Lecture by Mark Greco at Yeovil BKA

On Saturday 21st June Yeovil BKA hosted a talk on Diagnostic Radioentomology by Mark Greco, an Australi- an academic working at Bath University, where he keeps eleven colonies. The talk was preceded by an excellent and sociable lunch at the Royal Oak in Over Stratton. (Before you ask, the title means studying insects using a scanner rather than physically.)
Mark started his career studying Australian stingless bees, which are used for pollination in greenhouses. These are tiny (about 3mm long) and store their honey in little pots like our bumble bees. In a year they gather about 1kg of honey, compared with the 20kg plus Australians expect from their honey bees. Despite not having stings, they defend their colony very effectively by clinging onto the aggressor and effectively disabling it. Humans need to wear a veil to prevent the bees clinging around their eyes. Mark needed to study their behaviour in the nest, but a physical inspection was not feasible because of the way they fly up when the hive is opened and the honey released from the damaged pots drowns the bees. He had the idea of putting the whole hive through a CT scanner so that they were not disturbed at all, and it was very successful.
Mark continued his research in Switzerland, imaging honey bee colonies and individual bees. His slides and what they show are fascinating and contradict many of the conclusions we beekeepers hold based on our experience of colonies we have opened. For example, what shape do you think the winter cluster is? He has shown that it is an inverted bell shape attached to the crown board. This takes advantage of the warm air-flow in the hive. We never see it because it disintegrates as soon as we remove the crown board. He has also shown that the queen patrols the cluster, presumably to spread her pheromone.
His technique allows him to study the way the colony stores nectar. He gave a colony two sources of food, one 50% sugar and one 70%. This showed that the bees stored the different concentrations in separate sets of cells.
He constructed a special box with three chambers. Two chambers were separate from each other whilst both could communicate with the third through mesh. He put bees from two different colonies in the first two chambers and bees from one of those colonies in the third, which had a feeder. This demonstrated that the bees in the third chamber fed their compatriots in preference to the strangers. He then repeated the experiment with drones and showed that drones feed other drones and workers. As the NBU has shown that drones carry EFB, this means they could spread EFB to the colonies they visit. It may not just be careless beekeepers that are spreading EFB.
He whetted our appetites by telling us he had designed his own type of hive, based on a National (groan), but did not give us any details of what features he had incorporated. A Bath beekeeper has made one and they are waiting to see how successful it is. That sounds like the basis of another talk in the future.

 
Many thanks to Paul Edwards for writing this report.

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