Gardening with Georgia

Archive - August 2013

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Snakes, snails and rainfall tales

Wed, Aug 28, 2013 at 09:03:27 AM

This summer in South Florida, rain has put our plants on liquid steroids. Lucky for them, but maintenance has kept us running with pruners. On those occasions when the sun appears, a good day’s work has meant several changes of appropriate attire – T-shirts and shorts designated for gardening by telltale stains of plant blood. (I know that bananas and crotons can stain, but they cannot possibly account for all the drips and drabs I manage to accumulate.)

In times like this, we must give plants some elbow room or it’s mycelium city, root-rot ranch and snails as transformers. Take a hard look at what’s going on in your garden and if your plants have out-performed your wildest expectations, then nip, prune or move them around in their containers so air easily circulates around them. Snoop around the garden early in the morning to find snails and dispense with them. Leave offerings for the sun god.

Nonetheless, we are approaching fall, and here’s a reminder of what is to come in September besides the up scaling of worry about the hurricane season.

Trimming bougainvilleas – always a sticky exercise.  A blood bank should be on standby. The idea is to increase new growth on which flowers form as the days shorten.

To increase the flower power of bougain-
villeas, trim back in September.

Which means a lighter pruning than is called for in spring when you can prune the things nearly to the ground. Fertilize afterwards. There’s a bougainvillea fertilizer on the market that is a 6-8-10 formulation with micronutrients. Or, use palm special, 8-4-12 with micronutrients that is made for South Florida soils.

Cutback poinsettias and fertilize, using palm special or 4-6-8.

Some orchid growers also like to apply bloom booster fertilizer (3-9-6 or 10-30-10) to orchids that flower in the winter and spring, such as cattleyas and phalaenopsis orchids. If you want to try it, use it two or three times in a row.  Or, just continue with 15-5-15 orchid fertilizer. Martin Motes recommends potassium nitrate – 1 tablespoon to a gallon of water – on every third or fourth application throughout the year. Potassium is important in photosynthesis, transporting nutrients and increasing heat and cold tolerance.






New EPA label for bee-toxic pesticides

Sun, Aug 18, 2013 at 05:05:30 PM

EPA's bee icon to appear on four pesticide
labels that will kill bees and other insect

The Environmental Protection Agency has released a new pesticide label that prohibits use of four chemicals "when bees are present." The label will contain a bee symbol and information about spray drift and timing for use to avoid bees. The pesticides include are  imidacloprid, dinotefuran, clothianidin and thiamethoxam, all neonicotinoides.

The new label will state this product can kill bees and other insect pollinators. The agency said it will work with pesticide manufacturers to revise their labels, although the agency has not suspended use of the pesticides. A bee advisory box will tell applicators when to use the chemicals if necessary.

In July, Congressmen Earl Blumenauer of Oregon and John Conyer of Main introduced H.R. 2692, the Save America's Pollinators Act of 2013 that directs the EPA to suspend use of the most bee-toxic neonicotinoids for seed treatment, soil applications and foliar spray until reviews show they are save. The bill also asks the EPA an Secretary of Interior to report on native bee populations and show potential causes of any declines. There is no report on any action on the bill.


European honeybee working flowers of firebush, Hamelia patens. When
purchasing garden plants, ask if they have been treated with pesticides, or
grow your own plants from seeds or cuttings you know are pesticide-free.




Plight of the Honeybees—Part Six

Sat, Aug 17, 2013 at 01:30:00 PM

Jeff Pettis leads the Bee Research Lab of the Agricultural Research Service in Beltsville, Md. “From the beekeepers standpoint, we’re not finding answers fast enough. They’re struggling,” he says. And more attention on the research side is focused on neonicotinoids because “they move through the system of the plant and can concentrate in the pollen. It’s a new route of exposure for pollinators. In general, the jury is out, but pesticide exposure has come up higher and higher on the radar.”

Richard with bees
Bees at the Fairchild Farm

There also are mite-resistant queen bees. “If a beekeeper is willing to purchase queens so those lines can continue in the colonies, it’s one way to keep mite levels low,” said Tucson’s Hoffman. “But it requires an area-wide approach because of the mite migration problem.”

Hoffman believes the problems will be overcome, “but the beekeepers, researchers, growers and chemical companies all have to come together to find solutions that actually are going to work.”

To that end, Jerry Hayes left his job as chief apiary inspector for Florida to go to Monsanto and set up a bee program two years ago. He got a lot of online flack, but stuck with it. Both Hayes and Mendes had been working with a small Israeli company called Beeologics to develop a way to use RNA to silence the gene that causes one of the bee viruses.

“If you could control varroa using a natural process, that would change beekeeping globally,” Hayes says. Monsanto purchased Beeologics, and has the money to fund the research. “Scientists in Israel have gene targets picked out in the mite and viruses that won’t turn off any honeybee genes,” Hayes says. “They say they would have a preliminary report by the end of the year. The actual product is still 3 or 4 years away.”

Hayes put together a bee advisory council for Monsanto and this past June he organized a Honey Bee Health Summit that Monsanto co-sponsored. “It’s a meeting that needed to happen,” says Mendes. It was a meeting of researchers, beekeepers, chemical reps and USDA officials, just what DeGrandi-Hoffman says has to happen.

To the 3 Ps afflicting honeybees – pathogens, pesticides and poor nutrition – Mendes says he would add a 4th: politics. “Trying to separate science from politics is messy. It’s not just a scientific issue. Companies involved in the manufacture of pesticides are multi-billion and multinational and making a lot of money from some chemicals beekeepers are concerned about. EPA is in the thick of it because they’re charged with showing that the products are safe. It’s messy.”


Plight of the Honeybees—Part Five

Fri, Aug 16, 2013 at 01:28:21 PM

Eric and Sue Olsen from Yakima, Washington, have been in the beekeeping business 32 years. They lost 65 percent of their bees in 2010 in California. Like others in the bees-on-wheels pollinator business, they transport their hives on trucks to different parts of the country when different crops come into flower. After the California die-off, says Sue Olsen, they had to get a $700,000 bank loan to buy new bees, “They were sprayed with something,” she says. “It probably wasn’t the chemical itself. There are nasty little secrets about some chemicals.”

 Adjuvants, or spreader-stickers that help active ingredients adhere more readily to leaves, are added to agricultural chemicals, especially fungicides. Some adjuvants “appear to be good enough to move viruses through insect tissue,” says Mussen. “So if they could do that, they could move chemicals through tissues. So the world is continually changing and maybe neonicotinoids are synergizing all the others.”

Most of the adjuvants don’t have to be added in today’s products, Mussen says. “But pesticide applicators can’t make much money on products already in the can. They can’t mark those up much. But a lot of guys work for companies that make adjuvants and so they get them cheap, put them in, and make all their money on adjuvants.”

These inert ingredients historically have not been considered toxic enough to warrant risk assessment. Nonetheless entomologists at Pennsylvania State University have found that they impair bees’ navigation abilities, their ability to smell and can kill larvae in the hive. Many of the adjuvants are said to be proprietary and are not listed on pesticide labels. In 2010, Penn State and ARS scientists found 121 different pesticides and metabolites in honeybee, wax, pollen and hives, with samples coming from 23 states.

Mendes takes his colonies to the southern end of the San Joaquin Valley for almond pollination because there's not a lot of rain and growers don't use fungicides. "One hundred miles farther north, where there is a lot of fungicide use, you bring them back and the bees are sick," he says. "Raising bees today is like raising a child with a lot of health problems."


Plight of the Honeybees—Part Four

Thu, Aug 15, 2013 at 01:24:12 PM

bee hive
Bee hive at the Fairchild Farm

Dave Mendes says his colonies have grown dramatically to almost 20,000 hives over the last three years because he now is engaged in “high-input beekeeping” that requires far more work than beekeeping did a decade ago. He splits his hives annually, introduces new queens often, and he takes his bees to California in the spring to pollinate almonds, having switched from honey production.

California almonds command the biggest pollination event on the planet. Some 800,000 acres are planted with the trees, and the acreage is growing. Two-thirds of the country’s honeybee colonies are needed to pollinate them. In 2006-07, there weren’t enough honeybees in the U.S. to pollinate all the almonds, and bees were imported from Australia. That stopped when Asian mites were found on them.

"Before varroa and tracheal mites got here (in 1987 and 1984 respectively) there was a 5 to 10 percent annual loss," says extension bee specialist Mussen. "When we started to bombard colonies with (chemical) mite controls, losses jumped to 15 to 20 percent. Now, we're up to an average of 30 percent. Now, we have varroa mites with viruses that they move around. And yes, neonictinoids are on the market. Put all that together, and meanwhile all the rest of the chemistries are changing, too."


Plight of the Honeybees—Part Three

Wed, Aug 14, 2013 at 09:25:07 AM

Habitat loss has depleted bee foraging areas, impacting bee nutrition. “Acreage of corn and soybeans have high dollar value, and the acreage is expanding either into conservation areas or prairies or places good for pollinator habitats,” Mendes says.

Richard beehive
Richard Campbell examines a beehive.

In mid-summer at the Fairchild Farm, Campbell’s six bee colonies would starve if they weren’t fed honey in a landscape altered by nurseries, farms and houses. “That’s the biggest limitation here at the farm,” he says. “About a month ago (May), when everything finished blooming, they started to starve. Hungry bees get weakened and you get [problems with] hive beetles and varroa mites.”

Campbell fed his Farm bees honey to counter the lack of natural flowers. The bees at the Garden feed on palm and mangrove flowers in the summer.  Mendes also relies on palms and mangrove flowers, followed in September and October by melaleuca blooms and Brazilian pepper. When he has to supplement food for his bees, he mixes brewer’s yeast, sugar, dried eggs, and some oils to give them protein, “which seems to make a difference” in keeping his bees healthy.

At the Tucson Bee Lab of the USDA’s Agricultural Research Service, team leader Dr. Gloria DeGrandi-Hoffman spent four years analyzing nutrients in pollen and developed a protein supplement with lipids, minerals and carbohydrates called Megabee. It now is in commercial production. Her next long-term research will focus on how microbes in bees affect pollen that is mixed with honey to become beebread, or food for the hive.

Hoffman also has worked with a team of researchers to come up with a natural miticide made from the byproducts of hops used in processing beer (now sold as Hopguard). While doing that work on varroa mites, she said she found that mite population in a beehive is dynamic—mites are highly migratory and move into hives all the time, "so you can lose control of the population quickly. So I'd say beekeepers need constant vigilance. Check the populations monthly and rotate controls."


Plight of the Honeybees—Part Two

Tue, Aug 13, 2013 at 08:55:41 AM

In April, European regulators suspended for two years the use of systemic pesticides related to nicotine called neonicotinoids, which, in high doses, can cause paralysis and death in insects.  The U.S. Environmental Protection Agency has not suspended their use – although the Oregon Department of Agriculture stopped the use of 18 products containing one of the related chemicals after two massive bee kills in June while it investigates the incidents.  The EPA established a Pollinator Protection Workgroup in 2011. It also is reevaluating risk assessment standards that have been used since the 1950s, which only measure direct killing effects on adult bees and do not account for sub-lethal and accumulative effects of chemicals on the social lives of bees inside the hives – the queens, nurse bees, drones and developing larvae.

bees close up

Honeybees, which were introduced to the United States from Europe beginning in 1662, began disappearing in huge numbers here in 2004 and 2005. By 2006, the disappearance got a name: Colony Collapse Disorder (CCD).

In Fort Myers, commercial beekeeper Dave Mendes says, “Varroa mites are in the center and pesticides are in the thick of it because bees are exposed to them either on agricultural crops or because beekeepers use them to control mites. It’s a crappy position for beekeepers to be in.”

Eric Mussen, extension apiculturist at the University of California, Davis, describes CCD this way: “Foragers stop returning to the colony. They leave and don’t come back. Once you deplete the foragers, then the house bees come out and don’t come back.  Only a handful of bees with no experience of flying and the Queen are left. That handful of bees cannot take care of the queen. And eggs, larvae and pupae are left behind. The few bees cannot keep the brood alive. You normally cannot pry nurse bees off brood with a crow bar, but in this case they leave. They just go.”

Yet, entomologist Jamie Ellis, who directs the University of Florida’s Honey Bee Research and Extension Lab, says “CCD is only responsible for a fraction of the losses. I don’t even use the term anymore. When you combine mites, pesticides and nosema [virus], that’s when you get losses. I wonder if we haven’t already discovered the factors and are unwilling to believe there is not a single smoking gun. Pesticides are one of the stressors but not the only stressor.”

Read more about bees and pesticides:
"How to Reduce Bee Poisoning from Pesticides."


Plight of the Honeybees

Mon, Aug 12, 2013 at 08:51:33 AM

Richard Campbell sprinkles powdered sugar on his honeybees to control parasitic varroa mites that attach themselves to backs of bees like small ticks and drink hemolymph, or bee blood. Campbell, director of horticulture at Fairchild Tropical Botanic Garden, long has had a hobby of beekeeping and oversees hives at the Fairchild Farm, at the Garden in Coral Gables and at his home in Homestead. The powdered sugar causes honeybees to groom themselves and scrape off the mites.

Powdered sugar honeybees
Applying powdered sugar to honeybees.

“This year, I had a big problem because I didn’t have enough drones and ended up with queens that only lasted six months,” Campbell says. “There was not enough sperm. My queens had varroa and I didn’t know it. I had one queen I really liked and collected (larval) cells from her, but they’d all been damaged by varroa and were rejected. When the larvae come out, the colony will force them out or kill them.”

Campbell’s bee woes, from fewer drones and queen longevity to mites, have been repeated everywhere across the country, with the result that the inner workings of beehives have never been more fully studied than they are today. Since 2006, beekeepers in North America and Europe have been losing bees at an average rate of 30 percent a year – making it harder and harder to produce enough healthy honeybees to pollinate such crops as almonds, cranberries, blueberries, carambolas, avocados, eggplants, rapeseed, watermelon and many others.

Dusting bees with powdered sugar is a remedy for varroa mites that most commercial beekeepers don’t have time to apply, but it is increasingly discussed online as beekeepers struggle to maintain their colonies. The mites, originally believed to be from Java but now found worldwide, have been found to depress the immune system of bees, making them more susceptible to diseases and pesticides and to spread viruses such as deformed wing virus and acute paralysis virus. To control varroa mites, which arrived in the United States in 1987 from Brazil, beekeepers initially relied on chemical miticides, which depress reproductive activity in the colonies.

Other diseases that may plague honeybees include nosema virus (which is actually a gut fungus that gives bees dysentery when they are confined to their hives in winter), bacterial diseases, hive beetles and wax moths. But more attention is being paid these days to a relatively new form of systemic pesticide that may be adding to the misery.