Ether Roll Test for varroa jacobsoni
by David Morris
Maryland Beekeepers need to test for the varroa mite in the Spring, late Summer, and the Fall. The test is conducted using ether, regular car starting fluid in a spray can available at car parts stores, and a wide mouthed glass jar.

To perform the test, open the hive to the brood chamber. Locate the Queen! Remove a frame with emerging brood from the center of the hive, making sure the Queen is not on the frame. You need to scrape about 300 bees into the glass jar.

Sampling Technique: Everyone has their own technique, try this. Hold the frame vertically by an end bar or rest one end on the edge of the hive and incline the frame towards you a little. Now slowly and gently scrape the mouth of the jar from the bottom of the frame to the top, through the bees on the frame.  You want about 300 bees. 300 BEES!? How do I know I have 300 bees? Okay, try to get about 2 inches of bees in the bottom of the jar.


Knock the bees down to the bottom of the jar by gently tapping the bottom of the jar on something. Don't break it!. Now squirt about 2 seconds of ether into the jar and cap it!

Caution! Ether is extremely flammable! Don't do this near your smoker or any other open flame. You could be seriously burned!
Shake the jar for 10 seconds. Now hold the ends of the jar in both hands and slowly roll the jar. Look for small red spots stuck to the inside of the jar. These are varroa mites. Count the mites.
Results: Beekeepers differ on how to interpret the results. Fewer than 5 mites is a light infestation. Up to 10 mites is a moderate infestation. Over 10 is a serious infestation. Treatment depends on the number of mites, the time of year and the condition of the hive. Ten mites before the Spring buildup is not as serious as the same number in the Fall when bees are preparing for Winter.

Treatment: READ ALL MANUFACTURER'S INSTRUCTIONS! The current recommendation is to use one (1) APISTAN© strip per five (5) frames of brood for 6-7 weeks. Do not leave the strips in longer than 8 weeks! They are ineffective after that and will create resistance to the effective chemical in the APISTAN© strips. COUMAPHOS© is a new treatment that is favored if you believe the varroa mites in your hive have developed a resistance to APISTAN©. Use rubber gloves when handling any chemical treatment.

Timing: Timing of tests and treatments is important. Test hives in the early Spring before the buildup. If the mite count is high a treatment will help the buildup for Maryland's early nectar flow. If the mite count is moderate, the population buildup for an already strong hive should outpace the varroa. If the count is low, treatment is not called for.

Test again in late August. This is when the hives are raising winter brood. If the brood is heavily diseased fewer adult bees will survive the Winter resulting in a weak hive in the Spring, if the hive survives at all. If the test shows a heavy infestation, treat immediately. Depending on the strength of the hive, a moderate number of mites may not need to be treated until later. Re-test in one month.

Robbing of hives is a common problem in area where untreated hives die from varroa mite infestations. Survivor hives, when robbing a dying hive, also carry back the adult varroa that killed the victim hive. The robbing hive may be strong in the beginning of September, with a low mite count, but collapse at the end of November because it became re-infested by robbing other hives. Watch your hives closely and re-test your hives in a second time later in the Fall, whether or not you treated your hive in August or September.

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