The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.
|Option 1||Option 2|
|Forewings leathery (semiopaque) or hard, at least in the basal half||Wings entirely membraneous, usually transparent between veins, but may be variously colored, darkened, or covered with hairs or scales|
|Remaining orders: Coleoptera, Hemiptera, and Orthoptera||Remaining orders: Diptera, Ephemeroptera, Hymenoptera, Lepidoptera, Megaloptera, Neuroptera, Odonata-Anisoptera, Odonata-Zygoptera, Plecoptera, and Trichoptera|
5 Example Specimens
I'm glad I finally got one of these Belostoma water bugs under my good camera. I had been hoping to get one in my kick-net samples for a while with no luck, but I ended up finding this one drifting midstream just below the surface while I fished. I have frequently seen water scorpions do that, too, and I'm beginning to suspect that is a common situation travel for these large Hemiptera bugs, and perhaps the way trout are used to seeing them.
I found this cicada and several like it in the grass near my car as I put my waders on. Some of them were singing in the trees above the river, too, but I did not see any fall into the water.
Here's a big water scorpion (no relation to actual scorpions). These guys are just about the most sinister-looking creatures you could find, and what's especially creepy is that they can come up out of the water and fly around, as I learned when one left my aquarium and buzzed my head while I was peeking into the microscope at a mayfly nymph.
5 Example Specimens
I had some trouble working through the genus key for this one because I'm not great at interpreting caddis wing venation. Fortunately, figure 19.707 in An Introduction to the Aquatic Insects of North America (Fifth Edition) shows the distinctive color pattern of the striking forewings on Hydatophylax argus, which is a perfect match for the pattern as well as venation. As there are no other species in that genus in this area, I can be pretty confident in the species ID.
I first just assumed this was Dicosmoecus based on anglers' conventional wisdom since it's a large orange "October caddis," but Creno set me straight. I should have keyed it out. After another look under the microscope, it lacks an anepisternal wart on the mesopleuron, which rules out Dicosmoecus. The midtibiae have 2 apical spurs and 1 pre-apical spur, and from there the color pattern of the wing points to Onocosmoecus. The location then narrows the species to unicolor.
|Go to Couplet 2||Go to Couplet 4|