Bees, Colony Collapse Disorder: See bees.

What is Colony Collapse Disorder? ‘A mysterious syndrome that has plagued beekeepers in North America and Europe. Unlike a natural swarm, in which a large group of worker bees leave with their queen to form a new colony, CCD involves bees suddenly disappearing for no obvious reason, leaving their queen behind. Although recent reports suggest there has been a reduction in bee die-offs, according to some estimates 10m hives in America alone were wiped out by CCD from 2006 to 2013. Besides hitting honey production, this can also hinder the pollination of certain crops,’ (‘What’s the buzz?’, The Economist print edition March 31st 2018, p.78).

What might cause CCD? | Prof David Goulson (Professor of Biological Sciences, Stirling University in Scotland) and his team of researchers at Stirling University found a link between bee population collapse and pesticides (neonicotinoids), but received no industry funding for this research which they did in their spare time. INRA in France also linked these pesticides to bee collapse. Several European countries banned neonicotinoids several years ago. However research in 2009 paid for by DEFRA and partly by Syngenta (a pesticide manufacturer) and which was undertaken at Warwick University and Rothamsted Research looked at fungal infections, mites, and environmental factors, but did not look specifically at neonicotinoids. Source: ‘Colony collapse – Better bee-lieve it’, Private Eye 6 April 2012, p.30.

Possible solution for CCD: Source: ‘Honey, I’m home?’, The Economist print edition 22nd June 2019, p.64. ‘A decade ago a mysterious phenomenon called colony-collapse disorder, in which worker bees deserted hives for no apparent reason, struck apiarists in Europe and America. More prosaically, crowding brought about by domestication can promote disease. A particular risk is Varroa destructor, a parasitic mite that has been spreading through the world’s hives since the 1970s. The mites themselves suck body fat from their hosts. They also carry a virus that affects bees’ development, deforming the insects’ wings.

Travis Dynes of Emory University, in Atlanta, Georgia, and his colleagues may, however, have found a straightforward way of improving bees’ prospects in mite-infested areas. In a paper published in PLOS One they report on a study carried out in apiaries around Athens, Georgia, which did just that by changing the arrangement and appearance of their hives.

Hives in apiaries are usually laid out a metre or less apart at the same height above the ground and in a regular grid formation. They are generally painted the same colour and usually have their entrances facing in the same direction. It has been suggested that this arrangement may confuse bees when they return from foraging trips, leading them to drift between their natal colony and others. If true, that would probably aid the spread of mites.

Dr Dynes and his team therefore compared three conventional arrangements of eight hives with three others in which the hives were painted in different colours and arrayed in circles, with each hive ten metres from its nearest neighbours. The entrances of these hives faced outward from the circle and each bore a symbol, different from any of the others, to increase its visual distinctiveness. As a final touch, the hives were also raised to various heights above the ground.

To understand better what was happening, Dr Dynes and his colleagues marked a representative sample of the workers in each hive with individually numbered tags. The result was a clean sweep for the new arrangements. Their bees drifted less between hives, supported fewer mites, produced more honey and survived the winter better than their conventionally housed counterparts.

How easy it will be to translate Dr Dynes’s insights into the world of commercial beekeeping remains to be seen. Apiarists maintain hives at high density for good reason—they may have to manage hundreds in a limited area. But even if they cannot compromise on density, there is nothing to stop them painting their hives different colours, randomising hive’s heights and the orientations of their entrances, and marking them with symbols.