Native bees & our local apple orchards

Native bees at two Fannin County apple orchards were the topic of the second of two Southeastern Naturalist journal articles last month. Researchers found that not only were there over one hundred bee species in the orchards, but that native bees might be capable of replacing the European honey bee as pollinators of the economically important apple crop locally.

Mercier Orchards and Mountain View Orchards are two of the four north Georgia apple farms that were studied by researchers Mark A. Schlueter and Nicolas G. Stewart for their native bees. From Georgia Gwinnett College, the two authors sought in 2010 to develop a picture of native bee diversity and abundance in Georgia’s apple orchards.

This project wasn’t a matter of idle curiosity. To know the state of local bees is to get a handle on the possible fate of a major local industry. As Schlueter and Stewart pointed out, the introduced European honey bee (Apis mellifera) has for decades been the linch-pin of an American agricultural economy. The honey bees contributed $15 billion annually through their pollination of fruit and vegetable flowers. That pollination is necessary for the plants to finally bear the fruits or vegetables. A recent phenomenon, “Colony Collapse Disorder,” has wreaked havoc on the honey bee. In many areas, up to 90 percent of the bee colonies have been destroyed. Gilmer County, known as the “Apple Capital of Georgia,” and adjacent Fannin County are particularly vulnerable. Georgia produced $8.8 million in apples in 2010, much of it for the fresh fruit trade, according to state statistics. That apple trade also contributes to a vibrant tourist industry that draws thousands of visitors to Ellijay and Blue Ridge to purchase a bag of apples, a jar of apple jelly, or a bottle of apple cider while “leaf peeping,” dining at local restaurants, or attending the Georgia Apple Festival. A failure in the honey bee could mean a failure of the apple crops with a compounding effect upon the mountain economy.

The spotlight that Schlueter and Stewart brought to our bee situation indicates that the apples may be safe even in the face of a honey bee crisis. Over the 2010 growing season the scientists collected over 2000 bees in the local orchards as well as two orchards in northeastern Georgia. What they found was that we enjoy both a great diversity and abundance of native bees. The authors found a whopping 128 species among the 2,000 bees that were collected. Of those species, 93 percent of them were natives. The species that was best situated to supplement the honey bee is a mining bee,  Andrena crataegi, which was especially prevalent and abundant in the orchards.

andrena_crataegi-female-back_2012-08-07-18-42-36-zs-pmaxi_sd12664
Andrena crataegi. Image courtesy of DiscoverLife.org.

One disappointment was that the authors observed that Mercier did not have quite the level of native bee abundance and diversity seen at other orchards. Nevertheless, that’s something that might be improved. In doing some extra reading I found that Catherine Schlueter, with Mark Schlueter and Nicholas Stewart, presented a paper in 2013 in which they suggested that digging trenches around orchards might create additional opportunities for Andrena  and other bees to dig nests.

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Want to learn more? 

I learned that the Schlueters and Stewart have been local bee specialists for several years. Among them they have produced several papers about the topic, particularly as it affects the apple industry. A worthwhile first stop is their Bees of Georgia website.

Some sources that I reviewed include:

  1. Native Bee Abundance and Diversity in Georgia Apple Orchards (Research Article: Published in the Southeastern Naturalist (2015) volume 14(4):721-739.)
  2. Conference paper, Catherine Schlueter, Nicolas Stewart, and Mark Schlueter, The identification of Andrena crataegi as the apple bee in Georgia, Entomological Society of America Annual Meeting 2013.
  3. Species account, Andrena crataegi, DiscoverLife.org, Available at http://www.discoverlife.org/20/q?search=Andrena+crataegi.
  4. Honey Bee Health and Colony Collapse Disorder, U.S. Department of Agriculture, Agricultural Research Service, last modified 11/05/2015. Available at http://www.ars.usda.gov/News/docs.htm?docid=15572.
  5. Ag StatsUniversity of Georgia Cooperative Extension Service. Available at http://extension.uga.edu/agriculture/ag-stats-agencies/ag-stats/.
  6. Commodity Facts: Apples, University of Georgia Cooperative Extension Service. Available http://www.caes.uga.edu/extension/anr/gaagres/commodities/apples.html