July 1999 Veroa Notes

George Imirie’s PINK PAGES


It is most discouraging to have a strong colony of bees make a wonderful crop of honey in May and early June, maybe even a record crop for some, and then find the colony DEAD in July! This is happening all over the country, and Maryland is no exception. WHY?

Examine the life and source of food of the Varroa Mite. Female mites feed on adult bees for 1-2 weeks before moving into an open bee larva cell just before the cell is capped. After the cell is capped the female mite feeds on the developing bee for several days, and then begins producing young mites which also feed on the pupal bee. When the young adult bee emerges, probably injured by the mites, so do the mature mites emerge. On an average, when an adult female mite enters a workerbee cell to reproduce, 2 new fertile female mites are produced, and perhaps 3 new mites are produced from a drone cell because the 24 day gestation period for drones is 3 days longer than for worker bees. Obviously, mite population increases very rapidly during honey bee brood rearing, especially when drone brood is available.

Varroa mite “feasting” upon bee brood leads to dead bee pupae or deformed, under- nourished adult bees. Often, small deformed wings on young adult bees are a common sign of heavy infestation. These colonies usually collapse and die-off in mid summer to autumn, or very shortly after the main nectar flow ends. Further, if a colony begins collapsing from mite infestation, nearby colonies are reinfested through robbing and drifting bees.

If you are really a beeKEEPER rather than a beeHAVER, you will want to save your bees from death. This simply means TESTING FOR VARROA MITE INFESTATION, and that does not mean the bee inspector. They are your bees, so you make the test. You test everything else like checking for a fever with a thermometer, checking the dip stick of your car’s oil, checking your dog for worms; so surely you can check your bees. HOW? There are TWO different ways: A) The sticky board test which is the most accurate, but the most work and requires the use an an Apistan Strip., and 2) The ether roll test that kills about 300-500 of your bees (and even your queen if you are not observant) and is not very accurate, but gives an indication. I will describe both tests.

Sticky Board Test: Cut a piece of cardboard, masonite, or thin plywood about 1/2″ smaller than the inside measurements of your bottom board. Also, cut a piece of freezer paper and 1/8″ hardware cloth or screen wire to about the same size. Spray PAM (a cooking oil) on one side of the freezer paper and lay it flat on the piece of card- board, place about 4-5 spacers (each about 1/4″ high) at the corners and center of the paper, and place the hardware cloth or screen on top of these spacers. (The spacers are present to keep the bees from being stuck on the paper or removing any mites that fall on the paper.) Insert all of this on the hive bottom board. Now insert one or two Apistan strips between the brood chamber frames, and leave for 24 hours. If you can count 100 mites or more on the sticky paper after a 24 hour test, your bees are badly infected and should be treated with 2 Apistan strips in each brood body immediately and with NO SUPERS ON THE COLONY; and the word “immediately” does not mean next week or next month or your bees might be dead by then. Once a colony is so infested that collapsing is close at hand, emergency treatment is needed to save it.

Ether Roll Test: Scrape or shake about 300 bees off of 3 or 4 brood combs near the center of the brood nest into a quart jar. Shake them to the bottom of the jar and spray them for just 1 or 2 seconds with ether, engine starting fluid which immediately kills both the bees and mites. Close the jar and shake it vigorously for 30 seconds, then hold the jar in a horizonal position and roll it a few times. Most of the mites will be dislodged and stick to the sides of the glass jar where they can be easily counted. This test is not nearly as accuate as the Sticky Board Test, but it does give a crude indica- tion of mite infestation. If you find more that 15-20 mites in the jar, immediate Apistan treatment should be started

It should be noted that Varroa infestation is temperature dependent because colder areas have less brood time than warm or hot areas. Hence, areas near the Canandian border usually only require one Apistan Treatment each year preferably in the late fall or early spring. Contrastingly, areas in the South like Florida or Texas will require two separate Apistan treatments each year. In the Maryland area, a good 8 week apistan treatment beginning October 1st and ending about Thanksgiving is usually sufficient each year, but colonies should be tested by either the Sticky Board Test or the Ether Roll Test on March 1st and again about July 4th and treated again with Apistan if the test indicates a high mite infection.

If you lose your bees because your laziness prevented testing, you not only will have to spend about $50 next spring for a new package of bees, but those bees will not produce much honey for you for that entire year. TEST FOR VARROA IN JULY!

George Imirie
Certified EAS Master Beekeeper

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