Worms, Eggs, and Mop Flies

This was originally a sidebar in the "What Trout Eat" article titled "Junk Flies" from the 2021 Fly Fishing Made Easy special publication of Fly Fisherman magazine.

Before you start fishing, take a look in the trees and the bushes along the stream. Pay attention to the insects trapped in spider webs and in lamps and lights along the river. Turn over a few rocks in the river and see what type of insect life is most common. Scan the surface of the water for insects and for rising trout. All of this will give you clues about what the trout might be feeding on, and help you “match the hatch” when you tie on a fly.

We all love to find a hatch and to solve the riddle of what trout are eating, but that doesn’t always happen.

There’s an old adage that “the best time to go fishing is whenever you have time.” That might be the middle of winter, a bluebird summer afternoon when nothing is hatching,  an early morning before hatches begin, in high muddy water, or some other time when the fish are not keyed on aquatic insects. That’s when it’s time to delve into your “junk box,” a secret arsenal of flies not tied to imitate aquatic insects. These aren’t pretty Catskill-style dry flies or artful nymphs. These are designated hitters you use when nothing else seems to be working, and you really want to catch a fish. Be aware that serious fly tiers won’t appreciate these flies because they are easy to tie and not constructed from traditional material like feathers and fur.

Worms. Bait fishermen use worms because they work. It’s undeniable.  Worms are often washed into the river during thunderstorms. We’ve all seen parking lots covered in worms, and it’s a wormy feeding frenzy when events like these wash worms into a trout stream. Many fly fishers are not aware of it, but there are also aquatic worms that live in the sand and gravel of some river bottoms. Trout eat worms all year, so fly fishers shouldn’t be above using a worm imitation to capitalize on this tendency. The Squirmy Wormy is tied with a silicone noodle that wiggles and undulates in the water just like a real annelid.

Mop fly. A chenille mop from the grocery store has hundreds and hundreds of tiny little microfiber fingers that pick up dust and dirt from your kitchen floor. Chenille has been used by fly tiers for many decades, but there must have been an aha! moment when someone, somewhere first tied a piece of mop to a hook and made the first mop fly. The microfiber chenille fingers from a mop absorb water, making them soft and mobile, and the mops come in all sorts of colors. Bright green mop flies look like caddisfly larvae, inchworms, and caterpillars, while tan and off-white mop flies look like cranefly larvae or caterpillars. The secret to mop flies is how they move in the water and how they feel in a trout’s mouth. Trout consume and quickly eject floating debris along the river bottom all the time—it’s how they find food. The mop fly looks like something trout need to investigate, and because it’s soft and juicy like a real inchworm or caterpillar, I think they tend to keep it in their mouths longer than some other flies that are more quickly ejected.

Eggs. Trout eat the eggs of suckers and whitefish. Suckers eat trout eggs. Trout eat salmon eggs. Brown trout eat rainbow eggs. Rainbows eat brown trout eggs.  It’s the way of life in the river, and your junk box should always  have yarn egg flies of various sizes and colors. Even if there are no eggs in the water—and haven’t been for weeks—trout remember what eggs look like, or perhaps it’s just part of their genetic code to eat small round dots of color. Carry eggs that are cheese, peach, and salmon colored, and throw a few bright chartreuse ones in there as well.