Spiders are terrestrial arthropods and like all arthropods, they are invertebrate animals with an exoskeleton – a segmented body with jointed appendages.
Crabs, lobsters, scorpions and all insects are arthropods. What distinguishes spiders from other arthropods is the fact that they have eight legs and can inject poison.
Over 40,000 species of spiders have been identified. It is believed that between 200 and 500 species are found on our islands although they have not yet been studied properly and much work still needs to be done before we get a good picture of the species living here.
Spiders are found in nearly every habitat, with the exception of the sea and air. They are also found in every continent except Antarctica.
The close proximity of spiders to man has spawned a rich spider folklore including myths, tales and beliefs. Spiders have also inspired comic books and films. A classic example is the story of Spider-Man in which Peter Parker is bitten by a radioactive spider and acquires abilities normally associated with the insect, such as the ability to scale buildings and to shoot a web fluid from two boxes attached to his wrists.In many parts of the world spiders evoke fear. Taken to an extreme, the fear turns into a phobia, known as arachnophobia. Many Maltese have a phobia for the American cockroach (wirdiena) but I do not know anyone who is afraid of spiders locally.
In spiders the fluid is produced by an organ known as a spinneret, a complex structure consisting of several orifices each of which can produce one filament. Each filament is then combined with the filaments produced from the other orifices to create a very strong silk thread.
This silk thread has various uses: many species build sticky webs to trap insects while others trap their prey by running around them. A number of species hunt by making bolas which they throw at their prey.
Spiders are often abhorred because their webs are considered dirty. But spiders can be very effective non-polluting agents of insect control and it would be a good idea to allow them to set up home in houses. This article was published in The Times on 23 January 2013.