Hook - Daiichi 1740 (Size 12) / or perhaps a larger and looonger hook, like the Daiichi 2220 (4XL/size 10)
Thread - 8/0 UNI-Thread (Camel)
Hackle - Indian Hen Saddle Hackle (Speckled Brown)
Weighted Underbody - 0.025" diam. lead wire (tyed in along both sides of hook shank to flatten and widen profile)
Coat with Sally Hansens clear nail polish, after forming the body.
Rib - Maxima Chameleon leader (3 lb test/0.006")
Abdomen - Jaimeson's Spindrift Shetland yarn (Bracken 231)
Tails (*)/Back - Ten Strands (five on each side) of Pheasant Tail (Natural)
Thorax - Three Strands of Ostrich Plume (Tan)
Wing Case - Pheasant Tail Fibers pulled over the back of the fly
(*) The two separate tails are created by adding a small drop of SHHAN nail polish to the base of each bundle of tail fibers. The nail polish holds the bundles of fibers together, but allow the tips to move freely.
Close-Up View of the Yarn (Jaimeson Website/Bracken/No. 231)

Photo Credit - Jaimeson's Website: https://www.jamiesonsofshetland.co.uk/spindrift-1-c.asp
Top View:
Bottom View (before trimming hackle):
Bottom View (after trimming off excess hackle fibers):
This pattern was inspired by the photos of the natural insect, on the Troutnut website: http://www.troutnut.com/specimen/688


Tying materials and colors were chosen to imitate this stonefly.
I think the color "Yellow Ochre"/No. 230 might be a better choice for the imitation, but alas I do not have this color.
Yellow Ochre (No. 230):
