The woodlouse spider, scientifically known as Dysdera crocata, is a fascinating arachnid found across the globe. Its distribution spans diverse continents, including Australia, Asia, Europe, North America, South America, and Africa. As its name suggests, the woodlouse spider's diet primarily consists of woodlice, also known as pillbugs or roly-polies.
Classification and Physical Characteristics
Belonging to the Dysderidae family and the order Araneae, the woodlouse spider possesses distinct physical characteristics. It typically features a red, orange, or brownish-red cephalothorax (the fused head and thorax) and a bulbous, off-white to pale beige or yellow-brown abdomen, which can sometimes appear dark grey. Adult females have a body length of 11-15 mm (0.43-0.59 in), males 9-10 mm (0.35-0.39 in). These spiders have eight legs of the same reddish hue as their cephalothorax, along with six eyes and two rounded, black fangs (chelicerae) that are disproportionately large for a spider of this size. Males are typically smaller than females, a common trait among spiders.
Woodlouse spiders are sometimes mistaken for brown recluse spiders because of their similar color and size. A brown recluse spider is between 0.3 and 0.4 inches in length.
Habitat and Behavior
Woodlouse spiders are commonly found in damp, dark habitats, such as under logs, rocks, bricks, plant pots, and in leaf litter in warm places, often close to woodlice.. They seek out environments like piles of old logs, basements, cellars, or even within the walls of homes. During the day, these spiders typically reside in silken retreats, which they create within crevices of partially decayed wood or under rocks. They spend the day in a silken retreat made to enclose crevices in, generally, partially decayed wood, but sometimes construct tent-like structures in indents of various large rocks.
Unlike many other spider species, woodlouse spiders do not build webs to capture their prey. Instead, they are active hunters, venturing out at night to find food. Rather than spinning their webs at night, they use this time to search warm places for prey. They are known to be aggressive, especially females defending their egg sacs.
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Hunting and Diet
The woodlouse spider's diet consists principally of woodlice. These arachnids are sometimes called woodlouse hunter spiders because of their stealth when hunting woodlice. One of the most incredible facts about this spider is its fangs are capable of breaking through the exoskeleton of an insect. They rely on speed and their sharp fangs to capture woodlice and other insects. The spider typically stabs and injects venom into the woodlouse's soft underbelly while avoiding any noxious defensive chemicals. The woodlouse spider's powerful jaws are made to impale the thick armor of woodlice.
While woodlice are their preferred food, laboratory experiments have revealed that D. crocata will also consume other invertebrates. These include silverfish, earwigs, millipedes, burying beetles, and crickets. This suggests that woodlice are simply the most readily available prey in their typical habitat. This small but relatively large-fanged spider is very well equipped to prey on underground invertebrates of almost any kind. Because of its relatively large fangs and wide gape, the woodlouse spider is an unusually dominant predator for its size. Like many other Dysdera spiders, it frequently dominates, and sometimes kills, other spiders and centipedes.
Reproduction
The courtship of woodlouse spiders is known to be aggressive, with mating individuals risking injury from each other's large chelicerae. The female lays her eggs in a silken sac. These hiding places serve as a nest for the female's sac which can carry up to 70 eggs. She is believed to guard her young after they hatch. Making a sac for her eggs is an easy way to stand guard over them to protect them against predators.
Interaction with Humans
Woodlouse spiders are known to bite humans if handled or disturbed. Yes, this spider does sometimes bite humans. But they do so out of self-defense. For instance, a person may reach into a woodpile or stick their hand into a dark corner of a basement in search of something. That could result in a spider bite. Although their fangs are sharp and can be painful when pinching a human’s skin, their venom is not considered dangerous to humans, and verified bites have not caused any major medical problems. Although the woodlouse spider is a dangerous predator to woodlice, it is not known to be a health hazard to humans or smaller animals.
These spiders may enter homes in search of damp places to live and a steady supply of woodlice. They are attracted to damp areas. Woodlice are also attracted to the damp wood in a home.
Read also: Diet of the Brown Recluse Spider
Ecological Role
Woodlouse spiders play a beneficial role in gardens by preying on various insects that can harm plants. As a note, if you see a woodlouse spider in your garden, it’s a good idea to let it remain there. They may live beneath the rocks or under piles of sticks near a garden without actually living among the plants. These spiders eat lots of insects that are harmful to the vegetables and other plants in a garden.
Managing Woodlice Populations
Since woodlice are the main diet of this spider, controlling woodlouse populations can indirectly affect the presence of woodlouse spiders. Getting rid of woodlice is done by removing their preferred habitat. This means removing rotting wood in a home’s structure or moving a woodpile off the patio and away from a home’s walls.
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