Tiny White-Winged Blacks
This common name refers to only one genus.
These are sometimes called Tiny White-Winged Blacks.
A cult following is something to which few insects can lay claim, but the tiny
Tricorythodes mayflies certainly qualify. Their widespread, reliable, heavy hatches draw impressive rises of ultra-selective trout which demand the most of a technical dry-fly angler's skills.
It is surprising that such a great hatch took so long to come to the attention of fly fishermen. The Tricos were first introduced to anglers in a 1969 Outdoor Life article by Vincent Marinaro, who misidentified them as
Caenis. By the early 1970s the identification had been corrected but Swisher and Richards still wrote in Selective Trout,
"Few anglers are familiar with these extremely small but important mayflies." The next wave of publications boosted
Tricorythodes to its current fame. I suspect their early dismissal was due in part to tackle limitations; anglers in the 1950s had no means to effectively tie and present size 22-28 flies.