Honeybees' foraging choices for nectar and pollen revealed by DNA metabarcoding

Area of Science:

• Ecology
• Entomology
• Agriculture

Background:

• Honeybees (Apis mellifera) are vital managed pollinators for global food crops.
• Understanding honeybee foraging behavior and dietary selection is crucial for colony health and agricultural productivity.
• Limited knowledge exists regarding how honeybees choose floral resources for nectar and pollen collection.

Purpose of the Study:

• To investigate honeybee foraging preferences for nectar and pollen sources.
• To identify the floral origins of honey and pollen using DNA metabarcoding.
• To analyze the impact of season and location on honeybee diet and honey's specialized metabolite profile.

Main Methods:

• Studied 43 honeybee colonies across six apiaries during summer.
• Utilized DNA metabarcoding to determine the floral origins of honey and pollen samples.
• Recorded available flowering plants and analyzed specialized metabolites in honey.

Main Results:

• Honeybees primarily utilize the same plant genera for both nectar and pollen, but less than half are used concurrently by individual colonies.
• Pollen foraging showed higher selectivity and greater variability in plant genera composition compared to nectar foraging.
• Honeybees consumed only a fraction of the available floral resources, with seasonal and locational factors significantly influencing plant selection.
• Location affected both the plant species chosen and the specialized metabolite composition of honey.

Conclusions:

• Honeybees exhibit selective foraging behavior for both nectar and pollen.
• Seasonal and geographical factors play a significant role in shaping honeybee diets.
• A diverse range of floral resources is essential for honeybees to select an optimal diet and maintain well-being.