Nursery web spider

 The rough grassland on the old Brancepeth  colliery site, never grazed or mowed, is perfect habitat for the nursery web spider Pisaura mirabilis. This female had recently enclosed her egg cocoon inside a silken tent woven around grass stems - a nursery where the vulnerable spiderlings can hatch and grow in safety.

Over 250 years ago, the Swedish taxonomist Carl Alexander Clerck gave this species the scientific name Pisaura mirabilis, the marvellous Pisaura. Its fraught courtship ritual has been a source of wonder for arachnologists ever since. Males pacify females, which are notoriously prone to cannibalism, with the gift of a fly wrapped in silk. The larger the fly, the longer it will take to unwrap and eat, extending the opportunity to copulate before her hunger turns to aggression. So, there is a premium on males who are good hunters, though deceitful suitors sometimes wrap and present small twig fragments, risking death mid-copulation when she uncovers the fraudulent offering.

If she does accept his advances she'll eventually produce a ball of eggs wrapped in white silk that she carries in her jaws, slung under her body, until they are almost ready to hatch. The egg cocoon is so large that she is forced to walk around on tip-toe, to keep it clear of the ground.

 These pictures show what happens next - a remarkable example of spider maternal instinct. Her eggs have matured and the grasses have grown tall, so she climbed to the top and bound a few together with silk. Then in the space below she wove a tent, deposited her eggs inside, nibbling through the cocoon so that the spiderlings could hatch and then finally sealed them inside their silken nursery. 

Now, she’ll stand guard until they grow large enough to bite their way out of their nursery and take their first steps into the outside world. In the photographs below you can see her yellow egg cocoon, safe inside the nursery she has woven, with spiderlings beginning to hatch.

Two spiders in the bath - only one came out alive

Cellar spiders Pholcus phalangioides look fragile, with those long, slender legs, but they are formidable hunters. This is what happened when a house spider climbed down into our bath, to drink from a dripping tap, and became trapped. The cellar spider climbed down after it, snared it with silk, bit and paralysed it, then wrapped up its prey in a silken shroud.

The cellar spider had little difficulty in climbing out, with its prey slung under its body, then spent the rest of the day clinging to the skirting board, guarding its meal from rival spiders.

These lanky, harmless arachnids need warmth and are confined to human dwellings in Britain. In 1958 the eminent arachnologist W.S. Bristowe, in his book The World of Spiders, described how he zig-zagged across England on his motorcycle, requesting to see hotel rooms on the pretext that he might rent them, so that he could check for the presence of Pholcus and map its distribution. He only found it along a narrow corridor in southern England.

Since then this synanthropic spider has moved north – perhaps in furniture removal lorries, because it seems to have a predilection for living behind settees and under tables – and has even reached the Shetland islands.

The spider season

 There are some fascinating spiders around at this time of the year. This little beauty is a zebra spider, that lives in my greenhouse. It doesn't make a web, it leaps on its prey. The forward-facing pair of its eight eyes are especially large, giving it binocular forward vision and the ability to judge distance accurately.

The garden spider below has spun its web in my greenhouse, across the doorway: I have to duck under it to get in and out. I watched as it caught this wasp and wrapped it in a silken shroud in less that 20 seconds. In the second picture you can see the prey's jaws protruding through the silk, as it tried to bite its way out - unsuccessfully.

This house spider, below, had fallen into our bath - probably entering the bathroom through an open window after climbing up the outside wall. It most likely fell in when it tried to drink from the dripping tap. It's now re-housed in the greenhouse.

House spiders look fearsome but they are easy prey for cellar spiders that trap them in their silken threads, using their long legs to drape the thread around their prey, then paralysing it with venom. They guard their captured prey, usually taking a couple of days to eat them, leaving only a few pieces of its exoskeleton. 

Both cellar spiders and crane flies are commonly known as daddy-long-legs but when the two meet (below) the outcome is never in doubt. Most crane flies that find their way into our house end up in a cellar spider's web.

Cellar spider catches a woodlouse (arachnophobes look away now)

 

The cellar spider Pholcus phalangioides is a welcome guest in our house. In summer it's a very effective fly killerand it also catches and eats much larger spiders, of the kind that sometimes turn up in the bath or race across the ceiling and floor when the cold weather brings them indoors, in autumn. A few cobwebs in corners of the ceilings are a small price to pay for these services.

Sometimes these spiders catch woodlice, which is what this one has trapped in its web, alongside a fly that has already been encased in silk. But this woodlouse was a prize catch, because its a female that was carrying baby woodlice, known as mancas, in its brood pouch, under those armoured plates. They are the tiny translucent woodlice, as yet with no hardened armour, that you can see in the photograph below.

Female woodlice carry their young in a brood pouch under their body, and at this stage the young only have six pairs of legs. After their first moult they develop an extra body segment and after the second moult they grow an additional pair of legs, so they are then classified as juveniles with the full adult complement of seven pairs of legs.

For a closer look at woodlice, check out my Beyond the Human Eye blog here.

A fraught wolf spider courtship

  A pair of wolf spiders courting in the garden, with the male (in the foreground) frantically signalling his amorous intentions to her with his palps, moving closer a millimetre at a time. She is ultra-aggressive and lunges at him, so he dashes for safety. During a long, hot afternoon they repeat the performance many times, but I never witness a successful mating. But it happens, because .....

..... a few days later, here is a female wolf spider basking in the sunshine on a rock, carrying a silken cocoon of eggs under the tip of her abdomen.

Our two year-old granddaughter's favourite spider

Our two year-old grand daughter was fascinated by this magnificent house spider Tegenaria domestica that's living it its web in a corner of  a window in our house.

It's not often that you get this unusual underside view of the body, revealing the prey's-eye view of the jaws, and all the leg joints. Usually you just see them dashing across the floor late in the evening, or trapped in the bath when they search for a drink from a dripping tap.

Though large, they are harmless and do a very good job of catching those annoying flies that find their way into the house in autumn. These spiders in turn are preyed upon by cellar spiders (daddy-long-legs spiders) and, since there are two of these living behind the settee, this house spider's days may be numbered.

Enoplognatha ovata, the Common Candy-striped spider

I've been cultivating this garden for over 30 years and this is the first year that I've noticed these exquisite little candy-striped spiders Enoplognatha ovata

I might have missed them entirely, because in late July and early August they hide under leaves, guarding a ball of eggs that's covered in vivid blue silk.  But I must have carried them to the garden waste recycling bin in some plants that I'd cut down from an overgrown corner of the garden, because when I lifted the lid the next day several had climbed up, carrying their eggs, and were sitting around the rim of the bin.

I rescued them on my gardening glove and had an opportunity to watch their devoted care for their unborn young, carrying them around under their body in a search for a new, safe incubation site. The mother in the photo above is in defensive mode, waving her front legs at me.

So far I've rescued about a dozen of these spiders and released them in the strawberry patch, where they immediately carried their eggs under the leaves and used silken threads to draw the edges of the leaf together.

There are three colour morphs of this spider, including this one with a plain white abdomen. The third form has a single broad red stripe down the middle of the upper surface of its abdomen, but I haven't found that one yet.

You can find more information on this charming arachnid, and speculation about the possible survival significance of the three different colour morphs, at this British Arachnological Society web page.

If there is a moral to this story it is that, if you send garden waste for recycling, it's a good idea to check around the top of the bin before it's collected, because this is where small animals that have been accidentally thrown out with the herbage often take refuge. 

Biodiversity in a kitchen waste recycling bin

Today's Guardian Country Diary is all about the contents of our garden kitchen waste compost bins.

We have been recycling all of the vegetable waste from the kitchen, together with garden weeds and fallen leaves, for about 30 years now, using three black compost bins. During that time we must have produced tons of compost that has all been dug back into the garden, which is now a very fertile plot.

These are some of the organisms that do all the recycling work.

The first organisms to colonise the vegetable peelings and fruit skins are fungi. I suspect that this might be a Penicillium mould, which often grows on the skins of rotting citrus fruits.

This is the rather lovely pin mould, Mucor mucedo, with glassy hyphae and sporangia that look like beads of polished jet.

This, I suspect, is Botrytis, a common coloniser of dead vegetable matter.

Currently there are thousands of these tiny moth-flies (also known as drain-flies or owl-midges) in one of the bins.

They breed in vast numbers during the early stages of composting, when the bins are less than half full....

.... and provide a food source for some of the predators that live in the bins, like this small spider that has an egg cocoon under the bin lid.

The bins are home to a lot of slugs, that consume decaying plant material and are useful all the time they stick to this diet, though in spring they become a nuisance if they consume seedlings in the garden. 

To minimise that risk I raise plants in posts until they are large enough to show some degree of slug resistance when I plant them out in the garden.

A black snake millipedes, that feeds on the decaying plant material and probably on some of the fungi too.

As the composting proceeds and the bin contents become drier the numbers of these minute springtails increase. When you lift the lids they pole-vault into the air, using the special structure called a furcula under their tail end.

And finally ...... the most important recyclers of all, brandling worms Eisenia fetida. When composting is at its peak there are hundreds of these in each bin. 

Much of the compost that ends up in the garden has probably passed through the digestive system of one of these worms.

Nursery web spider

Although some spiders have a fearsome reputation, there’s no denying that others have endearing qualities – and none more so than the nursery web spider Pisaura mirabilis, one of our larger native species, growing up to about an inch long. It's quite common in our region in grassy places, where it spends much of the time hunting insects on the ground or sunbathing on leaves. 

Its peculiar way of resting with its front two pairs of legs held close together, so that at first glance it appears to have only six rather than eight legs, makes it easily recognisable.

The one in the pictures below lives in the garden of my eldest son and his partner, near Blaydon.

 When the time for courtship arrives in early summer the male spider catches a fly, wraps it in silk and presents it as a gift to a potential mate. Sometimes, if he can’t catch a fly, he’ll present her with a gift-wrapped piece of debris instead but it seems that the size of his gift, rather than its quality, is the crucial factor in determining whether she’ll choose him as a mate.

It's the thought that counts ...... as any bloke will tell you if he's forgotten his wedding anniversary then bought his wife a last-minute bunch of flowers in a petrol station.

If she does accept his advances she'll eventually produce a ball of eggs wrapped in white silk that she carries in her jaws, slung under her body, until they are almost ready to hatch. The cocoon is so large that she is forced to walk around on tiptoe, to keep it clear of the ground.

What happens next is a remarkable example of spider maternal instinct. By the time that her eggs have matured the grasses have grown tall and she climbs to the top and binds several together with silk. Then in the space below she weaves a tent, deposits her eggs inside, nibbles through the cocoon so that the spiderlings can hatch and then finally seals them inside their silken nursery. She’ll stand guard while they grow large enough to take their first steps into the outside world. 

This particular spider is unusual in that it has recently lost its right front leg and is regenerating a new one - in the picture above it's the dark-coloured leg at the bottom of the picture.

You can see the new leg, almost black and at 8 o'clock, in this closer image. Spiders can regenerate lost limbs will they are still growing and still moulting their exoskeleton, but once they reach their final moult at maturity they can't replace lost legs.