As someone who spends a lot of time observing the wildlife in my garden, I’ve always been fascinated by Joro spiders (Trichonephila clavata). One of the most common questions I get from people who see these spiders for the first time is, “How big are Joro spiders?”. The truth is, they are quite large compared to other common spiders, and their size makes them stand out.
In this article, I’ll compare Joro spiders to other well-known spiders and answer some of the most frequently asked questions about their size and identification.
How Big Are Joro Spiders?
Joro spiders have impressive leg spans, and their bodies can grow quite large. Here’s a breakdown of their average size:
- Female Joro spiders: Body length of 0.7–1 inch (17–25 mm) with a leg span of up to 4 inches (10 cm).
- Male Joro spiders: Much smaller, with a body length of only 0.3–0.4 inches (8–10 mm).
Their long, spindly legs and colorful markings make them one of the most noticeable spiders in my garden.
Joro Spider vs. Other Spiders: A Size Comparison
To better understand how big Joro spiders are, here’s a comparison with other well-known spiders:
| Spider Species | Body Length | Leg Span | Notable Features |
|---|---|---|---|
| Joro Spider (Trichonephila clavata) | 0.7–1 inch (Female) | Up to 4 inches | Bright yellow, blue, and red markings |
| Orb Weaver Spider (Araneidae) | 0.5–1 inch | 1.5–3 inches | Round body, varies in color |
| Banana Spider (Nephila clavipes) | 1–2 inches | Up to 5 inches | Golden web, large body |
| Garden Spider (Argiope aurantia) | 0.75–1.1 inches | Up to 3 inches | Yellow and black pattern, zigzag web |
| Writing Spider (Argiope spp.) | 0.75–1.2 inches | 2.5–4 inches | Creates distinct zigzag silk patterns |
| Giant House Spider (Eratigena atrica) | 0.5–0.8 inches | Up to 4 inches | Brown color, fast-moving |
As you can see, Joro spiders are among the largest orb-weaving spiders, second only to the banana spider in size.
Joro Spider vs. Orb Weaver
Many people confuse Joro spiders with common orb weavers, but Joro spiders tend to be larger and more vibrant in color. The most noticeable difference is their yellow and blue patterns on their abdomens, while most orb weavers have more muted, brownish tones.
Joro Spider vs. Banana Spider
The banana spider (also known as the golden silk orb-weaver) is slightly larger than the Joro spider, with females reaching up to 2 inches in body length. Their webs are golden-hued, while Joro spider webs appear more silvery.
How to Identify a Joro Spider
If you’re wondering whether the spider in your garden is a Joro spider, look for these features:
- Bright yellow and blue patterns on the abdomen
- Long, thin legs with black and yellow bands
- Large, orb-shaped web that shimmers in sunlight
Frequently Asked Questions
1. Are Joro spiders the biggest spiders in the U.S.?
No, while they are large, the biggest spider in the U.S. is the Carolina wolf spider, which can have a leg span of up to 5 inches.
2. How does a Joro spider compare to a garden spider?
Joro spiders are slightly larger than garden spiders and have more vibrant colors, while garden spiders have a black and yellow pattern.
3. Are Joro spiders dangerous?
No, Joro spiders are harmless to humans. They are not aggressive and their venom is not medically significant.
4. What’s the difference between a writing spider and a Joro spider?
A writing spider (Argiope species) creates zigzag silk patterns in its web, while Joro spiders do not.
Final Thoughts
Joro spiders are impressive in size and easy to distinguish from other common garden spiders due to their bright colors and large webs. Despite their intimidating appearance, they are harmless and beneficial for controlling insect populations.
