Summer plight of the honeybee is not music to the ears

ANOTHER LIFE:SOME EDDY IN the strange contortions of the jet stream has been sending the worst of this summer's rain through the south and east of Ireland. But here on the drizzly margins of Connacht the enveloping gloom and humidity have been bringing out the worst of the biting midges of the Culicoides clan.

Slathered in citronella, swathed in palest blue (midges like dark colours), my thinning silver safely if absurdly netted, I duck down the garden through the fuchsia of Midge Alley, trying not to breathe out the carbon dioxide that draws them to the nearest mammal.

Airborne midges seem not to mind any reasonable rain, but does a heavy shower knock them to the ground? A new report from scientists at Georgia Institute of Technology describes what happens to mosquitoes in a downpour. With high-speed cameras running, they showered “raindrops” on to captive flying mosquitoes and eventually managed to hit some.

With such little body mass, the mosquito offers almost no resistance to a raindrop perhaps 50 times its weight, simply joining with it for the lift-shaft fall. Then, in the split second before the raindrop hits the ground, the insect’s covering of water-repellent hairs allows it to escape, a Houdini-like act that may merit a closer view. As our woodshed swallows skim the ground in a mesmerising pas de deux, perhaps they are intercepting dropped-upon midges.

This relativity of drop size and body mass can be crucial to insect decisions on when to stop flying, but other things may matter, too. Several readers have commented on the scarcity of honeybees in their gardens, and it’s true that even light rain can keep bees in the hive. But dark clouds also frustrate their solar navigation. Wet summers inhibit the blooming and opening of many flowers and the flow and quality of nectar. Sometimes there’s no point in stirring out. Keep this up long enough and beekeepers need to feed their colonies with sugar syrup if they are not to collapse.

Nectar, the sugary raw material of honey, can be up to 50 per cent water, so plants need to drink enough rain to produce it. Too much while blossoming, on the other hand, can dilute the nectar flow or even wash it out of the flowers.

Surprisingly few of our wild plants offer beekeepers a surplus crop of honey. At the website of the Federation of Irish Beekeepers' Associations, irishbeekeeping.ie, Peter Whyte and James Doran have described the 10 best plants, and even these can have their problems. White clover, for example, yielding the market's most popular honey, is often mown for silage just as it starts to flower. It stops secreting nectar if the topsoil dries up, and in the cooler west and north the weather reduces its nectar flow.

Hawthorn is often generous with nectar and makes an almond-scented connoisseurs’ honey, but its heaviest flows may last only a few days. Honey from heathers fetches a premium price, but taking hives to the moors needs good timing, and many hills have their heather grazed away. Oilseed rape gives a long and golden abundance of nectar, but its honey needs spicing up with clover.

Dandelion and willow have been called “cornucopia” species, especially valuable in spring and early summer, but the dandelion closes its flowers in the rain, and willow rushes into seed. Fuchsia, on the other hand, protects its nectar by hanging down in the rain.

In a summer like this one, the long-flowering bramble can be the main source of the surplus honey crop – if the county-council hedgecutters have left it alone. And while people with colourful gardens may see them as bee-friendly, they need to remember that many exotically double flowers have little or no nectar.

Along with weather problems, the imported honeybees of Irish hives are prone to all sorts of diseases, notably the viruses arriving with varroa, the Asian mite that so troubles Ireland’s 2,500 beekeepers. What to do about each disease is dealt with in Having Healthy Honeybees, a new book by John McMullan, scientist and beekeeper. It is published by the federation and costs €15, plus pp, at the website mentioned earlier.

More cheering to read – and arousing, indeed, no little wonderment – is Bees, Hives, Honey! Beekeeping for Children, the work of Tim Rowe, who manages about 100 hives near Bantry, in west Cork.

The book's happy young faces, safely netted as they tend the bees, are some of the 23 children, from seven-year-olds to teenagers, led by Rowe into building hives, collecting swarms, managing the colonies and harvesting their honey. As a project for bonding children to the natural world it seems inspired. The book is €20 at greenhatbooks.com.

Eye on nature

I found little red pods attached to the underside of leaves on an oak tree. They seemed to be on one tree only, in a plantation of young oaks. Aiguini O'Grady, Adare, Co Limerick

They were common spangle galls, which are one stage in the life cycle of the cynipid gall wasp Neuroterus quercusbaccarum. A previous generation were currant galls, which appeared on the catkins or on the young leaves.

Recently I was awakened by shrieking. I looked out to find a pigeon pinned to the ground by a sparrowhawk. It was surrounded by a flock of angry birds, including rooks, jackdaws, magpies and a jay, which saw off the hawk, and the pigeon flew off. It had barely got in the air, however, when it was attacked by a second hawk. Again a group of assorted birds came to its rescue, and it eventually escaped. Is this unusual behaviour?

Ramor Craigie, Ballylickey, Co Cork

Local birds will mob a sparrowhawk taking prey in their territory.

On June 24th a turtle dove visited our garden. The last time we had a visit from one was in May 2008, and it stayed for a few days. Kieran Fitzpatrick, Greystones, Co Wicklow

Michael Viney welcomes observations at Thallabawn, Carrowniskey PO, Westport, Co Mayo, or email viney@anu.ie. Please include a postal address