In reality, the male dies accidentally. It’s just that when he finishes depositing the sperm in the female’s genitalia, he makes a sudden withdrawal and breaks his reproductive device (bulb). “It is not always that he loses the bulb, but when that happens, he dies due to the loss of a vital fluid: the hemolymph. It’s as if the spider died of hemorrhaging”, explains Paulo Goldoni, an arthropod specialist at the Butantan Institute.
Although it does not kill its mate, the black widow’s (Latrodectus mactans) killer reputation comes from the fact that it feeds on it after mating. The female does not mean any harm, she just takes advantage of her lover’s corpse to replace the energy spent in copulation.
DYING WITH PLEASURE
Despite her fame, the black widow is not to blame for the death of her sexual partner.
1. The mating ritual begins with the male making his appearance. He arrives softly and, with one of his paws, shakes the web. The gesture causes a vibration, which draws the female’s attention.
2. To increase the black widow’s interest, he throws web on her paws. The most exhibited ones cut pieces of the web and then remake it. The ritual can last until the female surrenders fully.
3. When she accepts her partner’s presence, the black widow allows him to climb on her. They stand facing each other, with him looking at her abdomen. Is that the copulatory bulb is in the head of the male, and the epigene (the female genitalia), in the lower part of the abdomen
4. The spiral bulb is introduced into the female genitalia to spread sperm. Shortly after fertilization, the female lays the eggs inside silk sacs built by her. “A black widow can have up to 40 young at a time”, reveals Goldoni
5. If it is pulled out abruptly, the bulb will break. When this happens, the male loses a lot of hemolymph, a blue liquid with a similar function to mammalian blood. It is not known whether this is due to carelessness or the intention of blocking rivals’ access to the female’s genitalia.
6. Death is so fast that there is no time to escape the web. When noticing a dead animal at home, the female takes advantage of the easy food and ruthlessly traces to replenish the energy spent on sex. Although there are cannibal spiders – this is not the case for the black widow – they usually eat other species.
DOMINANT
The female black widow is about three times the size of the male. An hourglass-shaped mole on the belly is a hallmark of the black widow and other species such as the yellow widow and the flamingo.
FAMILY DINNER
The crab spider, yes, deserves the fame of killer. In some cases, after copulation, the female wraps her lover in the web and keeps his remains to serve as the first meal for her young, about 60 days after mating.
USED, LOST
Each type of bee has a function. The queen lives to lay eggs, the workers produce honey and the drones fertilize the queens – but their life is not easy. After sex, the genital organ is trapped in the queen bee and breaks, leading the drone to death
LOSING MY HEAD
After having sex, the female praying mantis grabs her partner and eats him alive, most often starting with the head. The meal guarantees energy for her to build oothecae (place where she lays her eggs) that are more resistant and have a capacity for more eggs.
SEXUAL APPETITE
In the game of seduction of the red-backed spider (Latrodectushasselti), anything goes. To have sex, the male positions his abdomen close to his partner’s mouth, letting her eat him during the sexual act. This sacrifice occurs in 65% of matings of the species.
CONSULTANCY Paulo Goldoni and Vanessa Penna Gonçalves, researchers at the Butantan Institute
SOURCE Sexual Cannibalism in the Brown Widow Spider, by Michal Segoli, Ruthie Arieli, Petra Sierwald, Ally R. Harari and Yael Lubin