My conservatory spiders

The sun has been shining for a couple of days and it was warm enough that I started taking plants out of the conservatory into the garden and having a little tidying up. While doing this, I found a few spiders. Many were very tiny, very young individuals that I was unable to photograph properly and identify. Others were quite impressive. They have survived the winter in the dry, not too cold environment of the conservatory.
 First up, a Steatoda bipunctata, a false widow spider, which was on the side of a pot, a fully grown female. It has a very tick-like appearance, especially when it drops and tucks its legs in.

In between the bags of compost, I noticed the sheet webs of a Tegenaria. Here she is a bit camera shy, but shows her pretty abdominal patterns.

A few cob-webs came out of a corner, and then a Pholcus phalangioides ambled around trying to settle again.

This slim, fast and jumpy male Clubiona which I call black-face (possibly C. terrestris, but pedipalp examination is needed to confirm species) also featured on the top shot, fell from the foliage of a pot plant.

Finally, a Pardosa wolf spider on the window frame. There are dozens of young pardosa that have overwintered outside and sunbathe in loose groups on tiles and stones just outside the conservatory. This one got in through the crack of the window.

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.

Agelenidae: funnel weaver spiders

The agelenidae comprises 11 species in three genera, the best known, Tegenaria, or house spiders, includes several species difficult to identify without microscopic examination, and some that hybridise, further complicating identification. They weave sheet webs ending in a funnel. The spiders of this family, in particular house spiders appear to elicit fear or disgust in many people. Even William Bristowe, passionate arachnologist, confessed his 'horror' of the house spiders. The male's habit of rapidly running across the floor in the night, or appearing in the bath in the morning doesn't gain them any friends. Their amazingly long, hairy legs and large size doesn't make them endearing either. 

Males on the prowl

Tegenaria males mature in summer and autumn at two years of age and it is at this time of the year that them, which would have been living unobtrusively, in the corner of a room or behind a counter in the kitchen, leave their webs in search of females. They are most likely to be encountered then, either running across the floor a night or, in the morning, having fell into a bath from which they cannot escape. When a male meets an immature female he will stay on her web, waiting for her to mature and eventually mating with her. She accepts the male in her web and after more mating, the male will die.

A male Tegenaria sp. in the bath.

A Tegenaria moving across the floor.

Maternal spider

Female Tegenaria will lay several batches of eggs in spring in eggs sacs decorated with soil, debris or remains of prey. The spiderlings remain on their mothers web for a few weeks until ready to disperse. Read more about this topic in this post at Bugblog.

A female Tegenaria by her sheet web.

Tegenaria on her sheet web on ivy. I enticed her out of her retreat with some water spray.

A male Tegenaria, probably a T. gigantea x saeva hybrid. Males are slimmer and have longer legs than females. The modified male palps, used during mating, are visible in this photo and in the top photo of the same male.

A spider safari

Today for 30 days wild we did a spider safari. Any day is as good as the next for spiders if you ask me, but I am aware there are many people either fearful or wary of spiders. If you are in either of those categories, thank you for reading on, I hope that at the end of the post you look at them for the wonderful and diverse group they are and by understanding them better you might keep a certain level of respect for them, but enjoy them more. All the photos were taken today.
 My daughter found a large cluster of Garden Orb Spider Araneus diadematus spiderlings in between two pots (above). These spiderlings balls are now everywhere (even on my car!). Once they hatch from their silky cocoon, they will stay in a tight ball for a few days in a communal web. After they moult they will disperse to make their individual webs and start catching tiny insects, mostly aphids.
 There are two age groups of Araneus in the garden now. The tiny newborn spiderlings and the year old spiders which have survived the winter and are not mature. This large male has built its web in a flowering sage with is always busy with insects.

Male Araneus diadematus on his web.

A male Philodromus aureolus

 We also found this lovely spider crawling on a hedge, on our way back from school. Males of some crab spiders have iridescent scales on their bodies. I think this is Philodromus aureolus. After failing to take a photos where it was as it was quite mobile, I potted it to photograph at home. Shortly after I released him in the garden I found another individual on ivy, and what could possibly be the female of the same species (below). Crab spiders don't build webs, instead sitting on leaves or flowers to ambush flying insects that stop to bask or feed on the flowers.There are several common Philodromus species, and without microscopic examination of their genitals (or palps in the case of males) identification to species is not possible, which is sadly true for many species of spider.

A female Philodromus sp.

 I searched on some bare ground in the garden and didn't take long to find a wolf spider, a Pardosa, (probably amentata). Wolf spiders don't build webs either, but they move about searching for insects, although they also do quite a lot of basking on sunny spots on the ground. As they don't have a 'home' females carry their egg sacs with them attached to their abdomen, which you can see in the photo below. This photo also illustrates the maternal behaviour of spiders: many species build a cocoon for their eggs, which they attach to a dry corner, or carry the egg sacs with them, or the spiderlings (wolf spiders do this!) or even feed the spiderligs with eggs, regurgitated prey or especial eggs. The most extreme form of maternal behaviour is matriphagy, in which the mother allows the spiderlings to eat her, and eventually kill her.

Female wolf spider, Pardosa sp., with her egg sac.

 Another favourite place for spiders is the log pile. I removed a few logs and found a Blue Lace Spider, Amaurobius similis. A spider that forms a very characteristic form of carded silk and can be found on crevices on walls or trunks or on thick ivy. Amaurobius is one of the bunch of species in which females sacrifice themselves to their first batch of spiderlings, a matriphagous species.

Amaurobius similis. 

 And a few logs later a large female House Spider, Tegenaria sp. House spiders built sheet webs funnelling into corners, where they have a retreat. When potential prey lands on the sheet they come out and trap them. You can entice them to come out by spraying some water on the sheet web. If you see a large spider with long legs in the autumn running around on your living room carpet, or you find one in the bath in the morning they are likely to be a male Tegenaria. They have abandoned their retreats and go about searching for mature females to mate.

Female Tegenaria sp.

 Then it was time to go inside. I have a thriving Pholcus phalangiodes (known as Daddy Long Leg spiders) population in the house. They hang from corners in the ceiling, not moving much. This mature female, which lives under a shelf in the toilet, with her distended abdomen, looks ready to lay her eggs. She will wrap them loosely with silk and carry them in her mouth until they hatch. Then she will sit by her spiderlings for two weeks (presumably not eating anything during this time). Despite their spindly appearance, Pholcus are fearsome predators, capable of subduing much larger and stronger spiders by wrapping them in silk with their long legs.

Pholcus phalangioides, mature female.

Do adult female house spiders roam?

As you gather from my last post, it is quite common to come across adult male house spiders, Tegenaria, roaming in search for females in late summer and autumn. Females are supposed to wait for them at the bottom of their web funnels. I was puzzled to find this fully grown, beautiful female inspecting my cat scratching post, in the open, an hour ago. Do females roam too?

Spider portraiture

It is quite flattering that several people have congratulated me over the years on the invertebrate photos I feature in BugBlog, thank you guys! I don't claim to be a photographer, but I am happy to share a few tips on the white bowl technique, which I regularly use on critters found around the house and garden, especially on non-flying ones. As today I found the first male house spider, Tegenaria sp., of the season, I thought a post on this topic was timely.
Before my daughter finished saying 'spider!' I got the little beast running across the kitchen floor into a little plastic pot. For this, I save any little plastic pot I come across. You know the onion salad pot from an indian takeaway? ideal! To hold the bug for a few minutes the pot does not even need to have holes on the top. I also have a 'proper' bug viewing pot (like the one featured in the photos below). My bug pots are always available on the side of the kitchen and I always carry one in my bag.
The second piece of equipment is the bowl. A flat-bottomed white bowl, like those used for soup, is ideal, as its sides help reflect the light. Better if there is a smooth transition from the bottom to the sides, as it will reduce undesirable reflections.
 I take the bug pot and bowl to the conservatory (or outside, weather permitting), as I like as much natural light as possible.

And push the cat out of the chair (sorry!).

 Then I remove the lid of the bug pot, put the bowl on top, turn it round to transfer the spider to the bowl surface.

I'd like to say that, although it is a common technique, I don't like to use the fridge to cool down the animal, I am impatient and I want to get the photos and release the animal as soon as possible. Many of the bugs are naturally slow and settle quickly on the pot, or stop long enough for the shots. Male spiders at this time of the year are challenging, as they are very jittery and require a bit of attention until they are posing well. Usually, tapping on the table will startle them and they will stop running around. Unfortunately, they often stop leaning on the side of the pot, so when you remove it, they are settled in awkwardly like so...

...which is not ideal. I move the pot slowly until the spider is in the middle and blow softly under the pot, until the spider spread its legs.

Now lets go to camera settings. I don't own a DSLR, just a bridge camera (Canon Powershot G12, if you are wondering), but you can achieve a similar effect with any portable camera. I first set the flash on, and increase the flash setting to +2, this is important if the bug is dark, as the auto flash setting will result on an overall dark animal and not a very white background. You might need to experiment with your camera to find the best flash setting.

No flash

Flash on to +1

Then I set the focal point to the top left hand side of the visual field (nearer to the flash itself), instead of the central position. This ensures the animal is not in the shade of the objective. If I didn't do this, once I cropped the photo, the bottom right corner would be grey, not white, as it would be shaded by the objective. You can simulate this on a cameral without this setting by focusing in the middle point and then moving the camera trying not to lose the focus so that the animal is located in the top left hand side of the visual field.
 Today, I experimented by holding the camera vertical, so that the flash light came exactly in front of the spider.
Set the camera to macro, and fire away. I usually take lots of photos, as I want to get the focus right on the animal's eyes and I try also several angles, which are often useful for ID purposes.
  I download the photos in the computer and do some basic processing. Crop the white/grey space out, adjust the levels so that the white background is actually white, remove specks of dust or dirt and sharpen a little. That's it!

Cropping

White level adjustment

 This one is my favourite of the session today. Although the white background is not perfect, as it is greyer on the right hand side, I like the spooky effect of the spider leg shadows.

Fangs!

A rainy day, I look around the house for things to look up with the little digital microscope and I find the shrivelled shell of a spider, probably a Tegenaria, in the conservatory, behind a pot. I notice the fangs and look under the microscope. It is not the best photo, but I am quite pleased with the fact that the tiny openings at the end of the fangs (where the venom comes out) are just visible. Click here for a scanning electron photograph of these openings. The fangs act as hypodermic needles, injecting the venom inside the prey's body. The teeth that help hold the prey while the venom is injected are visible at the bottom.

Spring at last!

The last couple of days have seen the temperatures finally rising over the freezing conditions we've had during March and early April. The lovely, milder, sunny weather we had today meant  I had many 'firsts' of the year. Until today this year, I had not seen a butterfly and I had only seen the occasional bees and bumblebees. Today Garden Ants, Lasius niger, were active in the garden, a clumsy female Dronefly enjoyed the sun and walked over the daffodil flowers feeding (above). Two male Anthophora plumipes patrolled around flowers, and even the first female of the year payed a short visit too. The males occasionally fed on wallflowers, hyacinths and wild primroses.
I saw my first butterfly of the year today, a Small Tortoiseshell, unfortunately, could get no photos, as my cat found her before me and chased her away.

This queen wasp, Vespula vulgaris, also first of the year, got in the conservatory.

A Tegenaria with its egg sac on a stilt. It is under the lid of the water butt, so I guess the photo is upside down

A male Anthophora plumipes rests for a few seconds on foxglove leaves.

My cat becomes quite the entomologist when flying insects start to appear. She often alerts me of insects in the garden, but also disturbs them when they try to feed, to my annoyance! Later in the year, she becomes disinterested, and I can relax and watch insects at my leisure.

House spider with egg sac

Under the lid of the water butt in the garden I found this small Tegenaria, guarding its curious egg sac. I had never seen a Tegenaria egg sac before, the reason being that, according to W.S. Bristowe, their egg sacs are normally attached inside the spider's funnel, where they would be hard to see. In this case I probably broke the funnel when opening the lid and the egg sac seems to hang from the plastic by a few threads of silk. This peculiarity and its small size compared to other Tegenaria specimens make me think it is T. domestica, a species found in or outside houses. I hope I didn't disturb the spider too much, as I plan to follow the development of her spiderlings, which stay with their mums for a few molts inside her funnel.

UPDATE 9/06/2014. I now believe the egg sac belongs to a spider of the genus Ero. See this BugGuide thread for more info.