Red-legged Purseweb (Sphodros rufipes)

Guess what? There’s a spider called the red-legged purseweb spider! It mostly lives in the southern United States, but some people have spotted it in places like Indiana and New Jersey too. Curious about this spider? We’ve got some cool facts to share, so keep reading!

Photo Credit: Vijay Somalinga

Physical Description and Identification

Adults

• Size: Female spiders are around 0.9 inches (2.5 cm) and males are smaller.
• Color: Both the sexes have a black body, with the males being shinier. Sexual dimorphism is observed in the color of their legs. They appear black in females, but red or reddish-orange in males.
• Other Characteristic Features: It has downward-pointing fangs and not crossed ones.

Eggs

The eggs are small and oval laid in sacs.

Spiderlings

The spiderlings replicate the adult red-legged purseweb species. Most of them have a reddish body with a black head.

Photo Credit: AgeOfErebus

The Web

They build tube-like webs near the base of the tree, 6 – 10 inches long.

Photo Credit: Nathanael Herrera

Are Red-legged Purseweb Spiders Venomous?

Yes, Red-legged Purseweb Spiders are venomous. They use their venom to help them catch bugs to eat, but it’s not very harmful to humans.

Photo Credit: AgeOfErebus

Can Red-legged Purseweb Spiders Bite?

Yes, Red-legged Purseweb Spiders can bite. They’re usually quiet spiders, but if they do bite, it feels like a tiny pinch and isn’t harmful for most people.

Photo Credit: Vijay Somalinga

Ecological Importance and Behavior of Red-legged Purseweb Spider

These spiders play a significant ecological role as predators within their environment. Their presence in temperate forests and urban areas contributes to the control of insect populations, including caterpillars, wasps, crickets, ants, and beetles. Their hunting behavior is quite specialized; they wait within their silk tubes and attack prey that crosses over the web.

Natural Predators: The natural predators of the Red-legged Purseweb Spider include birds and parasitic wasps. These predators help to maintain a natural balance in the populations of purseweb spiders.

Photo Credit: AgeOfErebus

Prey-Predator Dynamics: The Red-legged Purseweb Spider is an active predator, using its venom to subdue a variety of insects. This predation helps to regulate the insect populations, providing a check that is vital for ecological health. Conversely, as prey, they contribute to the diet of their natural predators.

Relationship with Humans: While they are venomous, the Red-legged Purseweb Spider’s bite is typically not harmful to humans, causing little more than a minor pinch. They are generally reclusive and do not seek out human interaction. Encounters with these spiders are rare due to their elusive nature and preference for undisturbed habitats.

Photo Credit: Nathanael Herrera

Photo Credit: Jim Moore

Quick Facts

Photo Credit: Joe Wolf

Did You Know

• The Latin word ‘rufipes’ means red in English and the red legs the males have given them their name.

In summary, the Red-legged Purseweb Spider is a noteworthy species with distinct hunting methods and significant ecological value.