Scotophaeus blackwalli
(Mouse Spider)

Featured spider picture The spider species Scotophaeus blackwalli, commonly known as Mouse Spider, belongs to the genus Scotophaeus, in the family Gnaphosidae. Scotophaeus blackwalli spiders have been sighted 32 times by contributing members. Based on collected data, the geographic range for Scotophaeus blackwalli includes 3 countries and 3 states in the United States. Scotophaeus blackwalli is most often sighted indoors, and during the month of May.

Taxonomic Hierarchy

Kingdom: Animalia
Phylum: Arthropoda
Class: Arachnida
Order: Araneae
Suborder: Araneomorphae
Family: Gnaphosidae
Genus: Scotophaeus
Species: Scotophaeus blackwalli

Other Common Names

Mouse Spider, Stealthy Ground Spider, Ground Spider

Author

Tamerlan Thorell, 1871

Primary Colors

Sightings Overview

There have been 32 confirmed sightings of Scotophaeus blackwalli (Mouse Spider), with the most recent sighting submitted on October 26, 2019 by Spider ID member mamawnanna. The detailed statistics below may not utilize the complete dataset of 32 sightings because of certain Scotophaeus blackwalli sightings reporting incomplete data.

Web: 6% of the time, Scotophaeus blackwalli spiders are sighted in a spider web (Sample size: 32)
Sex: 0 female and 0 male.
Environment: Scotophaeus blackwalli has been sighted 7 times outdoors, and 25 times indoors.
Outdoors: Man-made structure (7).

Location and Range

Scotophaeus blackwalli (Mouse Spider) has been sighted in the following countries: Ireland, United Kingdom, United States.

Scotophaeus blackwalli has also been sighted in the following states: California, Oregon, Washington.

Seasonality

Scotophaeus blackwalli has been primarily sighted during the month of May.

January:
February: 1
March: 2
April: 8
May: 16
June: 3
July: 1
August:
September:
October: 1
November:
December:

Additional Remarks

Important note: there are dangerously venomous mygalomorph (primitive) spiders in the genus Missulena, family Actinopodidae, that are also nicknamed “Mouse Spiders.” They are found in Australia and one species in Chile and, aside from also being spiders, don’t have much in common with the relatively innocuous Scotophaeus blackwalli.
The abdomen appears velvety and soft, and the spider often runs in quick “starts-and-stops,” similar to a mouse along the perimeter of a room; this is likely where the nickname “Mouse Spider” comes from.
Spider is fast, agile, and difficult to catch, let alone photograph.
Female chooses a safe, dark place to deposit her eggs and builds a silken “chamber” around herself. Within the chamber, she attaches a thin disc of silk to a flat surface. She then deposits her eggs onto the center of it and finishes off by covering them all with a thicker layer of silk about 10-12 millimeters in diameter. Contains anywhere from 50-130 eggs.
Sometimes scavenges already dead insects. The British naturalist and arachnologist, W. S. Bristowe, remarked that he knew of several cases where lepidopterists had caught the spiders eating their pinned specimens during the night (Bristowe 1958).