If standard equipment is used for two-queen management, two brood chambers are necessary for the bottom and two for the top queens. However, either the modified Dadant shallow 11-frame or the Farrar square 12-frame with hive bodies 6 5/8 inches deep provides a much more satisfactory size of equipment. With Farrar equipment, use a minimum of two brood chambers for the bottom and three for the top.

When many colonies must be divided to receive second queens, the old queens need not be found. Make the divisions as described and about 3 days later, when the second queens are being installed, introduce the new queen to whichever unit, top or bottom, is queenless. Queen cells must be destroyed and the new queen introduced by a cage method (preferably a wire push-in cage).

At 2 weeks after introduction, generally about the time of late willow or early fruit bloom, the new queen should be laying heavily. At this time remove the dividing inner cover and replace it with a queen excluder. One excluder is enough. When weather conditions are unfavorable at the time of removal of the screened inner cover and no incoming nectar is available, the bees in both brood nests should be gorged with sugar sirup.

The arrangement of brood nest and supers is shown in C of figures 1 and 2. As additional supering is required, manipulation is similar to that of single-queen colonies except that the larger two-queen populations require considerably more room. When a single-queen colony is receiving one super, a two-queen colony may require two or even three empty supers at one time.

Brood nests above and below the queen excluder should be reversed about every 7 to 10 days until about 4 weeks before the expected end of the flow. The honey crop on the colony may be so heavy at this time as to preclude any manipulations of brood nests. From this time on, brood nest reversal is discontinued and more attention given to supering and honey removal as the needs of the colony dictate. Supers should be extracted as soon as they are finished and replaced on the colonies as needed. Make sure the colonies have adequate room at all times for storing the crop.

"Wet" supers returned from the extractor are always placed above partially filled supers, never directly over the top brood nest because they are attractive to the queen. If such supers are placed directly over the top brood nest, a second queen excluder must be used in that position.

The top brood nest may tend to become honey bound. If this occurs, reverse the entire upper and lower brood nests around the queen excluder. This puts the top honey-bound brood nest on the bottom board and the lighter brood nest above the excluder. In such an operation the top queen must not be allowed to climb up into the supers above the upper brood nest.

Theoretically, the advantage of having a second queen no longer applies when about a month of honey flow remains. Eggs laid from this time on require 3 weeks to become adult bees and 2 weeks beyond this to become foragers, at which time the How is past. However, entering the brood nests is not practical during the middle of the How to remove the queen excluder and unite brood nests. The colonies are then fully supered and entering the brood nest for manipulations is difficult.

In practice, leaving the colony as a two-queen unit well into the end of the How is advantageous. The time to unite back to a single-queen status is after the bulk of the crop is removed from the colony, as in D of figures 1 and 2. More honey may be lost by uniting the brood nests too early than a little too late. By this time some of the colonies may already have disposed of one queen.

When two-queen colonies are reunited to single-queen status by removing the queen excluder, it is not uncommon for upper and lower queens to remain for a considerable time. From this time until the following April, the colony functions as a single-queen unit.

Each beekeeper can modify his operation to comfortably operate with a two-queen advantage suited to his locality and needs. Some may wish to use a two-queen package system (two packages, one above the other (10)). Others may find the system primarily useful for a requeening operation, benefiting from a shorter period of actual two-queen operation.