Pollinators 101

When most people hear the word pollinators, an image of buzzing black and yellow honey bees immediately comes to mind. While bees are certainly very prominent pollinators, many other types of insects and animals engage in pollination too! This includes butterflies, moths, birds, bats, ants, beetles, other animals, and even the wind. Humans could be dubbed pollinators at times, such as when assisting with hand-pollination, though the term is usually reserved for those that perform it naturally in the wild. 

Pollinators assist with the movement of pollen between or among flowers. The transfer of pollen from the male plant part (anther) to the female plant structure (stigma) effectively fertilizes the flower. Fertilization leads to the production of robust fruit and viable seeds, which allows the plant to reproduce. Or, to potentially feed others! 

Plants and pollinators have a beautiful symbiotic relationship. The plants are fertilized while the pollinators are fed. Some pollinators, such as bees, are seeking both pollen and nectar. Others are only interested in drinking the sweet nectar from flowers, like butterflies and hummingbirds. When they dive deep to get a drink, they inadvertently pick up and transfer pollen around too. 

Pollinators are so important that they are considered a keystone species group. The National Geographic Society describes a keystone species as "a plant or animal that plays a unique and crucial role in the way an ecosystem functions." Without keystone species, the ecosystem would be dramatically different or cease to exist altogether.

Did you know that pollinators are directly responsible for one-third of all food that humans consume, including everything from fruits and vegetables to coffee and chocolate? That is because approximately 75% to 95% of the world's flowering plants need pollinators to set fruit or seed, including the majority of food crops. Globally, the action of pollinators in food production has an estimated economic worth of 235 to 577 billion US dollars! Without the actions of pollinators, agricultural economies, our food supply, and surrounding landscapes would collapse.

Of the roughly 3,600 species of bees in North America, more than 90 percent lead solitary rather than social lives, each female constructing and provisioning her own nest without any help from other members of her species. Solitary bees usually live for about a year, although humans only see the active adult stage, which lasts about three to six weeks. These insects spend the other months hidden in a nest, growing through the egg, larval, and pupal stages.

Female solitary bees have amazing engineering skills, going to extraordinary lengths to construct a secure nest. About 30 percent of solitary bee species use abandoned beetle burrows or other tunnels in snags (dead or dying standing trees). Alternatively, they may chew out a nest within the soft central pith of stems and twigs. The other roughly 70 percent nest in the ground, digging tunnels in bare or sparsely vegetated, well-drained soil. A few species nest in eclectic places such as empty snail shells and potlike cells that they construct on twigs from pebbles and tree resin.

Each bee nest usually has several separate brood cells in which the female lays her eggs, one egg per cell. The number of cells varies by species. While some nests may have only a single cell, most have five or even many more. Female woodnesting bees make cells in a single line that fills the tunnel. Females of ground-nesting species may dig complex, branching tunnels. To protect the developing bee and its food supply (from drying out, excess moisture, fungi, and disease) the cell may be lined with waxy or cellophane-like glandular secretions, pieces of leaf or petal, mud, or chewed-up wood.