this spring and early summer calls for big bugs that land with a splat. Because the major emergences are infrequent, cicada patterns may not be on every angler’s annual checklist of must-have flies.

FLY-FISHERS in the eastern half of the U.S. are eagerly anticipating a hatch 17 years in the making: the Brood X cicada emergence. From around mid-May through June, billions of these chubby bugs will ...