On May 7, a beekeeper in Minnesota noticed his bees were dying. I went to the beekeeper’s location a few days later and saw all the below symptoms and took samples for the beekeeper. There were bees on the ground with their legs up and twitching. There were bees that, when placed on their backs, couldn’t right themselves. There were bees on willow blossoms (the first blooming plant of the year) that should have been actively collecting pollen, but would barely lift a leg when poked or were dead. There were dead bees all over one of the few remaining snow patches and in front of the colonies. Inside the hive, the colonies looked a bit depopulated for the amount of brood and stores. There was some fresh pollen being brought in from the willows, but I didn’t see any conclusive evidence that the brood was affected.

One of the many twitching bees.

So what caused this?  It is unlikely that it was a disease or pest since colonies show symptoms at different times depending on factors such as the initial inoculation or degree of susceptibility to the specific disease, and it looked like the colonies were all affected at the same time. Plus, I don’t know of any disease or pest that would cause this aggregate and severity of symptoms. Something was affecting the bee’s movement and killing them. With the number of dead and affected bees, and from my field experience, it looked like an acute pesticide kill.

The beekeeper’s theory on why the bees were dying was that when the corn fields right next to the bee yard were being planted with corn seed coated with a neonicotinoid pesticide, the high winds blew the dust onto the willow blossoms and the bees. It is possible the bees then became exposed to the pesticide through eating the dust on the willow blossoms or by trying to groom the dust off. This theory is not unique: beekeepers in Ontario experienced losses of bees during corn planting last year, researchers documented bee losses in Indiana in 2010 and 2011, and Bayer CropScience is working on reducing the dust exposure to bees during planting.

About a week later, a second beekeeper in Minnesota reported similar issues with his bees in a yard located near cornfields that were recently planted.

In both cases, representatives from both the MN Department of Agriculture and Bayer visited the beekeepers and took pesticide samples. I went to the first case as an impartial BIP bee person, and a coworker went to the second case. At both beekeepers, we colony assessments and took samples for Varroa, Nosema, and viruses. The cause of the bee deaths at the two beekeeper operations is not yet officially confirmed. We are waiting to hear the results of the sampling. Stay tuned.

Dead bee on willow blossom.

Corn field next to bee yard.

Dead bees on snow. There was still a patch of snow despite temperatures being in the 50-60s.

Bees taking a rest before bring pollen back to the hive.

Dr. Zachary Huang out of Michigan State University recently wrote a review titled “Pollen nutrition affects honey bee stress resistance.” Frustratingly, it is one of those papers where you need to either pay $35 to get access to it or have access via a University library. Since it is hard to get ahold of, I am going to review it since I think the content is really interesting and important.

Dr. Huang first talks about what makes a good pollen. There are two components that bees need: crude protein and 10 essential amino acids. The best pollens have over 25% protein and the complete set of the 10 amino acids. There are few types of pollen with all the amino acids, so bees tend to do best when they have access to a variety of pollens.

Frame with a diversity of pollen. Different colors indicate that the pollens came from different plants.

Dr. Huang’s paper showed that when bees have a better diet they are more resistant to many different stressors. If bees have good pollen diet, they have a lifespan almost twice as long as bees without and pollen affects genes for antimicrobial peptides. Bees exposed to Nosema apis or Nosema ceranae have a longer lifespan if they had a pollen diet verses infected bees without the pollen diet. Bees feed a pollen supplement had lower Deformed Wing Virus titers that those fed only sugar syrup. A pollen diet also had a positive effect on colony populations in the presence of Varroa mites, although the mites had a larger effect.

In cage trials, bees exposed to different pesticides were less sensitive if they had a quality pollen diet versed a poor pollen diet. However, this research was done in 1983 (by Walh and Ulm) and the pesticides they used aren’t common anymore. As Dr. Huang points out, it would be really interesting to see a study done with pesticides that are commonly used today.

Overall, Dr. Huang’s paper showed pretty conclusively that a better pollen diet leads to more robust bee colonies. Not necessarily groundbreaking, but it provides a really good argument for why plant diversity is important to help our bees be healthier.

This is my mom’s prairie. It has a wide diversity of flowers and, consequently, it is alive in the summer with insects and birds.

Hives next to a swamp with a 6′ alligator.

Jody Gerdts and a nice frame of brood.

After spending about a month in California, I flew south to meet Jody Gerdts and travel around East Texas, Louisiana, and Mississippi for three weeks. While most of the bees in the country are in California for almond pollination, there are a few beekeepers that have or bring bees down to the South for producing the next generation of bees to sell.  A number of the beekeepers the Midwest Bee Tech-Team works with migrate to the south for the winter, so we follow them. We visited nine beekeepers and did hygienic testing, and took samples for Nosema and Varroa for them. (Jody works on the Bee Squad at the University of Minnesota, helping hobby beekeepers keep bees or keeps bees for people or corporations that want bees, but don’t want to manage them.  She volunteered to get out of the cold and help me for a few weeks.)

Cottonmouth snake sunning itself in the Big Thicket National Forest.

The South is kind of a magical place for a girl from the North. The weather is drastically different from the North, and because of the heat you get all sort of living things like alligators, snakes, armadillos, and such a gorgeous variety of fungi. The South also has really good weather for raising queens – starting to get really nice out in Late February and March. Beekeepers that migrate to the south really get going at the end of February, but some travel down earlier. One of the beekeeper’s daughters calls North Dakota her primary home, but she had never seen a Midwest winter until she went to college at the U of MN. When we were there, the weather averaged probably around 55 – 60 as a high and the bees were bringing in pollen.

Yellow Jasmine blossom.

One obstacle for the southern beekeepers is the plant yellow jasmine, Gelsemium sempervirens. It is poisonous to both honey bees and humans. It causes death of the developing bee brood, and, consequently, queen cells that are being made by the beekeepers.  This year, it was fairly cold and rainy during much of the yellow jasmine bloom, so beekeepers are hopeful the bees didn’t bring back and store too much of the pollen.

Bearded tooth fungus. It is supposed to taste like lobster.

Southern hospitality was a real thing for us down in the Deep South. People were very polite, kind, and welcoming. But people are people wherever you go, and there were a few bad eggs in the south. The craziest was one beekeeper was having issues with a guy spraying his hive entrances with an insecticide. This is still unresolved, but moving hives may be more difficult than keeping the yard due to land availability.

Overall, It was great to spend some time in the beautiful southern US and even better to see healthy hives with all the terrible reports of losses coming out of California.

Grafted queen cells.