Black Widow Spiders
Facts, Identification & Control
What do they look like?
- Hourglass marking: Black widows are identified by red hourglass marking on the underside of their abdomens. This marking is bright red and signals danger to predators and attackers.
- Color: Black widows are shiny black in color.
- Size: Most black widow spiders’ bodies are 3 to 10 mm in size. Females are larger than males and can measure 13 mm in body length.
How Did I Get Black Widow Spiders?
Keeping yards in good condition is an important part of pest prevention, especially for black widow spiders. Tall grass and piles of firewood or debris make attractive places to find food, hide, and build webs.
Homes that already have an insect issue have the potential to develop a black widow problem. These spiders eat ants, flies, and other pests, so a crack in the door or window is an open invitation to come indoors and start hunting. Read more what and how they eat.
How Serious are Black Widow Spiders?
Black widow spiders are generally considered beneficial since they eat so many insects. However female black widow spiders can attack humans when they are provoked. The black widow spider delivers the most toxic spider bite in the United States. The venom of the black widow spider is comprised of neurotoxins that affect the nervous system. Read more about black widow bites.
How Can I Get Rid of Black Widow Spiders?
What Orkin Does
The Orkin Man™ is trained to help manage spiders and other pests. Since every yard or home is different, the Orkin technician will design a unique program for your situation.
Keeping spiders out of your home is an ongoing process, not a one-time treatment. Orkin’s exclusive A.I.M. solution is a continuing cycle of three critical steps — Assess, Implement and Monitor.
The Orkin Man™ can provide the right solution to keep spiders in their place…out of your home.
For more information or to schedule an inspection, please contact your local Orkin branch office.
Signs of a Black Widow
Black widows produce messy, irregular webs. Webs usually are located near ground level and under a protected ledge such as under lawn furniture or wood piles. The female with the iconic red hourglass marking also indicates their presence.
Black Widow Facts
Where Are Black Widow Spiders Found?
Black widow spiders favor dark, secluded areas such as crevices and woodpiles. Inside the home, black widows typically hide in sheltered, dimly lit locations such as garages, dark corners, basements, closets and cluttered areas. They thrive primarily in temperate zones and are known to be abundant in the American South.
Several species of Latrodectus or “widow” spiders are present in North America. The most common are: the southern widow (Latrodectus mactans) found in the American South and Northeast; Latrodectus hesperus found in the west; the brown widow (Latrodectus geometricus) found in the South; and the northern widow (Latrodectus variolus) found in the Northeast.
- Comb foot: An important characteristic of the black widow spider is its comb foot. This row of strong, curved bristles is located upon the hind pair of legs and is used to pitch silk over captured prey.
- Shy: Black widows are shy in nature. They are solitary, socializing only during copulation.
- Nocturnal: Black widows are nocturnal and spin webs during daytime.
- Hang upside down: They can sometimes be seen hanging upside down in their web, exposing a telltale hourglass abdominal marking.
Male vs. Female
On average, male black widow spiders are smaller than females, reaching only about half their size in length. However, the legs of the male black widow are considerably longer in proportion to the female’s and are marked by orange and brown at the joints. Males may exhibit red and white stripes on the abdomen depending on the species and are more colorful and finely patterned than females.
Black Widow Webs
Black widows spin a large web where the female suspends a cocoon that can contain hundreds of eggs. These spiders also use their webs to capture their prey, which includes insects such as flies, grasshoppers, beetles, etc.Read more about the black widow’s web.
Northern Black Widow
As designated by its name, the northern black widow spider (Latrodectus various) is found primarily in the Northeast United States. They may live as far south as Florida, as far north as Canada and as far west as Texas.
Species of widow spiders are also occasionally transported in shipments of household goods to states outside of their natural range. Northern black widows are primarily found in marginal land habitats with sparse vegetation, stumps, hollow logs and piles of debris. Northern black widow spiders are rarely found indoors. However, they may enter human dwellings on piles of firewood or other items brought inside. Most adult female northern black widow spiders are shiny black in color, with rows of red spots atop the abdomen. Crosswise bars that resemble a red hourglass appear on the underside of the abdomen.
Southern Black Widow
The weather in the American South is extremely conducive to the development of black widow spiders, and several species can be found. A great example is the southern black widow spider (Latrodectus mactans). They are one of the most common black widow species in the Southern United States. Females spin irregular and nonsymmetrical webs. They do not prefer to venture indoors but can be found in garages or basements near openings to the outdoors such as around garage doors.
Like the northern black widow, the female southern black widow spider is jet-black in color and is shiny. They also have a red hourglass-shaped mark on the underside which serves to identify it.
How the Black Widow Spider Received its Name
The black widow spider received its name due to a story about its mating behaviors. Courtship begins when males go out in search of receptive females. Upon approaching a web-spinning female, the male spider will wait for an indication of her willingness: females interested in mating remain still, allowing males to inseminate them.
As the story goes, following insemination, female black widow spiders kill and feed upon their mates. This story led to the black widow’s name. However, it is a misconception that all female black widows kill and consume their mates. Rather, this behavior is typically only observed in captivity.
The black widow contributes to the balance of the ecosystem by consuming insects such as flies and mosquitoes. It also controls crop pest populations, feeding on pests that defoliate plants, including locusts, grasshoppers, beetles and caterpillars.