West Coast Laceweaver
Callobius severus
This record describes Callobius severus (species). Recorded family: Amaurobiidae. Recorded order: Araneae.
Identification and Appearance
Callobius severus is a species of spider found in parts of the United States and Canada. Individuals reach roughly 19 mm (3/4") in size, with males typically appearing smaller than females. Cephalothorax and legs are reddish to dark brown and the abdomen is dark to light grey with fine hairs, often appearing with large, bilaterally mirrored paler spots. Males feature large, extended palps with prominent projections.
Identification notes
Palp (ventral/tibial apophysis) Epigynum
Wikipedia reference for Callobius severus: http://en.wikipedia.org/wiki/Callobius_severus.
Classification
- Kingdom
- Animalia
- Phylum
- Arthropoda
- Class
- Arachnida
- Order
- Araneae (Spiders)
- Family
- Amaurobiidae (Hacklemesh Weavers)
- Genus
- Callobius
Imported taxonomy record. Source availability varies; see the source references and editorial policy below.
Habitat and Range
Habitat
Inside old rotten conifer stumps and logs and under loose bark of old, rotten, damp stumps and logs
Geographic Range
Alberta and British Columbia south to California
About Spiders: the wider group
Order-level background for Araneae, the group containing Callobius severus. Species-specific details appear above.
Group overview
As of 2023, 51,673 spider species in 136 families have been recorded, though an estimated 150,000 species exist. Spiders rank 7th in total species diversity among all organism orders. Only 0.5% of spider species pose any risk to human health.
Ecological role of the group
Spider venom contains complex peptides with diverse pharmacological activities, making them valuable for drug development research. Spiders produce up to 7 types of silk from specialized glands. Spider silk genes have been inserted into mammals and plants for biotech applications.
Economic and practical significance of the group
The global spider community kills an estimated 400-800 million tons of prey annually (2017 study). Spiders provide billions of dollars in natural pest control for agriculture. Spider silk is 5× stronger than steel of the same diameter, driving a biomaterials research industry.
Recorded sources for this group: World Spider Catalog, PNAS, Nature, ScienceDirect. Imported estimates may describe particular regions or reporting periods.
Photos of West Coast Laceweaver (4)
Photo credits: (c) Asa Spade, some rights reserved (CC BY-NC), uploaded by Asa Spade | (c) Nicholas Pollock, some rights reserved (CC BY-NC), uploaded by Nicholas Pollock | (c) AHIOH, some rights reserved (CC BY), uploaded by AHIOH | Contributed by Lynette Elliott; Additional contributions by cheins
Frequently Asked Questions About West Coast Laceweaver
What is West Coast Laceweaver?
West Coast Laceweaver (Callobius severus) is a species in the family Amaurobiidae, within the order Araneae.
How do you identify West Coast Laceweaver?
Palp (ventral/tibial apophysis) Epigynum
Where is West Coast Laceweaver found?
| Feature | Details |
|---|---|
| Habitat | Inside old rotten conifer stumps and logs and under loose bark of old, rotten, damp stumps and logs |
| Range | Alberta and British Columbia south to California |