Preliminary survey of the nutritional and palynological traits of honey bee-foraged pollen from Liguria (Italy)

Abstract

It is known that the palynological features, and consequently the nutritional quality, of bee-foraged pollen vary according to several factors such as sampling site and period of year. In our two year study, carried out as part of the COLOSS CSI Pollen study between April and September in the eastern province of Genova (Italy), we explored the relationships between the palynological spectra and the protein content of corbicular pollen. We found that the differences are mainly driven by the collection season rather than by the site. This observation allowed us to employ the sample’s palynological traits for the identification of foraging seasons characterized by different protein content in pollen. The outcome of our study provides a useful tool for beekeepers, helping them to cautiously program certain apiary management practices. This work also provides suggestions for future monitoring programs, regarding the advantages of studying the seasonal pattern not only of the floral origin of pollen but also of its nutritional traits.

Se sabe que las características palinológicas y, en consecuencia, la calidad nutricional del polen apícola varía de acuerdo con varios factores, como el lugar y el período de muestreo del año. En nuestro estudio de dos años, realizado como parte del estudio de polen COLOSS CSI entre abril y septiembre en la provincia oriental de Génova (Italia), exploramos las relaciones entre el espectro palinológico y el contenido proteico del polen corbicular. Encontramos que las diferencias se deben principalmente a la temporada de recolección más que al sitio. Esta observación nos permitió emplear los rasgos palinológicos de la muestra para la identificación de temporadas de pecoreo caracterizadas por diferentes contenidos de proteínas en el polen. El resultado de nuestro estudio proporciona una herramienta útil para los apicultores, ayudándoles a programar con cautela ciertas prácticas de manejo del colmenar. Este trabajo también ofrece sugerencias para futuros programas de monitoreo, en cuanto a las ventajas de estudiar el patrón estacional no sólo del origen floral del polen sino también de sus características nutricionales.

Keywords:

• honey bee
• pollen
• palynology
• nutrition
• COLOSS
• CSI Pollen

Acknowledgements

The CSI Pollen project is a Task Force of the COLOSS (Prevention of honey bee COlony LOSSes) Association, which aims to explain and prevent massive honey bee colony losses. COLOSS was established through the COST (European Cooperation in Science and Technology) Action FA0803 and is now supported by the Ricola Foundation Nature & Culture. COLOSS supports regular workshops facilitating research discussions and collaboration between group members. The authors would like to thank the beekeeper association Nuova Assoapi Ligure and all the beekeepers who volunteered to participate in this project. A special thank is due to Dr Monica Vercelli (University of Turin, Department of Agricultural, Forest and Food Sciences, Italy), Dr Marino Quaranta (Council for Agricultural Research and Economics, Agrobiology and Pedology Research Centre, Florence, Italy), and Dr Bruna Ilde Menozzi for valuable comments and suggestions.