Many honeybee colonies are lost in Baghdad during the summer.
It is a very hot and dry season with no food available for the bees. There is no compensation for the massive loss of worker honeybees, whilst there is a simultaneous increase in the natural enemies of honeybees, particularly wasps Vespa orientalis, and bee eater birds Merops sp.
The purpose of the following experiment was to keep bees in cool confinement during the summer season, preventing them from leaving the hive. Would this help them to survive through a very difficult period?
In July 1996 ten colonies of honeybees were kept in a modified refrigerator with a temperature range of 6-8°C. The bees were in five-frame Langstroth nucleus boxes, about 2 kg of bees in each box (range 1.25-2.5 kg per box). Comb with open brood (eggs and larvae) was not included, but there was some capped brood, about to emerge. There were at least three frames of honey, sealed and unsealed, included in each nucleus box. The refrigerator was an automatic defrost type, and therefore did not become humid. Two weeks prior to the trial the bees were fed with Fumidil B and tetracycline using a dripping method. The remaining colonies in the apiary were used as a control.
The colonies in the trial were confined to the refrigerator for one week and then taken out for one day. During this day the bees flew and carried out foraging activities before being returned to their cool confinement at nightfall. After this time the colonies were divided into two groups of five colonies:
Group I was kept for periods of one week in the refrigerator and then taken out for one day;
Group 2 was kept for periods of two weeks in the refrigerator and then taken out for one day.
This system of confinement was maintained until conditions once more became favourable for brood rearing.
All ten trial colonies survived this experiment. The populations were kept strong compared with the colonies remaining in the outside apiary which dwindled sharply. and some of the weaker nuclei that died out. The trial colonies also escaped the annual predation by Vespa orienta/is and Merops sp during August and September.
When the bees were freed from confinement at the end of September the weather had improved and many flowers were in bloom. The bees that had stayed in the apiary were adjusted for defence, whereas those coolly confined were foraging better and ready to build up their nests. The weather in October and November in Baghdad is very good and the optimum for rearing; brood. The ten trial nuclei colonies were very strong before winter time and did well the next spring.
The author hopes to carry out further trials with larger populations of bees. Due to various problems there were constant electricity cuts during 1997 and 1998 which made more trials impossible. An electricity generator as a reserve for emergencies would solve this situation.
To be considered
This system works to protect bees in hot climates, but to make it a success the following are to be considered:
Cellar confinement could be useful during insecticide spraying times as bees can be confined for a few days instead of transporting them to a distant location.
First published in Bees for Development Journal 50