Drone surrounded by worker bees. © INRA, MORISON Nicolas

Scientists flying to the rescue of bees

Flowers: unrepentant seductresses

What attracts a bee to a flower during its first foraging expedition? It is as much the perfume it gives off as its colour. However, it is not simple to predict which flowers will be foraged each year. Indeed, there is considerable competition between flowers for foraging. The most beautiful and vigorous will be visited the most. Thus the species foraged most during one year may not necessarily be the most popular the next year. On their side, the same number of bees will not always be found at the same site each year, and they often seek to minimise competition between neighbouring colonies by specialising in a particular type of flower.

Updated on 03/23/2017
Published on 05/01/2014

Poppies: a godsend for bees

Despite its bright red colour, the poppy is a modest flower, but it is nevertheless crucial to the diet of honey bees in cereal-growing areas. There are several reasons for this. Firstly, it flowers in May and June, which are particularly difficult months for bees as few other flowers are available for foraging by colonies that are at the peak of their population. Secondly, poppy pollen is of excellent nutritional value. On the other hand, poppy honey does not exist, as this plant does not produce a single drop of nectar. Research carried out in the cereal-growing plains of the Poitou-Charentes region has shown that after maize, poppy is the second most popular plant visited by honey bees because of its pollen. So there are many very good reasons why the poppy should no longer be considered as a weed that needs to be eliminated through the use of herbicides.

Town bees, country bees

How do bees manage in towns, a strange environment that is not at all designed for them? On the one hand, they are less exposed to pesticides than in rural areas. Urban gardens and allotments offer them access to constant supplies of food. But on the other, they are subject to the actions of numerous other pollutants: diesel residues, heavy metals or polycyclic aromatic hydrocarbons, which can also affect their health. Ongoing studies at INRA will help us to understand whether it is better to be a town bee or a country bee.

Which flowers for which bees?

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Is there a better example in nature of the co-evolution of two species than that of honey bees and flowers? Flowers need bees to transport their pollen, and in exchange provide the insects with their sources of energy (nectar), proteins and lipids (pollen). The Florapis programme, led by INRA, is seeking to document the foraging activity of domestic honey bees with respect to French flora by means of observations and photographs shared between scientists, botanists, beekeepers and entomologists. The database thus being built is helping to understand the floral preferences of bees. More than 600 plant species, including more than 50 protected species, have been inventoried to date. Florapis is continuing and will be extended to all honey bee species in mainland France.

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Foraging a minefield

After a war, could bees help a country to rid itself of the curse of land mines? This is the original idea of a team of Croatian researchers, supported by experts from INRA in Avignon. To achieve this task, it may be sufficient to exploit the excellent sense of smell and good memory of foraging bees. The Franco-Croatian team thus trained colonies to recognise the odour of TNT. First of all, the animals were given sugar syrup (as a reward), associating it with the smell of the explosive. Then, out in the open air, they sited decoys soaked in TNT at various positions. The bees did indeed forage where the decoys were to be found. It is now necessary to perform this experiment in a real mine field, to determine whether these lethal artefacts give off sufficient odour to be detected by the honey bees.

The Apiformes network

How can we raise the awareness of tomorrow's farmers to the services rendered by pollinating insects, and their needs, while at the same time collecting data on populations of wild bees? This is the challenge that has been taken up by the Apiformes network. Set up in 2009, this observation and training network started with around twenty establishments spread throughout France, and INRA ensures its scientific coordination. Data are collected every year by a team of enthusiastic teachers and successive classes of their students, who soon become equally involved in the project. There is now a bee hotel at almost all the establishments which are partners in the network!