Terrestrials (ants, beetles, grasshoppers, etc.)
A terrestrial is defined by Merriam-Webster as.: 1 : of or relating to the earth or its inhabitants 2 : living or growing on land. To a fly fisherman/woman, a terrestrial is any living thing that lives on the land and ends up in the water as "fish food". This can vary from a tiny little ant to a mouse. Most common are ants, beetles and grasshoppers.
The vast majority of my fly fishing for trout has been done in the Western US...much of it in Idaho and Montana. I could tell stories all day about the large and often very wary trout I have landed with terrestrials in literally dozens of rivers. In many cases, I tied on an ant or beetle when I could not manage to interest a fish with the more traditional mayfly or caddis imitation even though they were in plentiful numbers on the water. If a nice trout will only move 6-8 inches for a mayfly, they will often move much further for a well presented beetle or ant. I have almost come to believe that when a picky trout sees a black beetle, it's brain sees a "banana split"...it is so enticing that it just cannot help itself.
Looking back through my 40 plus years of chasing trout with a fly, my very most memorable trout was caught on a #16 black deer hair beetle. The rainbow was 25-26 inches in length and very hefty. At the time, I had a cabin on the Henry's Fork. It was right on the river and just a couple of miles below the famed Harriman State Park...aka Railroad Ranch. As was common, we had a good spotting scope that was constantly pointed at the far river bank, One day as I was eating lunch, I sat in the chair by the window and looked through the scope and slowly searched the far bank for rising fish. It was that time of year when you can expect substantial PMD hatches throughout the day. Unlike the almost explosive takes that accompanied the green drake hatch just a few week earlier, the trout were back to their slow and delicate rises. It has been my experience that often the really big fish seem to be the most difficult to spot as they rise so slowly and just poke their nose up as they take these smaller flies leaving only the smallest of rise forms.
After a couple of minutes of searching, I saw (or perhaps thought I saw) a fish rise almost directly across from me. I kept watching and could see something creating the slightest disturbance every minute or so. If it was a fish, it was a big rainbow and it was in a place I had never seen a big fish hold for very long. I was interested...
To make a long story shorter, over the course of three days, I waded across the river 5-6 times and spent probably 15-20 hours either carefully watching the fish or actively casting to it. I was able to sit high on a rock just 15-20 feet below the fish. It was less than two feet from the bank and was holding under a pile of moss or aquatic weeds that had become lodged in front of a large rock. As the current carried the PMD's down the bank, the current split at the point where it encountered the pile of weeds. Most of the current flowed to the river side and a smaller current ran just between the weeds and the bank. As I sat there trying to decide how best to approach this fish, I was amazed that I had ever even spotted it in the first place and even more amazed at the trout's feeding behavior. Virtually every fly that fish ate was taken in the small slow channel close to the bank even though the great majority of the bugs were staying to the other side in deeper faster water.
If you have ever spent any significant time on the Henry's Fork, you quickly learn to cast a 12-15 foot leader with 5-6X tippet and do it with what I will call "delicate precision". I started with #16-#18 PMD duns and, over the course of the next three days went through a dozen or more different mayfly patterns from duns to emergers to "cripples" to even #20 unweighted nymphs fished in the surface film. As there were still a few green drakes around, I even tried a few of those. About half my time was bank sitting and the other half was in the water casting and cussing silently every time my fly floated over where he had last eaten. I think I had a fancy refusal on the second day but that was it. On the morning of the third day, I was sitting on my rock watching when a large bull moose came down to the river to feed and, in the process, it's very first step was within a foot of where I knew the fish to be holding. I was very unhappy and prepared to leave but, within just a minute or so, that fish came up in the same place it had for days.
I watched a few more rises and got back in the water and worked my way to the most advantageous position I could find given a soft breeze at the time. I tied on a #16 PMD "No Hackle"...3-4 casts resulted in nothing. I tied on a #18 PMD emerger...3-4 more casts and good floats over the fish...nothing. During this time the fish had eaten a couple of dozen PMDs with it ever so deliberate rise and just barely sticking it's nose above the surface.
To say I was frustrated is an understatement but that kind of fishing is my absolute favorite and is probably the reason I have favored the Henry's Fork over all other Western rivers. I was thinking of leaving as the breeze was starting to build and it would have made my casting even more difficult. Although it had crossed my mind several times on previous days, I decided to make a couple of more casts and tied on a #16 black deer hair beetle. The first cast missed just to the right of the pile of moss. The next cast was about right and it could go to either side as it floated towards the target. I tend to like my beetles to float as low to the surface as possible so I often do not apply floatant and depending on the light, they can be very difficult to see. Just as the fly was at the point where it had to go either right or left...3-4" above the weeds/moss, a big nose appeared and a mouth opened and the fly was taken. I raised my rod tip and happily felt the weight of the fish. It stayed put for a couple of seconds and I could feel just a slight head shaking. I applied a little more pressure as I was barbless and that fish took off for the deeper runs in the middle and then headed upstream making a couple of tarpon like jumps. I followed the fish and had to kick it out of a weed bed and in about 10 minutes it was in my net. I do not carry a measuring tape but my net was exactly 24" long and this fish was about an inch longer than the net and still had a slight bend in the body...so, very close to 26"...my story is "somewhere over 25". To this day, it remains the biggest I have ever had in my net.
A long story to make a simple point..."never doubt the beetle"! In the three days I had watched this fish feed, it had never once risen to the right or in front of the weed pile. Clearly it was very comfortable in it's narrow feeding lane and it had near perfect cover and was no more than 2-3" from a constant source of food. This big trout moved 8-10" to eat the beetle.
some thoughts to share...
...always a good idea when it is windy.
...often most successful when fished close to the bank.
...if a hopper, splash it down hard
...want a big brown? Fish a mouse close to undercut banks at night or low light.
...ever see an "ant fall?" If you ever do you will know and will need a few flying ant patterns (red and black both).