Bumblebees, fuzzy insects, are diligent foragers whose diet directly supports their survival and their role in pollination. They meet their nutritional needs primarily from flowering plants, which ensures the continuity of their species and many plant communities.
Nectar: The Primary Energy Source
Nectar, a sugary liquid produced by flowering plants, serves as the bumblebee’s main source of energy. This sweet fluid is primarily composed of various sugars, including sucrose, glucose, and fructose. Bumblebees consume nectar to fuel their high-energy activities, such as flight, foraging, and maintaining colony warmth.
Bumblebees collect nectar using a specialized proboscis, which functions like a straw. They extend this mouthpart into the flower to draw out the liquid. The collected nectar is stored in an internal “honey stomach” or “crop,” separate from its digestive system, allowing transport back to the nest. Nectar provides the carbohydrates necessary for immediate energy, making it their primary food and drink.
Pollen: The Essential Nutrient Provider
Pollen, the fine powdery substance produced by flowers, is a rich source of proteins, fats, vitamins, and minerals for bumblebees. This diverse nutritional content is essential for the growth and development of bumblebee larvae and supports the queen’s egg-laying capacity. Unlike nectar, which provides immediate energy, pollen is crucial for long-term health and reproduction.
Bumblebees possess specialized structures for collecting pollen. As they visit flowers, pollen adheres to their bodies. They then use their legs to brush the pollen into “pollen baskets,” or corbiculae, located on their hind legs. This collected pollen is carried back to the nest to feed the developing young. Bumblebees are selective about pollen, preferring sources with a protein-to-fat ratio of approximately five to one, which optimizes their nutritional intake.
Water and Other Dietary Aspects
While nectar provides hydration, bumblebees also require water, especially during periods of high temperatures. They may drink plain water from sources like puddles, dew on plants, or damp soil. Water is important for general hydration, to dilute stored honey, and for cooling the hive during hot weather.
Bumblebees primarily rely on flowers for their diet, obtaining both nectar and pollen. While less common, they might also consume other sugary substances like honeydew, a sweet excretion from aphids. A varied floral diet is important for bumblebee health, as different plants offer varying nutritional profiles in their pollen and nectar, ensuring a balanced intake of necessary nutrients for the entire colony.