eastern parson spider

not listed

NNR - Unranked

not listed

Eastern parson spider is a common, small to medium-sized, ground spider. It occurs in the United States and southern Canada east of the Rocky Mountains and in Mexico. It is common in Minnesota. It is found in deciduous forests and woodlands on the ground under stones and logs. It is also found in buildings.

The female is ¼″ to ⅜″ (6.6 to 9.0 mm) in length and has a ½″ to 1″ (12 to 25 mm) legspan. The body is very dark, appearing black at first glance, with distinctive white markings that are said to resemble the vestments of a parson. This is the feature that gives the spider its common name.

The front part of the body (cephalothorax) is oval and longer than wide but shorter than the abdomen. The upper side (carapace) is dark blackish-brown with a broad, white, longitudinal stripe in the middle (middorsal). It is covered with short, dark, recumbent hairs. There are eight eyes in two rows of four each. Both rows are nearly straight. When viewed from the front, the front (anterior) row is slightly curved forward and the rear (posterior) row is slightly curved backward. When viewed from above, the anterior row is slightly curved backward and the posterior row is straight. The eyes in each row are evenly spaced. The anterior median eyes (AME) are dark, circular, and larger than all of the others. The posterior median eyes (PME) are oval, angled, and a little smaller than the posterior lateral eyes (PLE). The jaws (chelicerae) are brown. They have three or four teeth on the forward facing margin and a single small tooth on the rearward facing margin. The underside of the cephalothorax is orange mottled with brown, and is covered with long erect hairs.

The abdomen is long and slightly flattened. The upper side is dark gray to dark brown and is covered with silky gray hairs. There is a broad white or pinkish longitudinal stripe on the basal two-thirds and a white or pinkish spot at the rear. The stripe is slightly narrowed near the one-third point, abruptly and sharply narrowed at the two-thirds point, and broadly crescent shaped at the rear. The front silk-spinning organs (spinnerets) at the rear of the abdomen are long, cylinder-shaped, and visible from above.

The legs are stout, medium long, nearly equal in length, and spiny. The fourth segment (femur) is the same color as the carapace. The remaining segments are brown, sometimes appearing black due to a dense covering of black hairs. There are two claws at the end of each leg, but these cannot be seen without magnification.

The male is similar but much smaller, 3 ⁄16″ to ¼″ (4.6 to 6.1 mm) in length.

Female Body Length: ¼″ to ⅜″ (6.6 to 9.0 mm)

Male Body Length: 3 ⁄16″ to ¼″ (4.6 to 6.1 mm)

Legspan: ½″ to 1″ (12 to 25 mm)

A silken tube-shaped retreat is made under a rock where the spider will stay during the day, but no hunting web is constructed.

Western parson spider (Herpyllus propinquus) is identical in appearance and can be distinguished only by examining the male genitalia under a microscope. Its range does not extend into Minnesota.

Deciduous forests and woodlands, buildings

April to October

Adults hunt at night and spend the day in a silken retreat. They move very fast.

Young spiders overwinter in a silken cocoon under bark. Adults also overwinter.

Sources

24, 29, 30, 82.

Platnick, N. I. & Shadab, M. U. (1977b). A revision of the spider genera Herpyllus and Scotophaeus (Araneae, Gnaphosidae) in North America. Bulletin of the American Museum of Natural History 159: 1-44.

Common

I found the spider on my wall in the bathroom.

Male

Location: Otsego, MN

I found the spider on my wall in the bathroom.

Location: Milaca, MN

Male