Entity scope
This profile covers widow spiders in Latrodectus, including several species called black widows. Sex, age, markings, range, and medical relevance vary; a skin lesion cannot identify the spider.
Quick identity
- Taxonomic scope
- Latrodectus genus
- Useful adult-female traits
- Rounded abdomen, irregular web, and species-dependent red markings
- Variation
- Males and juveniles may be smaller and more patterned
- Strong evidence
- A preserved spider with clear dorsal and ventral views plus geography
- Medical boundary
- A lesion or symptom pattern does not identify the spider
- Visual status
- NO_VISUAL — the prior misleading identity image remains removed
Key characteristics
- Adult females commonly have a rounded abdomen, but color and red markings vary among species and life stages.
- The familiar hourglass is on the underside and is not identical in every specimen.
- Males and juveniles may look unlike the familiar adult female.
- Web form and location support context but do not prove genus identity.
Life stages
01
Juvenile
Often more patterned than mature females; appearance changes through molts.
02
Adult male
Usually smaller and differently patterned from the medically familiar adult female.
03
Adult female
More robust rounded abdomen; markings vary across Latrodectus species.
Where it is found
- Undisturbed crevices, woodpiles, debris, outbuildings, and protected spaces where an irregular web can remain.
- Geography matters because Latrodectus species and lookalikes differ by region.
Behavior and activity
- Widow spiders are generally reclusive and bites usually involve trapping or direct disturbance.
- A spider in a web does not establish that a person was bitten.
- Symptoms after an unknown bite cannot establish Latrodectus identity.
Associated signs
A recovered spider plus compatible web and geographic context is stronger than a web, red mark, or skin symptom alone.
Common lookalikes
Related cobweb spiders can share a rounded abdomen and dark color.
Many Theridiidae build irregular webs.
Medical conditions and other exposures can be mislabeled as spider bites.
Why it matters
Identity does not determine envenomation or severity
Latrodectus venom can cause significant pain and systemic symptoms, but most spider sightings do not involve a bite and symptoms alone do not identify the spider.
- Seek urgent medical evaluation for severe pain, muscle cramping, breathing difficulty, faintness, or rapidly worsening symptoms after a suspected bite.
- Do not handle or deliberately provoke a spider to obtain a closer view.
- A clinician or poison center assesses symptoms; this Profile does not diagnose or prescribe treatment.
Management direction
- Photograph or preserve the spider only if it can be done without contact.
- Record dorsal and ventral markings, web, exact site, and geography.
- Use qualified pest help for confirmed activity in a high-contact area; control details belong in Guides.
Have a pest photo to check?
Start a new photo identification. This Profile gives comparison context; it does not transfer certainty or diagnose your image.
Identify a photoReviewed guidance and sources
Last reviewed August 2026. Sources support the claims listed with them; their limits remain part of the review.
- NIOSH/CDC — Venomous Spiders at Work
Supports: Widow morphology, habitat, defensive-bite context, and potential symptom severity.
Does not support: Identity from symptoms, a universal outcome, or individualized medical treatment.
Scope note: U.S. occupational context; species and care systems differ elsewhere.
- CDC Yellow Book — Poisonings and Envenomations
Supports: Global Latrodectus context, possible systemic effects, and medical escalation boundary.
Does not support: Diagnosis from a lesion or prediction of severity.
Scope note: Risk, distribution, and response guidance vary by region and individual clinical context.