You’re watching a video of a needle piercing an anonymous hand, sinking slowly into the web between the thumb and index finger. You wince as you imagine the pain that the other person must feel, and for good reason. As you watch, you nervous system essentially duplicates the experience, responding as if you were vicariously feeling the pain yourself. This is typical of what happens when people see others in pain, but Italian scientist Alessio Avenanti has found an important exception to the rule. Racial bias can negate this ability to feel the pain of someone from a different ethnic group.
The courtship rituals of the spider Harpactea sadistica start innocently enough, with a dance and a hug. The male spider taps the female gently with his front legs and embraces her. But from that point onwards, things for the female go rapidly downhill. The male bites her and she becomes passive, allowing him to manoeuvre her into position. Like all spiders, his genitals are found next to his head, on a pair of appendages called the pedipalps. But unusually, his penis ends in a needle-sharp tip called an embolus.
The embolus sits at the end of a loop called the conductor. The male hooks one of these loops around the opposite embolus to steady it. Then, by rotating the anchored needle, he drives the point straight through the female’s underside and ejaculates directly into her body cavity. On average, he does this six times, moving slowly downwards and alternating between his two penises. The entire cringeworthy sequence lasts about 15 minutes and throughout it, the male spider never penetrates the female’s actual genital opening.
The species was discovered in Israel last year by Milan Rezac from the Crop Rsearch Institute in the Czech Republic. He named it well. H.sadistica practices a style of sex that’s understandably known as “traumatic insemination“. It’s disturbingly common among insects and other invertebrates, and is most famously practiced by bedbugs. But this is the first time that the behaviour’s been seen among the chelicerates – the group of animals that includes spiders, scorpions and mites.
You can see it happening in the videos below. In the first, the male spider bites and incapacitates the female. In the second, he hooks the conductor of one pedipalp around the embolus of another and, with rotating motions, drives it into the female. These videos aren’t pretty – you’ve been warned.