Ethanol, acetic and lactic acid as key stimuli for food processing in bee colony

Temperature and moisture in the hive represent optimal conditions for growth and development of microorganisms, which at obtaining energy in fermentation process from sugars in honey and pollen, produce different metabolites, that include ethanol, acetic and lactic acid. In the first part of our research we wanted to determine which concentrations of acetic and lactic acid the bees consume. We also tried to find out if they are capable of distinguishing ethanol, acetic and lactic acid solutions on the basis of associative learning with proboscis extension reflex. Bees preferred lower concentrations of acetic and lactic acid solutions. The learning turned out to be unsuccessful, because the bees were not able to connect the conditional stimulus with the unconditional stimulus, where the conditional stimulus was ethanol or specific organic acid solution. In the second part of the experiment, we studied the role of our test substances for honey processing in the hive. The bees tended to open the honeycomb cells with ethanol solution, but they closed those with acetic and lactic acid solutions. The closing of a bigger number of cells was noticed at the honeycomb cells with acetic acid solution. We have proved that the mechanical damage in honeycomb cells has an influence on the reaction of the bees. The bees were namely opening the bigger holes and not the smaller ones. Fermentation products have a different role in the hive and this is the reason why they also have a different impact on the honey processing. Ethanol is a stimulus of spoilage, whereas acetic and lactic acid work as food stimuli