Queen wasp mating

 Poor photo (heavily cropped, taken with an old phone in deep shade) but this appears to be a queen wasp mating with drones. They all flew away, still locked together, before I could get a better picture.

Mid-July seems very early for new queens to be leaving a nest - they usually hibernate after mating - but still plenty of summer left for her to start a new nest this year, I suppose.

Two wasp generations in one summer? Are seasonal patterns of insect behaviour confused by changing climate, maybe?

This morning, riverbank footpath, Durham city

Ivy - the all-year-round carbon dioxide fixer

Ivy's flowers provide a wonderful nectar and  pollen resource for insects in autumn (see some examples at the bottom of this post) and its berries are a vital food  resource for migrant birds in early spring, but it also has another important attribute with more general implications.

As an evergreen that stores carbon in its woody trunk, ivy is an all year-round carbon dioxide fixer, constantly removing the gas from the atmosphere. In that respect it contributes towards combatting the build-up of carbon dioxide in the atmosphere, which is the underlying cause of global climate change.

Deciduous trees like this ash have a short growing growing season in our seasonal climate. It comes into leaf in May and sheds its foliage in September, so for about half the year it fixes no carbon dioxide at all. But when it supports a luxuriant growth of ivy the two organisms together fix carbon dioxide 365 days a year.







































The combined efforts of an ash tree with ivy cladding are likely to be more effective at fixing atmospheric carbon dioxide than an ash tree alone.

The tangle of  thick, woody ivy stems on this sycamore are as effective a store of carbon as the tree's trunk.

Ivy can even turn a dead tree into a carbon dioxide fixing pillar of evergreen foliage, as it did with this dead oak at Egglestone in Teesdale a few years ago. Even better, in autumn this stump became a tower of flowers, humming with insects that came for the nectar and pollen. In spring it was covered in berries.

Another example, at Wolsingham in Weardale.

Sadly, there are still plenty of ivy-haters around who are convinced that ivy is a parasite (it isn't, it just uses trees for support). They'll usually also advance the argument that a top-heavy mass of ivy is likely to bring trees down in winter gales, but most trees that are felled in this way are moribund anyway and topple because they have already been weakened by root-rotting fungi, not by ivy. Logically, a good cladding of well-rooted ivy stems is more likely to anchor a shaky tree, delaying its demise. 

The fact that trees that have been killed by fungi often have a healthy covering of ivy suggests that it might well be resistant to some of the fungi that kill trees.

From all of this you might have gathered that I'm something of an ivy enthusiast - not least because of the insect fauna that its flowers attract in autumn. All of the pictures below were taken in a few minutes late last October on another ivy clad tree just across the road from the oak-clad stump pictured above. 

The Perils of Picking Over-ripe Plums

I learned the hard way that seemingly perfect ripe plums can be hollow on the side that you can't see when you reach up to pick them, and likely as not contain a feeding wasp, so these days I always wear gardening gloves when I pick them.

This is probably what wasps dream about, when the hard work of raising a brood is over ......

....... spending their dotage chewing their way through a sweet, juicy plum. I piled some on our bird table and after the last couple of days of warm weather they've begun to ferment, so the wasps are becoming woozy on alcohol and are very approachable. Sometimes they are so inebriated that they fall over on their backs if you give them a gentle shove; reminds me of my student days.

They  need to take frequent feeding breaks to clean sticky juice off their legs ....

.... and faces.

There are some pictures of some rather different inebriated insects on rotting plums here.

Life in the undergrowth .....

Some insects in our garden undergrowth (it's a jungle out there!)

An anxious cabbage white butterfly, checking that the coast is clear. Beautiful eyes.

A marmalade hoverfly Episyrphus balteatus, hanging in the air in a sun fleck.

Amazing eyes of a much larger hoverfly Volucella pellucens , feeding on some leeks that we never ate and have now flowered - the big, spherical flower heads are very popular with bees and hoverflies. 

Volucella pellucens is a hoverfly that breeds inside wasp nests........ 

........... and might even have laid eggs in the nest of this wasp, that was hunting for small insects on dill umbels.

This froghopper was on the same umbel as the wasp but well beyond its reach, tucked in amongst the 'spokes' of the dill's umbrella-shaped inflorescence.

Trouble brewing.....

My son recently discovered this queen wasp building her nest just inside the garden shed door. He's going to try to gently remove it intact and transplant it to another location, otherwise the shed will be out-of-bounds until autumn.

For more on wasps' nests, click here

Paper engineering

Today's Guardian Country Diary describes an exploration of the nest that tree wasps built in our garden hedge.

Tree wasps Dolichovespula sylvestris have this distinctive little black spot in the centre of the clypeus (the central frontal facial plate), and a fine pair of jaws for catching prey and .........

... chewing fibres of rotten wood .

I suspect the wasp in this image is Vespula vulgaris.

They carry a ball of fibes away in their jaws and mix it with saliva. 

These three pictures show a red wasp Vespula rufa chewing fibes from a picnic table.

They use this material to build paper nests of exquisite beauty, lightness and remarkable strength. The queen, emerging from hibernation, starts the nest by building a downward-facing dome attached to a twig with a few breeding cells inside, where ....

.... she lays her first eggs that hatch into grubs, which she feeds with insect food until they hatch as adults.

Then these ever-growing ranks of workers construct the nest around her, enclosing tiers of breeding cells, with just a small entrance hole. Each strip of different coloured paper represents the work of a single wasp, with it's own predilection for the colour and source of wood fibres or hairs that it shaves from the surface of plants. The green patches on the nest above are constructed from hairs from the young twigs of the weeping pear tree in our garden.

This is this year's completed tree wasp nest, excised from the hedge after the wasps have abandoned it. As the nest grows it incorporates surrounding twigs, so the whole structure is very light and remarkably strong, considering the fragility of the components.

The view from underneath, where you can see how the exterior is constructed from successive paper layers ..

The entrance hole, a busy thoroughfare at the height of summer.

This year's nest had some red stripes in it, which I'm pretty sure came from the bark of a dead branch of a cypress tree in the garden.

One dead wasp guarded the entrance when I began to dissect the abandoned nest ....

....revealing the tiers of hexagonal breeding chambers inside ....

... and the multi- layered outer wall. When outdoor clothing companies advertise their cleverly designed products with layered insulation, remember that wasps invented this form of insulation millions of years ago!

These breeding chambers are built with astonishing precision by wasps working in total darkness, using wood fibre glued with saliva. Presumably they use the initial cells, built by the queen in daylight, as their template. Many of the cells on this nest contained grubs that died during development...... you can see one top centre in the above image.

 The grub weaves a white domed covering, that's opened by workers that come to feed it with chewed insects - and receive a sugary secretion that acts as their food in return for their efforts. This mutual dependence of grubs and adults ensures social cohesion in the colony.

The cells with the tattered white edges were homes to wasp grubs that developed successfully and chewed their way out at maturity.

Near the bottom of the nest I found these cells with dead grubs still sealed inside, almost on the point of hatching. One adult had begun to chew its way through the shroud but died in the attempt, never experiencing life beyond the darkness inside the nest. 

So near, yet so far .....

All the wasp-related info on this blog is collected here

What happened Next......?

I've been watching this female blackbird in the garden for several days, while she has been collecting nest material and building her nest in the ivy at the bottom of the garden. Now she's finished and yesterday evening I watched her preening and foraging for food in the brief period before egg laying and incubation begins. While she was perched on the fence a wasp became caught in a spider's web within easy reach and the blackbird's attention immediately locked on to the frantically buzzing insect. I could almost hear her thinking 'should I eat it?'.


I've no idea what would happen if a blackbird tried to swallow as wasp. On a couple of occasions I've seen frogs swallow wasps that have landed on the pond surface for a drink. On both of those occasions the frog looked a bit pensive as the wasp went down its digestive tract but neither frog made any attempt to spit it out, or appeared to suffer any visible ill effects. They just settled back with their eyes level with the water surface and waited for something else edible to cross their field of vision.


The blackbird hesitated for a few seconds - maybe that warning colouration really does work - and during that time the wasp managed to struggle free and got away. So I still don't know what would happen next if a blackbird swallows a wasp.


For another potential life-and-death encounter with an unresolved outcome click here

Some days, it's best to stay asleep....

Yesterday this wasp was coaxed out of hibernation in our conservatory by the bright sunshine, even though there was still plenty of snow on the ground outside in the garden. After buzzing against the window for a while it discovered the insectivorous pitcher plants (Sarracenia sp.) that I grow on the window ledge and began to feed on the sugary nectar that they secrete from around the tops of the funnel-shaped traps.

This is what it was after - the sweet drops of nectar, but they proved its undoing, because when it ventured too far into the trap it lost its grip on the smooth inner surface ...

..... and plummeted down to the bottom of the trap ....

.... where it became wedged head-first in a pool of the plant's digestive fluid.


That might of been the end of the story but it seemed a pity that it should enjoy such a brief life in the sunshine so I cut the pitcher, extracted the waterlogged wasp and exiled it to the greenhouse.


This morning there was no sign of it in the spot where I left it, so either it's crawled back into hibernation ...... or the greenhouse spiders have got it. All things considered, it would have been better if it had stayed asleep.


More insectivorous plants here, here and here ...

Wolves of the Water Surface

On sunny days wasps often land on the patches of duckweed on our pond, to drink from the surface - and sometimes they fall in and become trapped in the surface film. Within a few seconds the vibrations from their frantic struggles are propagated over the water surface and detected by the pond skaters that patrol the pond. Soon the first arrives and punctures its prey with its needle-sharp proboscis. In its eagerness to feed it has put its foot through the wing of the drwning wasp.

Soon another pond skater arrives ...

.... and another.

They home in like a pack of wolves ....

... until the doomed wasp is completely surrounded...

... and the feeding frenzy begins.