Healthier honey bees found near organic fields and flower strips
A new study reveals how farming practices affect colony health.
Based on a media release by Martin Luther University Halle-Wittenberg (MLU)
Organic farming and flower strips promote the health of honey bees, with colonies growing stronger and generally being healthier when living in their vicinity. This is most likely because these areas provide bees with a diverse and continuous food supply, and there is less exposure to pesticides, according to a new study published in the Journal of Applied Ecology.
The team of researchers from the German Centre for Integrative Biodiversity Research (iDiv), Martin Luther University Halle-Wittenberg (MLU) and the University of Göttingen analysed data from 32 bee colonies in 16 locations across Germany with differing proportions of organic fields, flower strips, and semi-natural habitats.
“The way that farmers cultivate their land has a major impact on nature. Intensively farmed fields, pesticides and monocultures pose a threat to many animal and plant species,” says Professor Robert Paxton, a bee researcher at MLU and iDiv Member. “This is particularly true for pollinators, which include honey bees.”
Around half of Germany’s land is used for agriculture, according to the German Environment Agency (UBA). Prominent measures counteracting this development have included increasing the proportion of organic farming, planting more flower strips, and creating perennial semi-natural areas near crop fields. “In theory, these measures all make sense. However, we know little about how each of these measures affects insects, especially honey bees,” continues Paxton.
To find out more, the team carried out their study in 16 locations across Lower Saxony, in eastern Germany. Honey bee colonies at each of these sites had access to differing proportions of organic fields, flower strips, and perennial semi-natural habitats for about a year. The researchers analysed, for example, colony growth and parasite infestation, paying special attention to the Varroa mite. Varroa mites are a particularly dangerous honey bee pest because they transmit viruses that are fatal to the bees.
The data gathered about the bee colonies was then compared. “Organic farming had the greatest impact – the larger the proportion of these areas, the lower the parasite infestation of a colony. This improved colony growth,” explains lead author Patrycja Pluta from MLU. One reason for this could be that organic farming uses fewer pesticides and opts for other plant protection measures. Flower strips were also advantageous to honey bees: Varroa mites were lower in areas with many flower strips. “This could be due to the fact that a diverse and rich food supply strengthens the honey bees’ immune system,” reasons Pluta.
Perennial semi-natural habitats, on the other hand, tended to be disadvantageous for honey bees. Larger areas generally meant a greater infestation of Varroa mites. And, unlike flower strips, the areas are not designed to provide an abundant supply of food for honey bees and other pollinators. “Perennial semi-natural landscapes are an important tool for promoting biodiversity, and they serve as a habitat for many animals. Honey bees, which are managed by humans, are the exception,” says Paxton. The study’s findings could help to improve agricultural landscape management for honey bees and other pollinators.
The study was funded by the Federal Ministry of Food and Agriculture on the basis of a decision by the German Bundestag as part of the Federal Organic Farming Programme and by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation).
Original publication
(Researchers with iDiv affiliation and alumni bolded)
Pluta, P., Czechofsky, K., Hass, A., Frank, L., Westerhoff, A., Klingenberg, H., Theodorou, P., Westphal, C., Paxton, R. (2024) Organic farming and annual flower strips reduce parasite prevalence in honey bees and boost colony growth in agricultural landscapes. Journal of Applied Ecology, DOI: 10.1111/1365-2664.14723
Contact:
Prof Dr Robert Paxton
Head of General Zoology
Martin Luther University Halle-Wittenberg (MLU)
German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig
Phone: +49 345 55 26451
Email: robert.paxton@zoologie.uni-halle.de
Web: www.zoologie.uni-halle.de/allgemeine_zoologie/staff/prof._dr._robert_paxton/
Christine Coester
Media and Communications
German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig
Email: christine.coester@idiv.de