Blue-winged Olives
Baetis
Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.
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This one seems to tentatively key to Holocentropus, although I can't make out the anal spines in Couplet 7 of the Key to Genera of Polycentropodidae Larvae nor the dark bands in Couplet 4 of the Key to Genera of Polycentropodidae Larvae, making me wonder if I went wrong somewhere in keying it out. I don't see where that could have happened, though. It might also be that it's a very immature larva and doesn't possess all the identifying characteristics in the key yet. If Holocentropus is correct, then Holocentropus flavus and Holocentropus interruptus are the two likely possibilities based on range, but I was not able to find a description of their larvae.
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True Bugs
This common name refers to only one order. Click its scientific name to learn more.
Insect Order Hemiptera
These are often called True Bugs.
The large, diverse family of "true bugs" contains several insects of importance to anglers, both aquatic and terrestrial.
Perhaps the best known are the water boatmen of Corixidae, which are a primary trout food source at times in many high lakes, spring ponds, and slow-moving rivers. They are generally aquatic, although they may come out of the water to mate. I have seen good numbers of them flying over a northwoods river in late March, a sight that had me baffled until I captured one of the odd insects that kept flying past me and plunging into the water.
Other aquatic true bugs have received very little attention in
fly fishing literature, but they probably deserve more, because they are among the largest insects native to the trout's environment. The giant water bugs of Belostoma are especially favored, but trout also feed on the water scorpions of Nepidae. I plan soon to spend more time researching and imitating these insects to confirm my hunches and early observations.
The most famous terrestrial members of Hemiptera are the cicadas, which make for good fishing on those rare years when a large brood appears. Late every summer some fly fishers turn to tiny related terrestrials they call Jassids, which are the leaf hoppers and tree hoppers of the families Membracidae and Cicadellidae.
Perhaps the best known are the water boatmen of Corixidae, which are a primary trout food source at times in many high lakes, spring ponds, and slow-moving rivers. They are generally aquatic, although they may come out of the water to mate. I have seen good numbers of them flying over a northwoods river in late March, a sight that had me baffled until I captured one of the odd insects that kept flying past me and plunging into the water.
Other aquatic true bugs have received very little attention in
fly fishing literature, but they probably deserve more, because they are among the largest insects native to the trout's environment. The giant water bugs of Belostoma are especially favored, but trout also feed on the water scorpions of Nepidae. I plan soon to spend more time researching and imitating these insects to confirm my hunches and early observations.
The most famous terrestrial members of Hemiptera are the cicadas, which make for good fishing on those rare years when a large brood appears. Late every summer some fly fishers turn to tiny related terrestrials they call Jassids, which are the leaf hoppers and tree hoppers of the families Membracidae and Cicadellidae.
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.
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