This spider
looks very much like a very big and fat species
of the cosmopolitan genus Araneus, if you imagine
one with a bright orange abdomen sporting white
lumps and grey/green stripes. This spider is a
renegade in the sense that it does not spin an
orb web like the rest of the species that are
related to this family of spiders.
The Bolas spider is furthermore
unique as it will hang upside down from a twig
(using the fourth pair of legs to anchor itself
and, obviously, a dragline to avoid falling and
injuring itself) and hold a single thread of dry
silk with one or several huge drops of sticky
silk at its end (which is also attached to the
dragline) with one of its first pair of legs.
I've seen this a few dozen times
in many different documentaries over the years
(in Germany, Spain and the UK), but what I
remember most clearly about this is that this
spider does something no other spider seems to
do, it uses pheromones (chemical attractant /
perfume of the female of a specific species of
moth) to attract the male moths.
Like most spiders this is a
nocturnal species. The spider only has to hang on
its twig and wait, in the knowledge that many of
the male moths of the particular species it
mimics will fly towards her from several miles
around, attracted by the pheromone.
I do not know whether this has
been scientifically demonstrated (although I am
almost certain it has), but it seems a very
logical explanation, since there is no other way
of explaining the success this species has in
trapping male moths. A spider without the
pheromone trap would hardly get as fat as these
spiders do (and believe me, they get extremely
fat) by hanging from a twig and trapping the few
flying insects that come close enough to it (it
only can trap insects that fly up to around 5 or
7 cm near the spider I would say).
This spider is a native of West
and Eastern Africa. Size: Male to 5mm (hardly
ever seen), Female to 18mm.
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