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Why so many starving bees?

It was a winter of bee starvation. In the past few weeks I’ve heard countless tales of beekeepers losing all or nearly all their hives to starvation. Many of these hives had not a drop of honey left. Others had full frames of honey remaining, but the bees starved anyway.

During cold weather, the bees cannot leave the cluster in order to find food. Oftentimes, honey stored just beyond the edge of the cluster is never touched. As the bees move upward, they consume the food the cluster encounters. The resulting pattern resembles a vertical tunnel through the stored food.

Warm periods during the winter allow the bees to move around and find more of the food. Sometimes the cluster may move toward one side of the box and eat the honey there. But after it becomes cold again, they are even further from the stores remaining on the other side of the box–which is why you sometimes see the dead cluster on one side or in one corner of the brood box.

A similar type of movement occurs in top-bar hives. Although the bees don’t move up, they may gradually move left or right. But if they eat their way to one end of the hive, they can’t turn around and traverse the empty combs to get to the other end. So they starve.

The cluster of bees won’t leave brood unattended, so even though there is very little brood in the winter months, it anchors the cluster to one spot. It seems like the bees would move freely inside their box, but instead, they are always attached to the nursery.

Placing feed–especially hard candy–just above the cluster is very effective because that is where the bees are most likely to find it. In addition, heat from the cluster keeps that area warmer than the surrounds, so bees can move onto the candy without freezing.

A lack of honey may be due to over-harvesting, but it may also be due to paltry nectar flows or particularly long winters. Whatever the cause, feeding sugar is a long, time-consuming, and expensive ordeal–but it may be the only way to keep your bees alive.

The photo below shows what typical starved bees look like. The bees–still in the shape of a cluster–all died head-down in a cell with their little butts sticking up in the air. Each is trying to survive by licking every last molecule of sugar from the bottom of a cell, but when that gives out, they die from lack of fuel or freezing to death. It is a very sad sight to see. The photo was kindly provided by Jared Watkins.

Rusty

A frame of bees that starved. Photo courtesy of Jared Watkins.
A frame of bees that starved. Photo courtesy of Jared Watkins.

The perils of spring

While it is natural to sigh with relief when spring finally rolls around, in truth, spring is one of the hardest seasons for both bees and beekeepers.

Spring colonies that have overwintered face a particularly daunting set of circumstances. For example:

  • By spring, the number of individuals in a colony is greatly reduced compared to the previous fall. Fewer bees are available to perform the many colony chores, including keeping the brood nest warm.
  • Bees weakened by cold are more susceptible to disease. Since there are few bees to keep the colony warm, the chance of disease rises.
  • If the colony is infected with mites, the mites are concentrated within a smaller population of bees, so the chance of a mite-vectored viral infection is high.
  • Food stores—both honey and pollen—are low so poor nutrition, or even starvation, is always a possibility.
  • Bees weakened by poor nutrition are also more susceptible to disease. So as the winter progresses into spring, the bees are more likely to succumb to a pathogen.
  • Many of the bees are old, having lived through the entire winter. These bees are not as strong or resilient as young bees.
  • Moisture may have built up during the winter. A wet or damp hive is a haven for various fungal infections, such as chalkbrood disease. In addition, water dripping onto the cluster may chill or kill the bees.
  • The bees may not have defecated in a very long time, increasing the likelihood of dysentery.
  • Not only does dysentery weaken the bees, but feces deposited within the hive can become a breeding ground for bacteria and other pathogens which may also weaken or kill the bees.

So don’t relax too soon. Help your colonies along until their populations are once again overflowing the hives.

Rusty

An update on “How I overwintered ten out of ten”

Since I published “How I overwintered ten out of ten” several people have asked me what I did with the slatted racks during the winter. Since I always leave slatted racks in place, I didn’t think of them as an overwintering strategy, so I left them off my list.

Now I see that my way of thinking about slatted racks–as a permanent part of the hive–was confusing to people. So I have now added another bullet to my list and it looks like this:

• The slatted racks remained in place in the Langstroth hives all winter long.

Comment: I consider slatted racks basic equipment in Langstroth-style hives, so I never remove them in any season. In summer they provide a place to hang out during hot muggy days, and the queen tends to lay eggs further down on the brood frames–apparently because this area is no longer near the “front door.”

In a traditional winter hive with the Varroa drawer in place, the slatted rack adds an insulating layer of air between the brood nest and the Varroa drawer. This will not exist in the same way with the Varroa drawers pulled out. However, during cold snaps–or other times when the Varroa drawers are in place–the slatted racks again provide a “dead air” space that helps to keep the bees a few degrees warmer.

Thank you to those who mentioned the omission. I appreciate your input.

Rusty

Snacking on sugar cakes: it’s a bee thing

Last week a reader wrote in to ask why her bees weren’t more logical. She said her hive is full of honey and a lot of it is right next to the bees. But regardless of the vast supply of honey, her bees scarfed down sugar cakes as if there were no tomorrow. Is this normal?

It is normal. Time and again I’ve watched bees eat sugar and ignore the honey. It seems as if they prefer it, although I have no idea why. Maybe it’s like a child’s preference for sweets over dinner, except that honey is sweeter than table sugar. Maybe it’s easier to eat. Maybe it melts in your mouth and not on your feet. Who knows?

The good news is that table sugar is extremely low in ash—ash being the stuff left over after you burn away a sample. In honey, the ash is made up mostly of minerals and oxides of metals.

A typical sample of honey may contain about 0.17% ash, whereas refined table sugar contains only about 0.07% ash. So that’s roughly 2.5 times as much ash in the honey as in the sugar. And of course if the honey is dark, it will contain an even greater amount of ash.

A diet high in ash is more likely to cause dysentery in bees that are not free to take cleansing flights. So while it seems like refined sugar might be an unnatural food that is not good for bees, in truth it can help them overwinter.

On the downside, refined sugar provides only energy and none of the vitamins, minerals, and other nutrients commonly found in honey. Just like our mothers told us, sugar is indeed full of “empty calories.” So for the long term health of a colony, the bees definitely need honey. But for those few short weeks between the end of winter and the first nectar flow when honey is scarce or difficult for the cluster to find, a few candy cakes will hold them in good stead.

Rusty

A great day for honey bees: down with dysentery

Here in western Washington it is a great day for honey bees. The temperature is hovering around 55° F in the shade and my bees are out in droves. All my hives are misted with bees, but my two nucs—stacked one above the other—really surprised me. The great cloud of bees milling around them is reminiscent of a warm day in July. They are acting like kids playing in the sunshine.

This sort of day is a beekeeper’s dream. There is nothing like a warm day in mid-winter to help protect a colony against honey bee dysentery. Unlike the dysentery that affects humans, honey bee dysentery is not caused by a pathogen; it is caused by an excess amount of fecal material in the honey bee gut.

Except for the queen—and sometimes the drones—honey bees do not defecate inside the hive. Workers routinely defecate outside as they fly over your car, your porch, and your lawn furniture. (The protocol for this is spelled out in the Honey Bee Worker Handbook.) However, when the workers cannot fly because of extremely cold or stormy weather, they retain their feces in the rectum and wait for a good day.

But bees can only retain about 30 to 40 percent of their body weight in fecal matter so, when the time between cleansing flights is too long, they will void inside the hive or just outside of it. This condition is called dysentery. If dysentery becomes severe the colony may die. Death may be a result of stress, disease resulting from unsanitary conditions, or a breakdown in the internal communication system due to the overpowering odor inside the hive. Having opened a hive with a bad case of dysentery, I can assure you that the stench is beyond description—although it was years ago, I can still smell it in my imagination.

Besides too many “no-fly” days in a row, dysentery can come from a diet high in impurities or from diseases such as Nosema. The ABC & XYZ of Bee Culture lists several feeds to avoid, especially in the north where warm days are few and far between. Among the feeds to avoid are dark honeys (which are high in ash), brown sugar, honeydew, fermented honey, or honey that has been heated to excess (such as that coming from a solar wax melter). According to the Mid-Atlantic Apiculture Research and Extension Consortium, dysentery can also be caused by feeding bees anything with a high water content in the early spring.

Most beekeepers agree that pure granulated sugar and high-fructose corn syrup are both “high-quality” feeds that can help to prevent dysentery. However, if you are opposed to HFCS you will have to use plain white granulated sugar. Better yet, make sure your bees have plenty of good quality honey so they can make it till spring on their own.

Rusty