Depending on the flyfishers knowledge of caddis, where even in a 1969 FlyFisherman there are caddis larvae flies for California & in a 1970 FlyFisherman the bucktail caddis "dry"; along with an ad for "The Hatch Matcher" for eastern & western streams which has a little black caddis, green caddis, etc. & suggests having all stages & sizes to fish with: nymph, wet, dry. Even back in the 50's there were sources for caddis dry flies, but the references were alot fewer & far between as compared to the internet of today, or even caddis encounters on the streams of the 70's & 80's unless it was where the best dry fly fishing was...........most likely secret fly patterns & recipes.