At ~7800' elevation along Rock Creek, south of Tom's Place, Mono County, California, USA
August 6, 2017
Joyce Gross first spotted the "blephs" here, flying and also perched on a boulder just above the splash zone in the middle of the rushing creek. A good trick for seeing blephs is to view such boulders tangent to their surfaces...as the bleph's leggy bodies then become more apparent in profile against the bright-white splash of the water; versus blending-in with the wet, algae-covered rocks as they do when seen "face-on".
Seems blephs often perch on the downward-facing side of rock overhangs just above the splash zone, making them difficult to get close to for a photograph. Fortunately, this one was on the upper face on a boulder next to the shore. Nevertheless, it was a bit precarious bracing myself on the wet slippery rocks and getting close enough for a decent macro shot...though, thankfully, it was cooperative and stayed put (unlike the other blephs nearby). The yellowed appearance of the normally white & black ("salt & pepper") granite substrate is from a film of algae and slime on the boulder's surface (somewhat reminiscent of what the bleph larvae feed on).
We we're hoping for a different species than Joyce had seen previously...but this keys to Agathon comstocki
in Hogue(1973), so we'll have to keep on looking :-)
Note the interesting "divided eye" (best seen in full-size image here
)...with relatively large-faceted, red ommatidia
above; and much smaller-faceted black ommatidia below. Kellogg(1903) discussed the divided eyes of blepharicerids here
...and included a cross-sectional diagram of the head & eyes (Fig. 1 here
Companion post below was taken at same time and place, but a different individual: