Friday, June 20, 2014

Signs of Swarming

While swarming occurs naturally as a means for a colony to reproduce, it may leave the existing colony in peril. The swarming colony leaves behind a virgin queen that must return safely from her mating flight. If the virgin queen is not properly fertilized or she does not return safely, the hive is set for doom. What are beekeepers supposed to do? 

Be Proactive. Know the tendency of a colony about to swarm and prepare counteractive measures. A colony does not decide to swarm overnight. Certain measures lead to swarming. Be attentive of these proceedings:

Size of the Brood Nest. Honey bees instinctively decrease the size of the brood nest in preparation for swarming. Imagine a populated colony capable of caring for ten full frames of brood. After swarming, half the population will only be able to manage half the amount of brood.  Room will be alleviated to store nectar and pollen as the colony begins to reduce the size of the brood nest. Beekeepers may mistake this as a honey bound hive when in fact the colony is prepping to swarm.

Swarm Cells. These are indicators that your colony intends to swarm. Multiple queen cups which are clumped together at the bottom of a frame are indeed swarm cells. Swarm cells are produced in preparation of swarming. At this stage it may be too late to prevent the colony from swarming.

Size of the Queen. Locating the queen within a hive can be difficult; therefore, noticing a reduction in her size is nearly impossible. In order to prepare for swarming the colony will reduce the amount fed to the queen so she will lose weight. For the queen to be able to fly with the swarm, she must lose weight.

Here are three situations that may encourage swarming preparations:

Congestion. Bees prosper from a crowded hive but can easily become overcrowded. A populated brood chamber allows the bees to maintain brood temperature, prevent robbing, and manage pests. A hive’s population size is directly related to the health of the colony. Once the hive becomes congested the colony can support being divided without compromising the survivorship of the parent or the swarm.

Abundance of Resources. The availability of resources corresponds to the congestion of the hive. The queen will be laying heavily as long as resources are brought into the hive. Bees work to bring in the resources they will need for survival. Nectar and pollen will be stored in cells that brood recently hatched from, eliminating the space the queen needs to lay. The hive becomes honey bound and the colony may swarm.

Old Queen.  The presence of an older queen bears a minimal influence on a hives inclination to swarm, but an older queen is more likely to swarm. The queen’s pheromone levels decrease as she continues to age. The colony will begin to raise a new queen when they sense a decrease in the existing queens pheromone and the existing queen will swarm from the hive.

Can a hive be managed or manipulated to reduce the tendency of swarming? If a beekeeper is able to identify signs that the colony means to swarm, he may be able to prevent the colony from achieving their intentions. Here is a manipulation method that will decrease the likeliness of swarming:

Checkerboarding. An overwintered colony will have a goal to send out a reproductive swarm but checkerboarding may help prevent swarming. Checkerboarding allows the brood chamber to continue expansion and prevents a honey bound hive. Once the colony is able to survive a majority bee-loss it switches from build-up to swarm mode. The goal of checkerboarding is to keep the colony in the build-up phase. Checkerboarding encourages the bees to expand the brood nest and honey stores until the colony is less apt to swarm. Conceptually, checkerboarding tricks the bees into thinking the brood nest is smaller than its actual size.

The premise of checkerboarding is to open the brood nest by alternating brood frames with empty frames, creating a checkerboard pattern (black, white, black, white…).  This will take one large brood nest and break it up into multiple brood nests. Rotate empty frames from the outside of your brood chamber with fully capped brood frames, creating the checkerboard pattern. If all frames are filled with brood and you are using similar sized supers, rotate frames up or down a story to accomplish the checkerboard pattern. If you use one deep and the rest medium, move frames into a split hive to accommodate empty frames.  The division of the brood nest is based upon the population of your hive. If your hive is not populated enough to fill empty bee space to keep brood warm consider splitting every two frames  or divide the brood nest in half with one frame. 

Checkerboarding is a preventative measure to swarming but it is not a guaranteed method. If the colony is insistent upon swarming, nothing may prevent it from happening. Have your Cardboard NUC handy in case they do end up swarming.