Aquatic Insects of Rivers/Creeks

By: Ethan Merrick

Introduction

Bugs are just a known thing. There are many kinds ranging from the smallest ant to the world's biggest stick bug. There are many different life cycles, and lifespans. There are many different colors, and shapes of bugs. There are different environments from the driest desert, to the very rainy forests. Many different ways to survive, and to overall thrive. Today we are going to talk about the most common and successful insects; Aquatic Insects. 

Living in almost every river in the world there are small but helpful flies in the waters. Most of these flies help with eating up the waste in the river making it safe for other animals such as fish to live in the waterways all across the world. These flies don’t only help the other animals in cleaning the water, but by also being a great food source. Most trout only feed on these flies, and the occasional grasshopper or ant that falls into the water. 

Caddis Fly (Trichoptera):

The Caddis Fly hatches in your April month, and depending on the species they can hatch in early October. The Caddis diet includes planken, algae, and plants when they are older. They help clean up waste as well keeping balance in the water. They have 5 life stages; starting with the egg. It then hatches into lavea, where it is free moving. Mostly under rocks or drifting at the bottom of the river or creek. Afterwards they turn into pupae. Wrapping themselves in silk so they can change from nymph to emerger. Almost exactly like a moth or a butterfly would. After they hatch from their cocoon they make the travel up to the surface of the water, where they start to lay eggs. They are now considered a Dun or an adult Caddisfly. They live in the water for about two years, some only for one. At the adult stage they only live for two months. 

Popular Fly Patterns for the Caddis Fly

The Caddis has a lot of patterns because of how much of the diet it takes up for trout and other species. The most popular fly to imitate the adult Caddis would be your Elk Hair Caddis. Almost fished by everybody. It was the first fly handed to me, and it did the job just fine during Caddis hatches. Another less popular fly is your Dyret Dry Fly. It does a great job catching fish like your Elk Hair Caddis, but it is very buoyant. With this in mind you can fish two fly setups with no problem. 

Fishing Caddis nymphs is always a blast as well. There are thousands of patterns out there for your caddis lavea and pupae. The Holy Grail Fly works great imitating your Caddis Pupa almost to a tee. The only thing you need to know about this fly is that you need to get it low in the water. As at this stage your Caddis pupa is mostly going down stream if it is at the bottom of the river. Most of the time Caddis will put themselves onto rocks, or other structures in the water when they get into their cocoon. Sometimes one may slip making it a great meal for a hungry fish. A popular fly for the lavea stage of the Caddis is going to be a frenchie patterned Caddis. It is great for all fishing. What you are going to find is there are endless fly patterns for your Caddis, so you need to find what works best for you. 

Stonefly (Plecoptera)

The Stonefly is another important bug in the aquatic ecosystem. They eat similar to the caddis, and help the river thrive. They are normally one of the bigger insects in the aquatic section of bugs. They take about 1-2 years under the water, and 1-2 months above the water(exactly like the Caddis) Unlike the Caddis though they only have three life cycles. Starting with a nymph, where they stay there feeding on plankton and algae. They then crawl onto the surface, where they hatch themselves into adults. Completely dodging the emerging procedure. They then take their two months to lay eggs. They are horrible at flying, and can only make it about a half a mile before they need a break. They most of the time spend their whole life on the water where they eventually die on the surface of the water. Making them a great source of food. 

Popular Fly Patterns for the Stonefly 

The Stonefly is a great pattern to fish, especially nymphs. They always seem to attract a bite as they are a big meal, and trout will bite almost anything that will fill them up quickly. Some of the most popular nymphs for the Stonefly are Double Beaded Stones, Pat’s Rubber Legs, and many others. Some great dun flies for the Stonefly would be your Stimulater Yellow Sally, the Yellow Sally(imitates the egg laying stage of a Stonefly), and the Foam Body Stone. Out of all these I love the stimulator Stone, as it is a bigger fly that the fish love. 

Mayfly (Ephemeroptera)

Mayflies are one of the most common flies to see on the water. Known for their vertical wings when they first are adults. Then there horizontal wings when they are in the process of dying. They mostly eat detritus, but some may eat smaller aquatic insects. Mayflies however do not eat in their adult stage, as their main purpose is to lay eggs at this stage. Their life cycle consists of Egg, Nymph, Dun, and then a spinner(a dying mayfly with its wings horizontal to the water). Most Mayflies range from 0.6 centimeters to 1.1 inches. Mayflies only live about 1-2 days at their adult stage making them one of the least between the three most popular flies. They spend 1-2 days reproducing, so they can keep the line of awesome flies continuing. 

Top Mayfly Patterns 

Like stated above the Mayfly is one of the most popular flies to see on the water. Therefore you are going to see a lot of fly patterns popping up. There are thousands of patterns ranging from your nymphs to your spinners. Some of the most popular being your Parachute Adams, your Adams Fly, and my favorite the Purple Haze. These dry flies let the beginner Fly Angler catch fish without having the best presentation and skill. 

Almost every nymph pattern works for fish. Nymph patterns range from simireaslistic

to hyperrealistic. Some of the most popular Nymph patterns are your frenchie, your rainbow warrior, and one of the most popular is the Pheasant Tail Nymph. 

Terrestrials

Starting with grasshoppers, which are found everywhere in the summer months make a great meal for trout. Sometimes they end up falling into the water, and fish are ready. They commany don’t think twice, and slurp that hopper up. Grasshoppers come in a ton of sizes ranging from a size 14 up to a size 2. Grasshoppers after falling into the water like to try to swim to the shore, and this makes them entice a bite, because fish will see this and will not want them to get away. Trout are predators, so when they see things move, and look realistic they get gobbled up; oftentimes quite aggressively. 

Ants are another great pattern for fishing in the summer months. They may be smaller patterns, but they seem to still do great. Ants are commany tied in sizes 22 to 16, but sometimes can range bigger on the hook scale. Ants like grasshoppers find their way into the water by falling, making them an easy target for trout. Ants also are not the best swimmers, and don’t really move that well on the surface. Sometimes they sink, and sometimes they stay on the surface. This makes an opportunity to fish them both dry and wet. Even though they are small, some huge fish have been caught on ants, and will forever be a great fly to tie on when other flies don’t seem to be working. 

Lastly we got Beatles which are again a terrestrial (lives on land) that only really finds its way into the water by falling into the water. Beatles are a bigger meal just like your grasshopper making a trout seeking for a bigger meal likely to bite. They oftentimes seem to freak out when they fall into the water, making them a great fly to twitch as the fish key onto movement. They will oftentimes let it pass by dead drifted, but attack it with some fast small twitches. Beatles can range from small size 16 hooks all the way up to your size 12 hooks, but you can fish them a bit smaller or bigger as well. 

Hopper Patterns

Starting with your grasshoppers, which have endless patterns, in different colors, sizes, and even legs. Some of my favorite fly patterns for the hopper are your Chubby Chenneble (one of the most popular patterns for a hopper), the Morrish hopper, and the Parachute hopper, which is my favorite hopper. There are many other hopper patterns, but these ones are great for your normal occasion. 

Ant Patterns 

Ant patterns are a fun one to tie on during the summer time. Ants are everywhere, and fish are dialed up on them. They may be a small snack, but fish still seem to think that they are a great snack during the summer months. Like almost every bug there are thousands of patterns to imitate them. Some of the most popular flies however are your Flying ant, your Cinnamon ant, and my favorite the parachute ant. 

Beatle Patterns

Beatles are another great meal maker for your trout (especially the bigger ones). Beatles are great swimmers, and can stay on the surface with no problem. They can however also stay under the water for up to 36 hours making them a great pattern for surface and subsurface fishing. Some of the best patterns for your topwater beatles are your Foam Beatles (My Favorite), Brown CDC Beatle, and Black CDC Beatle. They all make great buoyant Beatle imitations that you should try. 

Midges

Going back to your aquatic insects we got our Midges. Midges have a similar life cycle to most aquatic bugs; Egg, larvae, emerger, and finally dun. In the larvae stage they eat algae, and other plants. However once they are duns the females will feed on blood from animals to supply protein for their eggs. The males will feed on nectar from flowers, and other plants. Midges only live 3-5 days in the water where they go up to the surface to live only 3-5 more days. There are hundreds of life cycles throughout the year, and this continues year round. 

Midge Patterns

The Midge is one of the most popular flies that people use year round, as they continue to lay eggs, hatch, and emerge throughout the year. There are many different colors and variations of midges, but sizes are most commonly 20-16 with some all the way in the 22 range. The most popular patterns for your Midges are your Zebra Midges, Griffith's Gnat, and Manhattan Midge. The most popular will be your Zebra Midge, and you can find it everywhere. Most commonly in size 16. People love this pattern, and people have caught some huge fish on this small pattern. 

Worm Life

Worms are nether terrestrials, or aquatic insects. They are normally subsurface insects, and come up to land during a rain or a flood. They are commonly fished as bait, and catch fish. The main question with that is how? Most species don’t live in the water, but when fish see them they gobble them up. My one guess is that they may see them when it rains and the worms fall into the water. It’s just a guess, that seems to be correct. They could get into the water from a flood as well. No matter how they get into the water, fish love them, and that causes us to want to fish them. 

Worm Patterns 

Almost every beginner angler used worm patterns, just because they want to be able to catch themselves some fish and not have too much skill involved. The majority of the time fish for whatever reason will be keyed up on worms. There’s just something about them that makes them a fish favorite. Some of the most successful patterns that I have found for these fish are the San Juan Worm(First tied for the San Juan River), the squirmy worm(often considered a cheat fly), and the FF Worm(that you can get at Fly Formula Flies. All these flies have caught me great fish as they seem to work when nothing else is. In my opinion any worm pattern is a last resort, and is not near as fun as catching yourself fish on other flies. 

Conclusion 

As seen above there are thousands of options of flies ranging from aquatic duns to small ants that live on land. There are many different ways to hook into fish, and sometimes the fish may be keyed on a certain fly. Not all the time, but sometimes. You should at least have some knowledge on when a bug/fly is active. You don’t want to fish a grasshopper in the middle of winter. You may want to fish a midge, or another nymph during this time of year. You may realize that there are a lot of Caddis on the water, so you tie on an Elk Hair Caddis. You may see no bugs, and still tie on a Dry Fly; you may light it up or you might not. It’s all about trial and error. One day at the same may be different then the other. The creek may fish differently from how the river fishes. There may be more active trout at one certain period of time. There may be more bugs in the water at a certain time. Again you may find yourself in a state of confusion especially on bigger rivers as there are so many variants that can happen. Take the stress away and just try something out. Most of the time you should catch something. You may catch nothing, but at least you learned something. You are doing an activity that requires a lot of trial and error. You may want to hang up your rod and quiet after only catching the skunk, but everyone goes through this stage. Keep pushing through, studying your bugs(Especially your aquatic bugs).