After seeing a Dragonfly in the shrubbery last week, and with a return to warmer nights, I thought I’d take the still and camcorder cameras down to our natural ponds to see what was on the wing. We always get a selection of damsel and dragonflies making it into the garden to hunt for insects, but there are several species which remain closer to the water. I’ve decided that I need to get grips with trying to identify those which frequent the ponds, which were dug about 14 years ago and since then have been allowed to ‘naturalize’ with a ditch inflow, and outlet. One is about 3 feet deep, the other goes to nearer 5 feet in the middle, and both are now colonised with native marginal plants including Common cotton-grass, Bogbean, Yellow flag irises, Ragged Robin, Meadow Sweet and Purple Loosestrife as well as lots of rushes and Mare’s tail!
We’ve never really viewed them as part of the garden, but increasingly they seem to play a role in acting as a habitat for wildlife which subsequently makes it the 200-300 yards up the hill and into the garden proper. They’re yet another example of the slow long term ability of terrain to revert to a very diverse flora and fauna, simply by doing nothing – apart from allowing selective low intensity grazing, and not using any fertilizer of any kind. I’ve always been struck by the phenomenal beauty and diversity of the Fynbos vegetation in the Cape Province of South Africa, and how it’s evolved on nutrient poor soils over millenia into one of the most species rich flora on earth. So nutrient richness is not a prerequisite for successful plant growth. In fact quite the reverse. Perhaps an important point for us gardeners to remember.
Armed with the excellent ‘Field Guide to the Dragonflies and Damselflies of Great Britain and Ireland’ by Brooks/Lewington, I’ve been able to identify most of the ones I’ve seen so far. More will emerge as the year progresses, but for now I’ll include a few pictures.
Most are easy to photograph from a distance with the Camcorder zoom, although with my trusty still camera 50 mm macro lens it’s less easy to get close enough, but one species seemed to have a very canny strategy for avoiding the camera’s gaze. Even from 4 or 5 feet away it grips a vertical rush stem, with only its eyes visible either side, and its body completely hidden. To photograph it, I left the camera running and walked to the right in an arc – the damselfly matched my moves in a diametrically opposite shifting of position, so that (on video), I was able to get good images of its side and back, as it rotated round the stem. In fact I think that this avoidance strategy may be used by the immature forms which have just emerged from their pupa, and before they are able to fly.
All damsel and dragonflies have extremely large eyes, and very good vision for hunting other insects, and indeed to avoid being eaten by other larger dragonflies or birds, and this damselfly was using the less acute lower part of its eyes to do this monitoring of me. For this reason for any insect photography I try to remember to wear a green top and hat, and move very slowly – bright or light clothing, and sudden movements are very likely to spook any insect that can fly.
The meadows themselves are increasingly showing a wider diversity of flowers, and this year F took me to see an unfamiliar looking single plant stem which she’d spotted whilst billhooking Marsh Thistle flower stems. After trawling ‘Wildflowers of Britain and Ireland’ by Blamey, Fitter and Fitter, we suspect that it is a Broad-leaved Helleborine – a native orchid, which we haven’t seen locally before.
Like most orchids its seed, when produced, is extremely fine and dispersed in huge quantity and capable of widespread distribution, simply waiting to find the ‘right’ conditions, in particular the right mycorrhizal associations for the seed to grow. Perhaps after 17 years with no NPK fertilizer on our fields the declining soil fertility has allowed it to germinate and succeed? In addition the delay in grazing on the field this year has clearly been a key factor. Perhaps we shall have to tweak our grazing regime from now on to allow these plants to flower and set seed before being chomped off by the close grazing inevitable with sheep. Other flowers seen included early marsh orchids, lesser stitchwort, heath bedstraw, tormentil, heath speedwell and the first flowers of birdsfoot trefoil, which from a few scattered seed a few years ago is now spreading well, along with white and pink clover, as nitrogen fixing leguminous native plants.
I’ve been thinking a bit more about the Rosa moyesii flower and sonication or ‘buzz pollination’ by bumblebees which I mentioned in a previous post. This has continued throughout the last week, when the sun has shone on the few remaining flowers, and more flower visitors have been spotted – this 2 coloured spider, almost willing the small fly to move within range:
and this pair of mating bugs, which I haven’t yet identified but which also spent ages in one flower, the much larger female obviously eating something whilst the relatively diminutive male simply clung on.
But it was the buzzing bees which really fascinated me. I can’t see obvious pollen on the rose anthers, and then discovered that Rosa moyesii is a relatively unusual plant in that it is hexaploid – meaning that it has 6 pairs of each chromosome. Humans have only 2 pairs of each chromosome (diploid), and I wondered how this native to China plant should have come to have the extra copies. (The ‘chromosome’ section on Wikipedia is very enlightening on basic chromosome structure and function. And also what effect the extra chromosomes had on the plant’s flowers, and its pollen and nectar).
Then I discovered that modern wheat strains have all been bred as hexaploid, whereas the original wheat grain was diploid, and also that coeliac disease (which is on the rise throughout the world, particularly in India, and is caused by intolerance to gluten, one of wheat’s proteins), is speculated to be linked to the use of these hexaploid varieties by some researchers. Perhaps the hexaploid Rosa moyesii produces tastier or more micronutrient rich pollen than other rose species, and the bumblebee can detect this, or perhaps the anther structure is such that sonication is a better method for freeing the electrostatically charged pollen grains so that the bumblebee can then attract them up onto its hair, and thence to the special pollen carrying area on the hind tibia. The bumblebees don’t move their wings whilst working their flight muscles in this buzz vibration, and emit a higher pitched sound than when flying, of “middle C”. Since we have a piano I was intrigued. And hummed the bee sound inside and out until I reckoned I had a good match of pitch between bee and piano. And I have to report that our Welsh bumblebees have good vibrations at a higher pitch – of D natural, or possibly even D sharp. It could also perhaps just mean that our piano needs tuning!
The other time I’ve mentioned this pollination in a previous blog related to tomato pollination. Since our tomatoes (a bush variety called Maskotka) have been flowering for a couple of weeks I’d thought about a plant to encourage bumblebees into the greenhouse. And by chance a parsley plant had flowered in the greenhouse, and attracted a bumblebee inside, but the bee showed no interest in the few tomato flowers open at that time – they don’t really like the smell of tomato flowers apparently.
So I returned to thinking about the commercial growers who used to use mechanical or electrical vibrators to achieve better fruit yields, before those ‘clever’ folk at Koppert had the idea of selling boxes of bumblebees to commercial tomato growers (See my previous blog entry under Buzzing). One article reported a doubling of yield by using an electrical vibrator of this type on the flowers, every other day, ideally between 10.00am and 2.00pm for optimal results. Now if the yield uplift had been about 15-20% I probably wouldn’t have bothered, but the prospect of doubling the yield, and bringing it forward in time before the dreaded tomato blight hits, sounded appealing. (All you gardeners who have been growing tomatoes successfully for years will no doubt be amused by my research, and have your own invaluable tips for good cropping)
So, I remembered a few months ago reading about a pair of marketing executives who decided to set up a new internet based business. They researched various ideas, and in the end narrowed the possible product down to 2 completely different possibilities where they felt there was a gap in the market. Either cross-stitch kits, or upmarket sex toys. They chose the latter, and since they featured in a mini-series entitled ‘My First Million’, you can deduce that they chose wisely, at least from a financial perspective. So now, every other day I nip out around lunchtime with an old paintbrush, and power up the intriguingly shaped lurid pink vibrator (which F rightly insists is kept well hidden from garden visitors!). And today, 17th June, for the first time I even produced a momentary but visible cloudburst of pollen from 3 of the flowers.
And the result? Well, I’ve sadly no comparisons, but I can report that to date I seem to be getting 100% fruit set, so I have no complaints. Apparently some folk have tried electric toothbrushes, but as with the bumblebees’ actual sonication, the frequency of vibration is important, and toothbrushes just don’t seem to do it at the correct higher level.
And the name of the firm in case you’re interested? Well I haven’t made it up. It’s called Love Honey – rather appropriate for a bee, albeit bumblebee, substitute!