Dysderidae

Common Name

Woodlouse Spiders

Overview

The family Dysderidae comprises a small but intriguing group of spiders recognized primarily for their specialized diet and hunting techniques. Often found in Europe, these spiders have made their mark as adept predators of woodlice.

Taxonomy

• Order: Araneae
• Infraorder: Araneomorphae
• Superfamily: Dysderoidea
• Family: Dysderidae

Key Characteristics

• Size: Typically ranging from 5 to 15 mm.
• Coloration: Generally displays a reddish-brown cephalothorax with a paler, almost translucent abdomen.
• Eyes: Possess six eyes arranged in a semi-circular pattern, unlike the typical eight eyes seen in most spiders.
• Fangs: Prominent, forward-projecting chelicerae (jaws) designed for piercing the tough exoskeletons of woodlice.
• Legs: Most species have relatively short and stout legs.

Life Cycle

• Egg: Females lay eggs in silk-lined retreats.
• Spiderling: After hatching, young spiders undergo several molts before reaching maturity.
• Adult: Adults are solitary hunters, living up to two years under suitable conditions.

Behavior and Ecology

Primarily nocturnal hunters, woodlouse spiders do not spin capture webs. Instead, they rely on stealth and speed to catch their prey. They are often found in leaf litter, under rocks, and within the damp crevices of human habitats where woodlice thrive. Also known for their relatively reclusive behavior, they prefer environments with abundant cover.

Notable Species

• Dysdera crocata: Perhaps the most famous member of the family, known for its worldwide distribution and specialized diet of woodlice.

Conservation

Currently, there are no significant conservation concerns specifically directed at Dysderidae spiders. However, their habitats should be protected to maintain ecological balance.

Significance to Humans

While they may appear intimidating due to their large jaws and reddish coloring, woodlouse spiders pose little threat to humans. Their bites are rare and generally result in only mild discomfort.

Fun Facts

• Woodlouse spiders are unique for their diet specialization, focusing almost exclusively on woodlice.
• Despite their fierce appearance, they are quite docile and often avoid confrontation unless threatened.
• Dysdera crocata’s large fangs are not just for show—they are perfectly adapted for piercing the armor of their woodlouse prey.
• These spiders exhibit a peculiar behavior known as "autotomy," where they can lose a leg to escape from predators, regrowing it in subsequent molts.