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Testing For Varroa Mites

Your doctor always takes your temperature with a thermometer to "test" for a fever. If telephone book numbers get harder to see, you go to the ophthalmologist who puts drops in your eyes, darkens the room, and then "tests" your eyes with an ophthalmoscope.

Your dog runs across your driveway and you accidentally hit him; and the veterinarian "tests" for leg damage with an X-Ray. Your car has to have an emission "test" every two years. Airplane pilots have to be "tested" before they can be licenced.

Since mites are in 49 of our 50 states (not yet found in Hawaii), don't you think it is high time for you to test your own bees to see how bad they are infected with mites?

Testing for mites is so easy, and you can chose between two different tests: the ether roll test (which I despise because it is not very accurate, kills bees, and often kills the queen because of beekeeper carelessness); and the sticky board test, which I will describe.

Bee scientists and researchers have proven that the most important time to kill varroa mites is at the end of flying weather when brood rearing is about to stop, which in Central Maryland is October and November, so my bees are always treated with Apistan beginning Oct.1 for 8 weeks ending about Thanksgiving.

Since this is "AUTOMATIC", I don't test for mites prior to treating. However, depending on the weather, location, colony strength, etc., bees may become mite infected before the spring honey flow and probably are infected by July, because the mites "favorite food", bee larvae & pupae, is so available because the queen bee has been laying eggs in abundance for several months.

There has been a large number of colony losses to mites in July or August, even after the bees made a record crop of honey. Hence,- I always perform a sticky board test for mites on March 1st and usually find zero or very few; and I absolutely test on July 4th (after I have harvested honey) and always find some mites, but rarely enough to indicate treatment, so the colonies are can wait until the "automatic" October 1st treatment which lasts 8 weeks.

How do you make a sticky board? It is quite simple and cheap. Inside measurements of a hive body are 14 1/2"x 1 8 1/2". Cut a piece of 1/8" masonite or wallboard to 14" x 18". Cut 3 pieces of wood (like big popcicle sticks) about 1/8" thick and, mount these on both the 18" lengths of the masonite and just one of the 14" length.

Cut a piece of 8 mesh wire or screen wire to 14 x18 and staple this on the "popcicle stick edges".

Cut a piece of freezer wax paper to a size of 12" x 16", spray the wax side with PAM, and insert that in the "envelope" PAM side up, made by the screen wire and masonite; and your sticky board is ready for use.

Open up your colony, so only the bottom story shows, and insert one Apistan strip between frames 5-6 or insert two Apistan strips between frames 4-5 and 6-7, and put colony back as it was.

Slide the sticky board in the hive front entrance on the hive bottom board and leave it there 1-3 days (I like 48 hours) and remove it.

Count the number of mites you find on the paper, and if there are more than 50 mites, add two more Apistan strips to the second story and leave until supering time. Then remove all strips and put on supers.

You probably will not have more than 50 mites for your March test if your fall treatment was good. Regarding your July test, by now you will have mites, but how many?

If your test shows 100 mites, make sure no supers are present, add 4 Apistan strips and treat for just 10-14 days, remove the strips, and if you are determined to get some of that crystalizing goldenrod honey, put supers back in place.

Treating with Apistan for 10-14 days will NOT protect the bees through the fall and winter; but is just an emergency use to keep your bees from suddenly dying of mite infestation. You will still have to put NEW strips in your colony on October 1 and leave them there 6-8 weeks, but NO LONGER because you might make mites resistant to APISTAN, which is our only licenced chemical treatment.

I doubt that this will happen, BUT if your July test shows a large number of mites like 200- 500, or more; forget the supers because those bees have to have a full 6-8 week treatment with APISTAN IMMEDIATELY if you are going to save your bees from sudden death.

It has come to my attention that many people do not understand why you cannot RE-USE Apistan strips if they have only been used a few days.

The Apistan strip is a plastic that has 10% fluvalinate absorbed in it. The effective varroa mite killing fluvalinate is leached out (extracted from) the plastic by honey bees walking on it or the mite touching the plastic or by sunlight; and hence the Apistan strip is a CONTACT miticide.

Obviously, most of the chemical is near the surface of the strip, and its effectiveness decreases rapidly the moment it is first taken out of its sealed wrapper.

Further, the chemical deteriorates with age and more rapidly from heat, and hence, hanging in a hive covered over by 90-95 degree warm bees for just a few days really diminishes its effectiveness rather quickly.

You might ask, "Pray tell, why is the treatment time of 6-8 weeks the suggested treatment time, if the strip loses its effectiveness so quickly?" Since a varroa mite is "born" in the larval or pupal cell of a bee, emerges as an adult, travels around feeding on an adult bee perhaps for a few days before more eggs are laid in DIFFERENT larval or pupal bee cells 2-3 weeks later, it is best to keep apistan on the scene for 6-8 weeks in an attempt to get to get close to a 95% kill as possible.

Mite increase is far faster and greater than honey bee increase because there can be as many 2, 3, or 4 mites raised in many bee cells, so the more we can kill per treatment, the healthier our bees will be.

George Imirie
Certified EAS Master Beekeeper