I came up with this Cripple pattern several years ago after a particularly frustrating Green Drake hatch on the Frying Pan River. It seems as though Drakes actually hatch into adults under the water and emerge through the surface film as full-blown duns. At least, this is how it is supposed to work. More often than not, though, the emergers make it to the surface before they have completely freed themselves from their nymphal husk and end up trapped in the surface film with their wings and thorax partially out of the shuck and the rest of their bodies stuck inside it. They flop around on the water with a conspicuous urgency, seeming to know that their short life will not last much longer if they don’t free themselves soon. Bad for them, good for the trout…The fish really key in on this unkempt emerger flopping around on the surface and eat them with wild abandonment.
After watching several of these bugs emerge, the idea for this pattern spawned in my head. It really is a pretty simple pattern to tie and one that allows you to make a few departures from traditional tying rules. I make this fly asymmetrical, with one wing flat and the other upright to mimic the naturals trapped wing and flapping wing. The dun colored soft hackle imitates the struggling legs and the olive colored thorax matches the head of the natural as it pokes out of the nymphal husk. The back end of the fly (tail and abdomen) matches the nymph in both color and shape to replicate the still attached husk. The CDC under wing provides flotation and subtle movement. I have also tied this fly in smaller versions and in the appropriate colors to match PMDs as well. They hatch in the same way as the Drakes, so it makes sense that this pattern could be modified for use in either hatch.
I find this fly works best on flatter water, where the bugs have more trouble breaking through the surface film and the fish have more time to inspect them. It works quite well on faster water as well but can require a bit of maintenance to keep it afloat through the rougher sections. As a side note, if the fly sinks a bit, go ahead and fish it out through the cast. As I said above, the emergers start to hatch underwater and this pattern is totally appropriate under the water as well. I use Frog’s Fanny desiccant to dry the fly after each fish. One tip I may offer is to be sure to rinse the fly off in the water after releasing your fish, then daub it on your shirt to remove any excess water and fish slime. Brush on the Frog’s Fanny and get back after ’em!