What You Can Do

Why should we care about pollinators?

Three-fourths of the world’s flowering plants and about 35 percent of the world’s food crops depend on animal pollinators to reproduce.  Some scientists estimate that one out of every three bites of food we eat exists because of animal pollinators like bees, butterflies and moths, birds and bats.  Perhaps the most critical pollinator groups are bees: bee pollination is responsible for more than $15 billion in increased crop value each year in the United States.  Bees of all sorts pollinate approximately 75 percent of the fruits, nuts and vegetables grown in this country, and one out of every four bites of food people take is courtesy of bee pollination.[1]

The Xerces Society for Invertebrate Conservation puts it in an ecosystem framework:[2]

Pollinators are essential to our environment . . . Beyond agriculture, pollinators are keystone species in most terrestrial ecosystems. Fruits and seeds derived from insect pollination are a major part of the diet of approximately 25% of all birds, and of mammals ranging from red-backed voles to grizzly bears. In many places, the essential service of pollination is at risk from habitat loss, pesticide use, and introduced diseases.

Honey bees get all the press

We often think of honey bees as the primary pollinator of food crops.  Honey bees (genus Apis) were brought over by European colonists in the 17th century, possibly as early as 1622.  According to early American writers like Thomas Jefferson, Native Americans called honey bees “white man’s flies” since the appearance of honey bees in America was associated with the arrival of European settlers.  And like many insects, once introduced, they increased their range both by swarming and travelling with the settlers as they moved across the country.  Today, honey bees are considered a critical pollinator for food crops and as a result, much of the recent focus of pollinator decline has been on their demise because data are being collected and the news is alarming.  In the United States, beekeepers have lost around 30% of their colonies every year since 2006, with total annual losses sometimes reaching as high as 42%.[3]

Native bees are important and often overlooked

Native pollinators face similar population declines with some species like the rusty-patched bumble bee threatened with extinction.  Across the U.S., there are an estimated 4,000 native bee species with the greatest diversity found in the western states, [4] from the Quarter-sized carpenter bee (Xylocopa spp.) to the tiny sweat bee Perdita minima, a rarely seen specialist that nectars on wildflowers in the spurge family.  Native or “wild” bees pollinate native plants like cherries, blueberries and cranberries, and were here long before European honey bees arrived. Honey bees are well known for pollinating food crops like almond and lemon trees, okra, papaya and watermelon plants. But native bees are estimated to pollinate 80% of flowering plants around the world.  New research shows that at least 120 species of wild bees like the blue orchard, mason, bumble and even sweat bees were found in Pennsylvania orchards during the growing season, and are more efficient pollinators than honey bees.  When farmers provide good adjacent habitat[5], orchards adjacent to wild bee habitat can be fully pollinated without using honey bee hives.[6]

Bees are vegetarians who descended from wasps about 125 million years ago when the first flowering plants evolved. Some wasps switched from hunting prey to gathering pollen, evolving to become bees.   Many modern wasps do feed on nectar and pollen during different phases of their lives.  Bees feed on both nectar and pollen – the nectar is for energy, and the pollen provides protein and other nutrients. Most pollen is used by bees as larvae food, but bees also transfer it from plant-to-plant providing the pollination services needed by plants and nature as a whole.

Butterflies, moths, beetles, wasps and hornets are also important pollinators although playing a relatively smaller role than bees.  Many wasps, hornets, and beetles provide additional services by preying on pest insects and help to keep crop and garden pests in check.  Population changes in these pollinator species have not been as closely tracked as honey bees.  There are several hundred thousand species of pollinators and tracking all of them is not possible.  However, surveys have documented disturbing population declines and even local extinctions of select pollinator species across the U.S. and Europe. [7]

Reasons for pollinator declines

Chief reasons for pollinator decline are (1) loss of basic habitat requirements in our landscapes such as floral resources (nectar and pollen) other than flowering crops, (2) pest and diseases affecting managed pollinators like honey bees that can spread to the wild populations, (3) introduced species that change ecological systems, and (4) our heavy reliance on broad spectrum pesticides by both agricultural industry and individual homeowners and other property managers.[8]  Land management practices, in other words, have led to this result.

Engaging private and public landowners to help pollinators

In 2016, TVWO decided to focus on what we can do to help pollinators of all stripes that make the Tennessee Valley area home.  Inspired by the Greater Atlanta Pollinator Partnership (GAPP)[9], we launched the Chattanooga Area Pollinator Partnership (CHAPP)[10].  CHAPP’s mission is to improve pollinator habitat for butterflies, bees, moths, hummingbirds and other pollinators with the overarching vision that we will restore habitat corridors across the mid-south by connecting landscapes that provide food, water, shelter and avoid using pesticides.  Furthermore, we would map a growing habitat corridor and connect this corridor with other regional pollinator habitat corridor projects like GAPP to help measure, display and promote these habitat connections.[11]

As educators and advocates, our chapter members spread the word through our public meetings, presentations to garden clubs and master gardener groups, tabling events, newsletters and websites.  Wild One’s mission is to promote sustainable landscaping practices and the establishment and restoration of native plant communities.

Our message is:

Your yard is an important ecosystem. Because of the widespread destruction of native habitat, Doug Tallamy, author of “Bringing Nature Home” and University of Delaware entomologist emphasizes the importance of native plants and the insects that feed on them.  “We must look at our yards in a different way. We must turn from an agricultural desert made up of green chemically treated lawns with shrubs and trees from Asia, to yards that are pesticide free and contain native flowering plants that bloom from spring to late fall.  Americans have a misplaced love affair with the lawn, Asian plants, and biologically inactive plants.  It is a problem easily ten times larger than that caused by modern agriculture,writes Tallamy.  Therefore, restoring native plant communities is crucial.

We have been taught to hate and kill insects, not realizing that they support the entire human and wildlife food web.  Plants convert the sun’s energy into food, and insects move that energy through food webs.  Killing insects deprives other members of the ecosystem an essential food source.

Most plant-eating insects are specialists,[12] having a relationship with specific native plants in their life stages without which the insect will perish, as opposed to being generalists that feed on a variety of plants.  One insect specialist is the Monarch butterfly caterpillar that only feeds on milkweed (Asclepias spp.).  There are many other butterflies and moths whose larvae will only feed on specific native plants.  Specialist insects and native plants have evolved together and plants from other regions cannot supply these ecosystem services.  Some native bees are floral specialists like blueberry and squash bees that pollinate their native plant namesakes.  As these host and nectar plants disappear from the landscape, so do their specialist insect.  This point underscores why it is so important to have plant diversity and particularly native plant diversity.

Keys to improving pollinator habitat

CHAPP promotes four strategies you can use to improve pollinator habitat:

  • Provide native host, pollen and nectar plants from early spring through late fall when pollinators are active;
  • Offer a safe place for pollinators to reproduce and raise their young;
  • Provide water, and
  • Avoid using pesticides, especially pesticides deadly to insects.[13]

Choosing native plants can be confusing and frustrating because there has been so little information available in gardening magazines, newspaper feature articles and other information sources.  We have aimed at filling that void by providing plant lists of easy to grow native plants that flower across the long growing season in the Southeast as well as more detailed lists of native plants that grow in different conditions (sun-shade, dry-moist, et al).  Our goal is to build tool kits that are informative and easy to use.  This information is posted on this website.

We also provide grants to schools for to purchase native plants and seeds for pollinator gardens through a new Seeds for Education initiative modeled after the Wild Ones’ national program by the same name.  Schools, churches, parks are all fertile ground for expanding pollinator habitat and connecting habitat corridors.  And our members consult with those schools to help them design functional and sustainable pollinator garden installations.  We want everyone to pitch in and help save the pollinators!

REFERENCES

[1] USDA https://www.nrcs.usda.gov/wps/portal/nrcs/main/national/plantsanimals/pollinate/

[2] https://xerces.org/pollinator-conservation/

[3] https://cmns.umd.edu/news-events/features/3867).

[4] At this writing, there is no exhaustive listing of bee species native to Tennessee although the www.discoverlife.org database might be useful.

[5] “Good habitat” as defined by the USDA NCRS and Xerces Society for Invertebrate Conservation and a growing number of state extension services is plant native wildflowers that provide a diversity of floral resources through the entire growing season, provide shelter, and minimize pesticide use.

[6] https://extension.psu.edu/wild-bees-in-orchards

[7] https://beeinformed.org/

[8]  Status of Pollinators in North America, National Academy of Sciences, 2006.

[9] www.gapp.org

[10] www.chapollinator.org

[11] The CHAPP map can be found here:  https://chapollinator.org/map-your-garden/chapp-map/

[12] The global distribution of diet breadth in insect herbivores, Forister, et al, Proceedings of the National Academy of Sciences of the USA, vol 112, no 2, 442-447, January 13, 2015, http://www.pnas.org/content/112/2/442.full?tab=author-info

[13] See Xerces for comprehensive research regarding the safety of a particularly lethal class of insecticides called “neonicotinoids” http://xerces.org/neonicotinoids-and-bees/