The Black Widow (Latrodectus) is a highly venomous spider known for its distinctive red hourglass marking and potent neurotoxic venom. Due to their formidable reputation, Black Widows are often regarded as apex predators in their micro-habitats, such as woodpiles, sheds, and garages. Despite this status, Black Widows are not invincible and are actively preyed upon by specialized predators, including several other spider species. These araneophagic (spider-eating) arachnids have evolved specific behaviors and adaptations that allow them to successfully neutralize and consume the dangerous widow.
The Cellar Spider Specialist
One of the most effective predators of the Black Widow is the Cellar Spider (Pholcus phalangioides), often mistakenly called a “Daddy Long-Legs” spider. This species is an araneophagic specialist, meaning its diet consists primarily of other spiders, even those much larger and more venomous. The Cellar Spider is physically frail, with a small body and extremely long, thin legs, contrasting sharply with the Black Widow’s robust abdomen.
The Cellar Spider’s preference for dark, sheltered spaces like basements and sheds creates a significant habitat overlap with the Black Widow. This cohabitation means the two species frequently encounter each other’s webs, as the Cellar Spider is highly active and will venture from its own loose web to invade others in search of a meal.
Other Araneophagic Spiders
Several other arachnids occasionally prey on Black Widows, though they are generally opportunistic or geographically specific. The most notable are the False Widows (Steatoda genus), particularly the Cupboard Spider (Steatoda grossa). These spiders are close relatives of the Black Widow and are known to capture and consume them when they cross paths.
Competition within the Latrodectus genus itself has produced another predator: the Brown Widow (Latrodectus geometricus). In areas where their populations overlap, such as the southern United States, the Brown Widow aggressively targets and displaces the native Black Widow species. Studies have demonstrated that Brown Widows are significantly more likely to attack a Black Widow than other spider types, suggesting a specific predatory behavior that leads to the decline of Black Widow populations in favor of the invasive species.
Hunting Strategies and Countermeasures
The ability of a smaller spider like the Cellar Spider to subdue a larger Black Widow relies on tactical maneuvers and specialized silk use. When a Cellar Spider detects a Black Widow, it avoids a direct fight that could expose it to venom. Instead, it uses its lengthy legs to maintain distance while quickly launching specialized silk from its spinnerets.
This rapid web-wrapping technique thoroughly immobilizes the Black Widow, encasing it entirely in a dense shroud of silk before the victim can retaliate. This silk-flinging action is a precise countermeasure to the Black Widow’s own defense mechanism of throwing sticky silk at intruders. Once restrained and unable to move or bite, the Cellar Spider delivers its venom. Some araneophagic spiders also possess venoms highly effective against other arachnids, featuring specialized toxins for rapid incapacitation of spider prey.
Safety Profile of Black Widow Hunters
Knowing that these spiders consume Black Widows often raises questions about their danger level to humans. The Cellar Spider (Pholcus phalangioides) is considered harmless to humans; they rarely bite, and if they do, their venom is not medically significant.
Similarly, the False Widows (Steatoda species) pose very little threat to people. While they possess venom, a bite is an uncommon defensive reaction that occurs only when the spider is accidentally trapped or provoked. Symptoms from a False Widow bite are generally mild, often resulting in localized pain and swelling comparable to a common wasp sting. These spiders that help control the Black Widow population are not dangerous and are considered beneficial to have in a home environment.