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Thursday, June 28, 2018

APIARY MITE CHECK by beekeepers Fred and Jon--REV. 1


There’s nothing like opening up a full strength hive on a hot summer day.  A smoker and full protection were the order of the day.   The bees still extracted their revenge a few times.  After watching the “making a varroa plan” webinar on Tuesday Beekeeper Jon and I decided to run comparative alcohol wash and powdered sugar shake mite checks on four (4) of my hives.  To do the mite checks properly you need to get nurse bees from the brood chamber; hence disassembly of the hives. 



This is my homemade sugar shaker made from two spreadable cheese containers with a screen sandwiched between. 

The powdered sugar shake requires a ½ cup (roughly 300 bees) from the brood area.  Mites preferencially latch on to nurse bees.  To these bees add 2 teaspoons of powdered sugar.  The sugar either causes the bees to furiously groom or causes the mites to lose their grip on the bees.  No one knows the real mechanism.  Then vigorously shake them to ensure they coated a sugar coating.  Then let two minutes elapse before removing the powdered sugar.  Put the sugar into a plastic bowl and adding a little water makes the sugar dissolve and reveals the mites.  The bees are returned to the hive.

Here is Jon's homemade alcohol washer.  The bees are captured in the cheesecloth.  After shaking the mites fall into the bottom of the cup with the alcohol for counting. 

An alcohol wash is similar.  Again, use ½ cup/ 300 bees as the sample.  In a sealed container add rubbing alcohol to the bees.  This kills both the bees and mites.  Remove the bees and the mites are suspended in the alcohol. 

I chose to test four hives. 

Hive 1 was an overwintered hive with an Ankle Biter queen.  This is a strong hive and starting on its third honey super.  This hive had had been treated twice with oxalic vapor in early April and had a ½ dose of MAQS in mid-May.  The alcohol wash yielded zero (0) mites as did the powdered sugar shake.

Hive 2 was an overwintered hive with a Russian queen.  This was the strongest hive and is also working its third honey super.   This hive had had been treated twice with oxalic vapor in early April and had a ½ dose of MAQS in mid-May.  The alcohol wash yielded two (2) mites while  the powdered sugar shake yielded zero (0) mites.

Hive 3 was started with a package on May 1st.   Bees have only recently been moving up to the honey super.  This hive was treated in early June with a ½ dose of Formic Pro.   The alcohol wash yielded zero (0) mites as did the powdered sugar shake.

Hive 4 was also started with a package on May 1st.  This hive had a single oxalic vapor treatment in mid May.  The alcohol wash yielded 2 (possibly 3 mites) while the sugar shake yielded zero (0). 

I was under the impression that alcohol wash and sugar shake would give similar results.  This small test did not confirm this.  I suppose my sugar shake technique may not be effective.  Or this may only be true for a heavily infested hive, but may not be true for light mite loads.  I think the alcohol, which kills both the mites and bees, probably loosens the mite’s grasp on the bees better than the powdered sugar. 

At first glance these results look good; zero (0) to two (2) mites per 300 bees.  But this is only the end of June.  Playing around with Randy Oliver’s varroa model on the Scientific Beekeeping website I adjusted his model to account for my miticide treatments in the spring and to get 2 mites/300 bees on July 1st.  This model predicts that the two hives with 2 mites will probably have a varroa caused crash in the fall if I took no further action. 

Another formic acid treatment (either MAQS or Formic Pro) in early August should put these hives in good shape to survive the winter.   I will be treating all hives because of the tendency for drones to drift from hive to hive and thus redistribute mites throughout the apiary.  NOTE: Other treatments can be used.  I have chosen to use Formic and Oxalic acid treatments. 

TO THOSE BEEKEEPERS THAT HAVE NOT DONE ANY MITE CONTROL TO DATE THIS SUMMER  YOUR HIVES ARE IN TROUBLE!  IF YOU WAIT UNTIL HONEY REMOVAL IN AUGUST OR SEPTEMBER THE MITE NUMBERS, ASSOCAITED VIRUS LEVELS AND INFECTED PUPAE AND BEES WILL BE PROBABLY SO HIGH THAT YOUR HIVE MAY NOT BE ABLE TO RAISE RELATIVELY VIRUS FREE WINTER BEES.  TREAT YOUR HIVES NOW!!!!  PLEASE BE AWARE THAT FORMIC ACID TREATMENTS SHOULD NOT BE USED WHEN DAYTIME TEMPERATURES EXCEED 85F FOR THE FIRST SEVERAL DAYS OF TREATMENT BECAUSE OF THE POTENTIAL TO HARM THE QUEEN.  OTHER TREATMENTS HAVE RESTRICTIONS AGAINST THEIR USE WHEN THE HONEY SUPERS ARE ON.  




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