The terms "cellar spider" and "daddy long legs" are often used interchangeably, leading to much confusion. However, these names actually refer to two distinct groups of arachnids, though they share some superficial similarities. Understanding their differences is key to appreciating their unique roles in our ecosystems. This article will clarify the distinctions between cellar spiders and the arachnids commonly referred to as daddy long legs, addressing common misconceptions along the way.
Are Cellar Spiders and Daddy Long Legs the Same Thing?
No, cellar spiders and daddy long legs are not the same. The confusion arises because both are long-legged arachnids often found in similar habitats, like dark corners and cellars. However, they belong to different arachnid orders.
What is a Cellar Spider?
Cellar spiders (family Pholcidae) are true spiders, belonging to the order Araneae. They are characterized by their:
- Small, fragile bodies: Generally less than 1/2 inch in body length.
- Long, thin legs: These legs are disproportionately long compared to their body size.
- Tangled, irregular webs: Unlike the neatly organized webs of many spiders, cellar spiders create messy, three-dimensional webs.
- Defensive behavior: When threatened, they vibrate their webs rapidly, making them difficult to see and catch.
What Do Cellar Spiders Eat?
Cellar spiders are opportunistic predators, feeding on a variety of small insects and other invertebrates they catch in their webs. Their diet often includes other spiders, which they can sometimes overpower despite their smaller size.
What is a Daddy Long Legs?
The arachnids commonly called "daddy long legs" belong to the order Opiliones and are not true spiders. Key differences include:
- Fused body segments: Unlike spiders, which have a distinct cephalothorax (head and chest combined) and abdomen, daddy long legs have a single body segment.
- Two eyes: Most daddy long legs have only two eyes, positioned on a small tubercle, instead of the eight eyes typically found on spiders.
- Short pedipalps: While spiders have pedipalps that are often modified for grasping prey, daddy long legs have relatively short pedipalps that don't serve this function. Instead, they have strong mouthparts for chewing.
- Different leg function: Daddy long legs' long legs are primarily used for locomotion and sensing their environment, not for prey capture.
What Do Daddy Long Legs Eat?
Daddy long legs are primarily scavengers and detritivores, feeding on decaying organic matter, dead insects, and plant material. They also consume small living invertebrates.
Are Daddy Long Legs Poisonous?
This is a persistent myth. While daddy long legs do have a pair of small chelicerae (mouthparts), they lack venom glands and are harmless to humans. They cannot bite in a way that could inject venom even if they did have any.
Are Cellar Spiders Poisonous?
Cellar spiders are venomous, meaning they possess venom glands. However, their venom is generally considered harmless to humans. Their fangs are too small to penetrate human skin effectively, making a bite unlikely.
How to Identify Cellar Spiders vs. Daddy Long Legs?
The easiest way to differentiate them is to look at the body segmentation. Spiders have two distinct body parts, while daddy long legs have a single fused body. The leg-to-body ratio can also be a helpful indicator, but it's not always conclusive. Observing their web-building behavior can also be informative; cellar spiders build irregular, messy webs while daddy long legs do not create webs.
Conclusion:
While often confused, cellar spiders and daddy long legs are distinct arachnids. Cellar spiders are true spiders with venom, albeit harmless to humans, while daddy long legs are not spiders and are entirely harmless. Understanding these differences helps appreciate the diversity within the arachnid world.
