Colony Collapse Disorder: a loss of resilience?

In Science, Francis Ratnieks and Norman Carreck write about what has been learned about the collapse of bee populations in Clarity on Honey Bee Collapse? (2010 327 (5962): 152)

Over the past few years, the media have frequently reported deaths of honey bee (Apis mellifera L.) colonies in the United States, Europe, and Japan. Most reports express opinions but little hard science. A recent historical survey pointed out that extensive colony losses are not unusual and have occurred repeatedly over many centuries and locations. Concern for honey bees in the United States has been magnified by their vital role in agriculture. The California almond industry alone is worth $2 billion annually and relies on over 1 million honey bee hives for cross-pollination. So what is killing honey bee colonies worldwide, and what are the implications for agriculture?

In fall 2006 and spring 2007, many U.S. beekeepers encountered hives without adult bees but with abandoned food and brood. It was widely believed that these were symptoms of a new and highly virulent pathogen. In the absence of a known cause, the term “Colony Collapse Disorder” (CCD) was coined. What have we learned about this condition since then? Are the symptoms really novel?

The first annual report of the U.S. Colony Collapse Disorder Steering Committee, published in July 2009 (15), suggests that CCD is unlikely to be caused by a previously unknown pathogen. Rather, it may be caused by many agents in combination—the interaction between known pests and pathogens, poor weather conditions that diminish foraging, lack of forage (16), and management factors such as the use of pesticides and stress caused by long-distance transport of hives to nectar sources or pollination locations. The increasingly technical process of beekeeping itself merits further research as far as its impact on colony health. For example, although pollen substitutes are now widely used, little is known about the interactions between nutrition and disease susceptibility. Further research is also needed to develop effective ways of keeping colonies healthy through good hive management based on appropriate chemical, and other treatments such as “hygienic” bees that remove diseased brood and can be bred using conventional methods. In Europe, the COLOSS (COlony LOSS) network, consisting of 161 members from 40 countries worldwide, is coordinating research efforts and activities by scientists and the beekeeping industry to address these and other issues related to honey bee losses, including CCD (2).

In February 2009, the high pollination fee, combined with a temporary reduction in pollination demand due to drought and reduced almond prices, resulted in a surplus of hives in California available to pollinate almonds. But this leaves no room for complacency. Almond pollinating beekeepers had a poor summer in 2009 in the Dakotas and neighboring states, where hives spend the summer making honey, with heavy rains delaying and reducing the honey crop. This delayed chemical treatments for Varroa mites, and many colonies were probably in worse than usual condition going into winter back in California. It will be interesting to see what happens in February 2010 when the almonds bloom. On a longer time scale, there is a worrying downward trend in U.S. hives, from six million after World War II to 2.4 million today. Is the future of U.S. commercial beekeeping going to be based on pollinating a few high-value crops? If so, what will be the wider economic cost arising from crops that have modest yield increases from honey bee pollination? These crops cannot pay large pollination fees but have hitherto benefited from an abundance of honey bees providing free pollination.

4 thoughts on “Colony Collapse Disorder: a loss of resilience?”

  1. Perhaps, now is the time for more home gardeners to install their own hive(s). Bees are such docile creatures who do so much good, it’s hard for me to see a down side, especially when the number of bees for general pollination is in a downward spiral. And, of course, there is the benefit of the honey harvest.

  2. Regarding the reply by Carl Blanda and home gardeners keeping bees. This is a great idea for gardens of a reasonable size. In Great Britain we are also being encouraged to keep bees this way. I have been a beekeeper for 15 years and in American terms have a modest number of hives; around 100. What I have experienced on many occassion is the transformation of a gentle, docile colony into one that is vicious and without exageration dangerous.Usually it can be caused by too much interference by the beekeeper,the natural presence of a new queen,lack of nectar and even the type of nectar yielding flowers available.

    Nothing is safe within 200 metres. Immediate re queening of the hive with a docile queen may be a short term remedy but the same could reoccur.

    If you have a yard or garden as we call it be sure your beehive is situated well away from humans and livestock.

    Best wishes

  3. I have been reading all I could about the art of bee keeping since very young and have been a bee keeper on and off again for the last 30 years or so and still find new things to learn about bees. This new colony collapse syndrome makes me wonder if they haven’t suddenly bred the bees natural aggressiveness out of them until it also removed something else. There is no one that can really define all a certian gene or cromosone has controll over. If you constantly, over years and years, select for gentilness, will that not cause the bees to be weakened? I can now stick my hand directly in some of the hives and not even receive what I would consider a good challenge?? When I was a kid you would never take a short cut through anyones bee yard or suffer several stings even if you didn’t walk directly in front of any hives.
    Those hives produced gallons of honey and those hives were occupied constantly for years on end without all the modern bee keeping stragities used today. They may not have produced as pretty a product as they can with the modern breds but year in and year out those bees were tough and one hive in a bee yard I grew up with had an old plank hive with
    with no frmes, just cross pieces nailed here and there that had the same continuous swarm in it for a period of 15 years. They only died out when the old gentleman that owned them died and the “Gum” fell over and split open. Even then, the bees persisted for over a year within the rotting Gum. You don’t see that with these docil Italian bees. Plus, we can’t keep a bought swarm over a year or two without them dying out for various reasons. However, if you catch a swarm of wild bees and put them in a new hive body with new frames and good foundation they will thrive even without feeding them. They may be mean and a little small but they will make you some honey. Couldn’t this new malady be a sign of weak genes allowing things to come into the hive and stay that normally wouldn’t be allowed to even enter? It might not be an actual disease but a sudden lack of self preservation, or a genetic predisposition to return to the hive that had always been there before? Divirisity has always been an important success stragity in any breeding system. In breeding or selecting for only one or two traits has always led to disaster with animals, why not with bees?

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