[2] As is commonly seen in honeybees, ants and certain spider species, a male may put all his energy into a single copulation, knowing that this will lower his overall fitness.
Type B are monogynous, worker-reproductive colonies where there is no queen, but rather there are gamergates, which are mated workers who take on a queen-like role.
[7] In this way, males of the redback spiders in a monogynous setting increase their chance of paternity by actually surrendering themselves to be cannibalized by the female.
The male can cause severe physical damage to themselves by breaking off their pedipalps in order to plug the genital opening of the female.
Males of Argiope bruennichi remove their pedipalp into the females and thus reduce the risk of sperm competition.
[8] In other cases, we see the casting off of other body parts such as the anterior legs in the golden orb spider when the male is attacked by an aggressive female.
When males make up a large majority of the population, the likelihood of finding multiple females is slim.
[1] From a male standpoint, evolutionary theory suggests that the focus of mating is to enhance paternity in order to produce viable offspring.
In this respect, the benefit for the female is that she will receive the chance to eat if she is hungry; the cost for the male is the loss of life to increase his paternity.
Males in species of the golden orb weaver, for instance, can protect their paternity by obstructing the female's genital openings with fragments of their copulatory organs.
In these circumstances, selection may favor extreme mechanisms of paternity protection that amount to a maximal investment in a single mating.
Researchers have focused on sexual behaviour in systems where males have low paternal investment but frequently mate only once in their lifetimes, after which they are often killed by the female.
[1] Researchers have focused on species of web-building spiders with males that show high levels of non-promiscuous mating effort but apparently low paternal investment.
The mechanism of male monogamy (monogyny) in these species is indisputably the most extreme form of non-promiscuous mating effort.