tan jumping spider

not listed

NNR - Unranked

SNR - Unranked

not listed

Tan jumping spider is a small to medium-sized jumping spider. It occurs in the United States east of the Great Plains, in southern Ontario, Quebec, and Nova Scotia Canada, and in northwestern Mexico. It is found on foliage, on tree trunks under loose bark, on rocks and fences, in leaf litter, and on walls of buildings.

The female is ¼″ to 7⁄16″ (6.06 to 11.36 mm) in length and has a ½″ to ⅝″ (12 to 15 mm) legspan. The body is flattened vertically, which allows it to hide under loosebark.

The front part of the body (cephalothorax) is relatively flat, evenly rounded on the sides, and widest just beyond the last row of eyes. The upper side (carapace) is orangish-brown and is densely covered with white and reddish-brown hairs. On the sides the upper half is colored like the upper side, the lower half is blackish-brown. There are four pairs of eyes arranged in what appears to be three rows. The first row of four eyes, consisting of the anterior median eyes (AME) and anterior lateral eyes (ALE), is curved backward. The AME are the middle and forward-most pair of these. They are by far the largest of all of the eyes, almost twice as large as the ALE, and can be moved. There is a band of white hairs below and through the AME. The second row of two eyes are the posterior median eyes (PME). They are very small, one-third the size of the ALE, and are barely or not at all noticeable on most photos. Below each PME there is a pair of close tufts of long black hairs (hair pencils). The third row of eyes is the posterior lateral eyes (PLE). The PLE are set far back on the head and are only slightly wider apart than the first row of four eyes (AME and ALE together). The plate above the mouth (clypeus) is densely covered with gray and white hairs. The prominent mouthparts (chelicerae) corresponding to jaws are brown. There are two sensory appendages (palps) associated with the mouthparts. They are densely covered with white hairs.

The abdomen is oval, widest toward the front, and flattened vertically. The upper side is gray in the front and blackish-brown on the sides with a distinctive gray pattern in the middle.

The legs are short and mottled orangish-brown and blackish-brown. The sixth segment (metatarsus) is dark at both ends, pale between. The last segment (tarsus) is pale toward the base, dark toward the tip.

The male is smaller, ¼″ to ⅜″ (6.66 to 9.23 mm) in length. The band of hairs below and through the AME is reddish or orangish.

Female Body Length: ¼″ to 7⁄16″ (6.06 to 11.36 mm)

Male Body Length: ¼″ to ⅜″ (6.66 to 9.23 mm)

Legspan: ½″ to ⅝″ (12 to 15 mm)

Jumping spiders do not hunt from webs.

Eggs hatch in the summer. Adults hibernate in winter groups of fifty or more, each spider in its own silken sac, usually under the bark of a tree, sometimes under wood or a stone. The sacs are pressed tightly together forming a single silk blanket.

Sources

7, 24, 29, 30, 82.

Barnes, R. D. (1958). North American jumping spiders of the subfamily Marpissinae (Araneae, Salticidae). American Museum Novitates 1867: 1-50.

One of the biggest Jumping Spiders I have ever seen.

Platycryptus undatus

Platycryptus undatus, tan jumping spider, on the house next to Barnes Prairie, Racine Co., WI. Photo was taken on June 24, 2020.

found near the docks at a marina on the Mississippi.

Location: Saint Paul Park, MN

found near the docks at a marina on the Mississippi.

Location: Albany, NY

Location: Albany, NY

One of the biggest Jumping Spiders I have ever seen.

Location: Barnes Prairie, Racine Co., WI

Platycryptus undatus, tan jumping spider, on the house next to Barnes Prairie, Racine Co., WI. Photo was taken on June 24, 2020.