Will you step into my parlour?
By Nutan
Shukla
WITH many species of spider, the
female is threateningly large in comparison with the
male, and may easily mistake him for a trapped insect and
proceed to eat him. So any male wanting to mate must
approach with utmost caution. Different species of spider
use different tactics. A male may frantically wave his
legs or his pedipalps (the sensory appendages on his
head), or he may tread carefully over the females
web using a complicated dance-like step to distinguish
himself from any other insect. Alternately, he may resort
to bribery and offer her an insect as a distracting
snack.
In the case of Pisaura mirabilis, during
breeding season these spiders scurry about in fresh green
vegetation in search of a female. As soon as they come
across her tracks or the signal thread that the female
drags behind her, they set off with new energy to hunt
for flies. When the male catches a fly, it immediately
starts entwining it in its cobweb until a white ball is
formed.
He carefully holds the
wrapped fly in his mouth and ceremoniously carries it in
its silken packet to the female. When he sees her, he
freezes in a bizarre, grotesque position, and then, very
courteously, presents his gift. He stands in front of the
female spider like an enigmatic and incomprehensible
sculpture at an art exhibition. The male rests on the
bottom of his vertically extended abdomen and on his six
legs. His fourth pair of legs are raised over the fly
packet that he is holding in his mouth.
The female spider, who
must be stunned by this unusual sight, slowly moves
towards him as if she cannot believe her eyes. She then
accepts the wedding gift, tears up the packet and starts
sucking on the fly. Should the male turn up without a
gift, he is in for it. The female will eat him up. But
spiders can also cheat. Some bridegrooms pack up the
remains of a fly carcass for their date. Some males are
even more clever. They carefully wrap up nothing at all
and give their female a large but completely empty cocoon
to unwrap. The wrapping is important because it takes a
female a long time to unravel it and get at her prize,
and while she is preoccupied the male has long enough to
mate without being eaten. With tactics like these, speedy
sex becomes the order of the day.
Male spiders employ even
more varied techniques to avoid being their own wedding
breakfast. Some males overcome this problem by making a
series of special visual signals from a respectful
distance. Others tap out a code of distinctive vibrations
on the females web, tweaking the threads in a
rhythm that lets her know that they are males and not
meals. Some males are more assertive and put the female
into a kind of hypnotic sleep by biting her in a special
way, or by tying her down with silken threads and then
mating with her when she is well wrapped up. Many of
these tactics work and the males live to mate another
day, but from time to time they fail and the female
satisfies her protein hunger by sucking her mate dry
an undeniably efficient way of giving her newly
fertilised eggs a nutritious start in life.
Tarantulas or
bird-eating spiders do not have good eyesight, so they
communicate by touch. When a tarantula male meets a
female, he signals his presence by using his front legs
to drum a tattoo on her body. She is alarmed, and raises
her front legs ready to strike. It takes a lit of
soothing and stroking from the male to calm her down.
At last she raises her
body and opens the lethal fangs that could finish him off
with a single bite. But he is not unprepared. He has
hooks on his front legs specially for holding her jaws
apart. Safe at last, the male inseminates the female and
then makes his retreat as quickly as possible.
In the above mentioned
cases it is one kind of cannibalistic tendency where
adults eat adults, but there are cases where adults are
eaten up by their offsprings. Once the life-giving and
protective roles of the adults have been completed, they
are still good for a meal. The female wall spider often
dies before her young are ready to leave their cocoon
nest. If this happens, they devour her body when they
finally emerge. In this way they are provided with an
easily obtained first breakfast before they set off to
explore the world. A similar occurrence has been observed
in certain sheet-web spiders too.
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