Environmental Engineering Reference
In-Depth Information
FIG
162.
Herald moth, a species particularly associated with caves and often seen in the threshold zone. (Harold
Grenfell)
Another characteristic animal of the threshold zone is the large orb-web cave spider
Meta menardi
,
which occupies the deeper part of cave entrances, trapping insects on their way in and out. It has only
been officially recorded in Worms Head Cave, but as it is widely distributed elsewhere in South Wales it
is likely to be present in many of the Gower caves. It feeds on virtually any prey and catches both flying
and crawling invertebrates, feeding on woodlice and millipedes, among other animals. Spider eggs are
roughly spherical and about 1 millimetre in diameter, being laid in a compact mass and covered with silk
to form a sac. The number of eggs laid depends on the size of the female, with larger cave spiders laying
