Harpactea sadistica is a species of dysderine spider, found only in Israel. It was first described in 2008.
The species name refers to the seemingly sadistic habit of stabbing the body cavity of the female.
Both sexes have the same body characteristics. The length of the pale yellow-brown, smooth carapace ranges from 1.1 to 1.7 mm. The legs are pale yellow, with the first two pairs darker than the other two. The cylindrical, whitish opisthosoma is 2.3 mm long in the holotype specimen. The tip of the embolus of the male resembles the tip of a hypodermic needle, and the vulva of the female is atrophied.
Harpactea sadistica probably exhibits an annual lifecycle. Eggs are laid from March to April. The species is found in woodlands dominated by Quercus calliprinos and pine plantations, and in steppe habitats where Asphodelus is predominant.
