European Cave Spider

Spider

The European Cave Spider (Meta menardi) is not so much rare as rarely seen.

The adult spiders are repelled by light, and choose to live in dark places such as caves and disused mine tunnels, where people seldom go.

At Dolaucothi, where we regularly visit such places, we are practically on first name terms with some of these harmless, but rather impressive, creatures!

The underground workings of the old goldmines make an ideal habitat for the spiders, but their camouflage (being dark brown and black, the same as the shale rock) means they are quite tricky to spot. They are there, however, high up in the darkest corners of the adits and galleries, sitting on their finely woven, flat, round webs, waiting for unwary prey. The webs are not sticky, but they can have 'trip wires' on the outer edges to alert the spider to the presence of its next meal!

Cave Spiders enjoy a diet ranging from flies to woodlice, millipedes to slugs (Note: No people!!) In times of plenty, the spiders will eat till they are very full, and secure any remaining food in their web for later.

Meta menardi is most visible when nesting and we are privileged to have watched the progress of many a new generation of spiderlings preparing to hatch from their tear-drop shaped nests.

Despite the adult spiders' aversion to light, the nests, which are masterpieces of construction, will often be located nearer to a light source, e.g. at the mine entrances. This choice of location seems confusing, but it's all about the little'uns! When the spiderlings hatch, they are instinctively attracted to the light, so they will disperse and colonise different areas away from the parents.

Look out for Meta menardi on your guided tour, and remember that she is not alone. The dark, damp mines support a surprising variety of wildlife. What else will you spot?!