The entomologists from Czech Republic have spotted male spiders in the Judean foothills of Israel indulging in violent, sadistic, but evolutionarily effective sexual activity, involving direct fertilization of eggs in the ovaries. The researchers have reported that they have noted the peculiar mating technique of the male spiders of Harpactea sadistica species, which mate through piercing the abdomen of females and fertilizing their eggs directly into their ovaries.

Milan Rezac, entomologist at the Crop Research Institute in Prague in the Czech Republic, has claimed that he and his team of researchers have discovered peculiar mating technique in the male spiders of Harpactea sadistica species.  

According to the researchers, the so-called traumatic insemination, in males of the Harpactea sadistica species, is the mating technique that bypasses the structures in the females’ genitalia. This way of mating has been already noted in mites and bedbugs, but it has been first time seen in spiders.

In his report, Rezac has reported that normally male spiders pass their genetic material through sperm, which is deposited into a small web and manually inserted via a pair of appendages on their undersides known as pedipalps. Then, the sperm are held in a receptacle between the ovipore and ovary, known as a spermatheca, till the release of an egg.

But, the male spiders of Harpactea sadistica species deliver sperm directly to the ovaries through holes that the males drill directly in the females’ abdomens. The H. sadistica species male spiders have specialized sex organs at the ends of its pedipalps, with one part specialised for gripping and another, hypodermic needle-like structure for injecting sperm. The study has been reported in Proceedings of the Royal Society B.