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"A Nature Observer′s Scrapbook"

Spiders



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Garden orb spider

Garden Orb spider

Araneus diadematus

This brightly coloured beauty comes in a variety of shades of orange and brown, and is characterised by the pattern of white dots on its back which resemble a cross. The minutely spiny legs are banded light and dark.

Seen here at the centre of a 300mm circular web spun vertically between the leaves of Iris by the garden pond, this female (body length 13mm) was ready to react to any fly that became snared on the web. Small prey were taken back to the centre of the web and devoured on the spot. Larger prey were taken off to a more secure food cache in the event that the web would need to be rebuilt. The much smaller and less spectacular males might be found around the periphery of the web waiting to scavenge any leftovers.

In some cases the female takes up a rather less conspicuous position outside the web but maintains contact through a 'signal thread' that returns vibrations from the centre of the web.

At rest, after a full meal or pending a web rebuild, these spiders will often be found with their long legs tightly tucked up close to the body.

This is a common and widespread species that can be found throughout the northern hemisphere.



DateSighting
15.09.1999At rest, at the centre of a horse chestnut leaf.
31.08.2008Tending a web strung between pond vegetation.


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Green orb spider Green orb spider side view

Green Orb spider

Araniella cucurbitina
...... - A. opisthographa ?

There are two very similar looking species which can only be positively identified by microscopic examination. Both have been recorded in the Horncastle area but, as A. cucurbitina is by far the most commonly found, it seems safest to suggest that these images might be of that species.

This 5 -7mm brightly coloured spider spends most of its time in leaf litter and is most likely to be found around bushes or hedge bottoms from June to November. Although it is not a prominent feature, it carries a red mark at the rear of its abdomen.

It may climb some three feet or so to spin its web - the upper image was taken on the top of a farm gate and the lower one on a low hanging branch.

The web is characterised by having a 'vee' shape missing at the top of the wheel shaped construction.

It is a very cosmopolitan species in the northern hemishere, being found throughout Europe, North Africa, through Asia to Japan.



DateSighting
18.06.2005 Found on a farm gate between two hedgerows.
05.05.2007 On low hanging crab apple tree foliage.


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Walnut orb spider Walnut orb spider

Walnut Orb spider
    or - Evening spider

Nuctenea umbratica


The Walnut Orb spider - so called because of its colour and the circular webs that it weaves, is common outdoors throughout the UK but despite its respectable size - males can grow to a head and body length of 11mm and females can reach 15mm, it is not so frequently seen.


The Walnut Orb spider hides away during the day. It's flattened body allows it to hide in nooks and crannies or under bark, close by its web and it only emerges to secure any prey that gets trapped in the web. But after dark, it will emerge to construct a new web each evening and can then be seen sitting at the centre of its web waiting for it's next meal - hence it's common name of 'The Evening Spider'.


As with other insects, spiders do not have bony skeletons and their internal organs are held in place by muscles attached to their tough outer skin (their exo-skeleton). The dimples caused by these attachment points can be seen clearly on the back of the spider in the upper image.


At rest it has a habit of tucking its legs tightly up against it's body and that coupled with its dark colour means that it is easily overlooked.


When seen in motion in the open, it has a rather sedate and purposeful action and doesn't resort to frantic activity so common to other spiders seeking the safety of cover.



DateSighting
11.09.2005 Disturbed while adjusting a well worn garden gate.
14.04.2009 Found late at night in garage.
15.10.2009 Found late at night retrieving a moth from it's web.


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Zygiella x-notata

'Missing sector' Orb Weaver

Zygiella x-notata

The 'Missing sector' orb weaver, so called because of a characteristic missing vee shaped sector in its otherwise circular web. Within the missing sector a signal line thread runs to the centre of the web and the spider is usually found tucked away in a corner but in contact with this signal line.

It is found throughout the northern hemishere and is one of the few species to spin webs during cold winter months.

A medium sized spider at 6 to 9mm, it is found outdoors on trees, rocks and buildings.



DateSighting
14.08.2005 Found in the corner of the garage door architrave.



image of Meta segmentata

Common Garden Orb Weaver

Meta (Metellina) segmentata

This is another spider that exhibits more or less constant markings but can be quite variable in colour.

The circular web of Meta segmentata is characterised by an open hole at its centre. It is usually found outdoors slung at a slight angle from the vertical from supporting vegetation but I had one that survived for six months indoors over a workshop bench.

Outdoors, webs tend to get damaged quite quickly and are often re-sited. But the one that took up residence indoors used the same web for over 10 weeks.

This spider is not short of names. Apart from its two scientific generic names, it is also known 'commonly' as the Common Garden Orb Weaver, the Lesser Garden spider and as a Stretch Spider because of its habit of stretching its legs out in front and behind. At full stretch it's legspan can be nearly 25mm (about an inch) but it's body length is only some 7mm.



DateSighting
08.10.2006 On wire fence bordering fieldside drainage ditch.
Sept/Nov 2007 Indoors in workshop.
Jan/Feb 2014 Indoors by workshop window.


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Tetragnatha montana Tetragnatha montana

Long jawed orb weaver

Tetragnatha montana

In 2004 this species was found on a densely leafed Salix caprea tree apparently making no attempt to construct the horizontal orb webs that they are supposed to make. The spiders simply hugged the leaf stem and with their excellent camouflage just waited for prey to come within their long legged reach. And the evidence of several past meals could be found right next to them.

In 2006 several were found in a much more conventional habitat, on a patch of pond side Iris spreading their webs in normal horizontal fashion. Since the pond attracts many small flies they were not going hungry.

All the Tetragnatha species adopt the habit of stretching their legs out in front and behind to produce a stick like effect and can be very difficult to detect on vegetation. And even when exposed on the web can look just like vegative litter.



DateSighting
05.06.2004 Found on a densely leaved Salix caprea pendula tree which attracted a wide range of small insects.
04.06.2006 Several individuals on horizontal orb webs strung between pond side Iris plants.


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Common house spider Common house spider

Common house spider

Tegenaria domestica

This is the one that everyone knows. Given the opportunity, it creates great sprawling sheet-webs and will dart out of its web funnel to grab any insect that lands on the sheet.

There are several 'look alike' species but this one is identified by the chevron markings on the top of its abdomen.

Generally speaking, the males look smaller, slimmer and frail compared to the females and have a cephalothorax (head & thorax) region equal to or larger than the abdomen. While the females generally sport a larger abdomen. On that basis, the images shown are those of a male.



DateSighting
17.10.2004 Although we invariably have these visitors every year, we seem to have had fewer in 2004 than in previous years.
11.04.2005 Huge specimen


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Cobweb spider female Cobweb spider male

Cobweb spider

Tegenaria gigantea


The kitchen definitely feels crowded with one of these for company. This is a spider of substance and a presence to match.


The female in the upper image had taken up residence in the garage where it could be admired from a distance! The cephalothorax (head, thorax region) to end of the abdomen measured 17mm and the leg spread was 54mm.


The lower image is of a male - the abdomen length being smaller than that of the cephalothorax. This one had a body length of 19mm, and outstretched legs of 75mm - three inches, this was large by accepted standards and well worthy of its scientific name, Tegenaria gigantea.


It was seen to make a positive approach to an even larger female with a swollen abdomen and after a head to head, short 'embrace' hastily escaped with it's life.


Females can apparently live for several years and can survive for months without food or water. They make large and substantial sheet webs with a funnel to their safety retreat.



DateSighting
11.04.2005 Dominating the middle of the kitchen carpet, 9 o'clock at night.
17.10.2005 Another late night intruder. A large pale male
24.04.2007 Large male courting even larger female - escaped with his life.
08.06.2009 Several large specimens in residence in the garage.


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Mouse Spider female Mouse Spider male

Mouse Spider

Scotophaeus blackwalli

The Mouse Spider - so called because of its silky mouse grey abdomen and its mouse like habit of moving with body held low and running in short spurts.

One might almost be tempted to stroke this one - almost.

This is classed as a hunting spider. It is usually nocturnal, venturing out at night to seek sleeping insects but, it's lair is a loose web and it's silk spinnerets are clearly seen at the end of its abdomen.

At any given time of the year, female spiders will invariably be larger than the males.The female, pictured upper right, had a body length of 12mm when seen in June.
The male, pictured lower right in August and with the advantage of more growing time, was still only 10mm.
Generally, as can be seen, the females have a larger abdomen than the cephalothorax region (front half of the body).



DateSighting
04.06.2005 Found on kitchen wall late at night.
17.08.2006 Found in a dark cupboard.


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Snake's Back spider Snake's Back spider

Snake's Back spider

Segestria senoculata


This one gets its name from the markings on its abdomen which are somewhat representative of an adder's markings.


The carapace and abdomen are noticeably slimmer and more elongated when compared to the globular appearance of most spiders.


It is usually found at ground level where it lives in crevices between stones and lays out silken trip wires back to its hole so that it can sense when prey has approached close enough for it to dart out and drag its meal back to its silken nest. It is found throughout Europe and it's range extends through Asia as far east as Japan.


Whereas the majority of spiders have eight eyes (not that their eyesight is all that good) this one belongs to a group of families known as 'six eyed spiders'.



DateSighting
10.10.2004 Found under a paving slab laid on coarse hard core with many crevices.
06.06.2012 Disturbed in loose soil at base of tree.


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Amaurobius similis spider Amaurobius similis spider - head view

No common name

Amaurobius similis


This one was only named after taking learned cousel advice. Many distinct spider species can only be positively identified by microscopic examination - and, to this layman, this looks confusingly similar to A. fenestralis - but, without knowing what to look for, many things can look superficially similar.


The large abdomen (the back end) compared to the cephalothorax (the front end) indicates that this is a female.


This was found outdoors but close to the base of the house wall, under a piece of roofing slate lying on coarse gravel. Unlike the common house spiders which tend to gallop off at great speed when disturbed, this one slowly stretched out from a defensive crouched position and leisurely ambled off to find shelter.



DateSighting
14.04.2005 Found under a piece of roofing slate at the base of house wall.


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Amaurobius fenestralis m

a 'window lace weaver'

Amaurobius fenestralis

Comparison of the differencies between the male and female of the same species is a useful and valid exercise. But trying to compare the female Amaurobius similis above with the male A. fenestralis alongside is hardly fair.

The smaller body to leg proportions and the smaller abdomen to cephalothorax, suggest that this image is that of a male. Other generalisations are that the males are usually found towards the end of the year, and that the male's palps, the small leg like projections protruding from the head either side of the mandibles, will be swollen and club like compared to those of the female.

Amaurobius fenestralis is more likely to be found indoors, whereas A. similis, the previous species, favours an outdoor habitat, albeit close to habitation.



DateSighting
28.10.2005 Found indoors high up on a wall late at night.



 Male Steatoda bipunctata - 
a 'comb-footed spider'. Female Steatoda bipunctata - 
viewed from below.

a 'comb-footed spider'

Steatoda bipunctata

Steatoda bipunctata is also commonly known as the 'Rabbit hutch spider' because of its tendency to lurk in what can often be an insect infested environment. This one was found in a window frame which was often open for ventilation and which saw frequent fly traffic.

It has a glossy chestnut brown abdomen, usually with a thin pale band stretching across the front, just behind the head. The abdomen has four tiny indentations on its back which in the absence of an internal skeleton, serve as anchor points for internal muscles. The web is a loose tangled mass of silk with seemingly no structure.

The family to which it belongs, the Theridiidae, also includes such notorious members as the Black Widow. Indeed, one South African Steatoda species has a reputation for killing small snakes. Such venom as the UK species has, is very mild and unlikely to endanger humans.

The upper image is of a male which has a smaller abdomen and 'boxing glove' palps by the mouth parts.

The lower image is ventral view of a female showing three circular features in a row on the underside of the abdomen. The upper dark one is the female's genital pore. The middle one is where the silk 'fleece' is produced that is used to quickly wrap up prey. This is spread by the fine comb-like bristles (just about visible) on the rear feet. The lower feature is the group of single strand silk spinnerets used for web making.

Females, such as the one shown, grow up to 7mm and are to be found all year round. The smaller males, up to about 5mm, are usually only found in summer and autumn.



DateSighting
03.03.2007 Found in the crevices of a window frame.
25.04.2007 Found on inside of a garage window.



Theridion sisyphium Theridion sisyphium with egg sack

Comb-footed spider
..... the 'Mother-care' spider

Theridion sisyphium


These images of Theridion sisyphium are almost classic for the species. There can be some variation in colouring and young specimens need a bit of imagination to see the mature markings. When seen in isolation, like this, the markings are quite striking but, in the wild they break up the spiders shape and are very effective camouflage.


It frequents low foliage and strings a chaotic loose mesh of a web between grass and plant stems. Both specimens seen here were found at the base of a hedge.


It gets its 'Mother-care' common name from the female's habit of
a) carrying its grey/green egg sack around with it and
b) staying close to it's hatching brood of spiderlings and allowing them to feed on whatever prey she catches. The young of most other spider species are left to their own devices after hatching.


One can see in the lower image that, having produced her eggs, the female's abdomen does not appear quite so distended as in the upper image.


For an explanation of the 'comb-footed' grouping, see the text accompanying the previous species, Steatoda bipunctata.



DateSighting
31.07.2007 Found in dense rough foliage at the base of a hawthorn hedge.
15.08.2008 Female with egg sack found on Dog Rose growing through a hawthorn hedge.



 male Nursery Web Spider  male Nursery Web Spider  female Nursery Web Spider

Nursery Web Spider

Pisaura mirabilis


The Nursery Web spider is usually found in thick vegetation in the garden or hedge bottom. It is often seen at rest with the front two pairs of legs held close together rather than spread-eagled as more commonly seen in other species. Upper image refers.


Coloration is somewhat variable, ranging from grey through to dark brown but the contrasting markings are usually well defined, especially in the males. In the UK, the adult males have a body length of about 10mm and the females can be around 13mm but this species is found throughout Europe, North Africa and Asia and larger specimens may be found in warmer climes.


Determining males and females is not always easy but there are two features that help. Females usually have larger abdomens to accomodate all the unborn offspring. And then, their palps (projections from the front of the head) look like an extra pair of short thin legs but are really sensory organs. The male palps on the other hand are swollen, like boxing gloves, and are adapted for transferring sperm during the mating process. The lower two images show this difference.


Prior to mating the male will present the female with a gift wrapped parcel of an insect wrapped in silk. When the female produces her fertilised eggs she will then wrap them in a ball of white silk and will then carry the egg sac about, held by her palps and fangs close to her abdomen to ensure their safety. This means that she has to move around on 'tip-toes'. (Lower image.)


When the eggs are about to hatch, she attaches the ball shaped cocoon to a plant and spins a protective silk web around it. This is the nursery. She then remains 'on guard' and will chase all intruders from the site until the young spiders are fit to disperse and fend for themselves.


The reproductive phase, between May and July, is when the adults are most likely to be seen. After that they will remain well hidden in the undergrowth.



DateSighting
??.07.2005 Female with egg sac on hedge undergrowth.
22.05.2010 Male on ditch side vegetation.
21.06.2012 Female with egg sac on hedge undergrowth.



Xysticus cristatus

'Crab spider'

Xysticus cristatus

Xysticus cristatus is found throughout the UK. Like many crab spiders (so called because their legs tend to be held at right angles to the body, and some even walk sideways, crab like) it makes no web and relies on hunting its prey. It tends to wait on flower heads to ambush visiting insects or will actively hunt in the lower foliage or even on the ground, pouncing on passing insects, often much larger than itself.

At ground level it will even predate on ants, relying on its speed to get in the first bite which usually quickly paralyses its prey.

This species comes in a range of colour forms from pale cream to dark brown and also steel grey. A good image of a darker specimen can be at this link The males grow to about 5mm and the females to about 7mm.



DateSighting
24.06.2006 Found on patio paving slabs.



Woodlouse Spider Woodlouse Spider  - carapace detail

Woodlouse Spider

Dysdera crocata

Whereas most spiders have eight eyes, Dysdera crocata belongs to a group that have evolved with only six eyes. Whether this has any bearing on its choice of prey, the slow moving woodlouse, is open to conjecture.

In order to predate on the well armoured woodlouse it has developed a pair of substantial fangs (the largest of any UK spider) with which to pierce and grasp its prey. In the upper image these are seen as the two conical projections at the front of the head. The lower detail image shows how the fang tips are bent sharply downwards. In action, the fangs open sideways in a scissor action and are inclined inwards to achieve a very effective gripping action. They are capable of giving humans a painful nip but cause no lasting harm.

As indicated by the 'boxing glove' palps (seen either side of the fangs) and the abdomen roughly equal in size to the red carapace, this specimen is a male. Males grow to about 10mm and females, with their larger abdomens, to about 15mm.

They tend to be nocturnal hunters and are not often seen unless disturbed from their hiding places amongst rotting wood and compost heaps (where woodlice are also found). Being 'true' hunters, they do not spin entrapment webs but use silk to line their nests.



DateSighting
Summer 2002 Several seen while demolishing a derelict shed
27.01.2008 Disturbed from wood pile.



Female, Clubiona species Male, Clubiona species Male, Clubiona species

'Sac' spider

Clubiona species -
... possibly C. corticalis or C. comta?.


All spiders are carnivorous and have biting mouth parts but, in the main, most are harmless to man. Some, however, like the Woodlouse spider above, do have the ability to inflict a nip - as do the Sac spiders and some of the tropical ones have a nasty reputation. Within the UK none are regarded as dangerous but individual allergic reaction may give rise to localised inflamation or blistering.


Positive identification of this species is well nigh impossible without intrusive microscopic examination. In order to grow, spiders will moult their skin (exoskeleton) several times during their lifetime and immature specimens can be much paler than mature adults. Shortly after the upper image was taken the pale female moulted and became much darker, resembling the male in the second image.


The male and female C. corticalis tend to be roughly the same size - about 10mm body length but, their body proportions are different. The male has a smaller abdomen than its carapace and the female has a smaller carapace than its abdomen.


Sac spiders are generally regarded as outdoor species. C. corticalis, for instance, favours a retreat in the cracks of tree bark, while others may create a silken nest (or 'sac') within folded leaves. But, they may also be found indoors.


As hunting spiders, they do not construct entrapment webs but rely on quick, active foraging styles to hunt their small insect prey. This is usually done at night so, they may not be seen as often as other spider species.



It is not very often that a spider will conveniently lay on its back but this male feinged death for a short while and the two pale patches seen on its underside are ventral plates covering the lungs.



DateSighting
14.03.2008 Female found in garage - presumably sheltering from adverse weather. Pale when found, much darker after moulting.
28.03.2008 Dark male found indoors.


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Daddy-longlegs spider

Daddy-longlegs spider
- or Cellar spider

Pholcus phalangioides

If ever anything looked like an accident of evolutionary design, it has to be this. And yet it appears to be a practical concept because it is found throughout the world.

It favours cool, damp places indoors - hence it's common name of 'Cellar spider'.

It forms loose webs, usually in the corners of rooms and hangs motionless on the underside waiting for any passing insect to touch the web. It then shoots out its long front legs to capture its prey.

When disturbed, it has developed the technique of bouncing or vibrating on its long legs to 'blur' its appearance and frighten off any aggressor.

After mating, the female waits until she has had a meal before fertilising her eggs - which she then carries around in a pouch held in her mouth parts.



DateSighting
01.07.2005 Found indoors on a cool north facing wall.


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Red velvet mite

Red velvet mite

Trombidium holocericeum

Little things can cause big problems. With 20,000 different species of mite roaming the world, positive identification of mites is somewhat problematic.

This image is definitely a trombidiform mite (I think!) and I'm reasonably sure that it is Trombidium holocericeum, the one that is commonly found in gardens during Springtime. And if it's not, then it's similar.

It is readily found in loose soil and this accounts for it also being known as the 'Red earth mite'. It is predatory in its larval stage and vegetarian thereafter - but, the larva is quite catholic in its choice of food source and given the opportunity, will predate on humans and animals as well as soil living insects. The 0.5mm larva, shaped like a long thin cone, can puncture the skin and release an anticoagulent fluid which allows it to ingest the blood flowing from a tiny wound. These 'bites' can itch intensely and give rise to the commonly known 'heat-spots' or 'heat-lumps'. Many of us will have suffered these without appreciating their cause.

The 3mm adult mite in the image, was found and rescued from the garden pond in March but, larger specimens measuring 4mm have also been found. The common name is derived from the short velvety hairs which cover the body. They are just visible in the image on the silhouette of the right 'shoulder'.


DateSighting
10.04.2005 Three found floating in the garden pond - and not happy to be there.
26.03.2007 Another found on the surface of the garden pond.




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