Woodlouse Hunter, Woodlouse Spider, Sowbug-killer, Slater-killer
Dysdera crocata
Dysderidae (Woodlouse Hunters), Order Araneae. Characterized by six eyes and large, forward-projecting chelicerae.
Physical Description
A medium-sized spider with a smooth, glossy texture. It has a distinctive reddish-brown cephalothorax (head region) and a pale beige to grey, oval-shaped abdomen. A defining feature is the exceptionally large, pincer-like chelicerae (fangs) that project forward.
Size Estimate
Body length typically ranges from 9-15 mm (0.35-0.6 in). Total leg span is approximately 25-40 mm. Females are generally larger and more robust than males.
Coloration & Markings
Bicolored appearance: the cephalothorax and legs are a deep mahogany or rusty reddish-orange, while the abdomen is a contrasting creamy tan, greyish-yellow, or pale brown with no distinct patterns or markings.
Web Type
This is a hunting spider that does not build a web to catch prey. It only produces silk to create small, silken 'retreat' cells in crevices or under debris for molting and egg-laying.
Eye Arrangement
Six eyes (rather than the usual eight) arranged in a tight semi-circle or oval cluster on the front of the cephalothorax.
Leg Characteristics
Six pairs of legs (eight total) that are moderately long, smooth, and colored similarly to the head region (reddish-orange). They lack prominent banding or thick hair.
Venom & Safety Information
Venom Information
Contains cytotoxic components but is not considered medically significant to humans. The venom is highly effective against small arthropods but weak against mammalian tissue.
Medical Significance
Low danger level. Bites are rare and usually occur when a spider is trapped in clothing or handled. Symptoms include localized pain (similar to a bee sting), redness, and minor swelling. No long-term damage is expected.
Safety Recommendations
If found indoors, relocate using the cup-and-paper method to a damp area outside. Wear gloves when gardening in leaf litter. If bitten, clean the area with soap and water; seek medical attention only if an allergic reaction occurs.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution; originally from the Mediterranean but now found throughout North America, Europe, Australia, and New Zealand. Commonly found in damp areas: under logs, rocks, flower pots, and in basements or leaf litter.
Behavior & Temperament
A nocturnal, active hunter. It is generally shy and tends to run away when disturbed, but can be defensive if handled or cornered. They are known for their ability to hunt during cooler temperatures.
Diet & Prey
Exclusively specializes in hunting isopods (woodlice, pill bugs, sowbugs). Their elongated fangs are specifically evolved to pierce the hard calcareous exoskeleton of these crustaceans.
Seasonal Activity
Active year-round in warmer climates or indoors, but peak sightings usually occur in late spring and summer during mating season.
Description
The Woodlouse Hunter is a striking, nocturnal specialist. With its bright rusty-red head and large fangs, it looks formidable, but it is a beneficial predator that keeps garden pests in check. Its unique anatomy is a masterclass in evolutionary specialization for a specific diet.
Key Features
Reddish-brown cephalothorax, cream-colored abdomen, six eyes in a group, and very long fangs that project forward.
Similar Species
Often confused with Broad-Faced Sac Spiders (Trachelas tranquillus), which have eight eyes and smaller fangs, or the Brown Recluse, though Dysdera lacks the violin marking and has six eyes in a different cluster.
Life Cycle
Females lay about 70 eggs in a silk retreat. They provide some maternal care initially. The life cycle from egg to adult takes approximately 18 months, and they can live for 2-3 years.
Ecological Importance
Vital for controlling populations of woodlice and sowbugs in gardens and ecosystems, acting as a natural form of pest management.
Conservation Status
Not evaluated by IUCN, but considered common and stable throughout its global range; frequently benefits from human-disturbed habitats.
Interesting Facts
Despite their specialized diet, they can survive for months without food. Their fangs are so strong they have been known to pierce through a standard leather gardening glove if the spider is squeezed.
Photography Tips
Focus on the head region to capture the large fangs and the six-eye arrangement. Direct lighting helps highlight the glossy texture of the cephalothorax.
Identified: 2026-06-15T01:26:29.462474