Which spider is characterized by a bright coloration on its belly and is known to be poisonous?

The Western Widow spider, particularly the female, is recognizable by its glossy black body and the distinctive red hourglass marking on its abdomen. This bright coloration is a warning signal, indicating that the spider is venomous. Western Widows are part of the widow spider family, and they produce venom that can be harmful to humans.

Understanding this characteristic helps differentiate the Western Widow from other spiders. For example, the Brown Recluse Spider is known for its violin-shaped marking but lacks the bright coloration that signifies its venomous nature. The Wolf Spider, while also a dangerous predator, does not possess distinctive bright markings, and its venom is not considered dangerous to humans. Orb Weaver spiders are known for their wheel-shaped webs and are typically harmless, again lacking the bright coloration associated with venomous spiders.

Hence, the distinctive bright coloration of the Western Widow's abdomen is a clear indicator of its venomous nature, making it the correct answer.