Lesson 40: Taking a Bee Sample

Collecting bees and brood the right way, for mite counts and for lab testing

Sooner or later you'll need a sample from your hive: a measured scoop of bees to count mites (lesson 55), or bees and brood to send to a lab when you suspect a disease you can't identify by eye. A good sample is taken the same way every time, from the right place, and handled so it arrives in good condition.

Sampling bees for a mite count

For mite checks you need about half a cup of bees, roughly 300 bees, taken from the brood nest.

Why the brood nest? Varroa mites ride mostly on nurse bees, the young bees tending the brood, because those bees carry them to brood cells where the mites reproduce. A sample of bees from a brood frame gives a much truer count than bees from the entrance or a honey super.

How: 1. Pick a brood frame with plenty of bees on it, one with open brood if you can. 2. Make sure the queen is NOT on that frame. Look it over carefully first. You don't want to scoop her into your sample. If she's there, gently move her back into the hive or use another frame. 3. Collect the bees, either: - brush or shake them into a measuring cup and fill to the ½-cup line, tapping the cup to settle them for an accurate measure; or - roll a jar gently down the face of the frame so the bees tumble in, as in the alcohol wash (lesson 55). 4. Go straight on to the mite check you're using (sugar shake or alcohol wash; lesson 55).

Half a cup ≈ 300 bees, so mites found ÷ 3 = mites per 100 bees, the number used for treatment decisions (lesson 56).

Sending samples to a lab

When you see signs of a disease you can't confirm by eye (lesson 58 and on), or you want to know whether you have tracheal mites or Nosema, a laboratory can test a sample. Options include:

• the USDA ARS Bee Research Laboratory in Beltsville, Maryland, which has long offered free disease diagnosis to anyone. Penn State Extension (2025) lists the address as: Bee Disease Diagnosis, Bee Research Laboratory, 10300 Baltimore Ave., BARC-East, Bldg. 306 Room 316, Beltsville, MD 20705. Check the lab's current instructions before sending;
• your state department of agriculture's apiary program;
• university labs, or your county Extension office, which can advise or forward samples.

The quality of the sample decides how good the diagnosis is. Follow the lab's current instructions. The USDA guidance has been:

Brood samples - Cut a piece of comb about 4 square inches (a 2-by-2-inch square). - Include as much dead or discolored brood as possible. - No honey in the sample. - Wrap loosely in paper (paper towel, newspaper or a paper bag) and pack it in a sturdy cardboard or wooden box. - Don't use plastic bags, foil, waxed paper, tins or glass. They trap moisture, and mold grows and ruins the sample.

Adult bee samples - Send at least 100 bees. - Choose bees that look abnormal or died recently. Decayed bees can't be examined. - For mite or Nosema checks, put the bees in 70% alcohol (rubbing alcohol works) as soon as you collect them, in a leak-proof container.

With every sample: include a short description of the problem, and your name and address, and write your name and address on the outside of the package.

What to remember

• Mite samples: about ½ cup (≈300 bees) of nurse bees from a brood frame, and never the queen.
• Lab brood samples: ~4 square inches of comb with the sick brood, no honey, wrapped in paper, not plastic.
• Lab adult samples: 100+ recently dead or odd-looking bees, in 70% alcohol for mite or Nosema checks.
• Always include a note, your name and address. Check the lab's current instructions first.

Quick check

1. Why take mite-check bees from a brood frame rather than the entrance?
2. About how many bees are in half a cup?
3. Why shouldn't you mail a brood sample in a plastic bag?

Adapted from: USDA Agricultural Research Service, Alcohol Wash and Sugar Shake (Carl Hayden Bee Research Center), and Varroa Mite Life Cycle and Reproduction; Shimanuki, H. & Knox, D. A., Diagnosis of Honey Bee Diseases (USDA Agriculture Handbook 690, rev. 2000), Appendix C; UGA Bee Program, Honey Bee Disorders: Honey Bee Parasites; Penn State Extension, Nosema Disease of Honey Bees.

Adapted from university Extension sources. Experienced Georgia beekeepers are reviewing these lessons. See something that doesn't match your experience? Tell us.