Evarcha improcera

Evarcha improcera is a small spider with a body divided into two main parts: cephalothorax and an abdomen. The female has a rather high and broad carapace, the hard upper part of the cephalothorax, that is typically 2.2 mm (0.09 in) long and 1.6 mm (0.06 in) wide. It is brownish-orange, scattered with fawn hairs, with a darker eye field. There are brown hairs and dark rings around the eyes themselves. The underside of the cephalothorax, or sternum, is yellowish. The spider's face, or clypeus, is yellow with a covering of light long hairs. The fawn chelicerae form part of the mouthparts, which also include yellowish labium and maxillae.^[5]

The female spider's oval abdomen is narrower than the carapace. It measures typically 1.8 mm (0.07 in) in length and 1.2 mm (0.05 in) in width. The top is generally dark brown with a whiteish-yellow pattern, which consists of a large patch at the front, a stripe down the middle that meets another stripe in a cross shape, the bottom arm of which consists of a series of closely tessellating wide chevrons, and small spots on the sides. The underside is light. The spider has brown spinnerets. Its legs are light yellow with long brown spines and a few brown hairs.^[5]

The spider has distinctive copulatory organs. The female has a large depression in the middle of its epigyne. The copulatory openings are mounted to the back and lead to simple insemination ducts. The spermathecae, or receptacles, are small and shaped like beans. The accessory glands are unusually positioned. This, and the size of the spermathecae are distinguishing features of the species.^[5][12] The male has not been described.^[1]

Evarcha spiders live across the world, although those found in North America may be accidental migrants.^[13] Evarcha improcera is endemic to Yemen.^[1] The female holotype was discovered in 1999 near Taiz.^[5]