Sampling Method for Loose Cells
1. The most critical part achieving and accurate bee count is gathering an accurate representative sample.
This is done by pouring the bags or boxes of bees from one container to another and while they are flowing, gathering a handfuls from the stream of bees.
When you have finished, this sample will most likely still be too large to cut, so, to get a representative sample we use a device called a riffle splitter. You can see what this is on Google. Our riffle splitter has 12 - 1 inch chutes with 6 going to one side and 6 going to the other side. So regardless of the sample size, every time the bees are poured through, it divides the sample in half keeping the integrity of the sample. This allows us to reduce the sample to a cuttable size (approximately 20-40 grams) without losing the accuracy/integrity of the sample.
When we've poured the bees through the riffle splitter enough times and reduced it to the cuttable size, we end up with two comparable samples. We like to do two cuts to compare and they usually end up being very close. Then we take the average of both cuts to arrive at the count we will use to apply to the net weight of the loose cells to determine how many bees are in that lot.
If a riffle splitter is not available, make sure you pour the sample and take another smaller sample by gathering bees from the beginning of the pour to the end. This will give you an idea where the count is for interest sake.
WE DO NOT take a set weight, like 10, 20 or 30 grams, because as you try to arrive at a specific weight it is very difficult to add or take away and keep the sample representative accurate, this is the reason we use the riffle splitter. Weigh the entire sample. It should be between 20 and 40 grams. Some producers and even testing facilities like to do a series of 10 gram samples, but we prefer to cut a couple of larger samples just to help remove some of the margin of error which can occur during sampling and weighing.
2. Next measure the weight of your sample. We weigh all of our samples in grams.
3. Once you have your sample weighed, cut all the cocoons and count the live larvae, parasites, pollen, and whatever else you want to keep track of - for example: dead, damaged, 2nd generation, mold, crushed, etc. Record these numbers onto your data sheet.
Sample size 35.42 grams and from cutting this sample, we obtained:
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368 live larvae
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5 parasites
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1 dead bee
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14 pollen cells
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10 mold cells
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11 crushed cells
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1 2nd generation bee
4. Next you need to calculate the net weight of the bees by: getting the gross weight of bees (bees + boxes/containers + pallet) and subtract the total weight of the boxes/containers and the pallet.
(1415 - 103 = 1312)
The following are the formulas we use to determine the required data. Also see the PDF attached for a sample Loose Cell Data Sheet.
Formulas:
Note: all of the calculations we use are bees/pound (lb). Calculations for metric are also noted below.
We most often talk in terms of "gallons of bees" in sales. One gallon simply refers to 10,000 live larvae.
Bees/lb = 10 ÷ sample size x # of live larvae ÷ .022045
(10 ÷ 35.42 x 368 ÷ .022045 = 4712)
Metric: Bees/Kg = # of live larvae x 1000 ÷ sample size = Bees/Kg
(368 x 1000 ÷ 35.42 = 10,389.610 Bees/Kg)
Parasite percentage = # parasites ÷ (# of parasites + # of live larvae) x 100
1 ÷ (368+5) x 100 = 1.34% Parasites
5. Next you calculate the total gallons of bees.
Total Gallons = net weight in lbs x bees/lb ÷ 10,000
(1312 x 4711 ÷ 10,000 = 618 gallons)
Metric:
metric total gallons = net weight in kgs. x bees/kg ÷ 10,000
(595.11 kgs x 10,398.610 ÷ 10,000 = 618 gallons)
