About Wadicosa fidelis (O.Pickard-Cambridge, 1872)
Wadicosa fidelis is a medium-sized wolf spider that exhibits clear sexual dimorphism. Females are noticeably larger and more robust than males, reaching a total length of around 7.2 mm, while males measure 6.3–6.5 mm in total length. Females are also more densely covered in whitish hairs, giving them a somewhat fuzzy appearance, whereas males have less prominent pubescence.
Both sexes of Wadicosa fidelis have a blackish brown carapace. The carapace has a yellowish to dark greyish brown median field with jagged edges. Lateral bands are typically absent, or only visible as indistinct lighter spots when present. The abdomen has a pattern of yellowish spots and bars on a blackish background: it features a greyish yellow to blackish lanceolate stripe, followed by a series of 3–4 transverse yellowish bars posterior to this stripe. In females, these yellowish patches are more distinct, and each patch contains a dark dot with a long dark hair. The legs are yellowish brown with dark annulation.
Males can be distinguished by the distinctive structure of their pedipalps, specifically the tegular apophysis, which has an upper branch directed retrolaterad and a composite lower branch covered in numerous minute spinulae and verruciform outgrowths. The male embolus is long, with a rounded, non-sclerotized widening just before its tip. Females are characterized by the structure of their epigyne: the epigynal cavity is wider than it is long, and it is open posteriorly. The spermathecae are comparatively large, somewhat spherical, and positioned close to the midline. An elevated, triangular septum that tapers backwards is located in the central part of the epigynal cavity.
Wadicosa fidelis has been recorded from Macaronesia, North Africa, Southern Europe, Turkey, the Caucasus, the Middle East, Central Asia, China, Japan, Pakistan, India, Bhutan, Bangladesh, the Philippines, and Indonesia (Sumatra).
