#4 - Behavior

Consider both insect behavior and fish-feeding behavior when choosing a fly. This is when it’s time to observe.

Insect Behavior –

Observe adult and immature insects.
How are the insects flying around in the air or landing on the water?
- Soft, smooth, skittering, dipping, diving, frantic, falling from vegetation?
How are the insects moving subsurface?
- Swimmers, clingers, divers, crawlers?
Try changing your retrieves and drifts before changing your fly. The movement of the fly can play a huge role in being more successful in catching fish.
The way the fly moves within the water column is how you should fish your fly.

Fish-Feeding Behavior –

When trout are actively feeding, they give us clues about their rise.

Noses/Dimples = Small Insects Such as Midges and Mayflies or Spinners
Splashes with Bubbles = Caddis, Large Mayflies and Terrestrials
Splashes without Bubbles = Wet and Dry Emergers (Emerging Caddis Pupa or Mayfly Nymph)
Tail/Fins = Nymphs or Wet Emergers
Bulges in Current with Quick Flash – Aquatic Prey

Habitat

The kind of water in which an insect lives predicts where you will fish its imitation.

Fast vs. Slow Water

Fish searching/attractor patterns in riffles and faster water.
Fish impressionistic/imitators in smooth and soft water.
It is often necessary to consider a pattern style that offers a more exact silhouette of the natural insect.

Pattern Selection

Pick your pattern based on the size of the insect, then vary the color to match precisely what’s happening.
Also consider the impression the imitation makes on the surface film or the movement in the water.

December 25 2022

Fly Category Types

Blog, Education, Entomology, Trout Match the Hatch

We’ve covered the different fly types; now let’s discuss the four fly category types. Fly categories are not an exact science, like classifying an aquatic insect, but they are an excellent reference for choosing the correct fly to be a successful angler.

All these topics and more are covered in the “Match the Hatch” online course.

4 Fly Category Types

Searching Patterns
Impressionistic Patterns
Imitative Patterns
Attractor Patterns

Searching Patterns

A searching pattern is used first when you’re unsure what is hatching or what fly to use. These flies are not meant to look like anything in particular; they can imitate various insects. These are used when searching for what size, color, or profile of the fly the fish are looking for.

You might spend an entire day being successful with a searching pattern, or it might help narrow down to a different category.

Many searching patterns can also pass as a specific insect order. (i.e., Caddis, Mayfly, Stonefly, Midge)
Start to observe where you are catching fish with these patterns?
- In the Riffles, Runs, Pools, Tailouts, etc.
  - This will help you identify which stage of insects the fish are feeding on.
What is the feeding behavior of the fish? How are they eating the fly?
- Drag Free Drift, Twitch, Swing, or on the Final Lift.

Impressionistic Patterns

Anglers often start with an impressionistic pattern if they know what is hatching. This is the next logical step after fishing a searching pattern. How do you know what is hatching? Get to know and learn the hatches. Read our “Hatch Chart” blog.

These patterns can pass as different orders (mayflies, caddis, stoneflies, or midges) or genus (BWO, PMDs, Golden Stones) in multiple stages before you narrow down the specific species and stage to mimic an imitative pattern.
Once you’ve narrowed down the 5 factors of choosing a fly (size, profile, color, behavior, and habitat), you can switch to an impressionistic pattern.
- Example – Switch from a green parachute to a Flavilinea Dun pattern.
Usually, defined profiles and natural colors.
Impressionistic fly patterns are best used in faster-moving water. Faster water means less time for a trout to analyze the fly and make a quick decision.

Imitative Patterns

An imitative pattern mimics a specific species and stage.

Should be fished as a single stage.
Once you have figured out the imitative pattern, you’ll catch far more fish!
Size, profile, and color all mimic a specific genus and stage.

Attractive Patterns

The attractor pattern mimics nothing but attracts the many. This fly has been designed to attract the curious, sometimes less educated, fish.

Flashier, bright colors, legs, sparkle, and synthetic fibers.
Weak to no resemblance of a type of insect hatching or baitfish.
Use if you do not succeed with a searching, impressionistic or imitative pattern.
Use when there are no apparent insect hatches or trout eats.
Can be successful during a prolific hatch when you can’t match the fly. Color outside the lines by fishing with something big, loud, and obnoxious.

Conclusion

Knowing the 4 Fly Categories is an excellent reference for choosing the correct fly to be a successful angler. Start with a searching pattern and move to an impressionistic and imitative one if needed. Don’t forget to color outside the lines by fishing with a big, loud, and obnoxious attractor fly. Happy Fishing!

December 25 2022

Classification of Aquatic Insects

Blog, Education, Entomology, Trout Classification of Aquatic Insects, Match the Hatch

By: Heather Hodson and Megan Hess

Fly fishing allows us to get as nerdy as we’d like with almost every aspect of the sport. For some, it’s just a time to get outside and feel the effects of nature. For others, it’s about narrowing down an aquatic insect’s specific species and stage to fish the exact imitative fly pattern.

In the “Match the Hatch” Fly Fish Instruct online course, we want to appease all nerdiness scale spectrums. Let’s dive deeper into how aquatic insects are scientifically classified and what that means to us as anglers.

Disclaimer – We use common names for a similar group of aquatic insects. Example: When we say Blue Wing Olive, we are referring to the genus Baetis which encompasses more than 150+ mayfly species.

Classifications of Living Things

Scientists classify living things based on their shared traits. In addition to identifying each different kind of organism, classification can help us understand how living things are related. Scientists start at the most broad group (kingdom) and end at the smallest group (species).

Classification Types:

Domain
- Kingdom
  - Phylum
    - Class
      - Order
        
        Family
        
        Genus
        
        Speciesbro

Same Domain, Kingdom, Phylum and Class

All aquatic insects are classified the same until order.

Domain – (Eukaryote)
Kingdom – (Animalia)
Phylum – (Arthropoda) Have Exoskeleton
Class – (Insecta) Adults Have 6 Jointed Legs

Order

The order is another way to break down the Insecta class further. Think of it as “refining your search” for a specific type of aquatic insect.

Most Common Trout Fly Orders:

Diptera – Flies (Midge)
Ephemeroptera – Mayfly
Plecoptera – Stonefly
Trichoptera – Caddis

Family

The next level in the classification of living organisms is much like the people we call family. We are all different, but we share enough similarities that we belong to the same family; the same applies to all living things. Tip! You can identify an aquatic insect’s scientific family name because it will always end in “dae”. The family is usually some variation of the “genus name” + “dae”.

Examples of Aquatic Insect Families –

Baetidae – Small Mayflies
Chironomidae – Midge
Pteronarcyidae – Large Stoneflies or “Salmonflies”
Rhyacophilidae – Free Living Caddis

Genus

The genus is the first part of a living thing’s scientific name, known as binomial nomenclature.

Examples of Common Genus –

Baetis – Blue Wing Olive
Rhyacophila – Green Sedge Caddis
Pteronarcella – Salmonfly
Chironomus – Bloodworm – Red Larva Midge

Species

The species is the final and most specific level of the classification system. There are usually several to hundreds of different species for each genus. Unless you are super nerdy into insects, hardly ever do anglers refer to the individual species of an insect because it is usually too hard to identify to that level while out fishing and not under a microscope. Sometimes the difference between a species is the number of hairs on their forearm! As anglers, often we refer to the insect’s common name that encompasses the genus that they are within.

Number of Species For Each Genus –

Blue Wing Olive – 150+ Species
Green Sedge Caddis – 125+ Species
Salmonfly – 2+ Species
Bloodworm – Red Larva Midge – 90+ Species

Conclusion

It’s not necessary to know the scientific species of an aquatic insect, but it’s helpful to be able to identify the order and genus. Start with a quick research of these specifics, and you’ll be a step ahead in choosing the right fly to match the hatch. Happy Fishing.