Black widow spiders are present in Maryland. Found across many states, including the Mid-Atlantic, Maryland is home to both the Northern black widow (Latrodectus variolus) and the Southern black widow (Latrodectus mactans) species.
Where Black Widows Are Found in Maryland
Black widow spiders in Maryland prefer environments that are dark, sheltered, and undisturbed. They are commonly found outdoors in places like woodpiles, sheds, and garages. Other typical habitats include areas under eaves, beneath lawn benches or porches, and in basement window wells. They construct messy, irregular webs, often near ground level, under protected ledges. They are rarely found indoors, usually entering homes by stowing away on items stored outside.
Recognizing Black Widows
Identifying a black widow spider primarily involves observing the adult female. Female black widows are typically shiny black and measure about 1/2 inch in body length, excluding their legs. The most recognizable characteristic is a bright red or orange hourglass-shaped marking located on the underside of their globular abdomen.
Some female black widows may also display small dull red marks on the top of their abdomen or have the hourglass marking appear as two separate triangles or dots. Male black widows are considerably smaller, about half the female’s size, and may have red spots and white lines or bands on their backs, appearing more colorful. Juvenile spiders are orange and white, gradually turning black with each molt. No other spider species native to Maryland shares the same combination of a shiny black body and the distinctive red hourglass marking.
Understanding Black Widow Bites
Black widow spiders are not aggressive and typically bite only when threatened, such as when their web is disturbed or they are inadvertently touched. The bite itself may initially feel like a sharp pinprick or might go unnoticed. Within about an hour, localized pain, redness, and swelling can develop around the bite site.
The venom, which is a neurotoxin, can then affect the nervous system, leading to more widespread symptoms. Common symptoms include muscle cramps or spasms, which can be severe and affect the abdomen, shoulders, chest, or back. Other potential reactions include nausea, vomiting, sweating, headache, and fever.
While rarely fatal, especially for healthy adults, black widow bites can be medically significant. If a black widow bite is suspected, wash the area with mild soap and water and apply a cold compress to help with pain and swelling. Prompt medical attention should be sought, particularly if symptoms worsen or spread beyond the bite area, or if the bite involves children or older individuals.
Safety Around Black Widows
Caution in areas where black widows might reside can help prevent bites. Since these spiders prefer undisturbed locations, be vigilant in places like woodpiles, sheds, garages, and other cluttered storage areas. When working outdoors or handling items stored in such spaces, wearing gloves is a sensible precaution.
Shaking out shoes, towels, and clothing before use can also dislodge any spiders that may have sought refuge inside. Reducing clutter around the home and yard, especially wood, rock, and debris piles, eliminates preferred hiding spots for black widows. Sealing cracks and gaps in your home’s exterior, including around windows and doors, can help prevent spiders from entering. If you encounter a black widow web, carefully knocking it down with a broom or hose can discourage them from inhabiting the area.