Slide the slotted tungsten bead onto the jig hook, wrap 6-8 turns of 0.015 lead-free wire behind it and shove them up into the bead slot to seat it and add weight low and forward.
Start the olive dun thread and tie in 5-6 Coq de Leon fibers for a tail about one shank length long.
Wrap a smooth, slightly tapered thread abdomen forward over the rear two-thirds. Counter-wrap the white rib forward in 4-5 evenly spaced turns to segment it, then tie off. The white rib will show through the UV coat as crisp segmentation.
Tie in the black flashback tinsel where the abdomen ends, pointing back. Because a jig hook rides point-up, mount the wing case on the underside so it shows on top when fished.
Dub a small peacock synthetic thorax up to just behind the bead, pull the flashback over the top and tie it down.
Build a few turns of red thread as a hot-spot collar right behind the bead, whip finish, then coat the abdomen (and wing case) with a thin layer of UV resin and cure. The hard shell makes it sink fast and stay durable.