Fauna
Arachnid

Boreal Combfoot

Steatoda borealis

Also known as Northern False Widow

Boreal combfoots weave tangled, irregular three-dimensional webs in dark crevices, basements, and rock piles, waiting upside down for wandering prey to stumble into sticky anchor lines. Often mistaken for true black widows due to their bulbous dark abdomens, they bear a subtle pale midline stripe and lack bright red hourglass markings. Males produce faint acoustic signals by scraping ridges on their abdomen against their carapace to court females during the breeding season.

NocturnalWeb-weaverSynanthropic
Boreal Combfoot reference1 / 7
(c) Bill Keim, some rights reserved (CC BY), uploaded by Bill Keim · cc-by
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Not EvaluatedConservation statusIUCN Red List categoriesLCNTVUENCREWEXNot Evaluated — not placed on the risk ladderRed List categories, explained →
Key facts
Diet & preyFlies, Ants, Carpet beetles
Predators
  • Mud dauber wasps
  • Jumping spiders
  • Centipedes
ThreatsPesticide application and habitat clearance
HabitatsDeciduous forests, rocky crevices, basements, and outbuildings
Life span1–2 years
Classification
  1. OrderAraneae
  2. FamilyTheridiidae
  3. GenusSteatoda
  4. SpeciesSteatoda borealis
Range & activity
Range data is not available yet.
Safe observation
Interaction riskLow
  1. Low
  2. Moderate
  3. High
  4. Very high
Why interaction risk is low
Harmless to humans; bites are rare, defensive, and cause only mild localized discomfort.
Responsible observation
  • Observation: Look around dark foundation corners and woodpiles after dusk with a soft flashlight.
  • Relocation: Gently scoop stray indoor individuals using a clear cup and card to move outside.
Related species
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