These spiders are a bit unusual: females have two receptacles for storing sperm, and males have two sperm-delivery devices, called palps. Ordinarily the female will only allow the male to insert one palp at a time, but sometimes a male manages to force a copulation with a juvenile female, during which he inserts both of his palps into the female’s separate sperm-storage organs. If the male succeeds, something strange happens to him: his heart spontaneously stops beating and he dies in flagrante. This may be the ultimate mate-guarding tactic: because the male’s copulatory organs are inflated, it is harder for the female (or any other male) to dislodge the dead male, meaning that his lifeless body acts as a very effective mating plug. In species where males aren’t prepared to go to such great lengths to ensure that they sire the offspring, then the uncertainty over whether the offspring are definitely his acts as a powerful evolutionary disincentive to provide costly parental care for them.
On the mating habits of the orb-weaving spider:
Source: “The Social Instinct” by Nichola Raihani.
That’s fascinating. Which spiders are those?
The orb-weaving spider. I updated my original post to include the name.
Thanks :)