Category Archives: Apis mellifera

Bee comb, despite the weather

Like a boorish guest, winter is outstaying its welcome. Its hosts wait with forbearance, their energy reserves running low. This week has been dismal for the returning migrant birds (no flying insects on which to feed), the spring wildflowers (no pollinators, no photosynthesis) and the breaking buds of trees (temperatures have dipped low enough to cause some frost damage).

Bees have retreated to their hives. Inside, they turn honey to heat. The hive’s core stays toasty. In very cold spells, the bees ball up, rotating their positions from the exterior to the interior of the ball, kneading warmth into their gathered mass. But on days that are merely chilly, work continues. Brood is tended, the hive is cleaned and wax is lain down.

Two weeks ago, when winter seemed about to get up and leave, I cleaned up the hives that sit at the bottom of our garden. In doing so, I removed some abandoned “wild” comb from an empty hive box. This is comb that bees constructed without the aid of artificial foundations. These foundations make honey extraction easier for humans, but bees don’t need them.

The comb hung down in a foot-long tongue. It was slightly flexible, wobbling a bit as I moved it. The edges of the individual cells were drawn so thin that they powdered away if I handled them without delicacy.

bee comb in the sun

Held to the sun, the wax glowed, revealing the bee’s careful architecture. Cells on opposite sides of the comb are offset. The centers of cells on one side align precisely with the three-way joins among cells on the opposite side. In this way the whole structure is strengthened.

bee combbee comb closeEmpty cells, biding time. When this weather moves on, the bees will be ready.

Bee comb

This week I took advantage of what may be the last warm, sunny days of the season to tidy up the bee hives for winter. I removed unneeded boxes of frames from the tops of the hives and shuffled frames within the boxes to keep as much honey in the hive as possible. Thus prepared, winter hives are less likely to blow over in storms and, more important, all the honey is gathered into one place within the hive. In cold winters, bees huddle in a ball around their honey stores, slowly eating the honey as fuel to keep them warm (the center of the hive is as warm as human body temperature). If honey is thinly dispersed, the balmy bee ball cannot form.

I had forgotten just how beautiful the wax combs of honeybees are. The near-perfect six-sided geometry, repeated hundreds of times is a fabulous piece of natural architecture.

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The wax is secreted from chinks in the abdominal exoskeleton of worker bees. The bees then mold the wax into the six-sided pattern using chewed wax particles. This task falls to middle-aged (2-3 week old bees) worker bees. Younger workers look after the brood; older workers leave the hive and forage.

This weekend marks the 153rd anniversary of the publication of On The Origin of Species. It is therefore fitting to include here Mr. Darwin’s thoughts on the wonders of beeswax.

He must be a dull man who can examine the exquisite structure of a comb, so beautifully adapted to its end, without enthusiastic admiration. We hear from mathematicians that bees have practically solved a recondite problem, and have made their cells of the proper shape to hold the greatest possible amount of honey, with the least possible consumption of precious wax in their construction. It has been remarked that a skilful workman, with fitting tools and measures, would find it very difficult to make cells of wax of the true form, though this is perfectly effected by a crowd of bees working in a dark hive. Grant whatever instincts you please, and it seems at first quite inconceivable how they can make all the necessary angles and planes, or even perceive when they are correctly made. But the difficulty is not nearly so great as it at first appears: all this beautiful work can be shown, I think, to follow from a few very simple instincts. (First edition, Chapter VII, page 224).

He elaborated these thoughts with a series of calculations and experiments, summarized in a recent essay at the Darwin Correspondence Project. As you might expect, Darwin concluded that natural mechanisms could explain the structure of bee comb and that sophisticated combs could have evolved from simple beginnings.

This naturalistic view contrasts with the opinions of Darwin’s contemporaries. After reading Darwin’s passage, I pulled down Langstroth’s Hive and the Honey-bee, an important review of bee biology and bee-keeping published in 1859 (the 4th edition, 1878, is the one that I have on hand; post-Darwinian for sure, although Darwin is not mentioned). Langstroth writes of comb:

To an intelligent and candid mind, the smallest piece of honey-comb is a perfect demonstration that there is a “GREAT FIRST CAUSE.”

These enraptured references to the Divine are peppered throughout his work.

Langstroth was a priest, but depression kept him from many of the usual priestly duties. Instead, he studied insects, especially honey bees. Although his theology seems unsophisticated to modern ears, his entomology was not. His careful studies of bee behavior transformed bee-keeping. In particular, these studies led to him a new design of bee hive, a design that is still the preferred hive for most bee-keepers, especially in North America. Unless you’re eating honey from wild nests, you can almost guarantee that the honey in your kitchen came from a Langstroth hive. I use a modified design: Langstroth in the upper portion (from which come the photos in this post) and open in the lower part (no photos — I never open this part, leaving it for the bees to do as they will).

Aristaeus wannabe nearly gets what he deserves

I made a visit to the sisterhood at the end of the garden yesterday to see how they were doing and to add another layer to their stack of hive boxes. Both hives seem vigorous and well-stocked with bees.

The bees in the photo below were standing at the entrance to the hive, holding their bodies up on stilt-like legs, whirring their wings. They are the hive’s air-conditioning crew, keeping a steady draft moving into the entrance, cooling the inside of the hive. When things get really hot, the ventilation crew will bring water into the hive to encourage evaporative cooling.

Note below the bees with yellow baskets of pollen on their legs — this is food for the bee larvae inside.

Before opening the hive, I give the bees a puff of smoke. This causes them to gorge on honey and, in theory, to calm down.

A few did not get the message and tried to sting me through my gloves. One of them left her stinger embedded in the fabric (and thereby sacrificed herself for the hive — the act of stinging kills the bee). In this photo the lance-like part of the stinger is buried and we see the poison sac that continues pumping after the bee has torn herself away.

I pulled the stinger out (not easy — the lance is barbed) to get an idea of its length. Answer: not long enough to reach my skin.

For a view of the very tip of a bee sting, as seen under an electron microscope, see here.

Having given the bees the extra boxes that they need for the summer, I’ll now leave them in peace until it is time for me to make my annual bear-like robbery and collect rent.

White heath aster

White heath aster, Aster pilosus, is now in full bloom. Each plant stands about four feet tall and has hundreds of small blooms. The plant grows from a perennial root.

Honeybees adore this species. Most other flowers have gone to seed or died back completely, so the abundant nectar and pollen draws dozens of bees to each cluster of flowers.

Pollen basket, the "corbicula", of a honeybee, packed full of aster pollen. The basket consists of a flattened area on the hind leg surrounded by long stiff hairs. The pollen will be used to feed young bees in the hive.

Extracting honey

I took two boxes (called “supers”) of honey from our hives. Each super has ten rectangular frames that hang vertically inside the super. The bees store their honey inside wax cells on each frame.

Inspecting frames of honey

Each hexagonal cell on the frame is full of honey and capped with a thin layer of wax.

Cells full of honey

To get at the honey, I first scratch off the top layer of wax with a sharp fork made specially for the purpose. Some beekeepers prefer to use a hot knife to slice away the top surface.

Getting at the honey: vandalism of the bee's careful constructions

Then I put the frames into a centrifugal extractor. This tall metal cylinder has baskets inside which hold the frames vertically. These baskets are then whirled around at an alarming speed by cranking the handle on the top of the machine. This whirling motion flings the honey out of the frames and onto the inside of the metal cylinder. The honey then flows down through a mesh filter into a storage area at the bottom of the cylinder.

Honey frames (left), centrifugal extractor (center), and holding tank for opened frames (right)

After all the frames have been spun, I pour the honey into glass jars.

Flowing honey

The two supers had nearly six gallons of honey between them.

2011 honey harvest: the stored concentrated sweetness of Sewanee's forests and gardens

When I’m finished, I put the equipment and the emptied frames at the bottom of the garden. There, hundreds of bees come out to clean up the left-overs. Within a few hours, no trace of honey remains.

Bees gather for mop-up operations

Wriggling between frames to slurp up every last drop

I left each hive with one or two supers of honey to keep them happy through the winter.

Bees pollinating corn

Corn is usually described as “wind pollinated,” but honey bees love to gather its pollen to take back to their hive to feed to their babies. As the bees rummage through the corn tassels, they release clouds of pollen that drift away to land on the silks of the female flowers. These silks receive the pollen, then the pollen’s sperm cells migrate down the silks to fertilize the eggs in what will become the “ear” of corn. On days when the wind is calm, bees seem to be the primary cause of pollen movement. Corn is therefore perhaps better thought of as both wind and insect pollinated.

Honey bee gathering corn pollen into the "baskets" (corbicula) on her hind leg. These baskets are made of combs of bristles.

Three honey bees work one tassel

The garden is out of control -- photosynthetic anarchy. Beans, corn, cucumbers, watermelons and squash vie for space in this shot. Quite a change from the diesely air and cracked concrete of Pittsburgh.

City bee

This honey bee was working the ornamental dwarf boxwoods in front of a sidewalk café in downtown Philadelphia.

Bee in the urban jungle

Even the most urban of habitats has a few drops of wild sweetness. Somewhere in the concrete someone has a hive on a rooftop, or wild bees have found a hollow wall.

The bee's neighborhood -- her nest is hidden here somewhere