Cupiennius is a genus of wandering spiders, known by the common name banana spiders, found from Mexico to northwestern South America, and on some Caribbean islands. The genus includes both relatively small species where the cephalothorax is less than 9 mm (0.35 in) and large species where the cephalothorax can measure almost 40 mm (1.6 in). The larger species are sometimes seen far outside their native ranges in shipments of fruits, when frequently confused with Phoneutria spiders. However, unlike the dangerously venomous Phoneutria, bites from Cupiennius typically only have a minor effect on humans and have been compared to a bee sting.