Another blog, another torch-light discovery. A consequence I suppose of no TV to while away the dark evenings and the appearance of a new trial rabbit burrow amongst the snowdrops, primroses and hellebores.
Trying to spot the culprit, I nipped out on a chilly evening, and drawing a rabbit blank wandered round the rest of the garden looking at flowers and pulling off and squishing a few weevils which munch the leaves of some of our small rhododendron plants. Since they climb up from the leaf litter at night for their nocturnal feasts it seems that once plants get beyond a certain height the plants cope with the damage, but younger ones can get eaten to leafy skeletons.
Not much else was seen until I reached our small Rhododendron ‘Christmas Cheer’ which has flower buds just about to break. As I leaned over the plant a cloud of small flies flew up and around the torch-light, and I then realised there were nearly a dozen moths on the foliage. The question was why? I’d never seen moths on a Rhododendron flower before, and these weren’t even open. None of the other twenty or so other cultivars we grow had any moths or flies on them on this evening. Was the plant warmer, or exuding some attractive material? Most of the moths were stationary on the leaves or buds and not obviously feeding. Having taken a few photos, I returned indoors and mused on the fact that the leaves of this small plant seemed to have a covering of a black sooty mould.
This was more apparent by daylight, so I then researched the topic for images of moths and sooty mould on-line with no success. However, reading more about black sooty mould I discovered that it’s always a secondary plant ‘pathogen’, usually on evergreen leaves, after the plant leaves are attacked by some smaller sap sucking insect – either scale insects or aphids. These tiny creatures suck plant tissue fluids or chew plant tissue and extract nutrients – particularly nitrogenous protein rich materials, and excrete much of the residual carbohydrate rich plant fluids after they’ve completed this digestive process. So, the plant gets left with a covering of sugar rich insect excreta, which in turn allows the sooty mould to colonise the leaf surfaces. It seems from my observation that this mould, or more likely the sugary excreta still remaining on the leaves also attracts the flies and moths I’d noticed.
The following night was colder still, but two days later the insects were back in force and I was able to get this image of a Chestnut moth grazing or sucking using its proboscis on the mould covered leaf. Pretty clever recycling for insects on a cold night, refuelling from other insect’s excreta.
I wondered about any human examples of such excreta recycling, and the first example which came to mind was that of the shamanic custom of some Siberian populations in collecting the urine of people who’d consumed Fly Agaric mushrooms, since they were aware that the urine concentrated and hence intensified the hallucinogenic properties of the mushrooms. And I seem to think that the most expensive grade of coffee bean comes from those collected from the droppings of a wild cat (luwak) which has eaten them, so maybe the moths are in good company with us humans on this subject.
Back inside, in between my night’s observations of the sooty and sweet mould, the latest March edition of “The Garden” magazine arrived from the RHS and by chance had a small piece on cushion scale and black sooty mould, spotted by the eagle-eyed Fiona. But no mention here of the value of honeydew for other insects, rather the suggestion to blitz the affected plant with organic or chemical pesticides – so I guess that there might not be a wider appreciation in gardening circles of the value of honeydew as a late night ‘Red Bull’ equivalent, for shivering moths and flies.
Perhaps Samuel Taylor Coleridge was more aware of the interlinked magic of much of the natural world when he wrote in the last verse of Kubla Khan (or maybe it was just the result of an opium induced dream?):
And all who heard should see them there,
- And all should cry, Beware! Beware!
- His flashing eyes, his floating hair!
- Weave a circle round him thrice,
- And close your eyes with holy dread,
- For he on honey-dew hath fed,
- And drunk the milk of Paradise. (lines 48-54)
(Actually its well worth reading a fascinating background to the whole poem by clicking here for Kubla Khan).
(As an addendum to my initial post I can add that after emailing the RHS with my observation, I received a reply from their chief entomologist, Andrew Halstead, who solved a conundrum that my blinkered brain hadn’t been able to work out. How come if the scale insects are on the undersurface of the leaf, the sooty mould is only on the upper leaf surface? Answer – the insects’ excreta simply falls from their bodies onto the leaf surface below. Oh dear, how obvious!)
The last week has also seen huge gatherings of starlings and then fieldfares in the trees outlining our fields. Readers of a previous blog will recall I’d spent a very chilly morning in February standing for an hour to film the commuting flock of starlings with no luck. On this particular evening they flew from the fields all around me as I pottered in the garden and grouped in the ash trees, pending flying off to their nocturnal roosts somewhere towards Llanybydder. I’d managed to film a few decent clips of vigorous starling chatter already, but always spoiled by vehicle or transatlantic jet noise high overhead, when as the light slowly ebbed away they regrouped in trees about 80 yards from where I was standing. I refocused the camcorder on just the top of one ash tree, pressed the record button and stood back and listened and watched.
As the minutes ticked by, more birds flew in, in about 5 or 6 waves, and the clamour of chattering rose and fell, as the birds rejigged their positions on the branches. But as the numbers grew to thousands, I was willing them to make their final leaving flight and allow me to capture, even from this distance, the whoosh of all those wing beats, before a vehicle passed on the road and broke the spell. In the end, there was a sudden and synchronised pause in the cacophony of chatter (how do they do that?), and two seconds later the whoosh and take off from limbs by now creaking under the weight of extra bodies. YESSS. All recorded with no extraneous sounds in our valley’s natural amphitheatre. And how long was this clip of disconnect from the material world? 13 minutes and 12 seconds. I know because I’ve just worked the last few seconds into the updated version of my video presentation “The Botany of Desire” which will get its first airing of 2012 to a local gardening club shortly.
The fieldfares repeated the event with somewhat smaller numbers, but still several hundred, and a noticeably less raucous and chirring chatter about three days later. By now they have probably gone, returning to Scandinavia since they are nearly all winter immigrants to the UK, and almost none of them hang around to breed in the UK. Which perhaps is just as well, since it would be difficult for any landscape, even a biodiverse one, to sustain such a population of hungry mouths for any length of time. (Fieldfare image from 3/03/12 below).
Finally, there were two notable dates this last week. Firstly living in Wales, St. David’s day on March 1st. For us it’s sometimes been a challenge having any daffodils in flower on this day – last year we managed a single ‘Tête-à-tête‘. This year we fared better after the milder winter, and I’m showing the 6 varieties which made it, just in time, in some cases.
The second notable date for none save me, is that this blog has now passed its first birthday. Cause for celebration? Well maybe, in that I’m still here, and still blogging. Though perhaps not universal approval for the latter point! But I thought I’d allow myself the indulgence of mentioning just a few of the interesting posts out of the 42 of my last blogging year, with highlighted click-on-links if any of my more recent followers are interested in looking back at these posts. Apart from the slog of putting these pieces together the HUGE benefit for me is that I’ve learned so much of interest that I didn’t know before I started this venture. I guess that if this journey of discovery continues, I’ll continue to write about and photograph it.
- Thermogenesis in snowdrops, since this is what got the blog going.
- That we saw more bumblebees in our garden in 2 minutes in early April than we saw in 3 hours at Kew Gardens in London. Why?
- Discovering that almost all bought tomatoes require the unique buzz pollinating ability of bumblebees to produce them. And that a clever Dutch firm’s exploitation of this fact of this means that they’re bred and posted out around the world as a disposable, branded product. 6 weeks, job done, so chuck ’em away.
- It makes sense to know where to open your gob, and if in doubt, call in the experts!
- My feeling that my crafted waxcaps will decay more gracefully, and over a longer period than I shall manage.