For me the difficult part about Caddisflies as they relate to trout is determining what is going on. Seems kind of “duh” but it breaks down something like this. On stream, splashy rise, see a few adult caddis fluttering around, maybe catch one match the size/shape/color as best I can but that’s when things fall apart. Sure I can throw on any number of adult dries that might meet most requirements but the complexity of the Caddis makes further choices difficult. When that adult pattern doesn’t produce a rise no matter how it is presented something else must be determined. Which specie? What does the larva look like? What kind of pupa should I try? Perhaps that splashy rise came as a result of a pupating caddis attempting to make a break for freedom and not the adult I see fluttering around. My goal here is to not become an expert on Caddisflies (I’m not going scuba diving in my favorite hole like La Fontaine) but rather to be able to make a few educated guesses. So where to begin? Well I know where, it’s sitting at home on a shelf next to some of my favorite texts and you can view it here. I am fortunate to have a bound copy and glad to own it.

The Guide to Aquatic Invertebrates of the Upper Midwest. You know your a bug nerd when you are excited to have this on your bookshelf, that or your in classes at the U of M to become an entomologist. So you get your hands on a copy of this beast. Now you have to decipher it, this can be challenging. Any number of terms that I have to look at twice just to pronounce make all the difference in the world of the caddis fly, especially when it comes to identifying the larval specimens. The U of M and a few other Universities have good aquatic insect identification tools. I point to the U of M’s Aquatic Insect Interactive Verification Program because it is meant to work in tandem with the guide book listed above. A second online identification resource comes from North Dakota with great images and explanations of all the complex terms that make up invertebrate identification. Collecting a few specimens, toting them home then using the verification program will help narrow the field with which I can look to the guide for further specific identification.

Out in the feild it becomes quickly apparent that the ratio of Caddisfly larva to say Mayfly larva is drastically skewed towards the Caddis just flip over a rock or shake a few weeds. Combine that information with the fact that fisheries biologists working for the DNR in our region can point to scientific research stating that the spring fed creeks we have here are so packed with trout food of all kinds that the need to feed on drifting insects diminishes with the age/size of an adult Brown trout. That is not to say they don’t feed on drifting invertebrates but rather they have a choice and the larger fish may be choosing to pick those millions of rocks packed with millions of cased caddisfly larva as an easier meal than waiting for the occasional drifting food item. That thought has me concentrating on the caddisfly larva, attempting to imitate the larval forms and use the indentification guide to hopefully gain a better grasp of which larval forms will transition to which pupal and adult forms.

I’ve got a long list of things that need my attention and from the beginning this blog/journal/whatever you call it was supposed to be a semi-organized/semi-scientific approach to the Southeast Minnesota/Driftless Area.  I have organized some of the better photo’s of the natural insects seen on our streams and included a bit of hatch information for the ones I managed to stumble across. This is an incomplete and on going effort that I hope will grow over the years, it can be found here.

Look for more from the Winona Fly Factory with the coming year and the season changes it holds. With the updated and organized photo galleries I will be able to quickly add and compile images that will help myself and hopefully others tie the flies that make the Driftless Area what it is all about. The hatch information presented is based on a combination of first hand experiences, information from other local anglers who truly know this place and entomology texts I’ve read. If you have anything to add or if I made a mistake please feel free to contact me at: winonaflyfactory@gmail.com

It seems that for the time being I have lost my Caddisfly book by Gary LaFontaine and will have to suspend my Entomology research with regards to the Caddisflies in my area until I can either find it or find a replacement. With that in mind I felt it important to still continue to learn more about that which I am ignorant and the world of Midge’s as I found is a large one indeed. After doing a bit of searching I found a good general Midge resource at Westfly.com

The Westfly page has information on all varieties of Midges and how to best represent them and present them to trout. One thing I found interesting is that Midge larva hang suspended in the water and that your fly should try to mimic that behavior so perhaps a very lightly weighted fly on just the head might help. The Westfly page also has several articles on how to tie various midge patterns and how to best present those patterns under different conditions. This should be used only as a general resource though, I know I will be going to find out what my water holds first hand, hopefully soon.

If the general resource doesn’t cut it for you, it didn’t for me I went further and happened to find a gem which happens to have been researched and produced in Minnesota. It turns out there is a Chironomidae Research Group associated with the University of Minnesota. Clicking a few links I found myself looking at A Guide to Aquatic Invertebrates of the Upper Midwest! I’m going to have to get my hands on a copy of this baby. For now though they have conveniently put sections of it on the web in PDF format. The Chapter on Midges is only 24 pages long and provides a guide to specific identification and information for several varieties of Diptera. 

Guide to Aquatic Invertebrates of the Upper Midwest

Click on the individual chapter you wish to look at and in a short moment a large amount of great information is at your fingertips.  Chapter 13 deals with Diptera the two winged general genre that Midges fall into.

Continuing the Caddis fly research for next season here is the next part of the series. I’m trying to keep things short and relevant I apologize for excess “fluff.” I would like to really point out what a resource Troutnut.com is, although most of you know that. 

The Summer Caddisflies pt.1 

Little Black Sedge (Chimarra aterrima) 16-18

• Adult Length: up to 8mm
• Wing: “Velvety” Black
• Body: Very dark Brown
• Legs: Brown
• Emergence from May-Late June

From the family Philopotamidae the Chimarra aterrima is a net spinning caddis and will look very similar to other free-living caddis fly larva but the picture on troutnut.com is of a yellow larva, I have not seen a yellow larva. They will live typically under rocks filtering food from the flowing current, they will emerge in typical fashion i.e. crawl out or swim to the top. The adults of this species dive to lay there eggs. I make this point because some of LaFontaine’s work and patterns take this fact into account. Note: Interesting point the book Caddisflies states “They share a particular rock with net makers of other families; Hydropsychidae larvae taking the exposed surface and the Philopotamidae larvae taking the protected pockets. pg. 292″  

American Grannom (Brachycentrus americanus) 12-14

• Adult Length: up to 13mm
• Wing: Almost White-Greenish Brown?
• Body: Bright Green-Greenish Brown
• Legs: Brown-Black
• Emergence from May-June

This is a tube-making caddis fly from the Brachycentridae family, one thing to point out right away is it has a distinct sharp square form to the shell with almost right angles, this is important when narrowing down the options in the field. These pupa do not swim to shore just to the surface of open water to emerge and they inhabit faster water being able to cling to the open surface of the rocks. This species uses an “Anchor” line of silk to catch them should they come loose from the rock. The book points to the fact that some fly fishermen have been known to color their tippet white with a marker when fishing the larval imitations. I don’t know if I think this is necessary but it might help. 

Speckled Peter (Helicopsyche borealis) 16-20

• Adult Length: up to 7mm
• Wing: Light Brown with Dark Brown Speckles
• Body: Pale to Straw Yellow
• Legs: Straw Yellow
• Emergence is from Late May-Early June (Shorter Period)

The Speckled Peter is the only caddis fly in it’s family (Helicopsychidae) of any importance to the fly fisherman. This is a tube making caddis but it is described as a “snail shell” building caddisfly, the shape is of a coil of small rocks. The larvae crawl around eating the algae and detritus off rocks. The pupa swim and emerge in open water. Apparently this species has an ability to survive harsh conditions which is why they are widespread and have important numbers. The larvae tend to inhabit moderate moving water. This caddis fly has a very wide range and has been found in almost every state.

Little Tan Short Horn Sedge (Glossosoma intermedium) 14-18

• Adult Length: up to 10mm
• Wing: Pale Tan-Medium Brown
• Body: Greenish Brown
• Legs: Brown Light-Dark
• Emergence in Later May thru Early July

From the family Glossosomatidae this is a “saddle” making caddis fly. They build something that would be described as a turtle shell to live in while eating algae and such. Interesting that this genre can be broken into 6 major groups and then spaced cooler-warmer water with G. intermedium in the colder end. Of all the case makers these are the ones coming in last in class and are the most primitive. The larvae live entirly in the case and leave only to emerge or to build a new larger case, this is a point where they are vulnerable to trout. The larvae in the case are a pinkish color and I belive on one of my recent hunting events I found a rock covered with something very similar to this and photographed the larva as an orange/pink grub.

I have effectively found information on all of the species of Caddisfly that the hatch chart from Lanesboro, MN describes. Now the question is how to present the information in a logical fashion, with the Mayflies I broke things down first by one of the four nymphal groups and then from earliest to latest in reference to potential emergence dates. Caddisflies are posing more of a challenge in that there are so many species that for my purposes I will be listing them starting with the earliest in emergence dates and ending with the latest. 

These first three represent the winter/spring emergence, February-Mid May. These should be fairly easy to distinguish on the water, only the last two have coinciding dates and are different in size and color. 

Medium Evening Sedge: (Dolophilodes distinctus) 12-16

• Adult Length up to 12mm
• Wing: Gray-Brown
• Body: Brown
• Legs: Brown
• February emergence

From the family Philopotamidae these are net spinning caddis larva living on the undersides of rocks. They spin a net to filter food from the water. Pupa swim or crawl to the banks or surface to emerge and the females dive underwater to deposit eggs.  Specifically D. Distinctus has a unique trait in that they will produce wingless females in the winter that are noticed running along the snowy banks.  These are going to be found in cleaner cooler well oxygenated water and perhaps less found on a larger warmer stream. Larva look like most free living caddis, like a green/olive worm with a black/brown head with six legs. Color for the larva is going to be harder to determine due to the variety in habitat thus finding them in the wild is important.

Summer Flier Sedge: (Limnephilus submonifer) 10-12

• 13-15mm Average Adult Length up to 20mm
• Wing: Ginger-Reddish Brown
• Body: Ginger-Brown
• Legs: Ginger-Brown
• April-May Emergence

This species of caddis fly is from the Limnephilidae super family that encompasses tube-makers of which there are many, over 56 different genus with each genus potentially having several species. L. Submonilifer are going to be found in much slower water sections, LaFontaine says he found these most in ponds in New Hampshire in much slower water, something to keep in mind. This specific specie builds a stick case in which to live, different from a spun net tube or rock tube.

Little Sister Sedge: (Cheumatopsyche pasella) 14-16

• Adult length up to 10mm
• Wing: Brown-Dark Brown
• Body: Green to Greenish Brown
• Legs: Light-Dark Brown
• Very Short Emergence Early May

Coming from the Hydropsychidae family of net-spinners this is a free living caddis larva. The information I’ve found indicate that the Cheumatopsyche is closely related to the Hydropsyche the main difference is size. The Little Sister Sedge is smaller than its cousin. These specific larva and subsequently adults will be more likely found further downstream in warmer water with higher sediment and algae content.

This information may be flawed or incorrect, I am not an entomologist, however sometimes I wonder why not? I’m sure there are bugs I wouldn’t like. If you think something is incorrect please let me know.

This is the 1st in what may be a long series on Caddis flies. As with the Mayfly Entomology series I did, I will be concentrating specifically on the species within the Hatch Chart that the Lanesboro Fishery put out, you can view it here. Armed with research tools and the chart I will be grouping the species into appropriate groups and posting information on each.  A few things should be discussed though before delving into the specific species of Caddisfly here in Southeast, MN.

I feel that Gary LaFontaine places special emphasis on the pupal state of a caddisfly and because the caddisfly has this stage in it’s development I thought this would be a good place to give some general information on the life cycle of the caddisfly.

Egg’s: Are deposited by female caddisflies some of whom deposit them by diving under the water fully submerging themselves and depositing the egg’s in a good location. Some species of caddis also fully submerge themselves but do it by crawling into the water from any location protruding from the surface. This is a good thing to note if you see concentrations of flies surrounding branches sticking out of the water or rocks.

Larva: Caddisflies exist as a Larva for most of the life cycle and as such these Larva are of great importance to the fly fisherman. As you probably know they come in many shapes and sizes. Anyone who has turned up a rock here has seen them even though they may not have known what they were looking at. Caddis larva live in a few ways, some species live uncased and cling to rocks with a spur or barb that protrudes from the back end of the larva. These typically are longer, green-olive and sometimes extremely bright green in color. Some species build cases from small pebbles weaved together with silk. Some simply weave a shell of silk around them while others build small bunkers in which they fully cover themselves like a small bomb shelter. The picture of the un-cased larva is of the underside and shows the tail which grasps onto rocks well. 

Pupa: When the caddis fly is ready and water conditions are right a larva will begin to change into a pupa. This pupa is different from a rising nymph in that caddis use a thin layer surrounding them which inflates with tiny bubbles to help them rise to the surface. LaFontaine goes into great detail with regards to this process because it was viewed improperly before his diving experiments and observations. The caddis will remain just below the surface after it has inflated its coating for potentially quite some time making this a good condition to imitate. With that LaFontaine used the Dupont product Antron to simulate the bubbles and how trout perceive the light reflected by these bubbles. The pupa remains just below the surface until the fly is about to emerge in which it does so fully able to fly off immediately unlike the Mayflies who must typically hang around the surface drying its wings.

Adult: The adult leaves the water immediately. Caddis flies can be seen in there adult form dancing over riffles and preparing to mate and deposit eggs thus starting the cycle over again.

Once again I will note that I am not an expert but attempting to learn as much as possible specific to the area of Southeastern, MN which may or may not pertain to Southwestern Wisconsin and Notheastern Iowa. I encourage comments which will either point out a flaw in my writing or will provide me with more information.

Left work the other day with an hour of light. The air temp on my way to the stream was 29 degrees but I was layered well and ready for a short romp in the water. There is something very calming and peaceful about being on the water at dusk. I stopped to watch a trout rise almost every two minutes to take something off the top of the water. I love watching trout hold a feeding pattern, something to take note of when it comes time to cast that fly. I collected samples from a specific spot on this stream because I fished downstream of where I took samples last season with my friend Heath. I remember I caught a few trout on Light Cahill dry flies. 

I drove home when I could no longer see well enough to take samples. Note: the water temp was a nice cool 40-41 degrees. I drove home in the dark listening to MPR. It reminded me of many trips this summer driving home after dark listening to the radio. It was a crisp but good hour in the stream. When I got home I examined my samples and found interesting results. 

It gave me confidence to remember I caught trout on Light Cahill patterns and then to find nymphs from the Macaffertium family. I haven’t come to a conclusion between Vicarium or Ithica but I’m going to figure it out. I also found several Baetis and Emphemerella nymphs. Note: the brighter yellow on the Baetis and as a result of that yellow I tied several size 16 and 18 Hare’s Ears with yellow and cream bodies. I’ll be posting new flies soon. One last thing to discuss here would be the second to last photo above. I have yet to figure out what it is. The side of the macro you can’t see has several suckers on it. It is definitely not a caddis larva, and it was very long probably 12-14mm. Anyone have any thoughts? I’ll be looking too.

Could it be a Cranefly larva?

Finished work today and took another quick run to a stream almost in town. I did essentially the same routine as yesterday but yesterday being my first time taking samples today I found it easier to find what I was looking for. 

Things I found interesting:

-The curious amount of both Scuds and the Cased Caddis found in the picture above on the rock next to the mason jar. 

-The amount of another insect that I haven’t seen in a stream before, rather I used to see these in basements and under rocks outside. I’m curious if these were around due to the amount of decaying leaves in the water.  I compared them to scuds I found but they really are different. 

Answer: Sowbug – Research, Learn, Fish Smarter. 

- I found more stonefly and Baetis nymphs today as well as Trico’s I think… Am I correct in thinking these two below are two types of Baetis? Same shape, size, tail, gills just a different color. 

I’m still working on the best way for me to take better images with what I have at hand. I do want to learn about this, I just would rather save for a new rod or something along those lines. So, thats another afternoon tromping in the water. I found so many scuds it was crazy 10-1 for sure. I just had to state that again, I was surprised.

After work I dawned a set of hip-waders and a rain coat, no rod, no reel, and no fly box just a backpack, camera, and items for research. I drove to a stream that I spent much of my summer on. I figured this would be a good place to start gathering samples. The rain poured down as I walked the stream searching for the areas I wanted to sample. I brought several small mason jars to hold the captives until they could be more closely inspected at home. I stumbled through the water not really able to see the bottom because of the rain obscuring the surface of the water, as a result I almost stepped on a few trout that were held up in places that I hadn’t seen them in the summer months. I used a strainer, the handle broke almost instantly and I was forced to used my arm as a replacement to gather samples from shaken aquatic plants and kicked up substrate. The stream water and rain made me rather cold and wet but I had a hard time quitting. Two hours of taking samples, looking for the specifics I’ve been reading about and I decided to pack it in before catching something nasty.

I wanted to take a semi-scientific approach to this so I labeled my samples with the types of substrate or plant they came from, this to help in the future determine what lives where. I also started a field log with date, time, weather conditions and location. I plan to continue this behavior.

I brought my jars home and after gathering a few house hold supplies I was ready to begin my investigation. I did a rough count of each type of insect caddis, mayfly, scud, and what I believe to be midge pupa (maybe not). I measured in mm. many of the subjects and tried to figure out each species. I was pleased to see that my little stream camera takes decent close up images. 

In addition to the pictures above I found several examples of scuds and non-cased caddis. I believe that the picture labeled Nymph 2 is a Baetis. I compared it to images I have and I am pretty sure, it fits the right size in mm, and the right attribute with regards to the slightly shorter middle tail. I found no burrowers but I think I found both an example of a fast swimmer (Nymph 2 above), and a feeble legged crawler (Nymph 1 above). I found several types of caddis both cased and non. The image on the bottom right is of a caddis larva removed from its protective rock built shell. Note: this is not a tubular shell, it is the kind that looks like a tiny pile of pebbles stuck to a rock.

This was a good time.

p.s. After looking the photo’s over I think Nymph #3 is a Stonefly nymph, thoughts?

The Swimmers

The Darting Swimmers Families Baetidae, Siphloridae and Metretopodidae.

The two main species found in S.E. MN are two forms of the ever popular BWO. We have the Baetis and the Plauditus punctiventris. These are both found in the Baetidae family when identifying these nymphs from the other two families size is the best indicator. Siphloridae and Metretopodidae fall into the Large Swimmers while Baetidae fall into the much smaller size category. All have gills on the abdomen sections 1-7. One more overall comment about the Swimmers, they are the most varied group in the mayflies and emerge in cases all year round based on water temperature. One will find swimmers in almost every stream.

Little Blue-winged Olive (Plauditus punctiventris) 20-22 Pale yellow olive Late June-Oct.

In Hatches 2 this is listed as Pseudocloeon anoka but has changed since publication. These are still swimmers and so they will have similar nymphal traits to the other swimmers but one quick way to distinguish these from other Baetis is the tail. Plauditus punctiventris has only two tails while Baetis has three, also the abdomen is thicker on these nymphs. These nymphs are 4-5mm in length, I’m noting this size for my own reference. These nymphs will most likely crawl on grass or other items to get out of the water during a hatch. They are less likely to swim to the surface and then hatch. Fish downstream of extensive weed beds.

Blue-winged Olive (Baetis) 16-22 Grayish olive to dark olive March-May & Sept.-Oct.

These nymphs will be found in underwater foliage. The slender bodies as well as legs make them ideal for swimming through aquatic plant life. The baetis nymphs have three tails like most other but the center tail is much shorter than the outer two. Note that the baetis will emerger early in the season and late in the season. One thing I’m finding is that the exact species of Baetis is not listed and as there are several this will be a task for me this coming year to determine which exact species inhabit the waters around me. The greatest numbers of these nymphs are found in alkaline waters with a ph. of 7.5 or greater. Hatching will occur between 11am and 4pm in March-April when water temp exceeds mid 60′s. Typically one will see these on overcast days and as a general rule overcast provides some of the best BWO fishing.