These are just a few fairly random photos I’ve taken on the allotment this season – some of them I’ve posted previously, including the emperor dragonfly, the ladybird larva and the comma butterfly on the bottom row. The two at the top were taken yesterday – a violet ground beetle – Carabus violaceus, and a hoverfly – Helophilus pendulus, apparently sometimes known as ‘the footballer’, although that sounds rather strained to me. They should remind us that there’s a good deal more important work going on behind the scenes on an allotment than we (who like to take all the credit) can claim to be responsible for.
We know, of course, that the allotment is a bit of a war zone, with pigeons stripping our brassicas to the ribs if the caterpillars haven’t got there first. Phytophthora infestans – or potato blight -is a tiny micro-organism but it can reduce a healthy crop of potatoes or tomatoes to a slimy mess almost overnight; and our local badgers wait patiently until the sweetcorn reaches perfection and then take it the night before we were due to harvest it. Squirrels, rats, mice, slugs and snails all disrupt our best laid plans and occasionally scythe our seedlings down before they’ve got their roots down.
In our compartmentalised way we tend to divide the rest of the natural world into friends and enemies and, even more dangerously we can begin to divide it up on aesthetic or emotional criterias – what looks nice or frightening, or what makes me feel good and what repulses me, for instance bunnies and slugs. Worse still you might divide the natural world by applying economic criteria – what’s a valuable resource and whats’s economic deadweight? – profit and loss.
But if you believe – as increasing numbers of us do – that the health of the whole earth depends on an intricate network of relationships, then the only criterion that makes any sense is the long term welfare of the earth upon which we’re utterly dependent, because contrary to polarised thinking, most curses bring their blessings and vice versa. It’s hard to think of a good side to potato blight, but the pathogen that causes it is a part of a whole bunch of microorganisms, many of which are indispensable to us. Squirrels distribute the seeds of the trees they raid, rats dispose of the hazardous food waste that we leave lying around; flies, or rather maggots dispose of the millions of dead little furry things, worms, slugs and earwigs chew up squillions of dead leaves for us and turn them into in-situ compost and all of them together tend to do the sorting out of the weakest individuals ensuring that Mr Darwin’s theories have never been effectively challenged. In the natural world of the allotment, for instance, predation is almost always fairly inefficient.
The hoverfly in my photo isn’t a bee it’s a fly, but it’s a marvellous pollinator. Just under half of the other hoverflies are also blackfly predators in their larval stage – like ladybirds. But because their adaptive defence is to look like bees or wasps we often regard them as enemies. In fact far more crops are pollinated by flies than are pollinated by honeybees. The violet ground beetle, believe it or not, is an effective predator of small slugs and other beasties. The fact is, we have to be content to share nature with a host of life-forms that we may not care for very much but which may be keystone species in the self regulating natural world.
Ponds really help
But there’s something else about the two species I noticed yesterday and that’s the fact that they both associate with water. We’ve got a river and a couple of large ponds near us on the allotments but in the way that things go in and out of fashion, there’s also been an explosion in the number of small, even tiny ponds on people’s plots. All sorts of vessels up to bath tubs have been pressed into service and you might wonder whether they’ll ever make a contribution to the local ecology. This year has shown that without doubt they do. There are three very small ponds on plots adjoining ours and we’ve seen the emperor dragonfly, several sorts of darters and chasers, not to mention the hoverflies who need water – preferably very stinky water – to lay eggs and pass through their larval stage as rat tailed maggots. All these in turn attract larger predators, and the knock on effect is noticeable. Little things really do make a difference.
I read in a magazine somewhere recently that scientists are developing robots to pollinate crops. Are they completely mad??? Many of the most intractable illnesses in hospital are known as ‘iatrogenic’ diseases, that’s to say they are a side-effect of the indiscriminate use of treatments for other things altogether. The same case exactly can be made against industrial agriculture. The pointless and inappropriate use of chemicals and heavy machinery has created a whole series of new problems that could be solved much more quickly by stopping doing the things that cause the problem rather than wasting millions of pounds developing robots to pollinate crops when you’ve killed all the natural and free pollinators.
Our response need not be to allow pests to run riot over or destroy our crops as the industry often claims, but to become inefficient predators ourselves. Thumb and finger predators, in fact. Just wash your hands afterwards.
Absolutely no certainty about this 2mm critter on our broad beans, but we discovered there were quite a large number of them when Madame added another tier of twine to support the beans during Storm Hannah which is forecast to pass by tonight. I decided to take it home to photograph and while I was setting up the macro lens and focusing, a flea beetle jumped on to my hand. We’d already seen their work elsewhere on the allotment, cutting neat scallops in the leaves; so neat, in fact, that you might imagine scalloped leaves were part of the design. So bug-hunting is beginning in earnest and this one is a puzzle since I have a great deal to be modest about in the entymology department. Is it a cluster of eggs? we wondered. Now I really need that dissecting microscope! If you look closely at the east, northeast side of the photo you’ll see a stumpy brown protuberence and so the next guess was that it’s the hatching of the pupal stage of …… something. We’ve scoured the horticultural pest books and searched the internet too, but nothing quite fitted. We hazarded a guess at a big hatch of ladybird eggs, encouraged by the recent warm weather. There were also a number of ants on the plants, and ants have a remarkable relationship with blackfly (bean aphids) so best case scenario is that when the population of aphids explodes fairly soon there will be hordes of ravenous ladybird larvae waiting to take advantage of them. However when I attempted to dissect it with a scalpel and my 15X magnifier I could just about make out a number of apparently empty, hollow chambers. I finished up not being convinced that it wasn’t some sort of multi-celled seed head. So I’ll just wait to see if there are any proper naturalists out there who’ll put me right – just for interest’s sake – we won’t be drenching the plants with neonicotinoids. Ever.