Platycryptus undatus, also called tan jumping spider, is a species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of jumping spider

Jumping spider

The jumping spider family contains more than 500 described genera and about 5,000 described species, making it the largest family of spiders with about 13% of all species. Jumping spiders have some of the best vision among invertebrates and use it in courtship, hunting and navigation...

.

Distribution

Platycryptus undatus occurs in North

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 and Central America

Central America

Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...

. The distribution of this species ranges from the Eastern States and adjacent Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

, to Texas

Texas

Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

 and Wisconsin

Wisconsin

Wisconsin is a U.S. state located in the north-central United States and is part of the Midwest. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. Wisconsin's capital is...

. Females of this species are between 10 and 13 mm in body length, and males range from 8.5 to 9.5 mm. Like some other species of jumping spider, this species appears to exhibit curiosity towards humans who come into its visual field (jumping spiders all have very good vision.) It favors vertical surfaces such as fences, walls, etc and because of its habits it is easily seen. It does not frantically flee humans and may be gently "herded" onto a hand, where it may make a thorough exploration and even jump from finger to finger. These spiders are not at all inclined to bite, but even though they are rather small they can deliver a defensive bite if they are pinched or squeezed.

Eggs are laid and hatch during the summer, and adults and other stages overwinter in their individual silken shelters. Although the shelters are built separately and keep the spiders out of direct contact with each other, Kaston reports that as many as fifty of them may crowd their shelters for hibernation together so tightly that they form a continuous blanket under the loose bark of a standing tree.

Physical characteristics

The bodies of these spiders are rather compressed in the vertical direction, which allows them to hide themselves under the loosened bark of trees and in other tight places. They have a prominent pattern on their abdomens which may make them more difficult to distinguish on mottled surfaces.

External links

• Picture of P. undatus (free for noncommercial use)
• Good information on spiders' lifestyles from the University of Kansas.
• Lucian K. Ross: A jumping spider feeding on an earthworm. Peckhamia, 71, 1, S. 1-2, September 2008 PDF