The bees gather pollen for their nourishment from different plants and carry it as "pollen load" into the hive. Pollen is the main protein source for the honeybees. In human diet it is an exquisite, functional food, and many therapeutic effects are attributed to it.
In Switzerland, only bee-gathered pollen is produced. About 1000 kg of pollen are produced per year, mainly by beekeepers from the Swiss Pollen Beekeeper's Society. The annual pollen imports are evaluated around 2-3 tons.
Pollen is a food. The legal food requirements, as well as the specific requirements for pollen are indicated in the Swiss Food Directive.
Schweizerischen Pollenimkervereinigung SPIV: Further information on pollen, especially on pollen harvest
Pollen is of great importance for the bees as a source of protein, especially for the development of the larvae and young bees. On the two trial sites – in Ticino and near Basel – the bees collect a very wide variety of pollen. In Ticino, the proportions of the most important pollen species correlate clearly with the weather conditions. For the Basel site, we show the succession of the pollen sources over the course of the bee season.
Pyrrolizidine Alkaloids (PAs) in Swiss pollen
We studied the botanical origin of pollen collected during the flowering period of Echium vulgare. Bees collected relatively few Echium pollen loads. Since E. vulgare pollen contains very high PA concentrations, just a few pollen loads are sufficient to contaminate the overall pollen production. Furthermore, we studied the stability of PAs in bee bread. The majority of PAs remained stable during storage. Hence, monitoring PAs by chemical analysis remains an important element of ensuring good quality of pollen products.
Beekeepers are therefore advised to avoid especially large areas of viper’s bugloss plants in the vicinity of the hives. By ending pollen collection at the beginning of July, beekeepers can avoid hemp agrimony-type alkaloids.