Mother’s Day is observed the second Sunday in May. That much we know. Mother’s Day came right on schedule on May 9, this year, and we duly observed the protocols for the day.
What we’re waiting for now is the Mother’s Day Caddis Hatch, that explosion of insect life that seems to get the flyfishing season going in earnest.
There are many kinds of caddisflies, and trout depend on them for a big chunk of their diet. The late Gary LaFontaine, in his landmark book, “Caddisflies,” cited scientific studies that estimate that caddisflies account for 44.7 percent of aquatic foods eaten by trout, significantly more than mayflies and stoneflies, though mayfly and stonefly imitations usually take up more space in a flyshop’s cases.
Caddisflies are of the scientific order of Trichoptera, and, according to LaFontaine, there are more than 1200 species in 142 genera and 18 families known in North America, and over 7,000 species known world-wide, and about now I’m wishing I remembered more from those high school biology classes.
The scientific name for the Mother’s Day Caddis is Brachycentrus, and a common name for them is Grannom. The caddis hatch happens on most western rivers. The trick is being around when it happens, as well as having fishable water.
The Mother’s Day Hatch, when it finally happens, can be impressive. The hatch on the Yellowstone River is famed for profuse hatches, when large rafts of insects float along the river’s currents, and an angler trying to get in on the action may find caddisflies crawling all over his/her face and into ears. On the Big Hole River, where I do most of my fishing, I don’t think I’ve ever seen any hatches that dense, though when there are clouds of insects buzzing around trees and bushes it’s still impressive, especially when they crawl inside your glasses.
On the other hand, by the time these masses of bugs appear on the water’s surface, as well as buzzing around trees and bushes, the trout may have already filled their bellies with emerging caddis trying to make their way from the stream’s rocky bottom to the surface. In fact, a good strategy, during the hatch, can be to use an emerger-type fly such the sparkle pupa patterns developed by LaFontaine, or a green-bodied soft-hackle fly.
As for fishable water, in most years that’s the real trick. All too often, the Hatch happens when spring runoff is really getting going, and while there are lots of caddisflies buzzing around, the trout are hunkered down, and not spending a lot of time looking up at adult insects on the water’s surface. I know I’ve had my best caddis action in years when runoff was more on the tame side.
There can be a fine line for optimal caddis hatch conditions. I specifically remember one spring on the Big Hole the water was running on the high side, though it wasn’t blown out. Shoreline willows were partially submerged, and trout were hanging right in the willows, in position to pick off caddis bugs dropping on the water. I had a banner day, even though the wading often seemed adventurous.
There are many caddisfly imitations available, whether you roll your own or buy them at a flyshop. Caddisfly imitations generally fall into several categories, depending on whether you’re trying to imitate a cased larva on the bottom of the stream, the pupa swimming through the water column, or the adult winged insect.
As mentioned earlier, green-bodied soft-hackle wet flies or LaFontaine sparkle pupa are good pupa imitations. The Elk Hair Caddis, developed by long-time Dillon guide Al Troth, is certainly one of the standards. I’ve also had a lot of success with a Renegade, a simple fly that possibly suggests a pair of mating caddis to a hungry trout. A small Humpy is also effective, especially when there are both caddisflies and mayflies buzzing around. If you don’t mind tangled flies and tippets, this may also be a good time for a dry fly with a wet fly dropper.
Best of all, once caddisflies show up, fish will be looking at caddisflies until fall.