The southern house spider (Kukulcania hibernalis) is a sexually dimorphic species of crevice spider (Filistatidae). Both the female and male have fine, light-colored hairs on their abdomen and both have been documented as employing autotomy as a defensive tactic.
These were photographed on my car port earlier this week (same male in both pics, two different females):
The brown recluse looking specimen is the male; the female is larger and darker.
