They are an important food source for trout in the lakes, reservoirs, rivers, and streams throughout the Rocky Mountain West. Here in Southwest Montana, we primarily use fly patterns that imitate these while fishing still-waters, spring creeks, and the larger Tailwater fisheries around the state such as the Missouri, Big Horn, Madison, and Beaverhead rivers.

While many Scud and Sowbug fly-patterns are tied in bright colors like pink and orange, the actual insects are gray or olive in color. Conventional wisdom tells us that Scuds and Sowbugs are more important in the winter, spring and fall season as a food source for trout as other insects are less active during those times of the year. The brightly colored Scud and Sowbug patterns are likely taken as egg imitations - rather than the actual insects - by trout during the spring and fall. Regardless, stomach sample of caught trout will typically include both Scuds and Sowbugs as well as trout eggs, midges, in addition to other invertebrate.

As we look forward to warming temperature this spring, this is the time of year to start going through the fly boxes and restocking these essential flies for Bozeman fly-fishing. Our Scud and Sowbug boxes tend to have a wide range of patterns and colors, here are a few of our “standard” patterns we use on our winter and spring nymph rigs while fly-fishing the Missouri, Big Horn, and Beaverhead rivers.