Imagine the world without natural fibers, fruits, vegetables or flowers. That’s what our world would be like without insects and other animals that pollinate our plants. Seventy-five percent of our flowering plants rely on insects, birds or bats to move pollen from one plant to another.
Pollination is critical to successful orchards, field crops, forage crops, home gardens, endangered species and ecological restoration. As food producers and consumers, we all need to be aware of the importance of pollinators to plants and our environment.
Most plants need to make seeds to reproduce. But many can’t do it by themselves. To make seeds, the female part of the plant, called a pistil, needs pollen from the male part of the flower, called a stamen. Cross-pollination is the rule of thumb in the plant world. This means not only does pollen have to be transported from stamen to pistil but it also must come from separate flowers. Some plants rely on the wind to do this. Many others depend on animals.
Pollinators use the nectar from flowers for food. Many, like bees, get sticky pollen grains on their bodies. By moving from one flower to another, they transfer pollen to the pistils.
Bees aren’t the only pollinators, though. Other insects, such as wasps, flies, butterflies, moths and beetles are important pollinators.
Larger animals, such as birds (especially hummingbirds), flying foxes, bats, opossums, lemurs, rodents and even a gecko, help to move pollen.
Plants often help their specific pollinators find their way. This co-
dependence is exhibited in many ways. Many night-pollinated flowers close during the day to prevent daytime thieves from getting at their nectar and pollen. On the other hand, many daytime-pollinated flowers close at night for the same reason. Flowers pollinated at night are usually white or pale yellow and very fragrant. This helps to announce the flowers’ presence. Darker-colored flowers, not as visible at night, are usually pollinated by day-flying insects.
Flowers assist the pollinator in finding where the pollen or nectar is stored. There are often bee lines, dots or color variations that direct the pollinator. Flowers’ shapes—bowl, cup, star or tube—are specific to pollinators and, in some cases, also keep out unwanted pollen collectors.
Despite their importance to our economy and lives, many pollinators are in trouble.
Honeybees raised specifically to pollinate crops are in decline. In the last 50 years, the domesticated honeybee population has declined by 50 percent because of parasitic mites, disease, pesticide poisoning and a phenomenon, Colony Collapse Disorder, where the bees go off in search of nectar and do not return to the hive. Wild pollinators are also disappearing at alarming rates because of habitat loss, pesticide poisoning, diseases and pests.
A healthy ecosystem provides pollinators with habitat for foraging, nesting, roosting and mating. Homes, businesses and roads are replacing the native fields, wetlands and forests that are home to many pollinators. In addition, many of the wildflowers used by pollinators for food, nesting or egg-laying are rapidly disappearing.
Pesticides are also a threat. Many pesticides used on farms and backyard gardens are broad-spectrum types, meaning they can harm non-target species. Many insecticides that get rid of plant pests are toxic to bees and other beneficial insects
Pollinators such as bats, butterflies and hummingbirds face even more problems. They may migrate many miles over the course of a year. These travelers need nectar-producing flowers all along their journeys. But wildflowers and natural habitats are being replaced by development. Less food and habitat is available to pollinators as they migrate.
There are many ways that the public can help pollinators:
- Reduce the use of pesticides or, if possible, stop using them altogether. If one must use an insecticide, apply it in the evening when many pollinators are inactive.
- Plant gardens filled with nectar-producing flowers that are native to the area. Refer to the Native Plants for Wildlife Habitat and Conservation Landscaping at www.nps.gov/plants/pubs/chesapeake/.
- Leave tree stumps, dead branches and rotting trees on your property, if possible. They provide nests for some species of bees as well as birds, bats, butterflies, bees and other insects.
If a bee’s nest is too close to a home, don’t destroy it. Contact a local beekeeper or state cooperative extension service for advice about removing the nest without harming the bees.
Pollinator Week is June 24–30, 2007. For information on pollinators and how to help them, visit www.pollinator.org.