Moved from Ceropales elegans elegans.

I've also left a comment on William Ericson's image as I think it will likely also be moved with this one.

Actually, there may be a wrench in the ID. In looking back at the reference identified by Nick, I'm noticing that the mid tibiae are a bit spinose. I don't see this in either of the other specimens from California. It also dawned on me that it appears to be fairly robust as well. But this individual is almost certainly (at least) congeneric with that specimen.

I noticed that we have very, very few male Tachypompilus records. All of what I've seen, structurally, seem to be in line with the aforementioned image of C. elegans. They differ from the females in the traits I noted earlier as well as differ from any other identified Ceropales I'm finding.

This sent me down the rabbit hole a bit when it comes to the literature. This certainly isn't one of the Tachypompilus ferrugineus subspecies we currently have (none of those occur in California). This leaves T. unicolor cerinus, T. unicolor unicolor, and T. ferrugineus torridus.

T. u. cerinus notably has very light wings (almost hyaline) for a Tachypompilus, so we should be able to exclude it, I would think.

Males of T. f. torridus according to Evans (1966) can have fairly extensive black markings. There should also be a darker apical band in the forewing with the rest lightly pigmented. As with the rest of the species, the third segment of the male antenna (first flagellomere) should generally be longer than 2x its width in the key, but the full description notes that the exact range is 2.0-2.5x for the subspecies.

T. u. unicolor males are noted to sometimes have considerable black markings on the thorax and propodeum. The black markings in this subspecies are noted as similar to T. f. torridus. As with the rest of the species, the third segment of the male antenna should not be longer than 2x its width. Using the numbers for T. u. cerinus, the exact range should be 1.4-2.0x.

Insofar as I can see in the photo (difficult to measure directly), this segment looks extremely close to 2.0x. The structure of eyes isn't something I'm able to readily compare with male specimens due to the predominance of females. Again, there are extrema to the measurements while becoming close enough that I wouldn't be able to compare with a photo (1.03x versus 1.05x upper to lower distance, at the closest values). Both also overlap in range… however, T. f. torridus is restricted to more southern California. This should place it out of range.

I think both your image set and William Ericson's image that Nick had previously identified may actually be males of T. unicolor unicolor.

Moved from Rusty Spider Wasp.

Woops, evidently I had the wrong destination up when comparing species. Daniel's comment on the third photo should be spot on. The bristles on the hind tibiae appear to be slightly shorter. I think this is pretty much a dead ringer for the C. elegans elegans identified by Nick.

♂ vs. ♀

Moved from Spider Wasps.

Moved from Tachypompilus.

Moved from Tachypompilus unicolor.

I thought that we could rule out Tachypompilus ferrugineus by the location, but that may not be correct.

Moved from ID Request.