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Christmas swarm saved by caring homeowner

About two days before Christmas I got an e-mail from an Arizona homeowner about a swarm of bees that were hanging from the eaves of her house. She said the weather had been unusually warm, but just as it started to change for the worse, the swarm of bees arrived. She didn’t want them to die but she didn’t want them to move into her house or yard so she wondered what she could do.

I wrote back and suggested she contact a beekeeper in her area—not an exterminator or pest control company—and see if someone would come and get them. I also told her that a beekeeper might be able to save them by feeding them honey or sugar syrup but that they would almost surely die if left to their own devices. A swarm at this time of year is often known as a “starvation swarm” because, most likely, they were out of food at home so they absconded in a last-ditch effort to save themselves.

Much to my surprise she e-mailed back the next day and said a beekeeper had come to her home and captured the swarm. She also said the beekeeper promised he would do his best to keep them alive. But here’s the clincher: based on what I had written, she had put out sugar syrup for the bees until the beekeeper arrived!

I thought this was one of the sweetest (no pun) and caring things I’ve ever known a non-beekeeper to do. I was so impressed. In my experience, people like to run out and kill swarms—or pay to have them killed—immediately. And here was a complete stranger reading between the lines of my e-mail and feeding sugar syrup to a hoard of insects—stinging insects that can be strange and intimidating, not to mention just plain scary, to a non-beekeeper.

I thought about this incident a lot during the Christmas holiday. It occurred just several days after my daughter told me about a friend of hers who recently had a swarm land on her porch rail. Instead of calling a beekeeper she went to Home Depot, bought a spray can of poison, and emptied it on the bees. My daughter was incensed over this indiscriminate use of pesticide—not only because of the dead bees but because of the unborn twins the woman is carrying. Chances are she was not wearing protective gear and she (and the twins) got a good dose of whatever it was before she was finished. So sad. So unnecessary.

To the lady in Arizona I say “Thank you!” To the lady in Washington I say “Hope your kids are okay.” To everyone else I say, “Call a beekeeper before an exterminator.” Just a little bit of empathy can go a very long way.

Rusty

HopGuard: the new Varroa pesticide

HopGuard is a new pesticide designed to kill Varroa mites. Although the product is not yet registered with the Environmental Protection Agency (EPA), three states have joined together to request a Section 18 Emergency Exemption to use the product in honey bee hives within the boundaries of those states. The Washington State Department of Agriculture, the Idaho State Department of Agriculture, and the Oregon Department of Agriculture submitted the request to the EPA on August 23. Working with the three agencies is BetaTec Hop Products, the maker of HopGuard and a wholly owned subsidiary of John I. Haas, Inc. of Yakima.

Section 18 of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) allows an unregistered product to be used in certain regional areas when an emergency pest situation exists and there is no viable alternative method of control. The three states argue that the seven pesticides currently approved for use on Varroa mites in the region are either ineffective or impractical to control the mites in commercial hives.

So what is HopGuard? HopGuard is made from one of the organic acids found in the hop plant, Humulus lupulus. An organic acid is simply a carbon-containing compound with acidic properties. Some of the current Varroa treatments also use organic acids, including ApiLife Var and ApiGuard, both of which contain thymol (found in thyme) and MiteAway II, which contains formic acid (similar to that found in fire ants.)

Hops contain two prominent organic acids, alpha acids—known to brewers as “flavor” hops—and beta acids, known as “aroma” hops. It is the beta acids that have been found to have anti-Varroa properties.

The new formulation is 16% beta acids painted on cardboard strips which will be used in the brood boxes. Two strips per brood box will be used up to three times per year. Since the product contains only “Generally Recognized as Safe” (GRAS) ingredients, the manufacturer believes the product can be used in the hives anytime—even during a honey flow.

The manufacturer is seeking registration as a biopesticide (short for biochemical pesticide) which is the EPA term for a naturally-occurring pesticide.

Will it work? In my opinion, organic acids are excellent pesticides because of their safety to both bees and the planet. However, in the past they have received only moderate acceptance in the beekeeping community—mostly because daytime temperatures and the brood-rearing cycle must be closely monitored. In addition, the hives usually must be made into “fumigation chambers” for the organic acids to work properly. This is time-consuming and hard on the bees.

Will HopGuard be any different? Only time will tell. In my experience the thymol products have worked great. But since I am not a commercial beekeeper, I have the time and inclination to fiddle around with the exacting conditions that allow those products to be effective. If HopGuard is simpler to use, it could revolutionize mite control, but the jury is still out. More data are needed.

For more information on organic acids in general, see Essential Oils and Organic Acids for the Control of Varroa destructor in Honey Bees (Apis mellifera).

Rusty

Transgenic crops and honey bees

Transgenic crops were first introduced into the United States in 1996 and have become a major component of American agriculture. In a transgenic organism (also known as a genetically modified organism) some genes from one species are spliced into the chromosomes of another species. This is quite different from traditional plant or animal breeding in which individuals with desirable characteristics are crossed with other individuals having desirable characteristics.

By 2007 three transgenic crops—soybeans, cotton, and corn—were planted on 280 million acres worldwide, mostly in the United States. Many of these plants are registered as pesticides with the Environmental Protection Agency. (That’s right, your morning cornflakes may be made with a registered pesticide, but I digress.) In Canada, a large portion of the 17 million acres of oilseed rape (canola) is transgenic and the percentage is increasing every year.

There are two major types of genetic modification, both of which have implications for honey bees. One type of transgenic crop is resistant to certain herbicides, and one type is resistant to insects. Some crops, such as cotton, have been modified to resist both. Honey bees are regular pollinators of oilseed rape, frequently visit cotton and corn, and occasionally visit soybeans.

Insect-resistant crops

The insect-resistant genes have been transferred from Bacillus thuringensis (Bt), a bacterium that lives in the soil. The introduced genes produce an endotoxin throughout the plant that causes damage to the walls of the gut in susceptible insects. The damaged walls leak their contents into the lumen (interior space) of the gut, causing death of the insect. Researchers fear that Bt toxin in the pollen could damage the adult nurse bee gut or the larval honey bee gut.

Although many scientists have looked at the possible effects of Bt plant pollen on bees, so far there is no evidence of injury. However, because the toxins in the plants are able to kill the larval stages of other insects such as moths, butterflies, beetles, and weevils, many people believe that trouble may lie ahead as other plants—which may produce slightly different toxins or different quantities of toxin—become available. Currently only corn, cotton, potatoes, and tomatoes are commercially available with Bt genes. But in 2008 field trials were conducted on 30 additional crops, including apples, cranberries, grapes, peanuts, rice, soybeans, poplar, sunflowers, and walnuts.

Herbicide-resistant crops

The herbicide-resistant crops have a gene that resists glyphosate (RoundUp). This gene, too, was isolated from a bacterium. While the gene itself seems to have no adverse effect on insects, the application of glyphosate eliminates all the plant life except the resistant crops. Flowering weeds within the crops, as well as those in ditches, borders, paths, and irrigation canals are all killed, leaving the bees a very poor diet of only one flowering species.

A large number of researchers believe that these monoculture diets are a major factor in honey bee decline. Poor diet leads to loss of vigor and a depressed immune system which makes bees more susceptible to pathogens, parasites, and other stressors.

Rusty

Water droplets sometimes carry insecticides

Guttation is a natural process seen in many vascular plants whereby drops of xylem sap exude from leaf tips or margins. Honey bees are known to drink this water, especially in the early spring before large numbers of nectar-containing flowers are available to foragers.

A problem with this type of water collection occurs in agricultural areas where plants are treated with systemic insecticides. Bees collecting guttation drops can be poisoned by the pesticides flowing through the xylem. Worse, sublethal doses of pesticide can be carried back to the hive and fed to the developing larvae by way of the nurses. Researchers are currently trying to determine the type and frequency of damage this may cause to honey bee colonies.

Tests were performed in Italy to see if the guttation drops of corn treated with seed dressings of neonicotinoid pesticides contained enough pesticide to damage bees. The researchers used corn seed treated with three different systemic neonicotinoids (imidacloprid, thiamethoxam, and clothianidan) and one moderately systemic pesticide (fipronil). The seeds were purchased from the manufacturer with the pesticide already applied and ready for commercial distribution.

Guttation drops were collected from seedling emergence through the first three weeks of growth. For each individual seedling, the drops were collected and held at 2? C. After 2-3 days half the liquid was sent away for analysis and half was used for the bee experiments.

Bees held in captivity were chosen at random and caged with the drops. The bees were monitored constantly and timed from the beginning of drinking until they began to show symptoms. The two symptoms monitored were arching of the abdomen and paralysis of the wings. Previous research has shown that wing paralysis is not reversible, so once that happened it was assumed those bees would die.

The results showed that there was easily enough of all three of the systemic pesticides in the drops to cause wing paralysis and death. The moderately systemic fipronil was not found in the guttation drops.

However, not all the drops containing the insecticides contained a lethal dose. In a way, this is even worse because doses low enough that they don’t kill the forager may be carried home and fed to the developing young–a result that could have serious effects on the survival of the colony. Doses of poison that don’t kill an adult bee may have developmental effects on the young larvae.

If you would like to read the whole article, the information is below.

Rusty

Girolami, V., L. Mazzon, A. Squartini, N. Mori, M. Marzaro, A. Di Bernardo, M. Greatti, C. Giorio, A. Tapparo. 2009. Translocation of neonicotinoid insecticides from coated seeds to seedling guttation drops: A novel way of intoxication for bees. Journal of Economic Entomology 102(5): 1808-1815.

Guttation drops on a leaf margin. Wikimedia photo by Noah Elhardt
Guttation drops on a leaf margin. Wikimedia photo by Noah Elhardt

A sad day for bees . . . death of a healthy hive

Yesterday I received a phone call from a friend who keeps one of my hives on her property. “I don’t see any bees,” she said, “and all the flowers are in bloom.”

I last inspected that hive a little over a week ago. It had overwintered nicely, had two deep very populous brood boxes, and a field force that was “going for bear,” as the locals say. I had been thinking about how I was going to manage it—section boxes or shallow supers.

When I turned into her long gravel drive, I was awed by the beauty of the meadow in front of her home. Cerulean camas in full bloom made it look like a mountain lake rather than a field. The acreage was bordered on one side by pine trees, and a dusting of tall golden buttercups ran along the split rail fence next to the road.

Once parked, I grabbed my hive tool and approached the hive from the back, but I instantly knew there was trouble. A huge pile of dead bees lie in front of the hive. I ran my hive tool through the pile. It was light and fluffy all the way to the bottom which meant two things: the bees died recently and they died all at once. If the bees had died over time, the pile would have compressed on the bottom and started to decompose.

I dismantled the hive and found the bottom board and slatted rack covered with another fluffy pile. There was plenty of pollen and honey, and no bees in the “starvation position” with heads buried in empty cells. There were no signs of Nosema or dysentery, no chalkbrood, no sign of foulbrood, no mold. There were no supersedure cells and plenty of brood, so it wasn’t queenless.

I sifted through the bees more carefully. They were mostly young, having lots of “fur” still on their backs. About 10% of the bees were drones—about right for this time of year. By this time I was fairly certain it was a pesticide kill, but with bees there is always room for doubt.

I began piling my equipment in the pickup when I spotted something that erased all doubt in my mind. Under the hive stand a hornet had started building a nest. It was still very small, containing only five cells. Right next to it, the hornet queen lie on her back with all six legs in the air. I picked her up. She looked healthy and young. I felt bad for her too. I can think of nothing that will kill both bees and hornets so fast and efficiently as a pesticide.

I don’t know where it came from or how it happened, although I have a couple of theories. But that is a story for another day.

Rusty

Camas Lily (Camassia quamash)
Camas Lily (Camassia quamash)