Terry, do you organize your daylilies by hybridizer in your garden? Is there any chance that just particular areas are being affected and that it isn't necessarily the hybridizer, but the location in your garden?
That's probably too simple of a suggestion, though, I'm sure you have already thought of it.
My next thought would be to ask you which years you got those varieties compared to when they died. Do you binge-buy from a different hybridizer each year?
