Thinking inside the box

First things first - let me describe the box. It is a wooden box. The dimensions are 18 inches by 18 inches by 9 inches. It is made of cedar wood and has a top and a bottom. For me it qualifies as a small space. Its construction from cedar wood means it is durable. Durable enough to act as a home with its own ecology. Let us recognise that the top is a weather proof lid or roof. The bottom is a floor made from wood and a metal mesh. The elaborations don't alter the fact that it is a box and is a small space. There is an adjustable hole on one side - let us call it an entrance. But an entrance implies that something wants to move in and out of this box. They do, tens of thousands of them. Add some furniture in the form of frames with sheets of wax. We have the basics of a movable frame beehive. Go back a couple of centuries and this small space would probably have been dome shaped and made of woven straw. Known as skeps these not very durable hives were only expected to last a year or two. The beekeepers who owned the skeps had to more or less destroy them to harvest honey. They were not the easiest of small spaces to manage. Inventive people came up with designs for the durable wooden box systems in use today. As an aside, plastic hives are now rather common. In the form of polystyrene boxes they are cheap and provide good insulation for bees kept in areas with a harsh winter. The evolution of the man made bee hive has occurred at a rather modest pace with occasional radical innovations.

Some recent changes to beekeeping have been neither managed nor at a slow pace. There have been a number of threats to the ecology of this small space with lessons for us all. The floor that I referred to earlier used to be a simple solid wooden item. The first of the new threats to the world inside the box occurred a couple of decades ago. The varroa mite. If uncontrolled they can be present in thousands and rapidly multiply in the hive gaining their nourishment by sucking on the bee's blood. The damage is done not only by stealing nourishment from the bees but by spreading viruses in the process. It is the viral diseases that pose the main threat to the wellbeing of the bees. Beekeepers now employ Integrated Pest Management (IPM) to minimise the damage from varroa. Part of the IPM protocol involves weakening the mite's grip on the bees and causing them to fall to the floor. Hence the perforated mesh floor. It allows the mites to fall out of the hive so they cannot climb back onto a passing bee making its way across the floor.

Honey bees have been subject to pests and threats forever. These vary depending on the part of the world where the bees are living. In the UK for example they include even smaller mites that live inside the bee's airways, various viruses, bacteria and fungal diseases, two species of wax moth, wasps, mice, woodpeckers even badgers. Some threats are managed by the beekeeper. Others, which have co-evolved with our western honey bees co-exist and healthy bee colonies manage some of them themselves.

So what is the problem? Varroa arrived and the IPM has evolved. That pest arrived from Asia where it co-evolved with local bees that have arrived at a level of tolerance. UK beekeepers and their bees are now faced with the threat of small hive beetle from Africa and Asian Hornet. All three of these pests arrived in Europe and are threatening the UK bees. Their arrival is the result of international trade with the pests being carried on otherwise innocuous items such as ceramic flower pots. Higher temperatures due to climate change are increasing the chance that these pests will spread from Europe and survive and thrive in UK. Our bees have no experience of these pests and need human intervention to safeguard them. By now you will have understood my theme. International trade and poor biosecurity leads to invasive species (including pests) moving around the globe. The lesson - the ecological balance of small spaces is vulnerable to invasive species.

I would like to revisit the theme of my earlier postings and think about over zealous clearing / eradication of a plant from The Park. This time a plant that in my locality is very important to the bees when topping up the winter pollen and nectar stores that will see them through till spring. I am referring to ivy, Hedera helix. Very close to my garden apiary were two abundant sources of ivy. I say were because both have gone, for reasons that I will explain. Thankfully there is still ivy within bee foraging distance but not so convenient as before. Over my garden fence, not strictly on The Park but running along its boundary when we moved here ten years ago were elderly Scots Pine and Larch. Both, but especially the pines were covered to their 60 foot tips with ivy. The soil here is very shallow over chalk. The trees were bending and leaning at slightly alarming angles. Given their proximity to our house I had watched them with interest over a decade. Winter storms toppled one and that prompted me to discuss things with the land owner. We were very reluctant to accelerate the demise of the remaining trees. What was decided however was the cutting of the ivy stems so that the ivy could die back and allow detailed inspection of the trees to assess their condition. One year later it become obvious at the next major storm that the ivy had been assisting the trees to stay anchored to the ground. Storm Doris felled the biggest of the trees and so the land owner had the others felled.

The other ivy clad trees were on another nearby site boundary. These are substantial sycamores. The story here is a little different. The trees were inspected by an arboriculturalist as part of a safety check of all trees on The Park. He favoured clearing ivy from trees as thick growths of Hedera can deprive the host tree's leaves of light thus weakening it over time. So the ivy stems (over two inches in diameter) were cut through. I can see the sycamores from my study window and have to concede that now the ivy has died away I like the shape of the sycamores better.

Here is the but. Apart from my concern for my autumn foraging bees I worry for our local birds. We are blessed with many tree nesting species and the removal of ivy and the demise of the 70+ year old pines must have reduced the safe nesting and roosting opportunities. So removal of the ivy for what seemed like sound reasons is not without its consequences for insects including honey bees, tree bumble bees, hibernating butterflies and birds. So all these losses need to be weighed against the possible benefit to the host trees of removing their ivy overcoats. As if to reinforce my point a neighbour and fellow wildlife enthusiast on The Park mentioned to me a few icy days ago that a male Bullfinch was feeding in ivy just down the road.