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My design for a bait hive

I have been using two of the commercially available flower-pot shaped swarm traps for years. Each year I hang them up at the recommended height (8-12 feet) and facing the recommended direction (south or southeast). Each year I purchase fresh pheromone lures (the three-component USDA-endorsed type) and each year I check the traps every day during swarm season. At the end of the year I take them down and store them. Storage is the worst part because they are huge and oddly shaped.

Of course, I have never caught a swarm in one and probably never will. I persist in hanging them up every year because I paid for them—or, more to the point, I paid for the oversize postage. So I will most likely continue this ridiculous pastime until they disintegrate, or until I do, whichever comes first.

But last year after a swarm settled into my empty top-bar hive, I became absolutely enthralled with the idea of building a bait hive from old bee boxes and frames. If I can catch anything it will probably be my own swarms, but that is fine. I’d rather catch my own then have them go off into the woods or nest in my neighbor’s barn. In fact, my bees seem healthy and I’d rather not introduce bees with an unknown provenance into my apiary.

According to Thomas Seeley in Honeybee Democracy, bees on the run prefer a nesting cavity that is approximately 40 liters. This morning I measured the inside dimensions of a deep brood box and it came to 14.75” x 18.38” x 9.63” or 2610.74 cubic inches (they really add up.) I ran this through Convert and came up with 42.78 liters. So, one deep brood box should do it.

Seeley also says that bees prefer an entrance that is 15 cm2. Again using Convert this comes to 2.33 square inches. (Sorry, but as a denizen of Fahrenheitland, I think in inches.) The square root of 2.33 is 1.53. So I can use a square hole of 1.5 inches on a side or a circular hole with a diameter of 1.72 inches (2.33=3.14r2).

I measured the larger opening on my entrance reducers and it is 5.2” x 0.38” or 1.95 square inches. So the question is this: should I enlarge the rectangular opening, or should I make a circular or square opening? Seeley says bees don’t have a preference for entrance shape, but all his nest box photos show square holes.

Just for fun I calculated the area of the entrance in the top-bar hive that the swarm moved into last year. It consists of three one-inch diameter holes. When I calculate the total area, it comes to 2.36 square inches (A = 3.14 x 0.52 x 3). Amazing! Just 0.03 square inches different from Seeley’s ideal size! Seeley never mentions whether the entrance area can be piecemeal, but it is an interesting question.

To make this easy, I think I will mount the brood box on a regular bottom board and block off part of the standard entrance. The entrance is 0.75” high, so I will allow a little over 3 inches of it to remain open (2.33/0.75 = 3.11). Okay, that’s two questions answered.

Height of the bait hive is the third issue. According to Seeley, bees prefer to nest high in the trees. (The wild hives he found averaged 21 feet off the ground.) But in his experiments, most of his bait hives were low to the ground. My top-bar hive is only about two feet off the ground. So I think I won’t bother trying to suspend this thing from a tree because, for me, it is just too heavy and impractical. I will just put it on one of my regular hive stands, face it south, and call it good.

From my reading in the past few months, I’ve learned that drawn comb that previously contained brood is one of the biggest attractants for a swarm, so I will definitely use old comb. Slumgum has also been mentioned as a swarm attractant, so I will smear some of that near the entrance. I will dispense with the regular lemongrass attractant because I have used that in my swarm traps for years to no avail.

So there you have it: my plans for a bait hive. About the only things I have to do are find some used brood comb, cut an entrance reducer, render some wax so I can collect slumgum, and then smear the stuff around. Mud pies for adults. I will let you know what happens.

Rusty
HoneyBeeSuite

Wednesday word file: footprint pheromone

Footprint pheromones, also known as trail pheromones, are common in social insects. Researchers found that surfaces where honey bees have walked become attractive to other honey bees. This observation led to the discovery that honey bees excrete a chemical signal (pheromone) from their feet as they go about their daily business.

At present not much is known about the chemistry of these pheromones. But if worker bees are forced to walk over a surface, especially of glass or plaster of Paris, these surfaces can be moved and used to attract worker bees to a different location.

In theory, footprint pheromone is used for orientation and may aid the workers in finding the hive entrance or in locating a good food source, but the specifics are not known.

Some research on bumble bees has shown that footprint pheromone left on flowers is at first repellant to other bumble bees (perhaps indicating the nectar has already been taken) and later turns attractive (perhaps signaling that the flower has had time to replenish the nectar supply.) But again, the research is preliminary and much remains to be discovered.

Laying workers raise nothing but drones

Laying workers develop when a hive becomes queenless or when an existing queen begins to fail. As the queen’s pheromone levels decrease, the ovaries of some of the workers may begin to develop. If other workers begin to feed these bees royal jelly, they begin to lay eggs. The whole process happens two to three weeks after the loss of the queen.

Since workers cannot mate, the eggs of laying workers produce drones. If you recall, when the queen lays a fertilized egg, the offspring is female and has two sets of 16 chromosomes—or 32 total. If the queen lays an unfertilized egg, the offspring is male and has one set of  chromosomes—or 16 total.

The worker-laid eggs will all have just the one set of chromosomes. And since a colony cannot survive with nothing but drones, it will soon die. In addition, it is almost impossible to re-queen a hive with laying workers. This is because the laying workers give off a queen-like pheromone that prevents a real queen from being accepted into the colony.

So how do you know if you have laying workers? There are four major indicators:

  • A scattered brood pattern (this occurs because worker eggs are often eaten by other workers)
  • Cells with multiple eggs (this occurs because there may be multiple workers laying eggs at the same time)
  • Worker-sized brood cells that have the conical cappings characteristic of drones (this is because the workers don’t seem to “know” they are laying all drone eggs)
  • Eggs adhering to the side of cells rather than being centered in the bottom of the cells (this occurs because the worker abdomen is too short to reach all the way down to the bottom of the cell)

So what do you do with a hive of laying workers that you can’t re-queen? One answer is to set up a new hive in the old position with a new caged queen and some brood frames taken from another hive. Then take the laying-worker hive to the edge of your apiary and shake the bees from the frames. Most of the bees will fly back and enter the new hive. The laying workers don’t usually make it back because they’ve become too large and heavy to fly (think pregnant.)

Keep your queen caged for a few days and check for laying workers before you release her.

If you don’t have a new queen on hand, you can combine the laying-worker colony with a queenright colony. You might want to use a double-screen board for a couple days until the real queen’s pheromones overpower the worker pheromones.

Rusty

Scattered drone brood typical of laying workers. Photo by the author.
Scattered drone brood typical of laying workers. Photo by the author.

Preventing a swarm is not easy

It is totally presumptuous to say we know what’s going through a colony’s mind, but it seems that bees swarm for two reasons: the colony is crowded or the colony wants to reproduce.

If the colony wants to reproduce, the “plans and preparations” have been going on for quite a while before it actually happens. It is very difficult to stop a swarm with the reproductive urge. Most steps you take will delay—rather than prevent—the eventual swarm.

Requeening in the early spring can help reduce swarming because young queens tend to produce more pheromone than older queens. As the amount of queen pheromone decreases the urge for swarming increases.

Cutting swarm cells is popular among beekeepers, but this often becomes a battle of wills: you keep cutting cells and they keep producing new ones. The beekeeper usually loses because if he misses a single cell or cuts a day too late, the swarm will issue anyway. Worse, if he unknowingly cuts the cells from a hive that already swarmed or is just about to swarm, he may leave the old hive queenless.

If swarming is imminent, one of the best things to do is split the colony in two. By splitting you are essentially initiating an artificial swarm during which you (try to) control when and where the bees go. By taking the old queen and some brood and nurses and putting them in a new hive, both parts seem to “think” they have swarmed and, if you’re lucky, they will both grow into strong colonies. Both colonies together won’t produce as much honey as one big colony, but you were going to lose them anyway so it doesn’t much matter.

If a colony has an urge to swarm due to overcrowding, anything you do to reduce congestion will help.

  • Follower boards between the brood box and frames give bees more room to cluster
  • Screened bottom boards not only separate mites from the colony but provide better ventilation
  • An upper entrance improves ventilation and decreases congestion at the lower entrance
  • Reversing hive bodies keeps the brood nest lower in the hive and provides room above the brood nest to store honey
  • Empty supers provide room above the brood nest to store honey
  • Burr comb built between the frames should be cut away. Not only does the queen need lots of room to lay, but she needs to be able to get there easily.

If you do all these things you may be able to prevent a swarm—or not. In spite of all we know about bees, we are not bee psychologists. The best we can do is note what has worked in the past and experiment in the future.

Rusty

Smoker fuels are as varied as beekeepers

If you’ve read my previous post about smokers, you know I’m not a fan. Nevertheless, I use one from time to time and have tried a variety of fuels.

Although no one knows for sure, bee researchers believe smoke does two things which calm honey bees. First, the smoke tends to mask the alarm pheromones that are released by the guard bees when they believe their hive is threatened. Without the ability to detect the pheromone, the rest of the bees don’t know anything is amiss.

Secondly, smoke seems to be a warning to the bees that they may have to evacuate their home. Before bees evacuate, they fill their stomachs with honey so they will have the energy necessary to start building a new place to live. Once their stomachs are full they are less able to curve their abdomens into the stinging position. (Think of touching your toes after a huge meal.)

It’s because of the second reason that you wait a couple minutes after smoking a hive before opening it. You are giving the bees some time to gorge on honey.

Most beekeepers like to use some kind of kindling to start the fire, and then feed it with something more substantial. Newspaper, dry pine needles, or commercial starter pellets are popular choices for starting a smoker. The main consideration with anything you use is that it be free of chemicals, plastics, paint, rubber, preservatives, or dyes. Any of these items could release toxic fumes when burned, causing injury or death to the bees.

Personally, I have a bucket where I throw things I might use as fuel, including sisal baling twine, burlap bags, corrugated cardboard, old cotton fabric, string, and pine cones. I also like wood chips—the kind used for animal bedding—and I keep a bag of those on hand as well.

Other popular fuels are punky wood from tree stumps or rotting logs, straw, dry corn cobs, dry bark, peanut shells, and paper egg cartons. You want the material to burn slowly with a cool flame and produce lots of non-toxic smoke. Every source of material will burn a little differently, so you just have to experiment.

British beekeepers—actually the British in general—are a very creative bunch. From their ranks I have heard that dried wild pony droppings make exceptional fuel (no word on where to find these), and dried puffball fungus lulls bees into a trance (no word on what it does to the beekeeper). By the way, I’m not recommending these items—just reporting.

Once you’re done smoking, stuffing a handful of fresh grass into the smoker spout will suffocate the flame and conserve the remaining fuel.

Rusty