Hasarius insularis

Hasarius spiders are medium-sized spiders.^[11] The spider's body is divided into two main parts: the cephalothorax and the abdomen. Hasarius insularis has a carapace, the hard upper part of the cephalothorax, that is typically 4.5 mm (0.18 in) long and 3.5 mm (0.14 in) wide. The carapace is rather high and is reddish-brown on top with a lighter brown area to the middle. It is covered in very short grey and brown hairs. The eye field is short and darker, with long bristles near the eyes themselves. The sternum, the underside of the cephalothorax, is yellowish. The mouthparts consist of dark brown chelicerae and lighter brown labium and maxilae that have pale tips. The spider has two teeth to the front and another bicuspid tooth to the rear.^[4]

The spider's abdomen is larger than its carapace, typically measuring 5.9 mm (0.23 in) in length and 3.9 mm (0.15 in) in width. The top is dark brown with an unusual yellowish pattern, clothed in brown and greyish hairs. The bottom is covered with dark dots and small patches. The spider's spinnerets are yellow. It has yellowish-brown legs, with brown leg hairs and spines, apart from the joints between segments, which are marked by dark rings.^[4]

The main determining feature for the species is its reproductive system. The epigyne has a notch at its rearmost edge and two rounded openings. The insemination ducts are relatively short, with narrow at their entrances and a wider section deeper in, and lead to spherical spermathecae.^[12] The walls of the spermathecae and insemination ducts are particularly thick, which distinguishes the spider from others in the genus.^[4] Otherwise, their shape is similar to the related Hasarius adansoni.^[3] The male has not been described.^[1]

Hasarius spiders can be found across many warmer countries across Africa and Asia, and have also been observed in greenhouses in cooler climates.^[2] Hasarius insularis is endemic to Yemen.^[1] The holotype was found near Mahfirhin on Socotra Island in 1999. Its island habitat is reflected in its specific name.^[4] It has not been found in other areas of the country.^[13][14]