Nectar is the fundamental currency in the partnership between flowering plants and their bee pollinators. This sweet, watery solution is the primary reward plants offer, ensuring insects carry pollen from one bloom to the next, allowing reproduction to continue. For honey bees, nectar is the sole source of carbohydrates, providing the energy required for flight, hive maintenance, and survival. Understanding how bees utilize this substance involves examining its chemical makeup, collection process, and transformation into the colony’s long-term food supply.
Chemical Composition and Plant Source of Nectar
Nectar is a sugar-rich fluid produced by specialized plant glands called nectaries, located within the flower or on other vegetative structures like leaves and stems. Floral nectaries attract pollinators, while extrafloral nectaries often lure defensive insects, such as ants, that protect the plant from herbivores. Nectar consistency and sweetness vary widely among plant species, influencing which pollinators are drawn to a specific source.
Nectar is mainly a watery solution, with moisture content typically ranging from 50% to 80% when first secreted. Dissolved within this water are the three main sugar molecules: sucrose, fructose, and glucose. The ratio of these sugars depends on the plant species, which helps determine the type of animal best suited to pollinate it.
Beyond the carbohydrate base, nectar contains trace amounts of other compounds that contribute to its nutritional value. These minor components include amino acids (the building blocks of protein), minerals, vitamins, and organic acids. Volatile organic compounds are also present, responsible for the distinct floral scents worker bees use to locate food sources.
Plants control the production of this sugary liquid, releasing it in specific quantities to encourage pollinators to visit multiple flowers. This limited reward ensures the bee does not become satisfied at a single location, maximizing the chances of cross-pollination. Nectar quality and availability are dynamic, changing with the time of day and environmental factors like temperature and humidity.
Foraging and Collection by Worker Bees
Locating and harvesting nectar is a highly organized, collaborative effort driven by the colony’s need for fuel. Foraging begins with scout bees, who venture out to find new flower patches and assess the nectar’s quality and abundance. Upon returning, a successful scout bee communicates the exact location of the resource to her nestmates using a symbolic language.
This communication takes the form of the waggle dance, performed on the vertical surface of the honeycomb. The angle of the waggle run relative to gravity indicates the direction of the food source in relation to the sun’s position. The duration of the waggle section conveys the distance to the patch.
Once the foraging worker bee arrives, she uses her proboscis (a long, flexible, straw-like tongue) to suck up the nectar from the nectary. The collected fluid is not ingested for digestion but is stored in a specialized organ called the honey stomach, or crop, which functions solely as a transport vessel. This muscular pouch is separate from the bee’s digestive tract, allowing the nectar to be carried back to the hive.
During the flight back, the transformation process begins as the raw nectar mixes with enzymes secreted from the bee’s hypopharyngeal glands. The primary enzyme introduced is invertase, which starts the breakdown of the complex sugar sucrose into the simpler sugars, glucose and fructose. This initial enzymatic action prepares the substance for the final stages of conversion once the forager returns.
Nectar’s Transformation into Honey and Colony Fuel
The conversion of harvested nectar into stable, long-lasting honey is a multi-step process essential for colony survival. After the forager returns, she transfers her load of partially processed nectar to younger house bees through trophallaxis (a mouth-to-mouth exchange). This communal transfer is repeated multiple times among several house bees, serving two important functions.
Each transfer allows for the continued addition of necessary enzymes, such as invertase and glucose oxidase, furthering the chemical breakdown of carbohydrates. The movement also helps reduce the water content. The house bees then deposit the nectar mixture into the hexagonal wax cells of the honeycomb.
At this stage, the water content is still high (50% to 80%), which would cause it to ferment and spoil. To create a stable food source, house bees collectively dry the liquid. They achieve this by generating a strong, constant airflow within the hive, vigorously fanning their wings near the open cells.
This fanning evaporates the excess moisture, concentrating the sugars until the water content is reduced to 17% to 20%. This low moisture level creates a supersaturated solution that inhibits microorganism growth, preserving the honey indefinitely. When the honey reaches the correct consistency, the bees cap the cell with a layer of beeswax, sealing the finished product for long-term storage.
This finished honey is the colony’s dense, reliable energy source, providing the carbohydrates needed for all bee activity, especially when foraging is impossible (e.g., winter or poor weather). The stored honey fuels the metabolism of adult bees and provides the heat necessary to maintain a stable hive temperature, ensuring the survival of the cluster and developing brood.