Web masters

One of my favourite novels when I was young was Charlotte’s Web by E. B. White. An endearing story of a pig named Wilbur and his friendship with Charlotte, the spider who could spin messages in her web. I yearned to find a Charlotte of my own, a spider who could show me the way to eternal enlightenment through messages in silk. Nowadays it is the webmasters of the internet that dictate my search for truth through HTML.

Common garden spider, Araneus diadematus, wrapping a bluebottle fly.

Common garden spider wrapping a greenbottle fly.

The true web masters of the world are spiders, spinning complex lattices in which to catch their prey. Early autumn is the time to see large orb webs glistening in the early morning sun, drooping under the weight of dew. Gardens are abundant with the criss-crossing of silk, sometimes invisible until you walk into them – I always feel guilty when this happens and find myself apologising to a disorientated spider who finds itself clinging to my coat. Those big round webs are built by the beautiful Common garden spider, Araneus diadematusour commonest orb spider. Masters of symmetry, these spiders spin their webs at night, constructing an elaborate sticky trap in readiness of catching dinner. They sit patiently in the middle of the web, waiting for something to fly in and get entangled. At this time of year juicy wasps and flies are the bounty. In Warwick Gardens most of these spiders are centred around the ivy bushes as they are in flower and teaming with flying insects. I can spend hours web watching… waiting for that moment when something lands on the web – the speed at which the spider catches and wraps an unfortunate insect in a silk tomb in a matter of seconds is astounding.

Nigma walckenaeri under web, and with prey

Green leaf web spider under web, and with prey

Another spider has a different tactic. The tiny Green leaf web spider, Nigma walckenaeri, spins a flat, rather untidy web across the top of a leaf and crouches underneath it, rather like a bivouac, shooting out when something triggers a vibration. The spider and its tiny web is virtually invisible against the green of the leaf. This spider punches above its weight in regards to size of prey, regularly catching large flies and hoverflies, and administers a powerful bite to paralyse it.

Nursery web spider with egg sac, and spiderlings in web tent

Nursery web spider with egg sac, and spiderlings in web tent

The large Nursery web spider, Pisaura mirabilis, uses web skills in another way. They do not spin a web to catch prey, instead lie stretched out on leaves and wait for flies and other insects to pass by, then use quick sprinting and strength to overpower them. The female lays her eggs into a silk cocoon which she carries around in her fangs. When her eggs are about to hatch she attaches the sac to a blade of grass and spins an elaborate tent. She releases her spiderlings inside, hence the name ‘nursery web’. The female will stand guard nearby until the spiderlings are old enough to disperse.

“The things nightmares are made of….”

That is the comment my friend Keeley Von Spambot posted on my Facebook status when I stated I was off to check the wasp spider in my park hadn’t been squashed by a football! Wasp. Spider. Two insects that put the wind up most people. In the press recently there have been scare stories about “deadly” false widow spiders, and the killer Asian hornets poised to jump the Channel and kill all our honey bees. False widow spiders are ‘… no more dangerous than eating a peanut. But quite often alarming headlines are used to draw people in.’ Bad press invades. We have no deadly spiders in the UK. The Asian hornet scenario, though, is rather real… even Defra have put out a nationwide warning.

Wasp spider Argiope bruennichi

Wasp spider Argiope bruennichi

Meanwhile… in Warwick Gardens I have found a Wasp spider. One of our prettiest spiders, it arrived in the UK in the 1920s and has slowly established itself in the southern counties. This is the second time I have seen one in the park. There has been a gap of 4 years since the last sighting – hence why I am super-excited! They build large orb webs in grassland and heathland. Our wasp spider has built her web low down in the grass, stretched between a nettle stem and a leaf of green alkanet. Their distinctive web has a wide, white zig-zag strip running down the middle, known as a ‘stabilimentum‘. Mating is a dangerous game for males; they wait at the edge of the web until the female has moulted into a mature form, then take advantage of her jaws being soft and rush in to mate. However, many males still get eaten during this time. The female attaches her silk egg-sacs to the grasses.

At the weekend the local boys come out to play football in the park, dangerously near to where the wasp spider sits. I have to hover in the background trying not to draw attention to our little lady hanging tightly onto her web. I couldn’t bear her being squashed by a stray kick…

Life in the silver birch trees

Silver birch trees

Silver birch trees

I love silver birch trees – the white peeling parchment bark, and the long flowing branches thick with catkins are like trusses of beaded hair waving in the wind. Edith Nesbit described them in her poem ‘Child’s Song In Spring‘ as: ‘The silver birch is a dainty lady, She wears a satin gown;’ Poetic indeed. They are the iconic tree of Russia, where the sap is revered as a wholesome elixir that can be taken as a spring tonic and the twigs are used as veniks in Russian banyas. Known as the tree of Venus, the silver birch symbolises love and fertility and in English folklore is said to ward off evil spirits. They are also amazing habitats for invertebrates.

Birch catkin bug, Birch shield bug and Red-legged shield bug

Birch catkin bug, Birch shield bug and Red-legged shield bug

There are four silver birch trees in Warwick Gardens, standing majestically near the railway line and flanked by a hornbeam and a red horse chestnut tree. The distinctive white bark punctuated with lichen clad fissures provide an assault course for insects, complete with nooks and crannies to hide in. Ants run up and down the trunks looking for aphids, deftly sidestepping the red velvet mites, and ladybirds trundle over the bark on the long climb up to a branch junction. There are two bugs that feed on, and lend their name to, the birch tree – the Birch shield bug and the Birch catkin bug. Both are common in Warwick Gardens and can be found chilling out on the catkins or posing on a leaf. Other shield bugs which enjoy living in these trees are Parent bugs and Red-legged shield bugs.

Running crab spider

Lichen running-spider

Evidence of spiders are visible with scanty webs draped across holes in the trunk. Last year something caught my eye when I was walking past a tree – a very camouflaged spider. I just managed to take a photo before it scooted away rather quickly. I uploaded it to Flickr and within minutes had offers of identification by excited arachnologists – a Lichen running-spider Philodromus margaritatus. Now this is a rare sighting of one of these spiders – the last sighting was in the south of England. It feeds on lichen, hence the name, especially that which grows on silver birch trees. The habitat is perfect – our trees are swathed in lichen. As a migrant from Europe chances are it was swept into Peckham by a passing train. I was asked to catch a live specimen to send to the British Arachnological Society for formal identification. Unfortunately daily excursions to the park and several night-time trips clad in dark clothes and a head torch armed with a pot, I was unable to find it. So I still don’t know if we have a rare spider in the park – but I like to think it is living somewhere in the trees.

Oncopsis flavicollis nymph and adult

Oncopsis flavicollis nymph and adult

The Buff-tip moth (though yet to be seen in Warwick Gardens) is a classic example of an insect using camouflage to blend into its environment as it looks identical to a twig of the silver birch tree. The leafhopper Oncopsis flavicollis can be found amongst the leaves and another invertebrate using this tree is the Nettle weevil. So next time you pass a silver birch tree it is worth taking a few moments to look closely at it. You never know what you will find.

Yummy mummy

Warwick Gardens is the perfect place for children – it has a safe playground, a dog free zone, and the log seating nestling amongst the long grass makes playtime for small kids seem like a day out in a meadow. A chance for mums to let them run around. Though sometimes I wish they would exercise constraint over their little ones when they run roughshod over the flowers and scattering the grasshoppers! On the other side of the park hanging tightly onto a leaf high up in the silver birch tree, and keeping her young nymphs close to her, is the ultimate mummy – the Parent bug.

Adult Parent bug, and sitting on her newly hatched nymphs

Adult Parent bug, and sitting on her newly hatched nymphs

Of the ten species of shield bug living in the park the Parent bug has to be one of my favourites. Looking very similar to the Birch shield bug, and sharing the same habitat, the Parent bug can be easily identified on the basis she sits on her eggs. This is very unusual in the bug world. They are reasonably easy to find… it just takes a keen eye and a thorough search through the leaves of the Silver birch tree. These trees have long flowing branches and in high winds wave around quite fiercely. Our bug lays her eggs in a tight cluster on the underside of a birch leaf and hangs on, bearing the brunt of the English weather. She then broods her clutch, sitting protectively over the eggs until they hatch.

Brooding her 2nd and 3rd instar nymphs, and 4th and 5th instar nymphs

Brooding her 2nd and 3rd instar nymphs, and 4th and 5th instar nymphs

Like all good mums the female Parent bug looks after her family until the young finally become adults. As with all bugs, shield bugs undergo an ‘incomplete metamorphosis’ which means they do not possess larval and pupal stages. The adults develop from several stages (instars) of nymphs (up to five) through successive moultings. Nymphs resemble the adults except for size and the absence of wings and they usually have different colouration or patterns. They feed on the sap of leaves.

Update 2nd October

Parent bug nymphs and adults, and a moult

Parent bug nymphs and adults, nymphs on the move and a moult

One month on and I have been watching 6 families of Parent bugs. They are living on separate parts of a silver birch tree branch. I have been fascinated with how they live: bunched together as nymphs as if scared to go out into the wide world, though a few have ventured off and spend their day alone on a leaf. One family insists on walking up a branch to visit a catkin, and later in the day I find them back on the leaf they started from. I have witnessed the moult into adulthood, the lone parent standing by the final nymph, adults waiting for their kin to moult, even a whole family finally becoming adults but still insisting staying together … but today I went to look and all my families had dispersed. I wish them love and luck – it has been a joy.

House-hunting in Peckham

People are queueing up to live in Peckham as it has become so damn trendy. House prices have rocketed and everyday there is a letter through my door from some unscrupulous estate agent urging me to sell my house as ‘you live in a highly desirable location and we have a long waiting-list of people wanting to live in your street’. Tough, I ain’t going nowhere!

Ectemnius cephalotes out hunting and in her tunnel

Ectemnius cephalotes out hunting and in the entrance to her tunnel

The digger wasp Ectemnius cephalotes is also house-hunting. Her requirements for the perfect nesting place is an old log, tree stump or timber stack. She is even happy to share with other females. There is a good choice of possible apartments in Warwick Gardens as there are nine large logs used as seating at the top end of the park. These double up as housing estates for various species of insect. Earwigs, woodlice, centipedes, solitary bees and wasps, beetles and spiders all find living here a ‘desirable location’. For the past couple of days our wasp has been scouring two particular logs, checking every nook and cranny for a suitable place to lay her eggs. Although willing to renovate an old nest, these digger wasps are super confident at DIY and will dig holes in the wood with their large jaws to create cavernous tunnels with separate cells for storing prey items.

Ectemnius cephalotes with hoverfly Syrphus ribesii, and pulling it into her tunnel

Ectemnius cephalotes catching a hoverfly Syrphus ribesii, and pulling it into her tunnel

Once the wasp has excavated her tunnel and constructed her cells she needs to stock up on food for her larvae to feed on. Ours favours large hoverflies, in particular Syrphus ribesii, which look very similar to her. She will catch them in flight and with supreme dexterity pull them into her tunnel. I was surprised at how quickly this happens and just managed to photograph it! They will be stored in the cells. When her cells are full she will seal up the entrance to the tunnel and lay her eggs. Each cell will have one egg and the larva will have up to 12 flies to feed on. The adult wasps emerge in early summer.

Anyone for bush-crickets?

The park gets rather busy in the summer. Children running around yelling, boys playing football and basketball, the occasional family picnic and people lounging around enjoying the sunshine. Competing to be heard above all the noise are the chirping crickets – that unmistakable sound of summer.

Roesel's bush-cricket nymph and female adult

Roesel’s bush-cricket nymph and female adult

Warwick Gardens is home to four species of bush-cricket. The loudest and most prominent is the Roesel’s bush-cricket. I have a real affection for these having spent much of the year watching them grow from tiny nymphs to majestic adults. They like to hang out in the long grass and are very well disguised making them rather difficult to see. The nymphs are especially cute, emerging in May and only noticeable if you stand still long enough to see this tiny insect hop around, especially after it has just rained. And they can really hop! The male adults start to sing (or stridulate) in July to attract females. Stridulation occurs when the weather is hot and sunny enough to achieve the peak temperature for stridulation. The song is similar to the ‘hiss of overhead electricity wires’. Interestingly the song gets louder when a train passes by the park or when a plane roars overhead. This is the best time to look for them as you can locate them by the sound and looking for the movement of the wings. But you have to be stealth-like as they stop singing altogether if you approach them with a camera!

Speckled bush-cricket nymph and male adult

Speckled bush-cricket nymph and male adult

Another common cricket you can see in the park is the Speckled bush-cricket. These secretive insects usually hang out in the lilac bushes or camouflaged amongst the leaves of the oak tree. I find them very graceful. They are bright green with a speckled body and very long antennae, with the male sporting a brown stripe along his back. They are flightless, relying on their long legs to hop. As with all bush-crickets the the females have broad and upturned ovipositors which they use to cut open plant stems and lay their eggs, and the nymphs go through several instars before maturity. Compared to the Roesel’s bush-cricket this cricket has a very weak call, their tic-tic only audible with a bat detector. Unlike other cricket species, the female is able to respond to the male’s calls with a weaker call of her own, which attracts the male to her. They feed on leaves and flowers.

Southern oak bush-cricket male adult

Southern oak bush-cricket male adult

The Southern oak bush-cricket is a more unusual cricket to find in Peckham. This is a non-native species having hopped across the Channel in the 90s, probably on the back of a lorry, as it another flightless cricket, or even in a Landrover as a friend texted me a photo of one sitting happily on his dashboard. It has become widespread in southern England and appear as adults in August. As an arboreal species I never seem to find any nymphs as they are tucked under leaves higher up out of my reach. It is carnivorous feeding on small insects. The male does not have a ‘song’ as such, but drums on leaves with its hind legs. Last year the BBC Radio 4 series Saving Species featured an article on the Southern oak bush-cricket and they came to Warwick Gardens, a guaranteed place to find one of these lovely crickets. It was an interesting couple of hours – entomologist Tristan Bantock, who was being interviewed, had to contend with inquisitive children as he swept the bushes, and several retakes as the interviewers microphone was so sensitive it picked up all the background noise of trains, planes and chatter. There was even a chance that we wouldn’t be able to find a specimen, even though I had assured them there was one hiding in the ivy! There was, along with an Orientus ishidae leafhopper…

Long-winged conehead nymph and female adult

Long-winged conehead nymph and female adult

Our final cricket has been rather elusive of late. I first found the Long-winged conehead in 2009 but didn’t see it again until this year – they seem to have bounced back as I have recorded five nymphs in the past couple of weeks. The long hot summer and an abundance of tall grass has been the perfect environment for them. Their stridulation is a ‘prolonged rapid chuffing noise inaudible to many’ but audible with a bat detector. Along with the Roesel’s bush-cricket it is omnivorous with a diet of insects and grasses. Two things noticeable about this cricket are the very long antennae and the extended ovipositor on the female. Their main form of locomotion is walking, though their long wings enable them to fly to escape predators.

Stocking the larder

Astata boops

I went blackberry picking in Warwick Gardens this morning. The bushes hang over the fence from one of the gardens and are laden with ripe, succulent fruit. I stewed some in red wine with star anise, cinnamon and a squirt of honey (yum!) and packed the rest away in the freezer for later.

Another creature stocking up her larder was Astata boops, a fine-looking shield bug-hunting wasp. She looked rather happy to have caught a Birch shield bug nymph and was running up and down the birch tree working out a way to carry it back to her nest. These wasps make their nests by burrowing into the ground and building cells. The tunnel can be 10cm long and usually contains two or three cells. Our wasp has her nest near one of the blackberry bushes as she flew off the tree and disappeared into a hole under the grass. The female fills each cell with a shield bug, lays her egg in it and seals up the cell. The entrance to the nest is also sealed and guarded by the male. The larvae feed on the shield bugs over winter and emerge as adult wasps in the spring.

Life and death on the Lesser burdock

The thistles have run out of steam so the pollinators have migrated to the other side of the park to a patch of Lesser burdock. This plant has wandered. Two years ago there was just one small plant and now there are four mighty specimens standing two metres tall. It has some fancy names: burweed, louse-bur, common burdock, button-bur, cuckoo-button and wild rhubarb.

The purple flowers are in bloom and provide nectar and pollen for bees, flies and butterflies, and the large leaves serve as platforms for grasshoppers and earwigs to sun themselves. The bumblebees are loving it and skit between the flower heads. Ants and Picture-wing flies run up and down the stalks. These are interesting little creatures – Richard Jones has written an informative article about them: Picture-wing flies.

 Braconid wasp and mummy cases

Braconid wasp and mummy cases

Yesterday I was wondering about some strange little aphid shells with holes that were attached to one of the stems. Further research identified them as ‘mummy cases’, caused by Braconid wasps. These tiny wasps are beneficial parasitic wasps, as one of their hosts is the aphid. After a female wasp injects her egg into an aphid, the larva slowly devours it. An aphid parasitised in this way is called a mummy. By the time the aphid dies, the fully grown larva has cemented it to the leaf surface and the aphid shell becomes parchment-like or black. The larva pupates inside the mummy, and when fully developed, the adult wasp cuts a hole in the casing and emerges. The empty mummy case, with its hole, remains on the leaf. There are lots of Braconid wasps flying around our Lesser burdock, and understandably not many aphids! 

Fairies in Peckham?

Gasteruption jaculatorOne of the prettiest creatures to visit Warwick Gardens has to be this wasp with the most fantastic name – Gasteruption jaculator. It is a parasitic wasp closely related to the ichneumon wasp, belonging to the Evanioidea family. They daintily dance around the flowers like fairies, stopping to feed on nectar. To us they are good fairies as they pollinate our plants, but to solitary bees and wasps they are BAD fairies!

Easily identified by the extremely long ovipositor, the female visits the nests of various solitary bees or wasps and pushes her ovipositor into the nest, depositing her eggs on or near to the eggs of the host. On hatching the young larvae will devour the grubs and supplies of pollen and nectar of its victim. The adults grow up to 10–17 millimetres.

Fly of the day: Conopid fly

Conopid fly - Physocephala rufipesThe park is looking rather brown after all the recent sun. There are very few flowers apart from yarrow and a scattering of mallow, and the last remnants of thistles have seeded and spewing fluffy spores all over the place. The brambles are heavy with fruit and the hawthorn berries are slowly ripening a deep red colour. But there is a flash of yellow that stands out in the middle of all the brown – ragwort. Its only a small patch, just nine plants, and it is a feast of pollen for flies and bees.

The conopid fly is a regular visitor to this patch. It’s more commonly known as a thick-headed fly and is rather ugly looking. It is a parasitic fly and lays its eggs in bees and wasps. This one – Physocephala rufipes – parasites bumblebeesThe eggs are often inserted by the female fly between the bumblebees’s body segments while in flight, and they hatch out soon afterwards. The larvae eat the bee from the inside.