Spider activity is heightened in the fall. Take the opportunity to add pest management services to your portfolio and create regular business during the slower cold months.
November 26, 2021
Fall is the peak time for spider activity, so as weather cools, customers may see spider activity in and around their homes. Lots of rain can cause insects to thrive, which become spider food. Spider activity is more obvious this time of year as they grow larger, build webs, and actively mate. Holiday décor can also bring in unwelcome pests.
Some bite when disturbed, but most species are not harmful to humans. Here’s some more background on the most common spiders customers may come across and tips and tricks on treatment and prevention
Types of Spiders
Common House Spider
This species of spider is the most often encountered indoors and is considered a nuisance pest. They are found worldwide and are common throughout the U.S. and Canada. A female house spider can lay over 3,500 eggs in their lifetime.
- Color: Typically brown, but color is highly variable; their abdomen is usually a dirty white with dark stripes meeting at an angle.
- Size and Appearance: Females range from 3/16” to 5/16” while males range from 1/8”-3/16”. Females are more spherical, while males are elongated. House spiders have 8 eyes with 2 lateral pairs almost touching.
- Favorite Web-building Areas: This species randomly selects sites to build their home and create tangled webs. If a web doesn’t produce prey, it is abandoned, and a new site is selected to build another web. Because of trial-and-error web selection, many webs can be constructed within days. The house spider is more likely to be found in garages, sheds, barns, and warehouses. Outside, these spiders are found around windows and under eaves, especially near light sources as they attract prey. Inside structures, house spiders are found in upper corners, under furniture, in closets, angles of window frames, basements, garages, and crawl spaces. In warehouses a common spider location is in corners near doors that stay open. Dust collecting on the web highlights its presence to humans.
- Venomous: No. They are not known to bite but may do so in threatening situations, such as being crushed.
Long-Bodied Cellar Spiders
Long bodied cellar spiders are also known as daddy-long-legs. There are around 20 species of cellar spiders in the US and Canada.
- Color, Size, and Appearance: They are pale yellow to light brown in color with long, skinny legs and a small body.
- Favorite Web-building Areas: Daddy-long-legs are typically found in places with high humidity and moisture, like basements and crawlspaces. Corners of garages, sheds, barns, warehouses may be hiding webs. They can also be found in eaves, windows, and on ceilings, as well as inside closets, sink cabinets, and bath-traps.
- Venomous: No. Long bodied cellar spiders are no threat to humans and not known to bite.
Found throughout the US, these spiders are commonly seen outside running over and around tree bark, bushes, fences, decks, buildings, and under stones. They are a unique species due to being active in the daytime and also seem to like sunshine. They cannot see well at night, although they have the best vision of all spiders and are able to detect movement from 18 inches in the distance.
- Color: They’re usually black and covered in dense hair, and sometimes have bright scales.
- Size and Appearance: Jumping spiders are sometimes mistaken for black widow spiders due to their compact shape and short legs.
- Favorite Web-building Areas: This species builds web retreats, which are found indoors and outdoors. Jumping spiders frequently hunt inside structures around windows and doors as insects are attracted to these areas and this spider’s vision is best in well-lit areas.
- Venomous: No. Jumping spiders may bite in defense but are not poisonous. In fact, they are more likely to run away from humans.
Black Widow Spiders
Black widows are found throughout the United States but are more common in southern regions where it is warmer.
- Color: They are black and shiny with a telltale red hourglass shape on their abdomen.
- Size and Appearance: They have round bodies and are 1 ½” to 1 3/8” long.
- Favorite Web-building Areas: Black widow spiders find dark and dry locations, such as under stones, decks, hollow tree stumps and in firewood piles, sheds, and barns. They create messy and irregular webs located near ground level. When webs are visible, be careful when putting hands and feet in the area and wear shoes and gloves.
- Venomous: Yes. The black widow spider is one of the two spider species with potent bites that can lead to issues. Females are known to be aggressive and can bite in defense, especially when guarding their eggs. Symptoms of a black widow bite are running a fever, increased blood pressure, sweating, and nausea. While it’s rare that cases are fatal, if bitten it is important to promptly get the proper medical attention.
Brown Recluse Spiders
Brown recluse spiders are typically found in the central Midwest from Ohio to Nebraska and southward through Texas and Georgia. They prefer warm, dry, and dark environments. While other species like to eat small flying insects, they like cockroaches and crickets.
- Color: As the name suggests, brown recluse spiders range from light to dark brown, with a dark brown violin marking on their back.
- Favorite Web-building Areas: Outside brown recluse spiders can be found in debris or woodpiles. Inside buildings, they can be found inside storage items, under furniture, baseboards, and the dark recesses of window moldings. Closets, attics, crawlspaces are their most common hiding places. These spiders are well adapted to living indoors and can survive months without food or water. Male brown recluses wander further from the nest than females, so they are more likely to crawl into shoes and other attire.
- Venomous: Brown recluse spiders are the other species with potentially harmful bites as a defense mechanism. If bitten, you may not feel the bite at first, but they produce a stinging sensation followed by intense pain, as well as restlessness, fever, and difficulty sleeping. In serious cases, a bite can lead to an open sore that requires medical treatment and may scar.
Signs of Infestation
If customers are seeing spiders and any kind of web in their home or on their property, they may have an infestation and should call you immediately for control treatments. Additionally, if customers see silken sac of eggs, that is another sign of infestation.
Methods of Prevention
First be sure to remove all harborage sites. Seal cracks around outside of home using silicone-based caulk. Install tight screen windows and doors as well as weather stripping and door sweeps. Move customers’ firewood at least 20 feet away from the home and on a raised structure. Wear protective gear when working on customers’ homes. Use a pesticide like LESCO Crosscheck both to control infestations as well as a preventative measure.
Advise customers to get rid of indoor spiders by vacuuming to remove adults, egg sacs, and webs. If a broom is used, spiders can usually escape. Remind customers to shake out and inspect shoes, clothing, and accessories like gloves before dressing, as well as keep boxes on shelves and not under the bed. Have them remove clutter from basements, attics, and garages and remind them to wear heavy gloves when moving items that have been stored for a significant amount of time.
If you’re interested in adding pest management to your portfolio, consider attending a SiteOne University in your area. If you have questions or need support for an upcoming job, visit your local branch and an associate will help with anything you need. You can also visit the pest management section of our website to pick up tools for the job.