4
Trust) which now has an impressive list of spiders,
including some species first recorded there as
new to the British Isles. Clearly careful study
pays off, and I have high hopes for the other
promising sites in Essex.
Recognising the need to assess the distribution
and status of Essex spiders, I would encourage
Field Club members to look more closely at this
group of animals simply for the variety in colour,
behaviour and evolutionary design they would find.
For instance, spiders have developed great
versatility in their use of silk. As a means
of catching prey the spider's web has taken
several different forms. Much has been written
on the instincts and behavioural responses
necessary for the garden spider Araneus diadematus
(see illustration) to make such a complex snare
as the orb web. But there are other, no less
effective web designs. The sheet web of the
house spider, hung in the corner of a shed,is familiar
to us all, and is constructed as a mass of trip-
wires for the fly incautious enough to land on it.
The "scaffold" web of the Theridiidae is designed
as an aerial maze which hinders insects very
efficiently if they are unlucky enough to fly into
it.
Many spiders are active hunters, stalking and
pouncing on their prey. When not hunting, these
species hide in cells made of silk, spun underneath
stones or in crevices. Many of the mouse-
coloured Clubionidae spin retreats on the underside
of leaves.
Female spiders use silk to protect their eggs.
Often this just takes the form of a cocoon
attached to the underside of a stone or tucked
away in a crevice, or slung in a web. Other
spiders carry their egg cocoons around with them.
The wolf spiders are immediately recognisable in