Ground bees are a varied group of wild bees that build their homes beneath the soil. While many associate bees with communal hives, a majority of species worldwide nest underground. These bees are a frequent sight in gardens, yet their habits and contributions are often misunderstood.
Who Are Ground Bees?
Ground bees are a diverse category encompassing species like mining bees (Andrena), digger bees (Anthophorini), and sweat bees (Halictidae). They typically range from half to three-quarters of an inch long. Their appearance varies significantly, with some resembling honeybees, while others exhibit metallic green, blue, or coppery hues. Many ground bees are solitary, meaning each female builds and provisions her own nest, unlike social honeybees. Many individual nests can be located close together in suitable areas, forming an aggregation.
Their Underground Lives
Female ground bees construct individual burrows in the soil to lay eggs and provision their young. Nests are typically found in warm, dry areas with sun exposure and well-drained soil, often with sparse vegetation or bare ground. Tunnels can vary from a few inches to 10 feet deep, depending on the species. Each female digs a main tunnel, often with several side tunnels, creating small cells within which she places a ball of pollen and nectar. An egg is laid on this pollen ball, providing the larva with food as it develops.
Their Role in the Ecosystem
Ground bees play an important role in the environment as pollinators. They pollinate a wide array of plants, including native species and crops like apples, blueberries, and melons. Some ground bees are specialized pollinators, effective for specific plant species. Their fuzzy bodies efficiently collect and transfer pollen.
Beyond pollination, their burrowing activities contribute to soil aeration, creating pathways for water, air, and nutrients to penetrate the soil. This aeration improves soil structure and promotes healthier plant growth.
Interacting with Ground Bees
Ground bees are generally docile and rarely sting unless directly provoked, such as being stepped on or handled. Unlike social bees that defend a communal hive, solitary female ground bees do not have a large colony to protect, making them less prone to aggression. Male ground bees may appear aggressive as they patrol for mates, but they lack stingers and are harmless. If ground bees are nesting in an undesirable location, regularly watering the area can encourage them to relocate, as they prefer dry soil. Maintaining dense turf or applying mulch can also make an area less appealing for nesting.