What’s the Difference Between a Cellar Spider and a Daddy Long Leg?
The key difference boils down to taxonomy: a cellar spider is a true spider (Araneae order), while a daddy long leg, also known as a harvestman, is an arachnid but not a spider (belonging to the Opiliones order). Despite their shared superficial similarities, they are distinct creatures with varying anatomies, behaviors, and lifestyles.
Introduction: Unraveling the Arachnid World
The world of arachnids is a fascinating and often misunderstood realm. Many people use the terms “cellar spider” and “daddy long leg” interchangeably, unaware that they refer to two different types of creatures. This article aims to clarify what is the difference between a cellar spider and a daddy long leg?, delving into their unique characteristics and dispelling common myths. Understanding these differences allows for a greater appreciation of the biodiversity within our homes and gardens.
Distinguishing Characteristics: Anatomy and Appearance
One of the most obvious ways to differentiate between a cellar spider and a daddy long leg is their anatomy.
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Cellar Spiders (Pholcidae):
- Possess two distinct body sections: a cephalothorax (fused head and thorax) and an abdomen.
- Have eight legs.
- Typically have eight eyes (though some species have fewer).
- Produce silk and build webs to capture prey.
-
Daddy Long Legs (Opiliones):
- Appear to have a single oval-shaped body; their cephalothorax and abdomen are broadly joined.
- Have eight legs (though they can autotomize, or shed, their legs as a defense mechanism).
- Have only two eyes, located on a raised structure on their cephalothorax.
- Do not produce silk or build webs.
These anatomical variations are key to understanding their different lifestyles.
Behavioral Differences: Hunting and Defense
The behavior of cellar spiders and daddy long legs also differs significantly.
- Cellar Spiders: Are predators that use their webs to trap insects and other small invertebrates. They are known for their distinctive shaking behavior when threatened, which blurs their outline and makes them harder to see.
- Daddy Long Legs: Are primarily scavengers, feeding on dead insects, fungi, and decaying plant matter. They are opportunistic omnivores. Their long legs allow them to easily navigate through leaf litter and other debris. They use autotomy (shedding legs) as a defense mechanism.
This table summarizes the key behavioral differences:
| Feature | Cellar Spider (Pholcidae) | Daddy Long Leg (Opiliones) |
|---|---|---|
| —————- | ————————— | —————————- |
| Predatory Style | Predatory (web builders) | Scavengers/Opportunistic Omnivores |
| Web Building | Yes | No |
| Primary Diet | Insects | Dead insects, fungi, decaying matter |
| Defense Mechanism | Shaking web | Autotomy (leg shedding) |
Habitat and Distribution
Both cellar spiders and daddy long legs are commonly found in similar environments, often leading to confusion.
- Cellar Spiders: Prefer dark, damp places such as cellars, basements, caves, and under rocks. They are found worldwide.
- Daddy Long Legs: Also thrive in moist environments, including forests, meadows, and gardens. They are also found globally, with a high diversity in tropical regions.
While they may co-exist in the same general area, their microhabitats can differ based on their specific needs.
Debunking the Venom Myth
A persistent myth surrounds daddy long legs, claiming they are the most venomous spiders in the world, but their fangs are too short to penetrate human skin. This is false.
- Cellar Spiders: Do possess venom glands and use venom to subdue their prey. Their venom is generally considered harmless to humans.
- Daddy Long Legs: Do not possess venom glands. They are not spiders and lack the anatomical structures required to produce venom. Therefore, the myth is entirely unfounded.
Taxonomy and Evolutionary History
Understanding their classification helps clarify the differences between these arachnids.
- Cellar Spiders: Belong to the order Araneae, which includes all true spiders. They are classified within the family Pholcidae.
- Daddy Long Legs: Belong to the order Opiliones. They are a distinct group of arachnids that predate true spiders in evolutionary history.
Therefore, what is the difference between a cellar spider and a daddy long leg? The short answer is: one is a spider; the other is not.
Frequently Asked Questions (FAQs)
What is the lifespan of a cellar spider?
Cellar spiders can live for up to two years in ideal conditions. Factors such as food availability, temperature, and humidity can influence their lifespan.
Are cellar spiders dangerous to humans?
No, cellar spiders are not dangerous to humans. While they possess venom, it is not potent enough to cause any harm. They are generally harmless and beneficial, as they help control insect populations within homes.
What do cellar spiders eat?
Cellar spiders primarily eat insects that get caught in their webs. They are opportunistic predators and will consume a variety of small invertebrates. They’ve even been observed preying on other spiders.
What is the lifespan of a daddy long leg?
Daddy long legs typically live for about one year. Similar to cellar spiders, their lifespan can be affected by environmental conditions and food availability.
Are daddy long legs dangerous to humans?
Daddy long legs are completely harmless to humans. They do not have venom glands and are incapable of biting or stinging.
What do daddy long legs eat?
Daddy long legs are omnivores and will eat a wide variety of things, including dead insects, fungi, decaying plant matter, and even bird droppings. They are important scavengers in their ecosystems.
How do cellar spiders build their webs?
Cellar spiders build irregular, tangled webs in dark, undisturbed areas. The web serves as a trap for insects. These webs are typically found in corners and crevices.
How do daddy long legs defend themselves?
Daddy long legs defend themselves primarily through autotomy, the shedding of their legs. When threatened, they can detach a leg, which will continue to twitch, distracting the predator while the daddy long leg escapes.
Do cellar spiders reproduce sexually or asexually?
Cellar spiders reproduce sexually. Males transfer sperm to females using specialized mouthparts called pedipalps.
How do daddy long legs reproduce?
Daddy long legs reproduce sexually. Males have a penis-like structure used for internal fertilization, a relatively uncommon trait among arachnids.
Are cellar spiders beneficial to have around the house?
Yes, cellar spiders can be beneficial to have around the house. They help control populations of unwanted insects, such as flies and mosquitoes.
How can I tell if I have a cellar spider or daddy long leg infestation?
You likely won’t have an “infestation” of daddy long legs, as they don’t build nests. However, you might see several in a moist environment. If you see numerous irregular, tangled webs in your home, it’s likely you have a population of cellar spiders. Addressing the moisture issue can often reduce their numbers.