Extension Master GardenerSM Volunteers of Buncombe County

bees

The bees are dying, the bees are dying…Really?

The media’s continuing coverage of bees and their challenges, especially pesticides, tends to incite, frighten and confuse most of us. Even among scientists the issues are complex and controversial, but everyone agrees that bees desperately need more and better food. The best way for all of us to help is to grow more flowering plants. Dr. Marla Spivak’s plea is more specific and compelling: “Plant flowers, mostly native and keep them free of pesticides.” For a clear, concise explanation about what is going on with bees, you can’t beat her TED talk,  http://www.ted.com/talks/marla_spivak_why_bees_are_disappearing?language=en

The oft-quoted ‘Bees are responsible for every third bite of our food’ is really an underestimation. The majority of our most nutritious and delicious foods rely on insect, largely bee, pollination. This includes foods such as fruits,  vegetables, nuts, berries, oils, and indirectly some of our dairy and meat products, since alfalfa used for hay and silage requires bee pollination. Today’s industrial agricultural system comprises huge fields of single crops (monoculture) and relies heavily on synthetic fertilizers and pesticides. Because these fields do not sustain populations of native pollinators, since flowers are only in bloom for a brief time, managed honey bee hives are brought in. In February, when the 800,000 acres of almond trees are in bloom in California, it can be a pollinator paradise. After the blooms are gone in a few weeks, the almond  orchards are a toxic food desert and will be so for most of the year. The bloom period is preceded and followed by a regimen of pesticide applications, most harmful to bees. A majority of this country’s 2.5 million honey bee hives, up to 1,600,000 hives, are transported to the orchards on pallets. Most of those bee hives are then trucked off to other crops across the country.

Moving Honey Bee Hives from South Carolina to Maine for Blueberry Pollination
Moving Honey Bee Hives from South Carolina to Maine for Blueberry Pollination

It’s a paradox. Bees working hard to help produce our food are in need of more and better food of their own. Hmmm.

Besides the mandate to plant flowers, mostly natives, free of pesticides, gardeners might consider using edible plants throughout the landscape for both their inherent beauty and their teaching value. Watch the bumble bees buzz-pollinate your tomato and pepper plants grown in attractive containers with artistic stakes. Catch the huge carpenter bees cheating at blueberry pollination. Instead of diving straight into the flowers, they drill holes through the petals, bypassing the pollen and going straight to the nectar.

Carpenter bees 'cheat' by cutting slits in the petals to reach the nectar without passing the pollen. Often other potential pollinators such as this honey bee nectar forager will use the slits and also bypass the pollen.
Carpenter bees ‘cheat’ by cutting slits in the petals to reach the nectar without passing the pollen. Often other potential pollinators such as this honey bee nectar forager will use the slits and also bypass the pollen.

Blueberry bushes are beautiful most of the year, having spring flowers followed by delicious fruit and then gorgeous fall foliage colors of oranges and reds that often last until winter. Let a squash or pumpkin vine wander through a flower bed, or stake a cucumber vine on a privacy fence. Five pollinator visits per flower to make a single fruit means lots of buzzing activity and gives kids of all ages a chance to learn about male and female flowers. Then observe the tiny ovary grow to full fruit size. Watch the ‘bee party’ in a patch of sunflowers at the back of your cutting garden or along a sunny fence line, and remember; no bees, no sunflower seeds or sunflower oil. While not a pollinator favorite, a border of Rainbow Chard with its crinkly large leaves of glossy red, pink, orange, yellow and green are stunning, and if you don’t mind the resulting holes, you might love seeing the goldfinches dining on them. The options are nearly endless for edible landscapes that are beautiful, educational and also provide food for you, the precious pollinators and the other wildlife in your neighborhood.

Written by Extension Master Gardener Volunteer Diane Almond.

Meet the Pollinators

Remember that roughly 80% of the quarter million or more flowering plant species rely on pollinators to move pollen from the male to female parts, thereby facilitating fertilization, fruit and seed production. That’s a lot of the food we and most animals eat, and that’s also the next generation of plant. The abundance and diversity of plants and their pollinators mystified early scientists, including Darwin who called it an ‘abominable mystery’. Plants have evolved complex strategies to attract pollinators using colors, scents and ultraviolet visual cues, with the strongest one being nectar, the ultimate sweet reward.

Pollinators adapted accordingly, some with long tongues to reach deep into tubular flowers, others with branched hairs or special sacs for carrying pollen. Flies developed a fondness for the scent of decay, pollinating stinky flowers that bees avoid. Moths took on the night shift, preferring highly aromatic, white flowers that bloom at night. Examples are nearly endless.

Carbing Up: Notice how the syrphid fly, disguised as a bee, gets covered with pollen when it pushes past the anthers to drink sweet nectar deep inside the flower.
Carbing Up: Notice how the syrphid fly, disguised as a bee, gets covered with pollen when it pushes past the anthers to drink sweet nectar deep inside the flower.

Many flowers are structured so that small pollinators such as birds and insects inadvertently brush the protruding pollen laden anthers en route to the nectar reservoir. They are ‘accidental’ pollinators, as are larger mammal visitors, such as human passersby or bats. Interestingly there are approximately the same number of pollinator species, from ants and birds to butterflies and humans, as there are species of angiosperm. In the tropics, birds, moths and butterflies are important pollinators; less so in the temperate zones. Most pollinators are generalists, visiting a wide range of flowering plants. Some plant-pollinator relationships are those of mutual co-dependence, called ‘obligate’, a precarious situation where a single species of plant relies entirely on a single pollinator and vice versa. The best example in this country is yucca and the yucca moth.

Despite the hundreds of thousands of pollinators, most plants rely on visits from bees. And while there are 20,000 species of bees, just two or three species do much of the work: honey bees. Why? Bees evolved from the ants, wasps and bees family of insects (hymenoptera), and unlike the other insects, they rely entirely on flowers for food. Pollen is their sole source of protein, without which they could not raise young. Bees’ total reliance on pollen means that they diligently collect pollen, rather than just bumping into it as they locate the sweet nectar. Studies show that these purposeful foragers are 10 times more effective than the ‘accidental’ ones. Equally important, most bees collect one kind of pollen per foraging trip making them exceptional pollinators (pollen from one species of plant (apple) cannot pollinate a different species (pear)).

Protein Bars: Honey bees return to the hive with loaded pollen 'baskets'. Nurse bees eat much of the pollen and plenty of water to produce the royal jelly that feeds the youngest bees and the queen.
Protein Bars: Honey bees return to the hive with loaded pollen ‘baskets’. Nurse bees eat much of the pollen and plenty of water to produce the royal jelly that feeds the youngest bees and the queen.

Another important fact: social bees such as honey and bumble bees feed their young directly, in the larval stage. Solitary bees like mason bees or leaf-cutters and most sweat bees, don’t feed their young directly, but they do provision the nest, laying eggs on a large ball of food made from honey and nectar. Honey bees are even more effective because they live in large, perennial colonies with big pollen and nectar requirements.

Bees as vegetarians must collect large amounts of protein-rich pollen most of which is fed to the young. They are exquisitely designed pollen collectors with their copious branched hairs and collection devices on legs or abdomen.
Bees as vegetarians must collect large amounts of protein-rich pollen most of which is fed to the young. They are exquisitely designed pollen collectors with their copious branched hairs and collection devices on legs or abdomen.

So what’s really going on with pollinator health and populations? And what does it all mean for us concerned gardeners? Stay tuned…

Written by Extension Master Gardener Volunteer, Diane Almond.

A word about pesticides…

…with some words about systemicsimage
The number of different pestiicides on a garden center’s shelves can be overwhelming so here’s a very basic guide to making a choice.

First, of course, is to answer the question: “Is the damage severe enough that you really need to use a pesticide.” Perfect really isn’t natural, and it comes at a cost. If “yes”, be very sure that you’ve identified the culprit, the type of insect or disease that is damaging your plants, so you know which shelves you should search. Insecticides don’t do much to cure a fungal or nutritional problem. And an herbicide would eliminate the problem by killing the plant. The large print on the label gives you this information.

imageNow, put your glasses on. Just like a contract, you’ll need to read the fine print. Find a product that lists your problem on the label. Then try to determine how the material will be applied. Do you need a sprayer? This information may be on a part of the instructions that is folded or wrapped so that you can’t get to it without breaking some type of seal. In that case, ask! You want to be able to apply it when you get home.

Unless you have used the product before buy the smallest amount possible. See if it works. You don’t want too much as it’s best not to store a pesticide for any length of time.
Ready to use (RTU) versus the concentrated mix-it-yourself: With RTU you’re paying for convenience in not having to do the measuring and mixing, and in many cases the sprayer is provided.

Pesticides are also classified by mode of action. Some must contact the bug or fungus directly. Others need to be ingested by the insect. Or be repulsive. Systemics though are absorbed by the plant and actually get into the circulatory system of the plant. Glyphosate (as in Roundup) is a systemic weed killer. You need to use special care with such formulations.

Another very important example: Imidacloprid is a systemic insecticide that has been quite successful in controlling the Hemlock Wooly Adelgid as well as many other insects that chew on leaves and stems ornamental plants. Unfortunately that includes those that use imagepollen from buds and flowers including, most importantly our friends, the bees and other insects who carry that pollen home and feed it in some form to their young ones. Our farms and gardens will be in sorry shape without the pollinators. In fact we’re already approaching the critical point with those populations.

The North Carolina Agricultural Chemical Manual in a table labeled Relative Toxicity of Pesticides to Honey Bees lists imidacloprid along with other systemics under the heading of Group 1 Highly Toxic, warning that “Severe bee losses may be expected if these pesticides are used when bees are present and foraging in the flowers, or the product is applied near beehives.” The same warning is in the label.

Bottom Line: Read the label before you buy and again before you apply. And follow it when using any pesticide!

Article written by Glenn Palmer, Extension Master Gardener Volunteer.

For more information:

Pesticide Environmental Stewardship Website
http://pesticidestewardship.org/Pages/default.aspx

Pesticide Use and Safety
http://content.ces.ncsu.edu/pesticide-use-and-safety-information.pdf

Disease & Insect Management in the Home Orchard
http://www.cals.ncsu.edu/plantpath/extension/clinic/fact_sheets/index.php?do=disease&id=7

 

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Buncombe County Extension Office
49 Mount Carmel Road
Asheville, NC 28806
Helpline 828-255-5522

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