The Mother’s Day Caddis Hatch has arrived in Colorado and fly fishing on the Eagle, Roaring Fork and Arkansas Rivers is all about this bug right now. After a long winter of eating tiny midges and mayflies, in late April and through May another, larger aquatic insect becomes an important food source for trout coming out of their winter doldrums. As daylight hours lengthen and flows increase, a species of caddis fly known as Brachycentrus, or more commonly the Grannom or Mother’s Day Caddis, is more active. Soon they will hatch en masse, providing some of the most outstanding dry fly fishing of the year.
These caddis flies are case builders that build portable houses out of woody debris. They crawl around on the bottom as they feed on plant matter and are very clumsly and become dislodged easily. As water temperatures warm in early spring they are more active and trout see them drifting by regularly. They are often consumed case and all and there are many cased caddis nymph patterns on the market that will catch trout.
Inside the case is a bright green wormlike larvae. These caddis larvae will exit their cases when they need to build a larger one. Fly fishing with simply tied # 12- 16 green or chartreuse caddis nymphs is always effective wherever this species is found. Dead drifted though deep riffles, these flies are a must have on rivers like the Eagle and Roaring Fork in April and May.
While nymphing with Grannom patterns is a good spring time tactic, the real attraction is the hatch and there are two effective ways to fish during this emergence and when it does happen area anglers are in for a real treat with trout feeding aggressively for the first time in months.
Before and during the hatch, the caddis pupae, which are very active swimmers emerge from their cases and begin ascending towards the surface to emerge as a flying adult insect. At this emerger stage they are particularly vulnerable and swinging soft hackles is a sure fire method to catch a lot of trout. Dark and green hued 14wet flies like a soft hackle pheasant tail, partridge and green, peacock and partridge, zug bugs, prince nymphs and the western coachman fished dead drift initially and swung and lifted up and across the current will result in violent strikes. Up size your tippet-3X is not too heavy.
As the bulk of the available food shifts towards the adults on the surface, trout begin looking up for their feeding sessions. The adult caddis resemble small dark colored moths that flutter and bounce on the water. Rises are usually very noticeable splashy disturbances as trout chase the flies. Good choices for dry flies to imitate the Mother’s Day Caddis are a#14-16 Elk Hair Caddis with a peacock, black or olive body, a peacock stimulator, or Puterbaugh’s Foam Caddis in black. Normal dead drift presentations work for picky fish but sometimes a dragging or skittering motion imparted on the fly will attract more strikes during this hatch.
For more information on this caddis fly check out http://www.west-fly-fishing.com/entomology/caddis/grannom.shtml . For anglers looking for some fast dry fly fishing after a long winter of slinging weights and indicators, the Mother’s Day Caddis is a welcome event during spring. The best hatches near the Vail Valley Anglers fly shop occur on the Eagle River, Roaring Fork and Arkansas River. Stock up on the best Grannom caddis patterns at the shop and stay tuned for when the hatch is happening with our up to date fishing reports.
Brody Henderson, Senior Guide and Content Writer
