Systematically move through your house, removing all webs and spiders. Insecticides are not very effective at controlling these spiders for a few reasons 1) the spiders don't move around that much so the chances of them walking through a residual insecticide are not good 2) even if they do walk through the insecticide they are walking on the tips of legs on claw-like tarsi, and 3) insecticides are often not as effective as we want because spiders are not insects, they are arachnids.įor cellar spider control the best thing is a vacuum with a hose attachment. Often the spiders and webs are concentrated in a dark, seldom disturbed, basement or cellar area. Long-bodied cellar spiders are difficult to eliminate from a home. Long-bodied cellar spiders are not poisonous to humans and are actually sort of good guys because they eat insect pests, house centipedes, and other things we do not like in our homes. Long-bodied cellar spiders leave what seem to me to be permanent webs in basements, corners of ceilings, walls, book shelves, basically just about anywhere. Sometimes long-bodied cellar spiders are seen hanging in their web, but most often just the webs are seen because the cobwebs do not become obvious until they are old and abandoned by the spider and have gotten covered in dust. Long-bodied cellar spiders have a long body that is usually a bit less than 1/3 of an inch, and very long thin legs that can make the spider seem quite large. In Iowa the most common species of spider that makes cobweb-like webs is the long-bodied cellar spider. There is a group of spiders we call the cobweb spiders, but many species of spiders make messy webs we would call cobwebs. If this document didn’t answer your questions, please contact HGIC at or 1-88.Cobweb is a term used for messy spider webs in homes, the flimsy webs that sort of drape down and get covered in dust. Installing weatherstripping and a proper threshold with a door sweep can prevent access into the building.Īppropriately labeled insecticides can be used to temporarily reduce cellar spiders however, their use should be minimal and not used as a substitute for proper sanitation and proper maintenance.
Use pole lights away from the structure but directed back to illuminate entrances to reduce insects and spiders around the building.īy sealing cracks and crevices around doors and windows or other entry points, insect and spider access into the structure will be deterred. At commercial locations, replace lights on buildings, especially over doors. Replacing exterior white lights to a less attractive yellow or sodium vapor lamp can indirectly reduce the number of spiders because yellow light is less attractive to insects. Humidity can be controlled in many ways such as a dehumidifier or through proper ventilation. Lowering the relative humidity in the area where cellar spiders are found may help eliminate them because lower humidity will deter insects from entering the building. Adequate insect control through proper sanitation, maintenance and insecticide use (if necessary) will help prevent spiders from becoming established. One key feature of spider control is to reduce the available food source. Removing the webbing also allows for easy reference of future spider activity. This can be very effective in reducing the number of spiders in a relatively short time. Spider webs, egg sacs, and individual spiders can be removed with a broom or vacuum. Several non-chemical measures can be taken to reduce the presence of cellar spiders from around a home or business. Once prey is captured, cellar spiders vigorously shake their webs to further entangle their meal. They hang upside down on the web until a food item gets tangled. Cellar spiders construct loose haphazard webs, often in corners, to catch insect prey. They continuously add to it, creating large amounts of webbing which becomes a nuisance to remove. Many species of spiders consume their old web before making a new one, but cellar spiders do not.
In instances where cellar spiders are pests, it is due to the large amounts of webbing they produce. Adult cellar spiders may live for an additional two years. Development from egg to adult usually takes about one year. Once the eggs hatch the spiderlings crawl onto the mother’s body for a short time. Both species carry the egg sacs in their mouthparts instead of attaching them to the web like many other spiders. The short-bodied cellar spider females produces about 10-27 eggs per case. Female long-bodied cellar spiders produce about three egg sacs over a lifetime, each containing 13-60 eggs each. The female short-bodied cellar spider has a 1/16 inch long body with legs extending about 5/16 inch. The female long-bodied cellar spider is approximately 1/4-5/16 inch long with legs extending another 2 inches. The two more commonly seen species are the long-bodied and short-bodied cellar spiders.