Fly tying strives to simulate or suggest bug life as it is, with only a glint of flash to suggest segmentation, translucency, or a gas bubble enveloping an emerging/rising insect. Also, there are the baitfish patterns which possess flash to mimic the scales of little fish. So, it isn’t very often that the tier over flashes or excites the pattern beyond the natural. A few patterns that do cross this flash point are seen below.
The Lightning Bug is a ‘mayfly’ nymph pattern. More by shape than actual looks. The mylar/flashabou abdomen is silver or silver with specs of other colors. You can see the wingcase pulled over the peacock thorax is mylar also and the silver bead adds additional flash. Is it exact of anything…no…but this is a productive little fly.
The Roxy Rainbow is another ‘mayfly’ pattern…an emerger. Here, I used a peacock tinsel for the thorax and Rainbow Krystal Flash for the abdomen. Not as flashy as the Lightning Bug, but in the right lighting this fly displays the spectrum. The original did not use Krystal Flash, but rather the same mylar/flashabou as the Lightning Bug.
Below is a variation of a Rainbow Emerger in which I pulled the mallard (or teal, or gadwall) feather over the top of the abdomen/thorax. The flash is evident and productive.
I didn’t tie this Lightning Bug, but you seem similar components and it is in gold.