9 of the World’s Deadliest Spiders

References & Edit History Related Topics

Images

A medically significant arachnid

Brazilian wandering spider

Illustration of a black widow spider (Latrodectus mactans) shown from above, with a close-up ventral view highlighting the red hourglass marking on its underside. A scale bar compares its size to 3 centimeters and 1 inch.

Brown widow spider

Illustration of a red widow spider (Latrodectus bishopi) showing its reddish legs and cephalothorax, with a black abdomen marked by red and white spots. A scale beside the spider indicates its size is about 3 centimeters or 1 inch.

A Redback spider (Latrodectus hasselti) with a shiny black body and distinctive red stripe on its rounded abdomen stands on a light tan surface.

Sydney funnel-web spider (Atrax robusta) with a shiny black body and thick legs, shown on rough brown bark in its natural habitat.

9 of the World’s Deadliest Spiders: References & Edit History

Article Contributors

Primary Contributors

John P. Rafferty
John P. Rafferty writes about Earth processes and the environment. He serves currently as the editor of Earth and life sciences, covering climatology, geology, zoology, and other topics that relate to the natural world.

Other Encyclopedia Britannica Contributors

Melissa Petruzzello

Article History

Type	Description	Contributor	Date
	Revised Australian funnel-web taxonomy and added cross-references throughout. Media added.	Melissa Petruzzello	Jul 17, 2025