Today at work, I had the chance of inspecting some glasshouses in the Thwaite Botanical Gardens of the University of Hull. They are heated glasshouses holding cacti, succulents, ferns and other plants from around the world. I was pleasingly surprised by the diversity of spiders in them. I found a single Woodlouse Spider, Dysdera crocata, under a bin (above). Quite fitting as we were collecting woodlouse for a practical on woodlouse diversity. The students were quite impressed!
 The first surprise was to find several Walnut Orb Weavers, Nuctenea umbratica. We dislodged an individual from a tree growing in a pot and it proceeded to play dead, legs drawn in, as they do when disturbed. They are usually nocturnal, spending the day in a crack in bark, but this large female I found later was sitting in the middle of her web, I wonder if the reason is it was a very dark, overcast day. There were many more smaller sized individuals, also sitting out in their webs, and it is quite likely this spider matures on her second year of age.

This is a small, but fascinating spider family. It comprises just 4 species of the genus Ero, two of them common and widespread.  They are small spiders, about 5 mm long, with globular abdomens, which have two or four tubercles. They have annulated legs, the first pair endowed with a series of spines.

Spider eaters
The Mimetidae are specialists in eating web-building spiders. Ero does not build a proper hunting web, it is a nomadic species which wanders in search of webs. Once found, she may invade the web, and then pluck it with her front legs. The owner might come to investigate, as it would do if an insect had fallen in, but then Ero will quickly grab and bite one of the spiders legs. The venom is quickly acting and then Ero will feed on the spider. In occasions the web owner might be able to escape minus a leg

Stalked egg sacs
Female pirate spiders produce characteristic egg sacs, which are more noticeable than the spiders themselves. They have a long stalk and are covered on coarse, brown wavy silk, presumable for protection, as the female takes no care of the egg sac or the spiderlings themselves.