Broad-leaved helleborine, pollinated by wasps.

We found a population of about 30 broad-leaved helleborines Epipactis helleborine beside the Deerness Valley walk, a disused railway track that has been converted into a pleasant route for walkers and cyclists. 

This is an orchid that thrives on woodland edges, in dappled shade. It's pollinated by common wasps Vespula vulgaris, but this was the first time I have seen the pollinators in action.

The flowers emit a scent that attracts the insects, which have short tongues, so they have to push their head right into the flower to reach a pool of nectar. When they do this the orchid's pollinia, which contain all their pollen, stick to the wasp's face. In the photographs above and below (rather blurred, because the light was poor) you can see a wasp arriving after visiting another plant, carrying the white pollinia on its head, ready to pollinate the flower.

Below, you can see a wasp leaving, taking the sticky pollinia with it, attached to its face.

Click here for a very good YouTube video, by Jean Claessens, of the whole process

Wasps - the end is near

Almost at the end of the wasp season now. but there are still a few lethargic common wasps Vespula vulgaris in the garden, feeding on rotting fallen fruit. After cold nights they move very slowly, so it's easy to get close to them and get a good view of those powerful jaws. All season long they've been chewing wood to make paper for their nests, then catching other insects to feed their brood. Now, in their final days, they search for anything sweet to boost their flagging energy levels.

A few are feeding on the last of the late-season red-hot pokers Kniphofia sp. These popular garden flowers grow wild in South Africa, where they are pollinated by sunbirds that come to feed on the large volumes of nectar they secrete. The nectar trickles downwards in the dangling, tubular flowers and the wasps force their way in, so they often become covered in the sticky secretion and need to spend a lot of time cleaning their antennae afterwards.

Click here for pictures of the remarkable structure of a wasp nest - a marvel of paper engineering.

Wasp vs. Hoverfly: no contest

Here's something I've never seen before - a common wasp killing a hoverfly. They both landed in a rose flower at the same moment and immediately there was a fierce tussle, as the wasp grabbed its prey. 

Then the wasp bit off the hoverfly's head by chewing through its joint with the thorax. Strange behaviour because at this time of year there will no longer be any grubs for the wasp to feed in the nest, and when the nest begins to break up wasps tend to focus on sweet liquid food, like nectar and rotting fruit, rather than on live animal prey.