rhamphotheca:

Female Black Widow, Latrodectus mactans.

Ventral view, showing the famous red hourglass. Black Widows prefer damp places. This one lives under the watering trough in a horse pasture across the road from me. The neighbor found it while flipping the trough to empty it in order to clean it and refill it. This specimen is a beautiful one and was most cooperative for the camera. The venom of the female Latrodectus macrons is a potent neurotoxin, but bites are rare—the animal must be strongly provoked to bite a human—and they are rarely fatal because the quantity of venom injected is very small. Bites may be very painful, however. The smaller male has no venom.

(via: EOL)         (photo: David Illig)