Apiary Population Estimating

As a beekeeper, have you ever wondered how many honeybees might exist in the typical Langstroth 10-frame hive?  Curiosity about the number honeybees flying around my backyard intrigued me and I decided to conduct some studies to figure out how many bees were in each colony.  Over the course of four months, I developed a method to estimate the average honey bee count per hive box.  If you calculate the average number of cells in a typical deep frame you find that there are approximately sixteen workers cells per side, in a one-inch square cut (see Research Project 1).

A deep frame has an average open comb area of 8.5” H x 17” L (actual size) or 144.5 sq. inches with sixteen cells per Sq. Inch or 2,312 peak worker cells for one side.  Hence, 2,312 x 2 = 4,624 peak cells per frame.  Now, consider an average of thirty percent (30%) of the cells are for honey and pollen, or they are possibly empty cells in a fully combed frame.

Math Estimate A:

Based on a seventy percent (70%) brood coverage with the remaining combed area being honey, pollen, or empty cells.

·     4,624 - 0.3 (30%) = 3,236 estimated cells for brood,

·     Figure an average of 3,200 brood cells per frame,

·     Estimate the brood bees per box:

o     10-frame box - 3,200 x 7-frames = 22,400 bees.

o     8-frame brood box - Estimated brood is 3,200 x 5-frames = 16,000 bees.

These “average cell counts” do not account for frames in the honey supers and as such it is possible for a colony to have a higher or lower threshold of honey bees.

1. Multiple hand-counts revealed an average number of worker/drone bees on this fully combed frame to be 766 workers per side, or an estimated 1,532 workers per deep frame.

2. Using an average of 1,500 "nurse/house bees," you can calculate the following:

Math Estimate: Nurse/House bees

·     10-frame box - 1,500 x 10 = 15,000 bees

·     8-frame brood box – 1,500 x 8 = 12,000 bees

3. Multiply this count times the average number of brood frames and the estimated count is between 7,500 (5-frames) to 10,500 (7-frames) of nurse bees- not counting the bees developing in brood cells.

4. Over a period of three weeks, this number fluctuated because old foragers are dying, and new nursery workers are hatching out.

5. The possible number of healthy bees per brood frame averages a respectable 3,200 brood cells plus 1,500 nurse bees for a per frame population of 4,700 honey bees.  Multiple that times the number of healthy brood frames in the colony and add in the honey or pollen frame workers for per 10-frame DEEP box total.

Granted, these figures are only estimates of what the average heathy colony might hold, but it gives the beekeeper a quick assessment of the value in honey bees inside the boxes.

Why is this important to the beekeeper?

     First, let us review the typical cost for a 3-pound package of honey bees (about 11,000 bees) at $150.  Second, as the colony grows in numbers during the build-up period (spring) so does its "live" value of the apiary.  Hence, a 10-frame deep hive box can accommodate an average of 34,200 honey bees.  So, 34,200 / 11,000 = 3.1 packages of bees per deep box.  At $150 per package that means a single box colony now has an approximate bee value of $465 (without honey supers added).  Third, as a healthy colony grows exponentially these figures show how a double deep colony can have a "future live value" of approximately $930.  Multiple this number by the number of colonies in the apiary and you get the picture! Forth, when beekeepers lose a 10-frame double deep brood colony, they are not losing just $150 worth of honey bees.  They lose $930 or the equivalent of 6.2 packages.  When adding honey supers to the colony the population increases again and so does the colony value.

     Finally, the total value of the apiary (honey bees only) would be the total number of healthy bees in all brood boxes and honey supers, divided by 11,000, times the cost of what the beekeeper paid for a single package.  In August 2024, the estimated apiary bee count for six colonies at ZBees Apiary totaled approximately 502,000 bees.  Thus, the estimated apiary bee value was 502,000 / 11,000 = 45.6 packages at $150.00 per package.  This equates into an estimated bee value of $6,840.00 for all bees in the apiary.  The original cost for three bee packages was $450.  Three colonies were swarms added to the apiary, so $6,840 - $450 equals a $6,390 growth in honey bees.

     As you can see, the loss of any colony has a great affect on the loss of bee dollars $$$ per colony.

EXAMPLE: 6 brood frames per box times 4,700 = 28,200 brood and nurse bees. Next, add 4 honey or pollen frames with approximately 1,500 worker bees = 6,000 and the estimated number of bees per 10-frame box is 34,200 honeybees.

Cells per side is 36:  6 rows high x 6 columns wide OR 72 cells per sq. inch per plastic foundation.

RESEARCH Project 2 (2019)

Population Counts: This research involved counting the physical number of honeybees on a single deep frame #19, at 1030 hours.

The actual number of worker cells is 24 rows high at 83 cells per row, and 24 rows high at 82 cells per row.  

The math:

·     24 x 83 = 1,992 cells + 24 x 82 = 1,968 cells

·     1,992 + 1,968 = 3,960 peak cells per side.

·     Double that value and the result is 7,920 worker cells per frame.

If we calculate that thirty percent (30%) of each frame side as pollen, honey, or empty, then, the queen has about seventy percent (70%) of the comb area to lay eggs.  Thus, 7,920 x 0.7 = 5,554 brood cells per frame for the queen to lay eggs.

Note: This value is a “dynamic” calculation, meaning the total count changes from frame-frame and box-box based on the laying ability of the queen and the amount of nectar or pollen the bees put in the empty cells.  Sometimes, the queen may lay an egg in 90% or more of the cells within the comb.

Summary: 5,554 brood cells exist per frame times 7 brood frames = 38,808 possible new bees per box (8-frame or 10-frame).  Add the other 1,500 nurse bees per frame times the total frames and we learn that about 15,000 nurse bees are in the standard 10-frame hive body.  The bee count is now close to a normal colony population of 39,046 + 15,000 for a total of 53,808 bees in a queen-right and healthy "single deep" colony.  Subsequently, adding brood boxes to the colony increases the bee population exponentially.