Tips on Terrestrials
Paul Prentiss

If you think terrestrial imitations are only for summer fishing, you're missing the boat. I've caught trout from early spring through November on terrestrials.

Numerous studies of trout stomach contents have shown that land-based insects are a dominant trout food not only in August, but also in May, June, and September. Well into October and November, beetles can be the most abundant food in a trout's stomach.
Do trout prefer terrestrials to aquatic insects? I would think that a size 14 beetle has a lot more caloric value than a size 14 mayfly, and that a big grasshopper must provide more calories than anything except a big minnow or crayfish.

If you fish small streams, terrestrials are even more important than in larger rivers. A trout's diet in such places is made up almost entirely of terrestrials because these smaller waters don't have large expanses of insect-producing riffles. I suspect this is the reason why "attractor" flies are so effective.

Unlike fish responding to a hatch, trout can be eating terrestrials and you'll never notice. When trout eat low-floating terrestrial insects, there is hardly ever a splash. Sometimes you see a subtle ring on the water, sometimes a snout poking above the surface, and sometimes you see a hopper just disappear into a hole in the water.

The best places to try your offering are where riffles deepen into a dark slot (especially near a deep bank but not necessarily), in concave impressions along a bank that form small bays, and along undercut banks, especially ones that flow through meadows.

Here are a few thoughts on the subject

  • Use stealth just like you would with any other kind of dry-fly fishing. Occasionally, a fly that lands with a distinct plop will garner attention. Do this without splashing line and leader on the water.
  • Don't ignore the center of the river with terrestrials. Most ants and beetles fall into the water along the bank, but the current eventually draws them to the center of the river.
  • An occasional twitch can be effective, but don't overdo it
  • Many terrestrials sink after hitting the water. Try a Hard-Body Ant, or a floating beetle or hopper with a small split shot or lead putty above the fly. Use a strike indicator with this arrangement.
  • Generally speaking, terrestrials are more productive on windy days and from late morning through evening, when terrestrial insects are active and more likely to fall into a river.
  • Trout eating hoppers will often follow a fly for quite a ways before eating or refusing it. Don't pick up to make another cast too early, even if the fly is dragging.
  • FISH DROPPER RIGS - a small nymph tied as a dropper to the bend of the hook of a beetle or hopper is absolutely deadly on any stream.