Trying to tackle aquatic entomology as a newbie fly fisherman is a big task. No one said there would be science involved, we are suppos...
Trying to tackle aquatic entomology as a newbie fly fisherman is a big task. No one said there would be science involved, we are supposed to be relaxing and catching some fish. But as we realize that we need to know more about the insects that these beloved fish subsist one, the amount of knowledge needed to understand can become overwhelming.
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| Caddis Larva via troutnut |
It is easy to see the transformation from nymph to adult in a mayfly or stonefly. The insect stops living underwater, molts, and emerges with wings ready to fly. That is clear to most of us that have been through a couple of thick mayfly hatches. Caddis, however, are a bit different. We don't see them "hatch" and leave an exoskeleton on the rocks like a stonefly, and we don't see them "emerge" like a mayfly floating down a riffle.
Let me say that I am no entomologist, and barely an amateur armchair entomologist at that. Stoneflies and mayflies are pretty easy. They have an underwater stage and an above the water stage (or two). The underwater nymphs look pretty similar throughout their entire time underwater. There are some subtle differences as they age and mature, but they remain pretty consistent, even if they molt dozens of times.
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| Caddis Larva |
Caddis are the same, but different... They start life in a "larval" stage underwater but then transform slowly into a pupa before emerging into an adult caddis.
Let me also give a big shout out to Jason from www.troutnut.com. Without his extensive collection of photos and information, I would not have the really basic grasp of bugs that I do. (and it is very basic)
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| Caddis Pupa - a best seller |
Here is what we need to know as fly fishermen:
Caddis larva live underwater for most of their life cycle. The larvae are long and skinny, usually longer than the adults or pupae. They can be free-swimming, cased or web-building. Often described as "worm-like", their slim profile often has them mistaken for green worms, as many types of caddis are called a "green rock worm". |
| Caddis Pupa via troutnut |
Caddis "Pupate" in the days before they emerge. They form their exoskeleton, wings and other features that are more recognizable in an adult than the larva.
A pupa is basically an adult that is underwater. It will emerge from the water and do it's adult thing without molting again. It will leave its casing or web, then it will crawl to the shore, and perch itself on the grass and rocks along the river's edge. After it finds a place to do that, it just needs to dry out and get those wings moving.
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| Adult Caddis via troutnut |
So a caddis pupa is a great bug to throw early in the day when there is a predictable hatch in the afternoons, but a caddis larva is a good bug to throw when early in the season or as a "searching pattern" when fish seem to be eating nothing, or a little bit of everything.
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| Slow Water Caddis |
Pupae are often breaking free from their underwater hideaways and are available in low numbers all year, while the larva come in big numbers in cycles as they hatch. Either way you slice it, caddis pupae and caddis larvae should be included in your fly box and used with precision when the time is right.
