Harsh March

A Minnesota beekeeper checks his hive and finds plenty of bees and ample stored honey. Shortly afterward, cold weather set in for several days. Two weeks later, he finds the bees in the hive are dead even though the hive still holds plenty of honey. March is often the harshest month for honey bees. Bee populations are growing; the increasing population of bees requires a lot of food; the hive's food stores are rapidly diminishing; and there are not many flowers blooming for bees to forage. On warm days, worker bees may expend more energy searching for food than they would consume if they remained in the hive. Also, when there is brood in the hive, the bees must warm the brood nest to 95 degrees Fahrenheit, requiring the consumption of honey to generate heat. The most likely cause of the death of the Minnesota bees is starvation. Starvation is easy to identify; the beekeeper finds the dead bees clustered with dead bees head-first inside empty cells as in today’s photo. Often, ample stores of honey surround the dead, starved bees.

In starvation, here's what typically happens: The bees expand their winter cluster on warm days and contract the cluster on cold nights. On warm days the bees eat the stored honey surrounding the cluster. Then, when outside temperatures fall, the cluster contracts leaving a ring of emptied cells surrounding the bees. If the winter colony has no brood, the cluster may move about the hive. However, if there is brood present, the clustered bees will not move away from the brood. During a prolonged period of cold weather the bees remain tightly clustered, and they can't move the few inches to the stored honey. Because the colony shares food, all of the bees die when the colony runs out of food that they can access. If beekeepers detect a hive is short of food stores in late winter, they can provide emergency feeding of dry sugar or fondant candy.

--Richard

Managing Top Bar Hives

Fall and spring hive management in top bar hives is similar to that of Langstroth hives. Bees tend to build their brood nest in a top bar hive near the hive entrance and expand horizontally with new combs. Two combs holding honey and pollen near the hive entrance provide food for the brood. Hive manipulations can be visualized as if a Langstroth hive is lying on its side. Just as the beekeeper moves the winter cluster downward in the fall in a Langstroth hive, he or she moves the cluster forward toward the top bar hive entrance. Over winter, the bees move horizontally away from the entrance into the honey storage combs. In the spring, empty combs near the entrance should be moved to the rear, and the brood nest pushed toward the entrance.

 All bee hive manipulations of modern hives can be accomplished with top bar hives if the bees build straight combs centered on the top bars. Carefully built top bars of 32 millimeter width are necessary for comb management. If the bees build combs connecting the top bars, the hive can’t be easily manipulated. Bees tend to curve their combs toward the hive entrance. Cutting away curved portions of combs encourages the bees to build straight combs centered on the hive's top bars. Ethiopian beekeeper Teshome recognizes that by building top bar hives of standardized dimensions he can move combs between hives. This allows him to de-queen poorly performing colonies or those with defensive behavior and bring in combs of eggs and larvae from his best colonies to control and improve bee genetics. He can also rear new queens and make colony divisions in his top bar hives. Today’s photo: a mud and dung coated Tanzanian top bar hive in use in Ethiopia. The Tanzanian hive design employs vertical box walls. This rear view shows one empty frame behind top bars. Under a thatched roof, the hive stand’s plastic sheeting and oiled posts protect hives from ants.

--Richard

Top Bar Hives

Beekeepers are making preparations for adding new colonies in the spring. While most will house their bees in modern bee hives, some will chose hives of other designs. The Kenyan top bar hive is the choice of a number of hobbyists who want to keep a few bee hives at their home. This removable comb hive is simply a box with sticks, called top bars, to hold combs. A benefit of top bar hives is that they can be constructed at low cost from locally available materials using ordinary hand tools and simple building skills.

Larry Tomkins, a knowledgeable beekeeper from Northeast Arkansas, shared his top bar beekeeping experience with the Arkansas Beekeepers Association. Tomkins, who began beekeeping with Langstroth hives, explained how he enjoys building top bar hives that he constructs from scrap lumber. Tompkins uses the hive design developed by the Peace Corps, http://www.tc.umn.edu/~reute001/Plan%20files/pTop%20bar%20Kenya.pdf. Tompkins built the top bar hive that he brought to the ABA Spring Conference for 79 cents, the cost of screws. There are no standardized top bar hive plans; there is only one critical measurement: Top bars must be 32 millimeters in width. A beer bottle cap makes a handy measuring device for constructing top bars. Building top bars of the proper width is important for maintaining bee space. Bees build cross combs on improperly designed top bars. Top bar hives are attractive to some beekeepers because, unlike modern bee hives, there are no heavy boxes to lift. All hive work is accomplished at a comfortable waist-level height by removing one comb at a time from the hive. Since harvesting of honey from top bar hives involves destroying the honeycomb, old beeswax is continuously replaced in the hive. Comb replacement is good for colony health; environmental chemicals and bee disease spores are removed from the hive. Today’s photo is a Kenyan top bar hive in use in Ethiopia.

--Richard

Sustainable Agriculture

The annual Farm to Table Conference held in Memphis at Rhodes College is designed to bring together farmers and those who buy and use their produce. I conducted an introduction to beekeeping session attended by a number of farmers considering adding bee hives for pollination. The farmers conducting other sessions spoke along common themes: sustainable agriculture, quality of produce, food security, and integrated pest management. Sustainable agricultural practices include irrigation water usage and conservation, soil erosion control, and soil moisture retention. Several farmers spoke of the effects of climate change on farming practices. Climate change especially affects water usage and plant variety selection. Certain plant varieties known to be reliable in the past must now be replaced by a diversity of varieties that thrive under new environmental conditions. Climate change also affects planting dates, growing seasons, and harvest dates. To grow high quality produce, the farmers stress testing for soil fertility, acidity, and nutrients. Integrated pest management involves disease and pest prevention and control. Specific crop pests must be identified, and broad-spectrum insecticides should be avoided. Non-chemical controls include selection of resistant plant varieties, crop rotation, removal of diseased plants, and mulching between crop rows.

Robert Hayes, a New Albany, Mississippi blackberry grower, who also manages bees to pollinate his berries, attracts hummingbirds to his farm. Adult hummingbirds feed crop-damaging thirps and aphids to their young birds, a biological pest control. Farmers recognize the need for beneficial insects, particularly honey bees, to pollinate their crops. As well as keeping honey bees, Hayes drills nesting holes in dead trees to make nesting sites for blue orchard bees, effective native pollinators. My presentation to the other farmers explored the reality of maintaining honey bees on today’s farms. It is unfortunate that with the high level of annual colony losses beekeeping can hardly be called sustainable agriculture. The farmers’ awareness of agricultural practices that help and harm bees is important. Cool weather today prevented honey bees from foraging elm trees in full bloom.

--Richard

Red Maple in Bloom

There are several milestones in the beekeeping year that we follow to give us an indication of what the bees are doing. Some of these milestones are the changes in seasons that we follow on our calendar. We know that queen bees start laying eggs after the winter solstice, December 21. Other milestones involve the bloom of major nectar and pollen sources. I always look for the red maple bloom. Maples and elms bloom in late winter. The weather at this time of the year is often unsettled. If the weather is cold when these trees bloom, the bees don’t fly; and they miss the reward of nectar and pollen. On warm days, bees head to the river bottoms to forage from flowering trees. Today, warm temperatures brought bees out in great numbers. Red maples growing in plains above rivers were covered with honey bees and native bees, including small, brightly colored sweat bees, native bees that forage close to their nest. Honey bees, like the one in today’s photo, travel great distances to river bottoms to fill the pollen baskets on their hind legs with dull yellow-colored red maple pollen. The sudden surge in pollen being brought into the hives is a strong stimulant to the queens to start laying eggs.

Other early season plants in bloom include the skunk cabbage located in damp soils of forest margins and dandelions in pastures and lawns. From the nectar, the bees collect carbohydrates; from the pollen, the bees derive protein, fats, vitamins, and minerals. Having a mixture of available pollens ensures that the bees will have a complete diet to feed their brood. The red maple milestone tells the beekeeper that the first nectar and pollen flows are beginning, and hive activity is ready to start increasing rapidly. As brood production expands, beekeepers need to monitor for hives that are light in weight and supply emergency feeding. If stored honey is depleted, late winter nectar sources may not be sufficient.

--Richard

Help from Birds of Prey

The bee hive in the fall is full of bees, brood, and food. However, by mid-winter, the hive is partially empty. Short-lived summer bees are gone; drones have been ejected; the year’s last brood has emerged; and a significant amount of the food stores have been eaten. The cluster of bees is slowly moving upward in the hive. As the bees eat their honey stores, they leave empty cells. The hive may have half of its cells empty. The empty air-filled cells make excellent insulation from cold winter drafts. Actually, little wind blows through the parallel sheets of bee hive comb.

If they are able to enter, mice find bee hives a welcoming home in the winter. Mice are known to build nests in the lower corners of bee hives. They are actually a greater nuisance to beekeepers than to the bees. If worker bees find a mouse inside the hive, they often sting it to death. Since they can’t drag the mouse outside, they entomb it in propolis. This prevents the spread of odor and bacteria throughout the hive. Beekeepers reduce the size of hive entrances in the winter to help keep mice out of the hive. Rodent populations, like those of many insects, expand widely every few years. This year, large populations of field mice and rats were observed over a wide area. Hawks and owls, birds of prey, are effective natural predators of rodents. Red-tailed hawks are common hunters throughout North America. Easily identified by their bright white breast feathers, they often perch on a low tree limb or fence post while waiting for a rodent to move. Then, they swoop down and grab their prey with sharp talons. The red-tailed hawk in today’s photo is frequently seen hunting on the ground in one Peace Bee Farm bee yard. Today, I found four nesting boxes occupied by sleeping screech owls, highly efficient night-time mouse catchers. Year-around, birds of prey help to control bee yard rodent pests.

--Richard

Regulating Hive Temperature

A beekeeper in Minnesota is carefully measuring the temperature inside his bee hives. He recorded a daytime temperature of 70 degrees Fahrenheit and a nighttime temperature of 38 degrees. He asks me what I think of the temperature differences, and he asks if I feel that there is a problem. While Minnesota experiences extremely cold winters, honey bees are very capable of regulating the atmosphere of their hive. They also employ measures to conserve energy and food reserves necessary to survive harsh northern winters. First, they do not attempt to warm their entire hive, only the bees and brood. The bees form a cluster to generate and conserve warmth. Loosely packed bees inside the cluster generate heat by eating their high-energy food, honey, and “shivering” their flight muscles. These bees can create about 104 degrees in their muscle tissue. Bees on the outside of the cluster form a tightly packed crust to hold in the generated heat. As bees on the outside chill, bees from the inside change places with them. The bees are not wasteful of honey stores needed to feed the workers generating heat. They do not attempt to warm the entire hive, just the cluster of bees.

The bees’ second honey conservation effort involves lowering the cluster temperature whenever there is no brood present. Brood must be kept warmer than adult bees. Brood is held at 95 degrees Fahrenheit. A number of races of bees, especially those originating in northern Europe and Asia, restrict the feeding of their queen to force her to stop laying eggs in the winter. When the colony is not tending brood, it lowers its colony cluster temperature to around 70 degrees, the daytime temperature measured in the Minnesota hive. The temperature of the hive outside the cluster drops at nighttime. In today’s photo, we see bees gathering granulated sugar that I placed for emergency feeding atop a hive’s inner cover. Bees access the sugar through the inner cover’s center hole.

--Richard