It’s August in Minnesota. The heat has settled in, and streamside vegetation hangs thick and heavy over the banks of coldwater streams and rivers across the state. In our backyard, my daughters love to pass the time catching grasshoppers in the tall grass and tossing them into the stream, watching the brown trout lurch over to take them. Typically, the trout just can’t resist. In fact, hoppers can play a surprisingly big role in their late-summer diet, even though they aren’t aquatic insects at all.
Ecological Role in Stream Ecosystems
Grasshoppers are classic terrestrial invertebrates, living and feeding in the meadows, prairie edges, and tall grasses that often border trout streams. By late summer, their numbers peak, and many inevitably find their way into the water, some blown by wind, others knocked from stems by passing wildlife, or simply making an ill-fated leap.
Once caught up in the current, hoppers become an easy, high-calorie meal for trout. In smaller prairie streams and Driftless creeks, hopper “falls” can be a major seasonal energy pulse, supplementing the more steady diet of aquatic insects. Even in northern streams along the North Shore, grasshoppers from alder thickets and grassy openings can find their way into the drift, especially near beaver meadows or restored riparian zones with tall vegetation.
This connection between riparian habitat and trout food underscores the importance of healthy streamside vegetation. Good vegetation not just bank stabilization (see the August Habitat feature!), but can also be a conveyor belt, buffet even, for terrestrial prey into the aquatic food web.
Fishing Grasshoppers in Minnesota
As late July rolls around, it’s time to start carrying a small row of hoppers in your fly box. Breezy summer afternoons when the tall grass along the banks are swaying and bending are when trout are most likely to see hoppers tumbling into the current. In the Driftless and other southern Minnesota streams, look for undercut banks shaded by grasses, where an accidental leap or a gust of wind would send a hopper into the water. One good plop near the bank can be all it takes to draw a trout from its hideout.
Up north, it’s a slightly different picture but the same story. Beaver meadows and open grassy stretches on freestone streams are great hopper water. The fish here don’t see them as often as their southern cousins do, but when they do, they’ll still go after them. Try a fly that won’t sink such as foam patterns in tan, yellow, or olive. Sometimes, my husband (and angling advisor) will tie on a small beadhead dropper below it, just in case a trout is more in the mood for something smaller. But either way, when hoppers are on the menu, there’s really nothing quite like watching a trout rocket up and take one off the surface.