Published on 04/23/15

Human landscapes can offer safety to imperiled pollinators

By Heather Kolich

There are more than 4,000 species of native bees in North America — from plump, stalwart carpenter bees to the hardworking blueberry bees that help pollinate the state’s top fruit crop.

This year the National Association of Conservation Districts is using its annual Stewardship Week celebration, April 26 to May 2, to recognize the importance of pollinators in our lives.

Whether on a farm or in your backyard, protecting pollinators helps to ensure their future and the future of our food system.

Pollinator Syndrome

Although it sounds ominous, “pollinator syndrome” describes the relationship between flowering plants and pollinators. The rich diversity of pollinators evolved hand in hand with the flowers they fertilize.

Over the thousands of years since angiosperms, or flowering plants, first appeared, flowers have adapted in shape, color and fragrance to attract specific types of insect or animal pollinators. Blue, yellow and bright white flowers, for instance, draw bees. Butterflies and birds frequent red blossoms. Strong, sweet fragrances get the attention of moths, while flies prefer putrid aromas. Plants that depend on bees and butterflies for pollination offer flowers as an inviting landing pad where the insect can rest as it collects pollen and nectar.

In return for the bounty of food — pollen for protein and nectar for energy — pollinators spread pollen among the flowers. This act of fertilization enables flowers to produce the fruits, nuts and seeds that feed other animals — including humans — and helps to ensure the plant’s survival.

Pollinator Niches

The thousands of native bee species in the U.S. each fill specific, ecological niches to keep from competing heavily with one another. Some, like orchard mason bees, emerge very early in the spring, before other types of bees, to pollinate fruit trees. Other pollinators are specialists. Southeastern blueberry bees only collect food from — and consequently pollinate — blueberry flowers. Similarly, squash bees only visit the flowers of cucurbits, like squash and pumpkins.

Pollinator Stewardship

Many of our native pollinators are in decline and need our help year-round. Factors that contribute to pollinator decline are largely man-made and include:

  • Loss of habitat.Manicured lawns, clipped hedges and tidy, suburban landscapes deprive bees of the habitats they need for reproduction.
  • Loss of sufficient flowering plants for forage. Exotic, non-native and cultivated, hybrid flowers may not produce the pollen that insects need for protein, or the nectar that bees, birds, butterflies and bats need for energy.
  • Pesticide use. Pesticides may kill pollinators directly, and the chemicals may be retained in the pollen that bees store to feed their young.

We can strengthen our pollinator populations by making small changes to our landscapes. Native bees and other pollinators need a variety of habitats that are easy to create. Bumblebees nest in the ground in slightly messy, undisturbed spaces, like small brush piles. Many native bees are solitary and nest in tunnels in bare soil. Orchard mason bees nest in tubes, like nail holes in fence posts or even plastic drinking straws. They need a source of mud nearby to build separators between eggs inside the tube.

While many bee species are active only for a few weeks, bumblebees and honeybees need to forage from early spring all the way through the end of fall. To help sustain them, Georgians can keep their yards in constant bloom with flowering trees and shrubs, and an abundance of flowers and herbs.

And, finally, don’t spray pesticides when plants are blooming. That’s when pollinators are busy collecting food. If you must use pesticides, wait until petals drop from flowers.

For more information on protecting pollinators, see UGA Extension Bulletin 1164: Bee Conservation in the Southeast.

Heather Kolich is an Agriculture and Natural Resources agent with UGA Extension in Forsyth County.

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