A Walnut orb weaver

It's not every day I find a new species of spider in the garden, so I was pleased this afternoon, when opening the garden gate I disturbed a young Walnut orb weaver, Nuctenea umbratica (above). It crawled up and hid in a crack between the planks of wood. This is a large and distinctive species, the females can reach 14 mm.
umbratica means 'of the shadows' in latin, which refers to their liking for dark cracks and crevices, where they hide during the day, aided by their wide and flattened abdomen. When discovered, they are often crouching in a characteristic position, which is the only explanation I can see to another common name: 'toad spider'. They can be very dark, almost all black, but this individual shows the wavy leaf-shape pattern on the abdomen, surrounded by a pale rim and pinkish sides with annulated legs. They like dry microhabitats, including wooden structures, like fence posts, dead wood, window frames (e.g. in birdwatching hides), greenhouses, and cliffs. They are mostly nocturnal, they emerge as it gets dark and make their stout, large orb web, of a similar shape to that of its relative Araneus diadematus, although they can also sit on their web during the day. Their tattered webs can be useful to detect the spider when found in suitable habitats during the day.
 Males peak in July and August, while females are found year round. I wonder if being a very large spider, like the garden spider Araneus diadematus, females may take two years to reach maturity.
Although I might have overlooked it due to its retiring habits, I keep finding it more often in recent years.

Adult N. umbratica in a window frame of a hide. (11/7/16, Tophill Low)

One of several N. umbratica adult female inside bird hide (11/10/15) Alkborough Flats.

A fresh egg sac found inside the same hide with several N. umbratica. It looks very similar in colour, shape and size to an Araneus diadematus egg sac.

An adult female N. umbratica sitting on her web during a dark November day inside a greenhouse (Thwaite Botanical Gardens, 3/11/15).

Spiders in glasshouses

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.

Mature female Nuctenea umbratica.

A student pointed this female Tegenaria to me, she found under a tarpaulin.

A mature, gravid Araneus diadematus sitting on her web.

This was the second nice surprise. One of the glasshouses held a healthy population of Garden Centre spiders, Uloborus plumipes.

By the toilets, a number of Pholcus phalangioides.

Where there are windows, there are window-frame spiders, Zygiella x-notata. 

I found a single Ero sp. egg sac. These spiders abandon their characteristic egg sacs, and they are not the easiest to find.

On a window ledged, a female Araneus diadematus looking like it has seen better days. Its abdomen shrivelled. Her days are counted after she lays her eggs and weaves her egg sac.