Joro Spider vs Yellow Garden Spider: Battle of the Arachnids

The Joro spider and the yellow garden spider are two visually striking species of orb-weaving spiders that have caught the attention of many due to their size and vibrant colors. While they might seem similar at first glance, there are key differences between these two spider species that help distinguish them.

The Joro spider, native to East Asia, has recently gained attention as it spreads across the Southeast United States. Sporting distinctive yellow and blue-black stripes on their backs, along with bright red markings underneath, this spider has gained a reputation online due, in part, to its bright appearance and large size, with females being almost 3 inches across when their legs are fully extended.

On the other hand, the yellow garden spider is a native species commonly found across North America. This large, black, and yellow-striped spider is known for incorporating a unique zigzag pattern, called a stablementum, into its web construction. One notable difference between these two spiders is that immature Joro spiders rarely make a stablementum and adults never do, making it a useful identifying feature of the yellow garden spider.

Joro Spider Vs. Yellow Garden Spider

Identification and Appearance

The Joro Spider (Trichonephila clavata) is a large, yellow-striped spider native to Japan and East Asia¹. Its key features include:

• Bright yellow and blue coloration
• Long leg span (up to 4 inches)
• Orb-shaped web pattern

On the other hand, the Yellow Garden Spider (Argiope aurantia) is a common North American species². Identifiable by:

• Yellow and black coloration
• Zig-zag pattern in their web (also called “stabilimentum”)
• Slightly smaller size compared to Joro spider

Geographic Distribution

Joro spiders have been introduced to the United States, first detected in Northeast Georgia in 2014³. They have since spread to neighboring states such as South Carolina and North Carolina⁴.

Yellow Garden Spiders are native to North America and widely distributed across the continent⁵. They can also be found in South Carolina and surrounding states.

Habitat and Environment

Both species of spiders are commonly found in gardens and other green spaces, and they both serve as predators of insects. However, Joro spiders prefer warmer climates, with their population density increasing in areas with higher average temperatures⁶. Yellow Garden Spiders can tolerate a wider range of temperatures and environments.

Comparison Table

Web and Silk Characteristics

Types of Webs

• Jorō Spiders: These spiders rarely make a stablementum (zig-zag pattern) in their webs, and adults never do ¹.
• Yellow Garden Spiders: They create orb webs with a trademark vertical zig-zag pattern, known as a stabilimentum ².

Properties of Silk

Jorō Spiders

Jorō spiders, like all orb weavers, produce golden silk. This type of silk has a unique property of being stronger than steel, is more elastic, and reflects light with a golden sheen. Here are some characteristics of golden silk:

• Stronger than steel
• Highly elastic
• Reflective golden sheen

Yellow Garden Spiders

Yellow garden spiders also belong to the orb-weaver family and produce golden silk like the Jorō spiders. Some of the shared properties of their silk include:

• Strong and elastic
• Golden sheen
• Used to create large orb webs

Comparison Table

Behavior and Ecology

Mating and Reproduction

The Jorō spider (Trichonephila clavata) and the Yellow Garden Spider (Argiope aurantia) have distinct mating and reproduction behaviors. Adult female Jorō spiders are larger and more brightly colored than males. Mating for Jorō spiders usually occurs in early fall, and females lay eggs in a cocoon hidden in vegetation (Penn State Extension). For the Yellow Garden Spider, males may pluck the female’s web to signal their presence, and the fertilized females lay their egg sacs around September (Gardens with Wings).

• Jorō Spider:
  • Large, brightly colored adult females
  • Mating occurs in early fall
• Yellow Garden Spider:
  • Males signal presence by plucking webs
  • Eggs are laid around September

Feeding Habits

Both Jorō spiders and Yellow Garden spiders are beneficial to their ecosystems as they help control insect populations. Jorō spiders feed on various pests in their natural habitats, while Banana spiders (Yellow Garden spiders) consume various insects such as flies, moths, and beetles (Clemson University). Both spiders construct large, orb-like webs to catch their prey.

• Jorō Spider:
  • Eats various pests in natural habitats
  • Constructs large, orb-like webs
• Yellow Garden Spider:
  • Consumes flies, moths, and beetles
  • Also constructs orb-like webs

Balloon-Borne Dispersal

Both Jorō spider and the yellow garden spider exhibit balloon-borne dispersal, known as “ballooning.” Spiderlings of both species release a silk thread that catches the wind carrying them to new locations (University of Georgia). This behavior helps them disperse over a wide area, facilitating the spreading of invasive species like the Jorō spider in the southeastern US.

• Jorō Spider:
  • Exhibits ballooning behavior
  • Contributes to their invasive spread
• Yellow Garden Spider:
  • Also exhibits ballooning behavior
  • Not considered invasive species

Danger to Humans and Pets

Venom and Bites

Joro spiders and yellow garden spiders are generally harmless to humans and pets. Their fangs and venom are not considered dangerous, causing only mild irritation and discomfort to humans when bitten.

• Joro spiders:
  • Native to East Asia, found in places like Korea
  • First detected in the US in 2013 in Georgia¹
  • Bright yellow and blue-black striped body, red markings²
  • Shy behavior, not aggressive
• Yellow garden spiders:
  • Common species, known for attracting gardeners’ attention³
  • Orb-weaving spider that constructs a zig-zag pattern in their web⁴
  • Fangs have a less toxic venom than East Asian joros

Comparing the bites between a Joro spider and a yellow garden spider:

Impact on Native Species

Joro spiders and yellow garden spiders have different impacts on the native species due to their distinct habitats and natural behavior.

• Joro spiders may affect other arachnids or insect populations
  • Can survive brief freezes, making them more adaptable⁵
  • Compete with other spiders for resources
• Yellow garden spiders:
  • Usually found in gardens, reducing pest populations
  • Serve as natural pest control

Thus, while both Joro spiders and yellow garden spiders are virtually harmless to humans and pets, they may have varying effects on the native species in the areas where they inhabit.

Spotting and Managing Joro and Yellow Garden Spiders

In Your Home and Garden

Joro spiders (Trichonephila clavata) and yellow garden spiders (Argiope aurantia) share some similarities, but they also have distinguishing features. Joro spiders hail from East Asia, while yellow garden spiders are more common across the southern United States.

Here’s a comparison table of their characteristics:

In both cases, these spiders are spotted in gardens, backyards, and occasionally near homes.

Control and Relocation

To manage these spiders in your home and garden:

• Avoid touch: While they are not harmful to humans, their bites can be painful.
• Natural predators: Encourage natural predators like birds to keep spider populations in check.
• Physical relocation: Carefully relocate spiders using a stick or other tool, avoiding direct contact with human skin.
• Limit prey: Reduce the number of other insects in your garden to limit the spiders’ food source.

Overall, it’s important to appreciate the benefits these spiders provide by keeping other insect populations in check.