Most trout fly fishermen are aware of the importance of aquatic insects in their quarry’s diet. These include mayflies, stoneflies, caddis and similar species. But while these water-born insects get most of the attention in trout fishing literature, in modern times terrestrial insects (those living on land) are becoming more and more important in the diet of trout.
These “bugs” jump, fall, get blown in by wind or washed in by rain and are eagerly gobbled up by waiting brook, brown and rainbow trout. Both hatchery trout and the wild native brookies of Shenandoah National Park love them.
Some of the most important ones we can imitate with our flies include beetles, leafhoppers, treehoppers, cicadas, crickets and ants. One of the most common of all is the grasshopper. This insect can provide great fishing right through the first frosts of fall.
Casting imitations of hoppers is particularly exciting because it often draws strikes from some of the biggest trout in a stream. Even small and average-sized trout will gobble them up, however. I once kept a trout about a foot long for a meal and found it had nearly a dozen hoppers in its stomach!
Grasshoppers start appearing along stream borders in April and May. It’s during summer and fall, though, that they reach peak numbers and trout key in on them for frenzied feeding binges. As you would expect, the best place to fish with these flies is around grassy meadow areas.
If you want to enjoy the fastest action, try to catch a few of the naturals along the stream or river’s edge. Examine their predominant colors and sizes and then select a pattern from your fly boxes that most closely duplicates the naturals. A precise match isn’t required. Just get one as close as possible. I’ve used sizes from 4 down to tiny size 18 hooks.
Fishing with terrestrials is most productive from mid-morning until late afternoon. That’s when the insects are most active and most likely to fall or get blown into a stream. Top weather conditions are hot and dry with wind also being a plus, since it might blow them into the water more frequently.
On rainy, cool days, opt for other flies than grasshoppers. Good terrestrials to turn to in that situation include ants, beetles, and caterpillar imitations, often called “inchworms”.
Larger terrestrials such as beetles and grasshoppers make a distinct “splat” when they enter a river. Trout learn to key in on this sound in their feeding by racing to any such sound. By dropping your fly with a “plop” you can duplicate this noise and draw strikes.
The best way to do this is to simply overpower your forward cast slightly to smack the fly onto the water. Another good delivery is the sidearm skip cast, which skitters the fly over the water and allows you to bounce the hopper back under shoreline brush, where big fish often lurk.
Large land insects such as crickets and grasshoppers often struggle in the surface film. Imitating this commotion with a gentle twitch can draw strikes from reluctant fish. Don’t make the movement too violent. Just move the rod tip gently to make the fly quiver or inch forward slightly.
Some of the heaviest trout often hang out within inches of the stream banks when terrestrials are tumbling in. I think they are waiting for them. Dropping your fly very close to the bank is a good tactic in this case since that’s where the fish are used to seeing the insects come from. The shore where the wind is coming from is often best. But don’t ignore mid-stream locations, either.
TERRESTRIAL TACKLE: These flies are sometimes bulky, so I like a rod with some backbone. A good choice is an 8 ½-9 ½ foot 5-6 weight rod with a weight-forward floating line. An 8-12 foot leader tapering to a 4-6X tippet completes the setup.
BASS AND PANFISH: Beetles, crickets, inchworms, and grasshoppers are large enough that they can produce excellent catches of bass. I like to fish them on ponds for largemouths and on streams and the Shenandoah River for smallmouths in sizes 4-8. Hand-sized bluegills will also nail small terrestrial imitations such as ants on ponds and lakes. Use hook sizes 10-14 so these diminutive panfish can get the imitations in their small mouths.