Cheiracanthium mildei
(Long-legged Sac Spider)

Featured spider picture The spider species Cheiracanthium mildei, commonly known as Long-legged Sac Spider, belongs to the genus Cheiracanthium, in the family Cheiracanthiidae. Cheiracanthium mildei spiders have been sighted 115 times by contributing members. Based on collected data, the geographic range for Cheiracanthium mildei includes 2 countries and 28 states in the United States. Cheiracanthium mildei is most often sighted indoors, and during the month of May.

Taxonomic Hierarchy

Kingdom: Animalia
Phylum: Arthropoda
Class: Arachnida
Order: Araneae
Suborder: Araneomorphae
Family: Cheiracanthiidae
Genus: Cheiracanthium
Species: Cheiracanthium mildei

Common Name (AAS)

Long-legged Sac Spider

Other Common Names

Sac Spider, Yellow Sac Spider, Black-footed Spider, Prowling Spider, Slender Sac Spider, Yellow House Spider

Author

Ludwig Carl Christian Koch, 1864

Primary Colors

Sightings Overview

There have been 115 confirmed sightings of Cheiracanthium mildei (Long-legged Sac Spider), with the most recent sighting submitted on December 4, 2023 by Spider ID member shutout. The detailed statistics below may not utilize the complete dataset of 115 sightings because of certain Cheiracanthium mildei sightings reporting incomplete data.

Web: 14% of the time, Cheiracanthium mildei spiders are sighted in a spider web (Sample size: 115)
Sex: 1 female and 33 male.
Environment: Cheiracanthium mildei has been sighted 3 times outdoors, and 112 times indoors.
Outdoors: Man-made structure (3).

Location and Range

Cheiracanthium mildei (Long-legged Sac Spider) has been sighted in the following countries: Canada, United States.

Cheiracanthium mildei has also been sighted in the following states: California, Colorado, Connecticut, Idaho, Illinois, Indiana, Kansas, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Nebraska, New Hampshire, New Jersey, New York, Ohio, Oklahoma, Oregon, Pennsylvania, Tennessee, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin.

Seasonality

Cheiracanthium mildei has been primarily sighted during the month of May.

January: 9
February: 5
March: 11
April: 26
May: 47
June: 4
July:
August:
September: 3
October: 7
November:
December: 3

Additional Remarks

General appearance almost the same as in the native species Cheiracanthium inclusum; the two should be separated only by microscope exam.
Historically, this spider has been implicated in necrotic bites, however, recent research has exonerated the species as a cause of necrotic wounds.
Cheiracanthium spiders are sometimes mistaken for brown recluses (Loxosceles reclusa) inside homes.
Typically most common inside homes and buildings, while our native North American species, Cheiracanthium inclusum, is found more often outdoors in fields and foliage.
The female usually encloses herself inside her egg sac and stands guard over the eggs until the spiderlings emerge.
Females probably mate only once, but they can create up to 5 egg sacs in their lifetime.
In March 2011, Mazda recalled approximately 50,000 cars (Mazda6) because this species of spider was building its retreats inside of fuel lines. At least that was the publicly-disclosed explanation.