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Brown Widow (Latrodectus geometricus)

Detailing the identifying qualities of the Brown Widow, including physical features and territorial reach.

 Updated: 2/13/2018; Authored By Staff Writer; Content ¬©

  Brown Widow  
Picture of Brown-Widow
Picture of Brown-Widow Picture of Brown-Widow

The Brown Widow is a more timid relative to the well-known and dangerous Black Widow, and though it is less toxic, its bite can pack a punch.

The moment the bright orange hourglass on her belly is visible, most people recognize this spider as a type of Widow. The overall brown/gray color and smaller size is standard for a Brown Widow. A black and white (or ivory) geometric pattern is visible on the dorsal (back) side of the abdomen. Legs are two-toned with wide bands of black and brown along the length of each one. It is likely that an observer will see her egg sac before seeing the female that made it. Egg sacs look like small, spiky golf balls. Other Widow spiders have smooth egg sacs.

Brown Widow spiders are native to Africa and have made a home in North America, most recently in California since 2003. The number of Brown Widow sightings in that state have led to research on the effect their presence is having on the native Black Widow population. They successfully compete for space and resources and seem to be outnumbering them in many areas.

While Brown Widows are venomous (as almost every spider is), their venom is not as toxic as the Black Widow because they are smaller-sized and transmit much smaller doses. The good news is that Brown Widows are extremely shy and prefer to flee from danger, rather than strike at the threat. Females protecting silky white egg sacs are most likely to bite since a retreat may cost them their eggs. Cornered or trapped spiders are also more apt to bite as a means of potential escape. Bites, though rare, are painful and victims would be wise to visit a medical professional in the uncommon case of a potential sensitivity to the venom.

Compared to other spiders in the Widow family, this is the least dangerous and most docile. They are becoming more abundant in places where humans tread. Silk webs can be built near houses, garages, sheds, parking lots and even gas stations. Despite the diminished risk of a bite, it is still wise to keep clear of the Brown Widow and leave it undisturbed. The Brown Widow bears a classic warning mark; it is best that we take heed.

Picture of the Brown Widow
Picture of the Brown Widow

Brown Widow Information

Category: Spider
Common Name: Brown Widow
Scientific Name: Latrodectus geometricus
Other Name(s): Grey Widow, Brown Black Widow, House Button Spider, Geometric Button Spider

Taxonomy Hierarchy

 Arrow graphic Kingdom: Animalia
  Arrow graphic Phylum: Arthropoda
   Arrow graphic Class: Arachnida
    Arrow graphic Order: Araneae
     Arrow graphic Family: Theridiidae
      Arrow graphic Genus: Latrodectus
       Arrow graphic Species: geometricus

Size, Identifying Tags and Territorial Reach

Size (Adult, Length): Size (Adult, Length): 3 mm to 17 mm (0.117 inches to 0.663 inches)
Identifying Colors: brown, black, orange, , yellow, ivory, gray
Additional Descriptors: hourglass, spot, biting, venomous, banded, striped

North American Territorial Reach (Though Not Limited To): Alabama; Arizona; California; Florida; Georgia; Louisiana; Mississippi; Texas; Mexico

A Note About Territorial Reach: Keep in mind that an insect's reach is not limited by lines drawn on a map and therefore species may appear in areas, regions and/or states beyond those listed above. Insects are driven by environmental factors, food supplies and mating patterns and do not nescessarily work within hard-and-fast territorial lines like we humans do.

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