How Do I Know Which Fly To Use?
Whether you’re an expert fly fisherman or are just getting started, getting to know your flies and choosing the right ones for the right conditions is crucial to having a successful day on the water. With thousands of different flies available, knowing the difference between them all can make your fishing experience easier – so you can spend more time fishing and less time deciding on which fly to use.
Unlike bait fishing, fly fishing utilizes small hooks that are tied with various strands of animal hair, colored strands of fiber, or wire in an effort to imitate an insect or baitfish. Different combinations of shapes, colors, and sizes, flies are designed to entice and deceive fish into thinking that they’ve found a bite to eat.
With so many options for different seasons and water conditions, picking the right fly can be daunting. Here, we will dive into the different types of flies and how to know which ones are best.
Understanding the Trout Menu
Colorado’s waters are known for its many varieties of trout. As the most sought-after fish in Colorado, it’s important to learn about how they survive and the ecosystem that they thrive in. From understanding and mimicking their natural prey to adapting your setup to tune in to their habits, getting a good understanding of their preferred menu can make catching one of them a whole lot easier.
If you are going fly fishing with one of our Orvis-endorsed fly fishing guides here in Colorado, they will explain how to observe the water and surrounding ecosystems and recommend suggestions for flies.
Trout tend to feed very selectively and prefer bigger types of insects. Whether you’re with a guide or fishing on your own, you can expect to use any of these flies:
Mayflies: Mayflies hatch from underwater nymphs. When observing your fishing ecosystem, make note of the color and size of the mayflies. As many varieties of mayflies exist in different parts of the world, mayfly imitations come in various colors, shapes, and sizes. If you are unable to gather an accurate observation, you can never go wrong with choosing a fly with natural colors such as olive, cream, or brown.
Midges: Found on most rivers and lakes, midges are tiny mosquito-like flies that hover near the surface of the water. As some of the smallest fly imitations, they are usually only a few millimeters long and come in a variety of colors, such as red, brown, and black.
Caddisflies: Resembling tiny, hairy moths, caddisflies are a favorite among trout and are an integral part of the water ecosystem. Caddisflies play a major role in eating and filtering algae on water surfaces and are harder to observe because they don’t tend to linger for too long on the water. Caddisfly imitations come in various styles and life cycle forms such as pupae and emergers, and can range in color.
Stoneflies: Stoneflies spend most of their life as aquatic nymphs and live under rocks and other structures in flowing streams. In their nymph stage, they serve as a very valuable food source for trout. They emerge from the water and transform into a winged insect in their adult stage. When choosing stonefly imitations, observe your fishing ecosystem to see what period of the stonefly life cycle is currently taking place so that you can decide whether you should use a nymph or an adult fly.
Terrestrials: Grasshoppers, beetles, ants, and crickets are some of the most common terrestrial flies in fly fishing. Terrestrials are land-based insects that occasionally fall onto the water’s surface — trout like to take advantage of these instances, making terrestrials a great choice for landing bigger trout. When using terrestrials, you want to focus more on the time of year and type of insect. Grasshopper flies might be the best option in the summer, while ant fly types are great for any time of the year.
Streamers and Baitfish: Streamers are imitations of fleeing baitfish. If you are fishing in the Fall, pre-spawn brown and rainbow trout typically occupy fishing waters to fight for a big meal before the winter. Streamers can be imitations of small fish such as minnows, bluegill, or crawfish and are often a little bigger than wet or dry flies.
When choosing these flies, bear in mind that not all flies are designed to be an exact imitation. Some variations of flies feature various colors or flashy added materials called “attractors.” In some cases, these flashier materials can appeal more to curious fish and trigger a strike. In cases where you are unsure of the trout’s natural diet or your other flies simply aren’t working, consider using an attractor to get results.
Observing The Water
Before casting out, look at your surroundings and note the ecosystem around you. Observe the water and keep an eye on any insects hovering above the surface. Note the season and climate and look for any new hatches of aquatic nymphs. Any information you can collect can be useful in ensuring that you choose the right fly for the occasion.
When you’re in the water, note any fish you see and observe their behaviors. If the fish feed near the surface, you can hypothesize that dry flies might be the best option. If they are closer to the river or lake floor and feeding on aquatic nymphs, you might want to use a wet fly to get more depth.
“ So, what I typically like to do is actually bring a Rite in the Rain notebook that fits in my fly pack with me. And so, when I’m out there, I kind of make, you know, notes of what I’m observing out there, what kind of insects I’m looking at, what kind of birds I’m experiencing, any wildlife spotting that I see that day or even the fish counts that I’ve hooked up onto.”
- Anna Le
Source: (Orvis Podcast: The Amazing World of Trout Stream Bugs, with Anna Le)
Mimicking Your Fly’s Movement
After you determine which flies are the best for your environment, you’ll want to make sure that you are able to mimic their natural movements. Dry flies, wet flies, and streamers are three types of flies that you should keep in your fly box:
Dry Flies: Dry flies naturally float on the surface of the water and are retrieved with a slight twitch or ripple. These flies are meant to mimic an insect struggling on the water and are typically imitations of terrestrials. Although dry flies remain mostly on the surface of the water, they will inevitably get wet and begin to sink. If you are with an Orvis-endorsed fly fishing guide, you might observe them using floatants such as dry shake to keep the fly above the water for as long as they can.
Wet Flies or Nymphs: Wet flies are designed to sink and imitate a drowned insect or a nymph searching for food at the bottom. These flies sink at a realistic rate and should be retrieved at a naturally slow pace.
Streamers: As imitations of fleeing baitfish, these flies should be retrieved with a jerking or stripping motion that imitates the quick movements of fish escaping danger.
Putting it All Into Practice
Fly fishing is a lifelong learning experience with many growth opportunities. Whether you’re a beginner or an experienced fly fisherman, each outing provides new opportunities to learn something new. You might encounter a particularly interesting behavior pattern when observing fish, or even experience a new phenomenon that requires outside-of-the-box thinking. Keep observing and learning, and don’t be discouraged if you don’t catch a fish on every trip.
From the thrill of casting to the rush of catching a trout, fly fishing is a great way to connect with nature and challenge yourself to go beyond your comfort zone. Be patient with yourself, give yourself time to fully observe your surroundings, and make note of which flies are appropriate for your environment.
If you’re still uncertain about what type of flies to use, visit us at Fly Fishing Outfitters. One of our Orvis-endorsed guides will walk you through fly fishing basics and teach you everything you need to know so that you can experience the thrill of the catch. Contact us to set up a guided fly fishing tour today!
