Cellar Spiders

The name, cellar spider, comes from the location where they are often found: damp cellars, basements, and crawl spaces. They have very long, thin legs and are often confused with the harvestmen or ”daddy longlegs”. Cellar spiders also commonly infest warehouses. There are approximately 20 species of cellar spiders found in the United States, with several being found in the Kansas City area. Their bites are harmless to humans.

The web of the cellar spider has no discernable pattern. They prefer to live within close proximity to one another, creating large amounts of webbing which becomes a nuisance to remove. Cellar spiders often construct webs in corners and hang upside down on the web until a food item gets tangled. Many species of spiders consume their old web before making a new one, but cellar spiders do not.

Biology

Female long-bodied cellar spiders produce about three egg sacs over a lifetime, each containing 13-60 eggs each. The short-bodied cellar spider females produces about 10-27 eggs per case. Both species carry the egg sacs in their mouthparts instead of attaching them to the web like many other spiders. Once the eggs hatch the spiderlings crawl onto the mother's body for a short time. Development from egg to adult usually takes about one year. Adult cellar spiders may live for an additional two years.