Which of the following is a sign of a black widow spider bite?

The hourglass marking on the abdomen is a distinctive feature that is commonly associated with female black widow spiders. This hourglass shape is typically orange or red in color and can be an important identifying characteristic of this species. These markings are essential for recognizing the black widow, as they distinguish it from other similar-looking spiders.

In the context of identifying a black widow spider bite, although symptoms such as fever and swelling may occur as a reaction to a venomous bite, the hourglass marking serves more directly to identify the spider itself rather than just the symptoms of the bite. Understanding these physical characteristics can aid in prevention and in seeking appropriate medical attention, as black widow bites can have serious health consequences.