Marbled Cellar Spider (Holocnemus pluchei)

Meet the marbled cellar spider! Many call it the “daddy-long-legs” because of its long, thin legs. These cellar spiders love to hang out in homes, especially in attics and basements, making silky webs. Discover fascinating facts about them as you read on!

Physical Description and Identification

Adults

• Size: Male: 0.5–0.7 cm Female: 0.5-0.75 cm

• Color: They are grey or tan in color.
• Other Characteristic Features: They have long legs covered with black and white tan circles at the joints.

Eggs

Female spiders lay approximately 200 eggs in a sac, taking about three weeks before hatching.

Spiderlings

After hatching, the female leaves the spiderlings, who construct their own sheet web to capture prey or join an existing one.

The Web

These spiders have a unique webbing behavior. Some weave solitary webs, while the majority of the marbled cellar spider species join the existing webs made by other spiders of their clan. Most of them shift to new webs several times in their lifetime.

They build two types of webs – curved prey-capture sheets and dome-shaped webs. The latter is used by females carrying eggs to give birth safely.

Are Marbled Cellar Spiders Venomous?

Yes, Marbled Cellar spiders do have venom. But it’s mainly for catching the small bugs they like to eat. It’s not something people usually need to worry about.

Can Marbled Cellar Spiders Bite?

Technically, they can. But these spiders are super peaceful. They might bite if they feel trapped, but they’d rather stay away and mind their own business.

Ecological Importance and Behavior of Marbled Cellar Spider

Marbled cellar spiders play a significant role in controlling pest populations, feeding on common household insects. Their tendency to occupy human dwellings turns them into inadvertent allies in pest management.

Natural Predator: Jumping spiders are known predators of the marbled cellar spider, capable of navigating the complex webs to hunt them down.

Prey-Predator Dynamics: The diet of marbled cellar spiders mainly consists of flying insects, which they capture in their webs. This interaction between predator and prey helps to control the population of pests within their ecosystem.

Relationship with Humans: Generally, marbled cellar spiders are seen favorably by humans due to their pest control contributions. They are non-aggressive, rarely bite, and their venom is not a concern for human health.

Quick Facts

Did You Know

• Italian naturalist Giovanni Antonio Scopoli first described this species in 1763.
• Both the male and female members possess stridulatory organs and use them in sexual activity. This is uncommon as in most spiders, only the male has these organs.

In summary, the marbled cellar spider is a fascinating and beneficial arachnid, whose habits and behaviors contribute positively to their ecosystem, and consequently, to human environments.