Yellow Sally stonefly nymphs are available much of the year, but more active during warm summer months. RIO's My Gal Sal is the perfect imitation of this natural, with a pale golden yellow belly covered by a dark brown and copper back tied on a barbless Gamakatsu hook with a tungsten bead.
The following are the bead sizes per hook:
Size 14 - 3.3 mm
Size 16 - 2.8 mm