Questions for Discussion
How the complex mating behaviour pattern in dragonflies and
damselflies evolved?
There is still not known exactly why the dragonfly male have
two sets of reproduction organs and why they evolved such a complex mating
behaviour.
The secondary genitalia is used as the intromittent organ
during copulation and have similar function as the pedipalps of a male spiders
introduce sperm into females.
All predator males have a common problem - how to avoid being
eaten by the females before, during and after mating. To a female point of
view, there is benefit and no disadvantage to prey on the male unless the male
has contribution to bring up their offspring.
Male dragonflies and damselflies successfully solved this
problem by clasping the female with their anal appendages before, during and
after mating. We seldom see male eaten by female. This could be one of the
reasons that they evolved such such a complex mating behaviour.
Male spiders also solved this problem, although not as good as
the dragonflies, as we know male spider is still sometime eaten by female. Male
spiders evolved their pedipalps to hold their sperm so that they can run away a
bit more easier after mating.
Praying Mantids, the relatively young order compares with
spiders and dragonflies, did not have enough time to evolved a solution yet. So
praying mantids male is known to be eaten by female from time to time.
This could be the reason why some assassin bug species breed
parthenogentically, i.e., reproduce by female without mating. Some assassin bug
species male help to look after their youngs.
