The “Ray Spider,” Theridiosoma gemmosum, newly discovered in Kansas

Abstract

The diminutive ray spider, Theridiosoma gemmosum (L. Koch 1878) (Araneae: Theridiosomatidae), is a common, widespread species in eastern North America. In the United States, it has been recorded from Maine to Florida, westward into Minnesota, Iowa, Missouri and Alabama. It is restricted to damp habitats in mesic woodlands, such as stream banks, ravines, swamps and wet rock walls (Coddington 1986). Due to its small size (1.5 to 2.5 mm) and secretive habits, the presence of this species is usually made known by the discovery of the characteristic egg sacs. Scheffer (1905, p. 95-96) describes them as: ...among the most interesting to be found; little golden brown balls, about one eight inch in diameter, suspended by a single glossy white thread nearly an inch long. They are paper-like in texture and are attached to this stiff silken pedicle by a dilation of the latter in the form of a cone. At the time of hatching this little cone lifts up like a lid, adhering by merely a point of the circumfer ence and uncovering a small, circular hole through which the young escape. The pedicle itself usually hangs suspended from two or