Arachnids are not insects; they have four pairs of legs, no wings and no antennae. They have only two body regions.
There are about 640 species of spiders in the UK. Spiders are carnivorous and are unique in having a spinner near the hind end of the abdomen which produces silk. Some spiders spin webs which are used as snares. Some lie in wait for their prey and others actively hunt.
Harvestmen are closely related to, and easily confused with, spiders. In harvestmen the two parts of the body are broadly joined, whereas in the spiders the body is clearly divided into two parts joined by a narrow stalk. Harvestmen have only two eyes whereas spiders have six to eight.
Spiders and harvestmen are very efficient pest predators. However, they are very sensitive to pyrethroids. Both can be important for bird diets.
Comb-footed spiders (Theridiidae) Great variety of shapes and colours Most have abdominal pattern Legs have few spines Uses individual sticky catching threads or criss-cross strands on bushes or trees to trap prey Theridion mystaceum