Titanic struggle: Garden spider versus bumblebee

 

We witnessed a titanic battle between an unfortunate bumblebee and a female garden spider Araneus diadematus that had spun her web on the flight path to Michaelmas daisies in the abbey garden, Hexham, Northumberland last week. For a while it looked like the frantically buzzing bee might escape, but then the spider’s poisonous fangs found a weak spot and the struggle subsided.

Then the spider suspended its prize on a thicker thread and spun it round and round with its feet, wrapping it a silken shroud paid out from the spinnerets on the tip of her abdomen.

The Spiders and The Fly

Today's Guardian Country Diary describes a walk along a stretch of the banks of the river Wear at Wolsingham in Weardale, along a footpath known as The Fly. The name probably refers to the fact that this is a good stretch of fly fishing river, but it's also a fine place for finding interesting insects and spiders.

The early part of the walk passes through meadows like this one, which have produced a wonderful display of buttercups this year. This might be because the buttercups, which store starch in their roots over the winter that can be used for rapid growth in spring, have responded to the unusually late spring by growing more rapidly than the grasses.

Then the path plunges into shady woodland with dense vegetation on the edge of the river .......

... before the trees - mostly alders along this stretch - thin our. At this point the soil is mainly fertile silt left by winter floods and the vegetation is luxuriant - these aniseed-scented sweet cicely plants were head-high. If you click here you can see what this spot looked like back in May, when the tallest plants were only ankle-high.

A crane-fly, showing the paired balancing organs rather nicely.

There were a many of these snipe flies Rhagio scolopacea (above) lurking in the last of the hawthorn flowers that bloomed almost until the end of June in the hedgerow along the first part of the path. They're predators, flying out to catch passing insects. Snipe flies have a distinctive habit of resting in this head-down posture in hedges. Those unusually large eyes are exceptionally sensitive to movement of prey passing through their field of vision.

The dense riverbank herbage is perfect habitat for these scorpion flies Panorpa communis. The curled up tail, which looks dangerous, is really the male's specialised genitalia.

Scorpion flies belong to a very ancient order of insects called the Mecoptera and fossils of their distinctive wings show that they evolved at least 250 million years ago. They are thought to be the ancestors of butterflies, moths, caddis flies and true flies. 

The two pictures above are of a female, which lacks the 'scorpion' tail of the male.

Bird cherries are a prominent component of the tree flora here and some have become infested with small ermine moth caterpillars, which weave a silken tent where they can defoliate the tree in comparative safety ....

... although this one has broken cover.

In years when there are heavy infestations whole trees can be enveloped in these silk tents.

There's a diversity of fly species along this footpath - and also plenty of spiders. The three pictures above show the cucumber-green Araneus cucurbitinus, whose abdomen can look like a flower bud. It weaves its snare across the surface of leaves.

This, though, was our most fascinating spider discovery - a ball of recently hatched diadem spiderlings (aka orb web spider, aka garden spider) Araneus diadematus. At this stage they huddle together for mutual security but if you give this seething mass of tiny arachnids a gentle poke .....  

...... the spider-ball explodes and they scatter in all directions.......

... racing away along the silken threads that suspend the ball ....

.... like sailors climbing the rigging of a sailing ship.

This'll Make Washing-up more Interesting ....

It's a sure sign that we're on the threshold of autumn when spiders become more conspicuous. The beautifully marked Araneus diadematus has spun her web outside our kitchen window, perhaps wise to the possibility that the kitchen light will attract prey to the window and into her web. 

Standing at the sink, washing the dushes, will be a bit more interesting now that I can monitor this predator's progress.

The colour of these garden spiders (also known as diadem spiders and cross spiders) is very varied and most in our garden are shades of brown - individuals with this attractive black, white and grey colour scheme are uncommon around here.

For more info on the biology of garden spiders click here

For more spider encounters, click here

Willowherb Blizzard

This diadem spider Araneus diadematus laboured to spin its invisible snare but made the mistake of weaving it downwind of a patch of Rosebay willowherb ....

... which made it instantly visible to insects that might otherwise have blundered into it. I watched the spider - perhaps driven by hunger after failing to catch any prey - meticulously trying to remove the cottony seeds from the web. It managed to clear the central  zone, but the outer sticky threads ....

.....collected more seeds faster than it could remove them, thanks ..

... to this large patch of willowherb upwind of the web, that released a blizzard of seeds with every puff of wind.

It's interesting to watch the willowherb seed pods open. First the four outer segments peel back like brittle banana skins, exposing ....

... a double row of seeds on each.  In still air they remain attached in rows....

.......pushed upwards on the cotton threads as they dry in the sun ....

 

.... until the slightest puff of wind whisks them away and up into the thermals. No wonder this plant is such a successful coloniser.

It's also the food plant of the elephant hawk-moth caterpillar 

Last Thursday's Guardian Country Diary was an account of pursuing this comma butterfly into a patch of willowherb.....and unleashing a blizzard of seeds in the process.

Embarrassment of Riches

There has been a major emergence of craneflies here recently and many - like the one in this photo - have almost instantly fallen victim to the orb webs of diadem spiders Araneus diadematus. This one had slung its web just at the right height above the grass to catch these gangly insects, that tend to flutter close to the ground when they're laying eggs amongst grass roots. Craneflies are easy victims and this spider had caught several.

When I disturbed the spider in the act of shrouding its latest victim in silk it raced back to the top of the web, to its lair amongst the ragwort seed heads, where its colour provided almost perfect camouflage and where it already had a ladybird in its larder. 

Diadem spiders' webs suffer a lot of wear-and-tear and soon become deranged, only lasting for about a day before the owner eats the old one and spins a replacement ........... so what does it do with its previous day's coccooned, uneaten catch? Transfer it to some temporary store somewhere? I'll have to get out there and have a look...