The term “banana spider” can refer to two entirely different arachnids, the nephila clavipes of North America and the phoneutria of South America. The varieties can be about the same size, but they have dramatically different appearances and habitats. The former type, which spins a web known for its incredible strength, is shy and fairly harmless. The latter kind, which travels over the ground and hunts instead of making a web, is aggressive and has a potentially lethal bite.
Phoneutria also are known as bananenspinne, kammspinne and wandering spiders. Some people also call them armed spiders. Common names for N. clavipes are writing spider and golden orb weaver.
The label “banana spider” is associated with phoneutria because they sometimes hide in banana bunches. This habit has resulted in people accidentally shipping them to grocery stores in other countries. North American versions earned this name because the females have a yellow body.
The body of the South American banana spider generally falls between 0.7 and 1.9 inches (1.8 to 4.8 cm). The leg span is between 4 and 5 inches (13 to 15 cm). The female North American golden orb weaver is comparable in size. It has a body length between 1 and 2 inches (2.54 to 5.08 cm) and a leg span of up to 5 inches (15 cm), making it the largest non-tarantula arachnid in North America. The male is smaller, with a body size up to 0.5 inches (1.27 cm) and a leg span of up to 1.5 inches (3.81 cm).
A phoneutria typically has a brownish coloring, similar to a male N. clavipes. Some species have a distinctive red coloring around the jaws. The legs of a female N. clavipes have alternating brown-black and yellow-green sections, which serves as a warning to predators. The coloring sometimes causes people to get golden orb weavers confused with another common garden arachnid, the argiope.
Individuals have encountered species of phoneutria in nearly every region of South America. These arachnids are nocturnal and hide in areas such as wood piles, banana plants, dark areas of homes and within clothing. People call them “wandering” because they move across the jungle floor when active.
N. clavipes reside mostly in southeastern North America. They usually stay around bushes and flower plants in gardens, but they prefer sunny areas and like trees. It is not unusual to find them living across walkways or trails. Unlike their South American counterparts, they are much more visible and typically don’t catch people by surprise as much.
Although wandering spiders can spin silk and use it during climbing, they do not build webs. The lack of a web means they must hunt for food actively. The North American variety does make a web, which can span several feet wide. It is common to find the webs at eye level, as this is a good height for catching insects. The durability of these homes is notable, as the silk is stronger than Kevlar®.
Both varieties of banana spider feast on insects found in their environment, such as wasps, fruit flies, locusts, crickets and bees. Larger phoneutria also may eat larger prey such as lizards and mice. N. clavipes can eat these bigger meals, as well, but they generally do not get the chance, as they are much more shy, have a less potent bite and rely on their webs to catch food.
South American banana spiders can live up to two years. The North American type has a slightly shorter lifespan. They usually do not live longer than a year.
Toxicity and Danger Level
Being able to tell these two types of arachnids apart through elements such as appearance, web building, lifespan and diet is critical because of the difference in venom toxicity. The venom of N. clavipes is similar in nature to that of the black widow, but it is far less potent, making it quite harmless to humans in the majority of cases. A bite from the North American kind usually doesn’t result in much more than a welt that passes within 24 hours. Some individuals do experience a more severe allergic reaction, however, which can cause difficulty breathing and muscle cramping.
Phoneutria, whose name means “murderess,” are among the world’s most dangerous arachnids, with the 2012 Guinness Book of World Records labeling them as the most poisonous. Their venom causes potentially deadly reactions in the nervous system. Bites result in severe, immediate pain, cold sweats and irregular heartbeat. Fast medical attention is necessary when these bites occur. The aggressiveness of phoneutria makes them even more problematic, as they will bite multiple times before retreating.
With South American banana spiders having the ability to kill, getting them out of living and working areas is a must. Many people don’t bother to remove golden orb weavers because they keep the populations of pesky insects down. When someone does want to get rid of them, all he has to do is tear down the webs so they will go somewhere else.