Facts About Banana or Golden Orb Spiders
To avoid confusion, I should firstly point out that there are three different types of spider in the world that are sometimes referred to as "banana spiders". This article is concerned with the golden silk orb-weaver, a spider that is mainly famous for its brightly colored, intricate webs and lives in North America, as well as certain other parts of the world.
This article is not about the Brazilian wandering spider, which is an extremely venomous spider found in Central and South America. Nor is it about the Argiope appensa, a black and yellow spider that can be found on several islands in the Western Pacific Ocean.
The golden silk orb-weaver spider is also known as the golden orb spider, the golden orb weaving spider, the golden orb weaver, the writing spider, or the giant wood spider. It is typically a black and yellow spider with stripy legs, although they can vary in color from reddish to greenish yellow.
What we'll cover here:
- Ten facts about banana spiders you don't already know
- Human uses of banana spider silk
- Benefits in the farm or garden
Ten Facts About Banana Spiders
Banana spiders are fascinating because:
1. They are also known as the golden silk orb-weaver, the writing spider, and the giant wood spider.
2.They grow up to about two inches in size, not including leg span, and females are larger than males. With the legs, some are over five inches in size.
3. There are banana spiders in Africa, Asia, Australia, and the southeastern United States, from Texas to North Carolina.
4. Web silk is golden in color.
5. The female normally eats the male after mating.
6. Their species is the oldest surviving spider genus. Fossil remnants are 165 million years old.
7. Textiles can be made with their golden silk, including a shawl woven in 2004 and a cape in 2012.
8. Fishermen in the Indopacific Ocean make balls with the spiders' silk. After being tossed into the ocean, the balls unravel and form a net to catch fish.
9. They are mildly venomous, causing redness, blisters, and pain at the bite area.
10. Their Latin name, Nephila clavipes, means "fond of spinning."
They grow up to about two inches in size (not including leg span). If you do include leg span, however, some species of the spider can be measured at over five inches in size.
Female banana spiders are larger than males. The biggest banana spider ever known was a 2.7 inch female found in Australia). The female of the species is the biggest spider in Florida to be found.
There are species of banana spider in Africa (including Madagascar), Asia, Australia, and the United States of America.
In the U.S., the species is called Nephila clavipes and can generally be found in the southeastern states, appearing as far north as North Carolina and as far west as Texas.
Banana Spider Webs
The yellow silk of the banana spider's web gives the golden orb its name. The silk appears golden when it shines in the sun and the webs are extremely complex. They can be as wide as one meter across.
The yellow coloring serves two main purposes, according to scientists: First, the sunlit web attracts and traps bees that are drawn to the bright silk strands. Second, the color blends in with background foliage, acting as camouflage in darker and shadier conditions.
The spider starts by building a non-sticky spiral and then fills in the gaps with sticky silk. The banana spider can vary the color of the web to maximize its effectiveness in terms of background light and color. The web needs regular maintenance in order to keep it effective for ensnaring prey.
Uses of Golden Orb Web Silk
There have been tries to make clothes from the spider silk in the past. At the Paris Exhibition of 1900, for example, there were two bed hangings created and put on display.
In 2004 a shawl was produced by a textile designer (Simon Peers) and an entrepreneur (Nicholas Godley), which used the silk from golden silk weavers collected in the wild. It took over three years to finish and the shawl was as exhibited at the American Museum of Natural History in 2009.
In 2012 the same pair succeeded in making a larger garment, a cape. Both the shawl and the cape were shown at the Victoria and Albert Museum in London, England.
Banana Spiders in the Garden
Both adult and juvenile banana spiders are predators. They are considered very beneficial farm and garden insects, as they eat a wide range of flying prey, including small- to medium-sized flying insects:
- small moths
- leaf-footed bugs
- beetles and dragonflies (rarely)
Banana spiders are rarely found in areas of row crops, because they need places to build their webs, but they are one of the most common orb-weavers in citrus and pecan groves.
Banana Spider Venom
Are these spiders venomous? The short answer is yes, but only mildly. The venom is similar to that of a black widow spider, but nowhere near as strong and not fatal under normal circumstances. A bite will typically cause symptoms such as redness, blisters and pain around the bite. These symptoms will normally go away after a day or so.
Allergic reactions to the venom are rare, but may cause breathing problems and muscle cramps. If this happens, then medical advice should be sought immediately. It should also be noted that like most spiders, orb weavers can be useful to people, especially gardeners, because they kill insects, such as fruit flies.
Banana spiders molt in several stages. About four days before reaching her final molt, a female stops eating and repairing her web. She is sexually active at this point. When a male approaches her for copulation, he vibrates his abdomen using a plucking motion. This activity arouses the female and prevents her from eating him (at that point).
Once inseminated, the female spins at least two large (about an inch in diameter) egg sacs on a tree. These sacs each hold hundreds of eggs and are surrounded by curly, yellow silk. The male guards her as she does this. After the final molt, females can live up to a month, while males live from two to three weeks.
Females may change web sites and male partners throughout adulthood. Banana spiders have one generation per year in North America.
© 2011 Paul Goodman