The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.
Latex? I remember in the seventies...
I can report that Mike Lawson points out this creation, to be a good looking pattern he accepted years ago only to find out it doesn't catch fish!!
...an example of man's trying to imitate trout food the way he sees it instead of the way it is believed to be visualized by the trout."