sex and incest in the insect world
mates male and female crickets
who mate with two males can choose between their sperm
to avoid having their brothers' offspring, according to
a new study by researchers Dr Tom Tregenza and Dr Nina
scientists believe that females mate repeatedly as a way
of choosing between males, and are able to recognise and
avoid using sperm from their relatives. Carrying out tests
with crickets, they showed that when females mated only
with their brothers, many of their eggs failed to hatch.
When they mated with both a brother and an unrelated male,
their eggs were as viable as when mating with unrelated
Tregenza said: "Because incest is a risk in many species,
it is likely that crickets are not alone in this ability
to use promiscuity to their advantage.
don't yet know how females avoid using their brothers'
sperm. They may be able to avoid taking up any of the
sperm packet passed to them at mating, if they recognise
the male is a brother, or receptors inside the female
may detect sperm from related males and avoid using it."
Nina Wedell said: "The reasons why females mate with lots
of males is a major issue for evolutionary biology. Female
mating behaviour has broad implications for understanding
competition between males, mate choice and why males produce
millions of sperm. It may also be important for issues
such as human infertility and animal breeding."