Nice photos, and interesting commentary. Like the way you transitioned from large-scale habitat to isolated larva. The habitat image and comments on the rock ledge niche are helpful for giving an idea of how to scope out habitat. Also interesting to see that wormlions will construct pits on fairly sloped substrate.

I have to say, I can't tell which end of the larva the head is on! Even seeing the larva in the context of the burrow (i.e. in the 8th image)...I can't tell from the still images whether it's entering (i.e. head at pointed end), or exiting (head at thickened end). Since it doesn't look like the burrow is in a pit, I'm guessing it was entering the hole (i.e. trying to escape from view of the large hominid nearby). I'm also wondering if the internal black blob at the "thick end" may be a partially digested prey item?

I viewed Charley's fascinating YouTube video of a wormlion capturing an ant, and read with interest his comment there about the distinction between the broad-based burrow of an wormlion vs. the pointed conical-shaped burrow of an antlion. It does seem to apply in at least some instances (see info page thumbnails). The rotating motion of a length of the wormlion larva during prey capture...versus the in-and-out jack-in-the-box movement of an antlion...presumably accounts for the more hemisperical shape of the pit. Of course, like nearly everything in biology, such a general characterization will only hold on average, and not absolutely.

Looks like the Red fir zone, so guess your at the higher 7720 ft location...though I'm still curious as to a bit finer fix on where this is in Mariposa County? If you're still in the area, adults may be out about now. (If you see some, try to get shots showing color of their palpi for Martin :-)

It's great BugGuide posts like yours are starting to accumulate...they're extending the fairly meager distribution records for Vermileo given in the literature (e.g there are none from Mariposa County).

Postscript: Just learned from Joyce Gross that Wheeler's 1930 book "Demons of the Dust" mentions collections from Yosemite...so I was likely in error above about Vermileo not being recorded from Mariposa County. Wheeler also mentions that the "dark contents of the stomach" are visible at the posterior end through the "pale grayish pink or flesh-colored" integument...so it seems I guessed correctly about the head and tail ends :-)

awesome.... glad you found them... I also think that they might be very widespread and not uncommon, although they are rarely collected. Great observation, good luck with the rearing, not too difficult from my experience in the past..

Thanks for posting.