Savory - Arachnida 1977

30
Economic Arachnology
The Arachnida, mites obviously excepted, are not animals that have
attracted attention because of their evident economic importance.
Indeed, it is possible to argue that the relative neglect from which they
have suffered is due to this fact. Spiders in particular, the commonest
and most obvious of the Arachnida, seem to do little direct damage
beyond that of nuisance and are of little apparent value. Of the rest,
scorpions in certain countries are poisonous or are at least an irritation,
but the others are inconspicuous. As far as can be seen, every one of the
Solifugae, Palpigradi, Opiliones, Pseudoscorpiones and Ricinulei might
be simultaneously obliterated without any immediate effect on prices in
the world's markets.
This, however, takes a narrow view of economic importance, limiting
that term only to such creatures as may be described as damaging pests
or obvious beneficial forms. \Vhen spiders catch flies, as they do in vast
numbers, and when the other Arachnida capture whatever their prey
may be, they are, one and all, playing their parts in the universal drama
of life. They operate within the balance of nature and to this extent
each one is important. For we know, only too well, how surprising may
be the consequences when either thoughtless acts of men or natural
cataclysmic events disturb this equilibrium, and how the accidental
removal of some natural enemy may be followed by the almost unlimited
increase of a pest species until subsequent happenings limit its
reproduction and the balance is restored.
Recent studies have demonstrated that spiders feed upon, and may
be capable of regulating, household pests, field crop pests, orchard
pests and forest pests. Riechert has stated "Spiders clearly serve as
stabilizing agents of invertebrate populations both in natural habitats
and in the monotypic areas associated with agricultural lands".
\Vho is to say that the same may not be true for those scorpions and
Solifugae that feed gluttonously on termites, and pseudoscorpions that
feed on Collembola and Psocoptera? Even the long-legged harvestman,