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Robber Fly - Promachus - female

Robber Fly - Promachus - Female
Mount Pinos, ~6800 ft., Kern County, California, USA
July 24, 2007
Size: 25 mm
While looking at some rather frustrating skippers, something big flew by. Pursuing it, I found this fly with anthophorid prey ~ 10m farther. Luckily it stayed more or less at the same altitude and didn't fly down the steep slope.
I'm still unsure as to who's who in Asilidae . Perhaps Herschel can help.

Moved from Giant Robber Flies.

Moved from Robber Flies.

Appears to be a Promachus and there are amazingly only three in CA and you don't get the widespread eastern P. bastardii. May be female P. albifacies.

seems good for now - moving to genus.

Thanks, Herschel,
I see that we have a couple of images of albifacies . By the way, do you know how the three CA spp. differ?

Hi, Hartmut
The comment thread under my post below attempts to address your question:


Of course, Herschel has far, far more experience than I do here!! So I'm hoping he'll chime in there.

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