Latrodectus variolus
(Northern Black Widow)

Featured spider picture The spider species Latrodectus variolus, commonly known as Northern Black Widow, belongs to the genus Latrodectus, in the family Theridiidae. Latrodectus variolus spiders have been sighted 15 times by contributing members. Based on collected data, the geographic range for Latrodectus variolus includes 1 countries and 8 states in the United States. Latrodectus variolus is most often sighted outdoors, and during the month of May.

Taxonomic Hierarchy

Kingdom: Animalia
Phylum: Arthropoda
Class: Arachnida
Order: Araneae
Suborder: Araneomorphae
Family: Theridiidae
Genus: Latrodectus
Species: Latrodectus variolus

Common Name (AAS)

Northern Black Widow

Other Common Names

Black Widow, Black Widow Spider, Widow Spider, Hourglass Spider, Shoe Button Spider, Cobweb Spider, Comb-footed Spider, Tangle-web Spider, Gumfoot-web Spider, Button Spider

Author

Charles Athanase Walckenaer, 1837

Primary Colors

Sightings Overview

There have been 15 confirmed sightings of Latrodectus variolus (Northern Black Widow), with the most recent sighting submitted on September 18, 2020 by Spider ID member arachno69. The detailed statistics below may not utilize the complete dataset of 15 sightings because of certain Latrodectus variolus sightings reporting incomplete data.

Web: 7% of the time, Latrodectus variolus spiders are sighted in a spider web (Sample size: 15)
Sex: 6 female and 6 male.
Environment: Latrodectus variolus has been sighted 25 times outdoors, and 3 times indoors.
Outdoors: Man-made structure (5). Low foliage (6). High foliage (2). Ground layer (6). Under rock or debris (4). Open field, pasture, grassland (1). Forest (1).

Location and Range

Latrodectus variolus (Northern Black Widow) has been sighted in the following countries: United States.

Latrodectus variolus has also been sighted in the following states: Arkansas, Georgia, Illinois, Maryland, Missouri, Pennsylvania, Rhode Island, Tennessee.

Seasonality

Latrodectus variolus has been primarily sighted during the month of May.

January:
February:
March:
April:
May: 7
June: 6
July: 1
August:
September: 1
October:
November:
December:

Additional Remarks

In adult females of this species, the red or orange hourglass-shaped marking on the underside of the abdomen is almost always divided (separated into two triangles that do not touch one another). Occasionally, a specimen may only have half of the marking (one triangle) or else none at all. However, males sometimes have a full hourglass marking, or one that is slightly connected in the middle.
Adult females typically retain red spots on the top (dorsal) side of their abdomen. Immature females may have red spots plus white lines, similar to the males.
This species tends to have larger adult males than Latrodectus mactans or L. hesperus.
This species is more common in the northern part of its range (eastern North America), but it still overlaps with Latrodectus mactans, especially in the southeastern states.
Egg sacs are white, tan, or grayish spherical or pear-shaped objects hung in the female’s web. They can contain anywhere from 100-400 eggs.
“Deadly” is a misnomer! Human deaths are extremely rare from a widow bite (or any other spider bite, for that matter). Anti-venom exists for treatment, but is rarely necessary; pain medication, muscle relaxers, and/or calcium gluconate are often all that’s needed.