I'm not sure what this digger wasp is -- I initially suspected it was Philanthus, a genus often called 'bee wolves' because the females catch and paralyze bees to provide food for their offspring.   However, an entomologist acquaintance tells me it's unlikely to be Philanthus, but the correct identity is unclear.   These pictures include both females (with large rake-like forelegs) and males.   They were attending burrows in sandy soil near the Salton Sea in extreme southern California.