Yarrow Achillea millefolium is a later summer wild flower that provides easily-accessed pollen and nectar for visiting insects, right up until the end of autumn. It's particularly popular with flies, like this greenbottle, and with hoverflies and droneflies. They can feed without expending much energy, simply by landing and walking from floret to floret across the flat-topped umbel.
But sometimes just landing on the flowers can be hazardous. About thirty yarrow plants were hanging over a wall along Mortham Lane beside Rokeby park in Teesdale. They had been blown sideways by high winds during their early growth, and at the same time their flower heads had defied gravity and curled upwards, so the whole plant protruded from the wall like a long coat hook. And in that hook, in every plant, a money spider had built its hammock-shaped web, beside the flower head. Money spiders usually sling their horizontal hammock webs in hedges or low in the grass, but this population had taken advantage of the yarrow scaffolding that an accident of wind and gravity had provided.
I watched these plants swaying in the wind, while a long procession of insects came to feed. Drone flies are skilled hoverers and negotiated the risky landing successfully, and .....
.... hoverflies timed their approach and landing with even more precision, avoiding the spider's snare. But there was plenty of evidence, in the form of wings and legs in the webs, that other flies had been less fortunate, and had made a fatal landing in the money spider's web. I saw a blundering greenbottle land in the web, but with good fortune and some frantic buzzing it just managed to extricate itself before the spider arrived.
And in this old web a well-fed occupant had evidently done enough feeding, and had woven its egg cocoon amongst the leaves below the flower head, that had acted as bait for its victims.
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