There sure seems to be a lot of interest in grannoms this year.
Goodfortune, Afishinado mentioned the Bookmailer (and provided a link, see above) as having the material (sparkle yarn) for the veil of the deep sparkle pupa (DSP) and Emergent Sparkle Pupa (ESP). As far as I know, the sparkle yarn sold at FFP is also apropriate. Call and ask. It is very cheap, and FFP will likley get your order to you very fast--they have that reputation for a reason.
Afishinado, I somehow didn't notice your discussion regarding sparkle yarn before I posted about the veil material controversy. That was not intended as a shot across the bow but after looking at it in sequence it seemed that way. Given how cheap and easily available sparkle yarn is, I see no reason not to use it and plenty of reasons based on testimony on its effectiveness to do so.
As mentioned, there are dark grannoms and light grannoms. In the north central and ne, the light, apple green grannom seems to be what produces the action. The dark grannom is heavy in the central PA limestoners except Spring Creek (that could change). They are also present in many other streams, just not in the same quantity in most cases. Also, just because a stream has not had a fishable hatch in the past, doesn't mean it can't show up this year in a big way. If stream quality is improving accross the state, and I think it is for the most part, then "new" bugs are always possible. If you look at the various historical reports, you notice that April 8 or 9 is about as early as the big central PA limestoners see the emergence. Further south the emergence can already be happening, but since much of the freestone water is closed, little notice is taken. I have a hunch there is some decent grannom activity right now on these southerly and less noticed freestones.
It would be logical to expect other bugs to be present during the grannom and maybe even mask it. There could still be BWOs around, and just as likely if not more so, Paraleps (Blue Quills).
If I fish this grannom hatch, I will be hoping for conditions allowing for a dry/dropper setup. You often hear reports that the emergence is one of many bugs but no risers, implying staying with subsurface or damp patterns. But you never know, and with the tandem you have it covered anyway.
Dry fly action is often considered an evening affair, which makes sense since these are typically wild brown trout waters (for the dark grannom) and the egg laying bugs on the one hand and low light levels on the other should be your optimal chance for finding risers. Getting them to pick your fly out if there is a multitude is another issue.
