My Theory on Terrestrials

Spring is here, and as the warming trend continues, the streams really come alive with insect life and fish activity.

The one type of insect that really picks up in late spring, for me, is terrestrials. Now presumably the warm air sweeping up the canyon carries a few flying ants and knocks others off streamside vegetation into the water. Beetles and hoppers round out the offering on the warmest days, with hoppers making exciting days, even in the heat of summer.

But I'm not entirely convinced fish often "Key In" on one of these terrestrial bugs.

The Southern California streams are remarkably multicultural, resembling Southern California itself. Sure, we never see blanket caddis hatches or massive mayfly spinnerfalls (at least not that I've ever seen), but what we do have is diversity. I remember one warm day last April, standing on the stream in amazement: Hoppers were hopping around on shore, with some undoubtedly finding their way to to the water. Ants were crawling over every rock and bush. Buzzing around the stream we had Golden stones in the Size 10 range, Mayflies, also roughly a size 10 or 12, plus a midge hatch. The only major species that wasn't represented as adults was Caddis, though their nymphs were found under every rock I turned.

But even in the presence of quite substantial aquatic life, terrestrials produced as well as anything, but telling to me is how terrestrials are taken. I rarely unhook an ant from the outside of a fish's Mouth, and I rarely get refusals. The fish take the terrestrials with authority.

There are a few places, I am sure, where fish key-in selectively of massive ant-drone falls, or massive hopper activity, but on most streams around the country, I just don't believe that ever happens.

So given the exception, I now propose the Rule: Terrestrials are always taken opportunistically.

Given that the fish are generally feeding on other, aquatic, food supplies, they're not sitting in their feeding lane for the next hopper to land, as they might be during a mayfly hatch. But when that hopper or ant drops in the water in their view, dammit, they're going for it. Its the opportunism that makes for the exciting takes - taking opportunistic meals when they come is the key to becoming the dominant fish in a lie, able to hold onto the best feeding lanes for the main course of aquatics. The terrestrials are always a "bonus".

Ants seem to be ever present, and is undoubtedly one of my go-to flies for creeking. My Favorite being a Hi-vis Parachute, tied "Royal" style with a bright-red or fire-orange beltline - to more closely imitate the native variety. It will someday soon warrant its own post in the fly-tying section, but for now Paul @ Dsflyfishing did a nice writeup on the version I tie.

For Hoppers, I generally like a Standard Parachute Hopper.

Beetles I don't generally fish too many of, not because they are less effective at all, just because I habitually stick to the hoppers and ants. Little foam, rubberlegged beetles have been effective for me in the past, and I suspect Smallish Chernobyl ants would do fine too.

So, the next time you're having a tough time picking out the right aquatic bug, think about terrestrials.