The largest hornet in North America is the Western Cicada Killer (Sphecius grandis). Although not technically a hornet, it is often referred to as such due to its large size and resemblance to hornets. The Western Cicada Killer is a species of solitary wasp found in western North America. The females can grow up to 1.5 inches (3.8 cm) in length and have a wingspan of around 2.5 inches (6.4 cm). These impressive insects are known for their ability to capture and paralyze cicadas, which they use as food for their developing larvae. Despite their large size, Western Cicada Killers are generally not aggressive toward humans and are more focused on their natural prey.