Joro spiders and golden silk orb-weavers look very similar. They are both large yellow and black spiders with long legs. Both can weave large intricate golden webs, and both are from the same family of orb-weavers (Araneidae). These spiders have some differences as well. One is native to the United States, and the other has just recently been introduced. One is tougher in cold weather, while the other prefers tropical climates. Let’s take a closer look at these giant yellow spiders, the Joro spider vs golden silk orb-weaver!
What Are Joro Spiders?
Joro spiders (Trichonephila clavata) are large colorful spiders about an inch long. Their heads are black and small compared to their bodies. Their bodies are cylindrical with yellow and black markings, but they also have red splotches on their back and underside.
Joro spiders have eight long skinny legs striped with wide stripes of yellow and blue. Their legs can span 3-4 inches! Male Joros are significantly smaller than the females and are mostly brown, not colorful. They are around a quarter-inch long. Female Joro spiders spin large golden webs, and you can find them in the center of their webs.
What Are Golden Silk Orb-Weavers?
Golden silk orb-weavers (Trichonephila clavipes) look similar to Joro spiders but are a little bigger. The female golden silks can get to be 1.5-2 inches long and have a leg span of 4-5 inches. The male golden silks are smaller than the females and are around a half-inch. The females are yellow and black with varying marking patterns. Their legs can be all black or banded with yellow. You can find tiny tufts of hair at the joints of their legs that look like little legwarmers. They are sometimes called banana spiders.
Similarities Between Joro Spiders And Golden Silk Orb-Weavers
Both Joros and golden silks are orb-weavers. They spin large webs out of gold-colored silk vs most spiders’ white webs. They have a similar body shape and size, and they are both yellow and black. Their legs can be the same or different, with some of both species having solid black legs while others are striped. They both live in Georgia and South Carolina, some of the few states you will find Joros.
Joro Spiders vs Golden Silk Orb-Weavers: Do Both Use “Ballooning” To Get Around?
Yes! Ballooning is a technique used by some spiders to float on air currents to get from one place to another. New spiderlings most commonly use it after they hatch. By dispersing, they can start new colonies in new areas and avoid being eaten by each other (some spiders are cannibalistic). Researchers in Berlin watched how these spiders take off and found that they follow a similar pre-take-off ritual. Videos show the spiders raising their front arms as if to test the wind speed and then raising their back legs like standing on the tip of their toes. They wait for specific conditions like wind speed and humidity. They then quickly spin a series of webs that form a triangle and are lifted off the platform, floating away. Further research suggests that the earth’s electrical field plays a role in spiders’ ballooning.
Differences Between Joro Spiders And Golden Silk Orb-Weavers
You can tell the difference between the two spiders by the markings on their backs and their legs. The golden silk orb-weavers have backs that are dull orange with yellow spots and tufts of black hair on their legs that appear to look like legwarmers or pipe cleaners. The joro spiders are quite often bright yellow or brown, depending on their sex and their legs do not have tufts. The webs of each are also different, with the Joro capable of making massive yellow-colored webs up to 10 feet wide, with a more three-dimensional look. You can find Joro spider webs high in trees, whereas golden silks prefer to make their traditional white-colored webs closer to the ground like most spiders.
Joro Spiders vs Golden Silk Orb-Weavers: Size
Golden silk orb weavers are a little bigger than Joro spiders. Their body can get to be 1.5-2 inches long, while Joros are 0.5-1 inches. The leg span of golden silk is 4-5 inches, while the leg span of Joros is 3-4 inches.
Joro Spiders vs Golden Silk Orb-Weavers: Web Spinning
Joro spiders spin bigger webs than golden silk spiders. Their webs can get to be 10 feet across. Even smaller webs are 4-5 feet wide. Golden silks have webs that are usually closer to 3-3.5 feet wide (which is still pretty wide when you think about it!).
Joro Spiders vs Golden Silk Orb-Weavers: Location
Joro spiders and golden silk spiders both live in Georgia and South Carolina. This is the only place they overlap for now.
Joro spiders are new to the United States. They are originally from Japan. They can still be found in Japan, China, South Korea, and Taiwan. In the United States, they are only in Georgia and South Carolina, with a handful of sightings in Tennessee and North Carolina.
Golden silk orb-weavers have been in the United States for 160 years and are located in all of the country’s southeastern states. They do not venture into the northern states along the coast. They are also located all over Mexico, Central America, and South America (except for Argentina and Chile). Golden silk spiders are not located in Japan, China, Korea, or Taiwan.
Joro Spiders vs Golden Silk Orb-Weavers: Which Can Tolerate Colder Temperatures?
A new research study out of the University of Georgia compared Joro spiders and golden silk spiders. They created an experiment in which both kinds of spiders were exposed to temperatures below freezing (less than 32°) for two minutes. They measured the spiders’ metabolic and heart rates and recorded which spiders survived. Here are the results from the research:
|Joro Spider||Golden Silk Spider|
|Metabolic rate twice that of the golden silk||Metabolic rate half that of the Joro|
|Heart rate 77% faster than the golden silk’s||Heart rate slower than the Joro’s|
|74% survived the 2-minute freeze||50% survived the 2-minute freeze|
The research suggested that Joro spiders may survive in cooler temperatures. The golden silk, which has been in the United States for 160 years, has not expanded into the northern states along the East Coast, but it appears that the Joro spider might do fine in cooler climates. This latest research has gotten people along the coast a little edgy about the prospects of giant spiders parachuting into their towns!
The photo featured at the top of this post is © iStock.com/David Hansche
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