Biology: What pollen is beneficial for bees?

Bees and pollen depend on each other: plants need bees because they distribute pollen, and bees need pollen as food. Bees obtain carbohydrates from flower nectar, while pollen provides animals with proteins and fats. Environmental changes that alter the availability and properties of pollen increase the risk of bee malnutrition.

Research team about the world of biology Sandra Rayhan From York University in Toronto, Canada, studied the nutritional value of 57 types of pollen. To do this, she collected samples of 57 plant species found in North America, either fresh flowers from the wild or dried flowers in the laboratory.

Pollen grains were prepared and their content of proteins – amino acids – and lipids – fatty acids was examined. Scientists also analyzed the ratio between amino acids and fatty acids to determine which plants were most suitable as food sources for bees.

It's all about the right proportion

Rayhan says the goal of the study is to better understand the nutritional value of plant species. Because the right mixture is very important for bees: without fatty acids such as Omega-6 and Omega-3, bees live shorter lives and have weaker immune systems. This makes them less able to cope with environmental stressors. However, if insects consume these fatty acids in an inappropriate proportion, cognitive problems may arise. Bees are known for their cognitive abilities – for example, they have a keen sense of direction.

Bees also need essential amino acids. These are essential for cognitive and reproductive health. Here, too, balance plays an important role: If bees consume too many amino acids with their food, they may be more susceptible to parasites such as mites, according to the study authors.

Clover, berries, buttercups, roses

In their studies now In the journal “Frontiers of Sustainable Food Systems” The research team came to the conclusion that pollen from clover, raspberries, buttercups and roses is particularly recommended in the diet of wild bees – because it contains an “optimal ratio between proteins and fats”. When renormalizing flower meadows, these plants should therefore be planted preferentially.

The research team also confirms that bees need a variety of plants to maintain a truly balanced ratio of fatty acids and essential amino acids. There appears to be some kind of trade-off between the amino acid and fatty acid content of pollen: plants with a high content of essential amino acids have a relatively low content of fatty acids and vice versa.

Each type of bee has its own pollen mixture

“This means that a diverse diet of flowers is more beneficial to bees than a single source of pollen,” first author Rehan said in a press release. Most types of pollen contain most of the necessary nutrients, but to achieve optimal nutrient levels, bees need several different types of plants. “No plant species alone is ideal for the health of wild bees.”

Scientists suspect that the large differences in the nutritional content of different types of pollen reflect the different needs of different bee species. If animals find the greatest possible diversity of plant species when foraging for food, this means that each bee species can feed itself with its ideal pollen mix.