The Science of Hatches: What the Salmonfly Project Is Teaching Anglers with James Frakes and Jackson Birrell

Watch the full video:  https://wetflyswing.com/salmonflyproject

Take the Angler Survey:  https://salmonflyproject.org/survey/

Support the Salmonfly Project:  https://salmonflyproject.org/donate/

In this episode, we dig deep into one of the most important but often misunderstood parts of fly fishing: entomology, or the study of aquatic insects, and how it directly connects to success on the water.

James Frakes and Jackson Birrell from the Salmonfly Project break this topic down in a way that makes it approachable, practical, and actually useful for anglers at any level. Instead of overwhelming you with scientific jargon or Latin names, they focus on what matters most: understanding bugs well enough to make better decisions when fish are feeding.

Right from the start, the conversation shifts the way you think about “matching the hatch.” It’s not just about picking the right fly—it’s about understanding timing, behavior, and movement. When you start thinking not only like a fish, but also like the bug, everything begins to click.

Why Bugs Matter More Than You Think

One of the biggest takeaways from this conversation is that bugs are not just “fish food” they are the foundation of the entire river ecosystem.

Aquatic insects:
Feed trout and drive feeding behavior
Support birds and other wildlife
Help clean and maintain healthy rivers
Act as early warning signs for water quality

In fact, over 70% of freshwater species are insects, which puts into perspective just how important they are.
The guys emphasize that it’s not just about having a lot of bugs it’s about diversity.

Different species hatch at different times, creating consistent feeding opportunities for trout throughout the year. Without that diversity, fishing becomes less predictable and often less productive.
 
The Big 3: Mayflies, Stoneflies, and Caddisflies
To simplify things, they focus on the three major insect groups every angler should understand:
1. Mayflies
These are the classic “dry fly” bugs most anglers think of. They have a unique lifecycle that includes multiple fishable stages:
Nymph
Emerger
Dun (adult)
Spinner (final stage)
Because mayflies take a long time to emerge and sit in the surface film, trout feed on them gently those classic sipping rises.
A key insight:
 Mayflies are often most vulnerable during emergence, making emerger and cripple patterns incredibly effective.

2. Stoneflies
Stoneflies behave very differently.
Instead of emerging mid-river, they:
Crawl to the banks
Hatch out of the water
Return to lay eggs by skittering or “splatting” on the surface
This creates a completely different feeding response from trout:
 More aggressive, splashy eats
One of the most surprising takeaways:
During big hatches like salmonflies, fish may already be completely full from eating nymphs
That’s why sometimes fish ignore giant dry flies even when bugs are everywhere

3. Caddisflies
Caddis are fast, active, and incredibly abundant.
Their lifecycle includes:
Larva
Pupa (fast-rising stage)
Adult (moth-like)
Unlike mayflies, caddis emerge quickly and don’t sit long on the surface. This leads to:
 Faster, more aggressive trout feeding (the classic “caddis rise”)
A big takeaway here:
Fishing wet flies or pupae is often more effective than dry flies during caddis activity

Understanding Behavior Over Identification
One of the most important themes in this episode is that you don’t need to memorize every bug species.
Instead, focus on:
What type of bug it is (mayfly, stonefly, caddis)
Where it lives (bottom, rocks, banks)
How it moves (slow drift vs fast swim vs skitter)
When it emerges
If you understand those basics, you can:
 Anticipate feeding behavior instead of reacting to it

Hatch Timing and Strategy
The episode also dives into how hatches actually happen and how to fish them.
Key concepts:
Hatches are driven by water temperature and seasonal timing
Spinner falls are driven by air temperature
Bugs emerge in predictable windows (morning, midday, evening)
Some practical strategies:
Fish nymphs before the hatch begins
Switch to emergers right before activity
Match surface patterns only when fish are clearly feeding up top
They also highlight how:
Cloudy, humid weather often improves mayfly fishing
Sunny afternoons can be better for stoneflies
Evening and even nighttime can be prime for caddis

Real Science Meets Real Fishing
What makes this episode stand out is how the Salmonfly Project connects science directly to angling.
Their work includes:
Studying insect populations
Tracking environmental changes
Running angler-driven data collection
They explain how insects act as “canaries in the coal mine”s howing early signs of river health changes before fish populations decline.
This ties into a bigger message:
 Understanding bugs makes you not just a better angler—but a better steward of the river

The Wild Side of Bugs
This episode also mixes in some unforgettable (and slightly crazy) insights:
Caddis larvae build underwater nets and fight over territory
Some stoneflies live underground and show up in people’s wells
Mayflies have been around longer than dinosaurs
Certain bugs can literally “chirp” underwater to compete
These moments highlight something important:
 There’s an entire world happening beneath your feet that most anglers never see

The Big Takeaway
If there’s one idea to walk away with, it’s this:
You don’t need to know everything about bugs—
 you just need to understand enough to predict what’s happening.
When you:
Recognize the type of insect
Understand its behavior
Match your presentation accordingly
You move from guessing…
 to fishing with purpose.

Final Thoughts
This conversation is a reminder that fly fishing isn’t just about casting or gear it’s about awareness.
The anglers who consistently find success aren’t always using the fanciest flies—they’re the ones paying attention to:
What’s happening in the water
What stage the bugs are in
How trout are responding
And once you start seeing the river through that lens, everything changes.