2 Types of Black Widows in California

2 types of black widows have a verified observation record in California. The most frequently recorded are Western Black Widow and Brown Widow. Here is the full list, ranked by how often each is reported on iNaturalist.

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2 types of black widows have a verified observation record in California. The most frequently recorded are Western Black Widow and Brown Widow. Here is the full list, ranked by how often each is reported on iNaturalist.

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Real sighting data, source iNaturalist

25,658 verified observations on iNaturalist of black widow have been recorded in California, most often in September, October, August.

When black widow are recorded in California

Verified species, source iNaturalist

2 types of black widows recorded in California

2 black widow species have a verified observation record in California, each with at least 10 confirmed sightings. The full list, ranked by how often each is recorded, is below.

1 of the 2 shown is recorded as introduced to California rather than native.

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    1

    Western Black Widow

    Latrodectus hesperus

    12,643 recordsNative
  • No openly licensed photo yet
    2

    Brown Widow

    Latrodectus geometricus

    11,427 recordsIntroduced

Counts from verified iNaturalist observations.

The Western Black Widow (Latrodectus hesperus) is the most commonly recorded, with 12,643 verified observations, about 53% of all black widows reported in California. If you spot a black widow here, it is statistically most likely to be this one.

Not every one of these is originally from here. Brown Widow is recorded by iNaturalist as introduced in California rather than native, so it arrived with human help rather than on its own.