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Help to honeybees from nature’s pharmacy

The flowers that honeybees visit can supply the bees with more than just food. It seems that the flowers are also capable of providing the busy insects with substances that help the bees to withstand disease.

[Translate to English:] Der er tegn på, at blomster kan forsyne bier med stoffer, der gør bierne bedre i stand til at modstå sygdomme. Arkivfoto

When honeybees visit flowers such as chives, sage and groundsel, they are not only shopping for food.  They also acquire medicine from nature’s pharmacy, according to postdoc Nanna Hjort Vidkjær from the Department of Agroecology at Aarhus University. She has received a grant from the Danish Council for Independent Research to investigate if bees actually pick up immune-promoting substances from flowers and if these substances protect the bees’ larvae within the beehive.


- Bees live on pollen and nectar collected from plants. From this food the bees take in a variety of chemical substances from the plants. We know that plant compounds can have an inhibitory effect on virus in humans, but have never investigated if this is also the case for virus in bees. That is what I plan to do, Nanna Hjort Vidkjær explains.


The goal is to find sustainable methods with which to control diseases in bees. This is important not only for the bees themselves, but also for us humans, because feeding the human population without the help of bees would be very difficult. Together with other insects bees pollinate approximately 70 per cent of the world’s crops. This service carried out by the small creatures is valued at approximately 153 bill. euros globally, which corresponds to 9.5 per cent of the total global food production.


- It is therefore very worrying that the number of bees has lately been decreasing and that nobody knows exactly why, says postdoc Nanna Hjort Vidkjær.


A range of factors, including access to feed sources, diseases, and pesticides, can affect the health and vitality of bees. Nanna Hjort Vidkjær will investigate if nectar and pollen from some of the plants that honey bees frequent in Denmark, and that contain known chemical substances with an anti-viral effect, have an inhibitory effect on the bee disease sacbrood virus.


Sacbrood virus is a globally widespread virus in bees. In Denmark the disease is particularly on the increase with frequent outbreaks such as are not seen in the rest of the EU. The disease causes the bee larvae to die. The adult bees are apparently unaffected but can act as passive carriers of the disease.


Colourful bouquet on the menu

In the course of her study, Nanna Hjort Vidkjær will use various flowering plants that are some of honeybees’ favourites and which are known to contain antiviral compounds. The chosen plants comprise a colourful bouquet and include, for example, chives, opium poppy, common sage, groundsel, figwort and gorse.


The plants will be grown in the greenhouse after which each plant species will be placed with an infected bee family. The bees and their larvae as well as their honey, pollen and nectar will be measured for their content of virus and plant bioactive compounds to see if there is a correlation between the health status of the bees and the content of plant bioactive substances. Studies will also be carried out in the field where beehives at various locations in Denmark will be followed throughout a whole season. In these studies the bees’ uptake of chemical substances from plant pollen and nectar will be determined using advanced chemical techniques. Measuring the virus content of both the bees and their larvae at the same point in time will contribute new insight into the effect of the bioactive compounds on the health status of bees under natural conditions.


Nanna Hjort Vidkjær will also determine the uptake and transfer of the bioactive compounds form the bees to their larvae in order to better understand the destiny of these compounds in the beehive.


- A greater understanding will form the basis for developing urgently needed environmentally friendly tools for enhancing honeybees’ natural defences against sacbrood virus. One method could, for example, be the placement of selected plants in the vicinity of beehives, says Nanna Hjort Vidkjær. 


The three-year postdoc project has been granted DKK 3.2 mill. from the Danish Council for Independent Research | Technology and Production


For more information please contact: Postdoc Nanna Hjort Vidkjær, Department of Agroecology, e-mail: nanna.vidkjaer@agro.au.dk, telephone: +45 8715 8213