What’s happening with bees?

Five years ago, if you brought up the subject of bees with farmers, you’d likely get a shrug and a comment like: “They sting, don’t they?” Not anymore. These days you seldom read a farming magazine or newspaper without seeing something about bees.

Bees are important. Some of our staple foods and most of our vegetables, fruits and nuts need to be cross-pollinated — the flower’s pollen grains moved from one plant to another — to produce what we eat. Bees do that. In the process of collecting pollen and nectar from flowers — their main sources of nutrition and energy — bees shift pollen to where it needs to be. And it’s not only food plants that benefit from bees, but also many trees, wild fl owers and garden flowers.

When it comes to bees, one usually thinks about honeybees or maybe bumble bees, but there are more than 800 types of bees flying around in Canada, and they all contribute to pollination, along with thousands of different kinds of flies, beetles, butterflies and other insects that feed on pollen and nectar. But honeybees are the pollination workhorses of agriculture, because they can be managed and moved to meet the pollination needs of many crops.

In recent years, beekeepers have been concerned that their bees are not doing well. In Canada, the health of a hive can be negatively impacted after a long wintering period. If bees go into the fall healthy, chances are better that they’ll emerge in the spring the same way.

But if bees go into the winter break unhealthy, it can be a very different story. Annual statistics as measured in the spring show that more hives are suffering following the overwintering period. Most beekeepers acknowledge normal losses of 10 to 15 per cent of their hives following the winter season, but lately it’s been anywhere from 20 to 30 per cent — double what they’re used to. So how do we improve bee health?

Lots of people are looking for answers. In Canada, it’s dozens of bee researchers and every one of our 7,000 or so beekeepers, and it’s the same story around much of the world. In the U.S., Europe and Russia, scientists and beekeepers are puzzling over high bee losses every year. Have they found a smoking gun? No. If there’s one thing that almost every scientist around the world agrees on, it’s that no single problem is causing bee losses; there are, in fact, many. They may debate about which of these stressors are the toughest on bees, but there is no clear main problem.

Keeping bees today is not as easy as it was 50 years ago. In those days, bees pretty much kept to themselves and you couldn’t go into the woods on a hot afternoon without worrying about being stung by a wild bee. Today, bees need full-time keepers, and bees that escape their hives and move to the forest almost always fail to form healthy self-sustaining colonies on their own. What’s changed? Well, quite a lot.

Some of the biggest challenges that beekeepers face today didn’t even exist prior to the 1980s, and others are more unpredictable. For example, two problems that cause the most headaches for Canadian beekeepers today are Varroa mites and Nosema disease; neither was a problem until recently. »

Left: A Varroa mite on a worker bee's thorax. Below: Scientists from around the world agree that there is no single problem causing bee losses.

Above: A Varroa mite on a worker bee’s thorax.

Varroa mites are parasitic pests that latch onto bees, bite through their skin and feed — a cross between a mosquito and a vampire — and are so large that you can easily see them on bees with the naked eye. They came to Canada in the late 1980s even though the government, in response to beekeepers pleas to keep Varroa out, closed the U.S. border, preventing bee movement back and forth for the first time ever.

Nosema, a kind of a fungal disease, causes dysentery within the colony and in severe cases may make bees unable to fl y. When a hive is infected, you can see evidence of visible stripes on the outside as the bees struggle to control their own digestive systems. Serious infections of either Varroa or Nosema are capable of killing hives, and most hives have one or the other or both.

Weather, identified by beekeepers as another major factor in bee deaths, is becoming less and less predictable as climate stability continues to change around the globe. Adverse weather conditions in the spring, for example, can cause significant difficulties for bees, which must get going early in the season as they come out of winter survival and start the normal processes of food gathering for egg laying and perpetuation of the hive.

Agriculture has changed significantly in the past 50 years as well. This is a critical adaptation for bees, since, by their very nature, they live in partnership with farming. What used to be a countryside filled with many different crops and plants that offer nutritional forage for bees — has become a short cycle of cereals and oilseeds in the west, and corn and soybeans in the east. Not much there for bees to eat, with the exception of canola, and beekeepers in the west are mighty glad it’s become as important a crop as it has.

Pesticides can also be an issue with bees if they are exposed to products that are toxic to them. Recent discussions about neonicotinoid insecticides (those applied to corn, soybean and canola seed) have placed them at the centre of controversy, although most bee researchers agree that there are a number of complex issues affecting bee health. In fact, large scale studies in Europe and North America show that poor bee health correlates well with the presence of Varroa mite and bee diseases, but not with agrochemicals, including neonictinoids.

A number of other factors can impact bees; for example; management techniques and experience, queen bees that don’t or can’t perform and a long list of diseases that can hit a hive. But, as in farming there are many things beekeepers can’t control so they understand the need to concentrate on those they can do something about. (See sidebar: A beekeeper’s perspective)

As a crop producer, here are some simple things you can do to make life easier for your neighbourhood bees and beekeepers:

  • Get to know beekeepers whose bees forage on your fields. Normally, there’s an arrangement made if bees are going to be put on your land, or close to it. If you know who the owners are, any kind of problem, from a bee sting to a sprayed hive can be more easily discussed. (An app, called DriftWatch™, is being built and will be introduced this year.) A commercial hive typically has about 50,000 bees in the middle of the summer and they will fl y several kilometres for a good meal.
  • Be aware of wind direction and speed when you’re planting treated seed or spraying crops — both dust and errant spray can cause problems. Leave a sprayer-width buffer if you have any concerns.
  • When planting seeds treated with insecticide, don’t shake all the dust out of the bottom of the bag and be careful where and how you dispose of those bags.
  • Bees forage outside the protection of the hive typically from between 8 a.m. and 10 a.m. to between 4 p.m. and 6 p.m., depending on weather and time of year. Any field activities outside that window generally will have a limited impact on bees.

Everyone seems to be concerned about bees and their health these days, with good reason. Anything that the agricultural community can do to help will be greatly appreciated.

David Drexler has had a 30-year career in the agricultural industry helping growers solve their pest problems. After graduating in 1982 from the University of Guelph with a M.Sc. in Plant Physiology, he worked for a number of international fi rms including Hoechst, AgrEvo, Aventis CropScience and Bayer CropScience, in Canada as well as France and Germany. David held senior positions with those organizations, primarily in the area of research and development, but has worked on a global basis in marketing and project development. For the past 10 years, his focus has been on the interactions between agriculture and apiculture (beekeeping), their dependence upon one another, and the challenges both are facing. David is now consulting privately on these issues.