The Spring 2013 edition of American Entomologist features an article by Dr. Michael Parrella of the University of California, Davis on the history of the entomology of fly fishing.
Dr. Parrella teaches a course called "Entomology for Fly Fishing" and this article is an expansion of one of his lectures.
The article is available for free (click on the PDF icon).
Click here for the article "A History of the Entomology of Fly Fishing."