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.

Winter active spiders in the house

We are having an exceptionally mild winter and, although much of the time it is wet and dull, winter invertebrates respond to the prevailing conditions. While some spiders overwinter in the safely of an egg sac, or as tiny spiderlings on leaf litter and tree trunks, others winter as grown young or adults. In warm conditions, some of these species overwintering as grown spiders continue to be active through the winter months, hunting or looking for mates. This post was prompted by a silky, silvery mouse spider Scotophaeus, that I found on the kitchen ceiling in the morning (above). So, I decided to investigate which other spiders were about inside and outside of the house. All the photos taken this morning.

Pholcus phalangioides.

The Pholcus spiders in my outside toilet, which is not heated, have been much more active than it is usual in winter. Pholcus adopts a curious flat position in cold conditions, but a large individual has been changing corners and looks gravid, or indeed very well fed.

Amaurobius similis with centipede prey

 In a crack at the bottom of the toilet door lives an Amaurobius similis. A couple of weeks ago I watched as a large springtail, Orchesella villosa, tripped one of her woolly silk lines. The spider sprung out like lightning out of her retreat, but the springtail, making use of its wonderful jumping abilities, escaped unharmed. Today the spider was luckier. I noticed she was out, which is unusual, and looking closer I saw she was busy with prey: a centipede, likely Cryptops hortensis.
What other spiders are out and about?
Inside the kitchen window, a mid-size garden orb-weaver Araneus diadematus, hung from her web. They occasionally wander inside and live on small plant midges or drosophila from the fruit bowl. Females have occasionally reached full size inside the house and attracted males.

A poor shot of an Araneus diadematus inside the house.

Zygiella x-notata legs visible touching its web.

On the sheltered top corners of windowsills you might find Zygiella x-notata, the missing sector spider, in a silky retreat, often next of her egg sacs and the empty wrapping, one of her front legs touching the guide thread to the center of her web. At night she comes out and sits in the middle of her web. They are active regardless the weather, building their new webs early in the morning even in hard frost.

Pholcidae: cellar spiders

The Pholcidae is a large family of spiders, although most of the family's diversity is in dry temperate or subtropical regions, where they can live in diverse habitats away from houses. In our latitudes, these warm loving spiders live in caves, cellars, wells, outbuildings, and houses. The most common and widespread species in the UK is Pholcus phalangioides - a male with his rounded palps is on the top photo-, which has also now been introduced in other regions of the world, including North America, from its native Eurasian range. There are several common names for this spider, one of them, daddy long legs, is certainly confusing, as it is also applied to crane flies and harvestmen. They like to build their almost invisible tangled webs on ceiling corners, from which they hang upside down looking like thin chandeliers. Their legs are, indeed amazingly long and thin relatively to the body.

The natural history of Pholcus phalangioides is easy to study, as they don't move much, residing for weeks on end motionless on quiet corners of the house, and are present year round. 

A pair mating. Mating can last more than an hour. Males are slightly larger (10 mm) than females (9 mm).

Mummy long legs

As many other spiders, Pholcus take extended care of their offspring. They hold their eggs with their chelicerae until they hatch. The egg brood is kept together by a few silk threads.

A gravid Pholcus, she laid eggs the following night. She resided under the outside toilet shelf.

Here is the same individual with her newly laid eggs.

These eggs are going to hatch soon. The linear whitish patterns in the eggs are the legs of the developing young.

In about two to three weeks, spiderlings hatch. Right after emergence, the spiderlings remain together for a few hours, before moving onto the mothers surroundings.

The Pholcus under the shelf, with her record number of offspring, I counted 65 (30 is the average).

A Pholcus mother with her meal, another spider, surrounded by her offspring. She will set her egg sac aside to feed or to mate, and may lay further egg batches after the young spiderlings have dispersed. These spiderlings are almost ready to disperse, having had their first moult.

Spider hunters

Despite their fragile, spindly appearance, Pholcus are fierce predators, and regularly hunt other spiders, often much larger than themselves, including house spiders (Tegenaria) and woodlouse hunters (Dysdera). They achieve this by quickly wrapping the other spider on silk using their long legs, which allows them to keep their distance. Once thus subdued, they bite their prey. Pholcus uses a sit and wait approach, which is probably very successful during the autumn, when male house spiders move about in search for females. They can also use an ambush approach, moving about and, when it finds another spider's web, it will make it vibrate to attract the owner.

They don't always succeed in spider hunting, through, and I have seen other spider, the mouse spider (Scotophaeus blackwalli) with the remains of a Pholcus. 

Another successful Pholcus with prey spider.

Pholcus with woodlouse.

A Scotophaeus blackwallii with captured Pholcus.

Pholcus before and after laying eggs

The first female Pholcus phalangioides laid eggs at the top of the porch last week. The gravid female I was following, which lives under a shelf in the outside toilet was still without eggs yesterday. This morning when I checked, she had laid. Check her abdomen before (below) and after laying (top).

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.

Newborn Pholcus spider

A female Pholcus phalangiodes carrying eggs has been in the outside toilet for over two weeks. Today, I noticed her shuffling a bit, and when I looked, the first spiderling had been born and was sitting on the eggs. The spiderlings' folded legs and rows of eyes are clearly visible through the egg shells. When I returned five hours later, the female was holding a fuzzy ball of baby spiderlings.

For more on Pholcus on BugBlog click here.

Adult pair of Pholcus phalangioides

 In the last few days, I have been keeping an eye on a pair of Pholcus phalangioides in my outside toilet. They are a male and a female, and given that both appear to be adults I guess the male is waiting for the female to become receptive. I got a close up of the male, showing its almost circular caparace and its palps (above).

Pholcus phalangioides. Male on the right, not its elongated abdomen. 

Spider scrum

I bet it is hard to find a higher leg density than in a freshly born ball of spiderlings. These 30 or so Pholcus phalangioides spiderlings hatched last night on the ceiling of my outside toilet, about 240 legs in just a few cubic millimeters. In the morning they were still clutching each other and their empty egg sac. By today's afternoon, they had arranged themselves under the vigilant eye of mum as in my previous post.

Dispersing Pholcus babies and the spider man

A few months back, I bought a tattered copy of the classic The World of Spiders, by W.S. Bristowe, the 38th book of the New Naturalist series. This book is a wonderful read and I recommend it to any spider enthusiast. Bristowe was in awe of spiders from an early age. He describes being greatly puzzled -  when he was able to read -  and after devouring any spider book he could get hold off, that

the great experts seemed to leave off where I wanted to begin. They had described with precision the appearence of the corpses, in words often unfamiliar to me, and had left to other people the task of writing about their habits

His book does not disappoint as he went on to describe the behaviour of many familiar and unfamiliar spiders with their own observations, displaying the author's never ending curiosity for the world of spiders. The book has photos (black and white and colour) and astonishingly beautiful line drawings by Arthur Smith, often portraying his subjects going about their business and demonstrating an incredible attention to detail. Bristowe describes his first meeting with Smith in the preface of the book:

he ended the afternoon perched on a table with a torch under one armpit whilst he busied himself with pencil and paper sketching a Pholcus on the ceiling.

Bristowe seemed to have a particular fascination with Pholcus phalangioides, the daddy long legs spider.

Pholcus did not live in my childhood home at Stoke d'Abernon, Surrey, although she thrived elsewhere only about ten miles further, so the quest of an explanation inspired me to trace her distribution. This had to await the acquisition of a motor-bycicle and then, with the impudence of youth, I zigg-zagged across England ostensibly seeking rooms in hotels or lodgings whose ceilings I viewed with nonchalant interest. My apologies are no doubt due to a host of hoteliers for gaining entry under false pretences...

 On the 23rd of August I noticed that the eggs from an egg sac a Pholcus phalangiodes female in the toilet had been holding had hatched. She was still holding the empty egg sac (above), and twenty-two  spiderlings hung still, upside down around her. In Bristowe's words:

The eggs may hatch in two or three weeks' time and the young then hang motionless like washing on clothes-lines for the next week or fortnight during which time they take no notice of any disturbance such as those caused by their mother catching an insect. Unlike nearly all other spiders, they do not molt until after they have emerged from the egg-sac.
  Directly they have recovered from this first molt they gradually begin to migrate, taking positions further and further along the wall and spacing themselves as though they had staked their claims to particular territories. Now they are interested in food and for several of them their first meal is of a brother or sister who is backward in his timetable of who dies or is injured as a result of the delicate operation of moulting.

A couple of days ago the spiderlings moulted and today, at the tender age of 12 days, some more adventurous spiderlings have started to explore and disperse away from their mother, their old skins hanging like ghostly gloves from the invisible web.

More information
Bristowe, W.S. 1958. The World of Spiders. The New Naturalist. Collins, 304 pp.

Pholcus phalangioides, the Daddy Long-leg spider

In dark, forgotten corners of houses and outbuildings, a spindly-legged spider hangs upside down - motionless - from a loose, barely visible web made of very fine threads. It is Pholcus phalangioides, the Daddy Long-leg Spider or Cellar Spider. Today, several hang from underneath a wooden shelf in my outside toilet, including the male above. This species is cosmopolitan but has recently expanded its range northwards in the UK, and it is almost always found associated to buildings.

A male showing its palps.

Mating pair. After an initial male approach and web and leg tapping, if the female accepts him, the partners approach their ventral surfaces and the male inseminates the female using his palps.

Pholcus is a very generalist predator and has no trouble subduing large prey. I have seen it with captured Tegenaria (above) even Dysdera (below), the latter a spider with enormous chelicerae. Pholcus is able to do so thanks to its long legs, as it throws silk to its prey and wraps it on silk while keeping a safe distance. It can also invade other spiders' webs and then makes them vibrate simulating the effect of an entangled prey, in order to attract the owners and catch them, a deceptive behaviour known as aggressive mimicry. It will also eat other spider's eggs and trapped prey. If Pholcus is disturbed in its own web it has a defensive behaviour called whirling: it moves its body rapidly in a circle, becoming a blur, while keeping its legs on the web, this might deter other spiders from entering its web but even so, Pholcus can often capture and eat these spiders.

 Pholcus is even able to capture and feed on woodlice, which often walk up the walls in my conservatory.

Female Pholcus are dedicated mothers. They hold their egg clutch of about 20 to 30 eggs by their chelicerae. The eggs in this clutch are close to hatching. The spiderlings' legs are visible through the egg shell as white threads.

 The spiderlings stay close to their mother for some days after hatching. She hasn't fed since she laid the eggs and she will have to wait until the spiderlings disperse.

 Pholcus go through five moults before maturity. The one below is molting.

Apparently, the most effective enemy of these spiders is that noisy generalist predator, the vacuum cleaner.

More information
Check this website for detailed information on Pholcidae.

Maciej Bartos (1998) Quantitative analyses of male courtship behaviour in Pholcus phalangioides
(Fuesslin, 1775) (Araneae, Pholcidae). In: P. A. Selden (ed.). Proceedings of the 17th European Colloquium of Arachnology, Edinburgh 1997. 171-176. here.

Kazuyoshi Miyashita (1988a) Development of Pholcus Phalangioides (Fuesslin) (Araneae, Pholcidae) under Long and Short Photoperiods. Journal of Arachnology, 16 (1), pp. 126-129.

Kazuyoshi Miyashita (1988b) Egg Production in Pholcus Phalangioides (Fuesslin) (Araneae, Pholcidae) under a Constant Temperature and Photoperiod. Journal of Arachnology, 16 (1), 129-131.

Jackson, R., & Brassington, R. (1987). The biology of Pholcus phalangioides (Araneae, Pholcidae): predatory versatility, araneophagy and aggressive mimicry Journal of Zoology, 211 (2), 227-238 DOI: 10.1111/j.1469-7998.1987.tb01531.x