Trachelas tranquillus
(Broad-faced Sac Spider)

Featured spider picture The spider species Trachelas tranquillus, commonly known as Broad-faced Sac Spider, belongs to the genus Trachelas, in the family Trachelidae. Trachelas tranquillus spiders have been sighted 6 times by contributing members. Based on collected data, the geographic range for Trachelas tranquillus includes 1 countries and 4 states in the United States. Trachelas tranquillus is most often sighted outdoors, and during the month of October.

Taxonomic Hierarchy

  • Kingdom: Animalia
  • Phylum: Arthropoda
  • Class: Arachnida
  • Order: Araneae
  • Suborder: Araneomorphae
  • Family: Trachelidae
  • Genus: Trachelas
  • Species: Trachelas tranquillus

Other Common Names

Broadfaced Sac Spider, Sac Spider, Bullheaded Sac Spider


Nicholas Marcellus Hentz, 1847

Primary Colors

Sightings Overview

There have been 6 confirmed sightings of Trachelas tranquillus (Broad-faced Sac Spider), with the most recent sighting submitted on January 20, 2018 by Spider ID member dani. The detailed statistics below may not utilize the complete dataset of 6 sightings because of certain Trachelas tranquillus sightings reporting incomplete data.

  • Web: 0% of the time, Trachelas tranquillus spiders are sighted in a spider web (Sample size: 1)
  • Sex: 4 female and 1 male.
  • Environment: Trachelas tranquillus has been sighted 1 times outdoors, and 0 times indoors.
  • Outdoors: Man-made structure (1).

Location and Range

Trachelas tranquillus (Broad-faced Sac Spider) has been sighted in the following countries: United States.

Trachelas tranquillus has also been sighted in the following states: Massachusetts, New Jersey, New York, Washington, D.C..


Trachelas tranquillus has been primarily sighted during the month of October.

  • January:
  • February:
  • March:
  • April:
  • May:
  • June:
  • July:
  • August:
  • September: 1
  • October: 4
  • November:
  • December:

Additional Remarks

  • Often found in silken retreats constructed in rolled-up leaves or occasionally under rocks.
  • Frequently strays indoors in late summer or fall during their mating season.
  • Egg sac is white and lenticular, around 10mm in diameter and 2.5mm thick, with around 30-50 eggs; often deposited under loose tree bark, rolled leaves, or under a rock.
  • Because of similar coloration, this species can be mistaken for the “Woodlouse Hunter,” Dysdera crocata. The Woodlouse Hunter can be distinguished by its very long jaws and fangs, as well as its unique eye arrangement: 6 eyes grouped closely in a semi-circle. Trachelas tranquillus has 8 eyes widely spaced.

Featured Pictures

Picture of Trachelas tranquillus (Broad-faced Sac Spider) - Dorsal Enlarge Picture
Picture of Trachelas tranquillus (Broad-faced Sac Spider) - Female - Dorsal Enlarge Picture
Picture of Trachelas tranquillus (Broad-faced Sac Spider) - Female - Ventral Enlarge Picture
Picture of Trachelas tranquillus (Broad-faced Sac Spider) - Female Enlarge Picture
Picture of Trachelas tranquillus (Broad-faced Sac Spider) - Male - Lateral Enlarge Picture
Picture of Trachelas tranquillus (Broad-faced Sac Spider) - Female - Lateral Enlarge Picture
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