The Difference Between Brown Widow and Orb-Weaver Spiders

Appearance

• Most orb weavers grow to between 2/3 inch and 1 inch long. They can vary greatly in both appearance and coloration. Most orb weavers have large, rounded abdomens and small heads. They can have bright colors, such as whites, yellows or oranges, or patterns on their abdomens, although many species remain a brownish color. Brown widow spiders grow to between 1/4 inch and 1/2 inch long. They are usually a mild brown color, but can be much darker, almost black, or lighter, appearing white. Like their close relatives the black widow, brown widows have hourglass markings on their undersides. These hourglasses are usually orange or yellow.

Habitat

• There are many different types of orb weavers, and they can be found in many different parts of the world. They are most common in North America, Hawaii and Alaska. Orb weavers tend to live in grassy areas. Brown widows live in warmer areas. They are common is the southern United States, but also live in parts of southern Africa, Australia and Cyprus. These spiders makes their homes in the corners of buildings, as well as among the branches of bushes.

Venom

• Both the brown widow spider and orb weavers are considered to be nonaggressive. These spiders rarely bite people, preferring to make a quick escape or stay out of the way. Bites most often happen when the spider feels trapped, such as if someone puts a hand too close to the spider in an enclosed area. Both types of spiders have venom. The orb weaver is not thought to be dangerous, delivering only a mild venom. Brown widows, however, have a neurotoxin that is more potent than a black widow's. Brown widows, though, tend to inject less venom.

Life Cycle

• Orb weavers and brown widow spiders hatch from eggs. As they grow, the spiders shed their exoskeletons. Female brown widow spiders can live for up to three years and produce thousands of eggs each year. Male brown widow spiders live for only between six and 12 months. Orb weavers live for only about a year. Males die after mating, while females die after laying the eggs, just before winter.