Black widow spiders are known for their distinct appearance, often featuring a vivid red hourglass marking. However, questions frequently arise about other potential markings, such as white spots. This article clarifies common misconceptions about white spots and explores the specific markings of black widows.
Understanding Black Widow Markings
Adult female black widow spiders, especially the Southern black widow (Latrodectus mactans), are typically shiny black with a red hourglass shape on the underside of their abdomen. This iconic marking can vary, sometimes appearing as two separate triangles. While the red hourglass is the most common identifying feature for mature females, prominent white spots are not typical. Some individuals may have faint red or orange patches, but these are not distinct white spots.
Variations in Black Widow Appearance
White spots are often associated with black widows due to variations in appearance among younger spiders, males, and other related species.
Juveniles
Juvenile black widows display different patterns than mature females. Young spiderlings are predominately orange, white, or yellowish-white, gradually acquiring black coloration and varying amounts of red and white as they mature.
Males
Male black widows are considerably smaller than females and typically lack the prominent red hourglass. They are usually lighter, appearing brownish or grayish, and may feature red and white stripes or spots on their dorsal abdomen. For instance, the Western black widow (Latrodectus hesperus) male is often tan with lighter striping, and the Northern black widow (Latrodectus variolus) male typically has faint red or white spots.
Other Widow Species
Other Latrodectus species, or “widow spiders,” also contribute to confusion about white markings. The Brown widow (Latrodectus geometricus), for example, varies from tan to dark brown and can have black and white patterns on its abdomen sides, along with an orange-yellow hourglass. The Northern black widow (Latrodectus variolus) female, while black, may have a row of red spots on its abdomen top and sometimes diagonal whitish markings on its sides.
Identifying Black Widows Beyond Color
Identifying black widows involves more than just color patterns; their body shape, web structure, and habitat offer additional clues.
Body Shape
Female black widows have a globular, shiny abdomen, which is often large, especially when carrying eggs. Their legs are long and slender in proportion to their body.
Web and Habitat
Black widows construct irregular, tangled, strong webs. These webs are typically found near the ground in dark, undisturbed locations like woodpiles, sheds, crawl spaces, and cluttered areas. Spiders frequently hang upside down in their webs, making their ventral hourglass marking visible.
Behavior and Safety
Black widows are reclusive, preferring to hide during the day. They usually attempt to escape when disturbed, biting only when threatened or unable to flee, such as when guarding an egg sac. If encountered, observe from a distance and avoid provoking it. For removal, contact pest control professionals.