Page 45 - The Miracle in the Spider

Spiders' Methods of Hunting 45

The Spitting Spider
The species of spider known as Scytodes kills its victims by squirting
a mixture of toxin and gluey substance over them. These liquids are
produced in an enormous gland behind the spider's eyes, which is
divided into two compartments: one contains a toxin, the other a gluey
substance. The spider contracts the muscles surrounding the latter and a
stream of glue is rapidly ejected from the animal's fangs. Sprayed out in a
zig zag pattern, the adhesive forms a net that fixes the prey to the leaf or
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twig it happens to be traversing. Then having immobilised its prey and
stuck it on to a branch or leaf, it can eat it later where it hangs.

Pasilobus' Trap

Pasilobus, only to be found in New Guinea, is a great expert at
preparing traps. The webs it spins are very sticky. The whole web is slung
between two fixed points. The knot at one end is very tight, but the one at
the other end is left quite loose. This is not a mistake, and is not a result
of the spider's not concentrating. That this is a hunting strategy can be
seen when the prey approaches. When a moth flies into the web, the loose
loop end becomes detached. Because the other end stays fastened, the
insect remains hanging like a bundle in the air. Later the spider
approaches it and sprays a sticky material all over it, starting from the
head. In this way the spider catches its prey alive.

This spider, which
purposefully builds its
nest on the top of sand
hills, springs out as
soon as a wild bee
begins to dig at its nest.
(Side picture) In order to
build up speed, the
spider first takes a few
steps, then, folding in its
five-jointed legs, it
moves quickly, like a
wheel rolling downhill.