Using Formic

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Using Formic Oxalic Acidsfor treatment of
Varroa Tracheal Honey bee parasitic mites

• Michael Young
• Institute of Northern Ireland Beekeepers

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Oxalic acid in nature

• Occurs naturally in plants
• Carrots contain 500 mg/kg
• Broccoli contains 900 mg/kg
• Rhubarb leaves
• Occurs naturally in insects.

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Oxalic acid in honey

• Natural constituent of honey
• Values range between 8 and 300 mg/kg in honey
• Moist vegetables contain much more OA than honey
• Low risk of residues in honey.

Bernardini and Gardi 2001
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Oxalic acid use in Europe

• Recently registered (2005) and extensively used
  in Europe
• Maximum residue limits established Dec. 2004 at
  50 millequivalents of free acids
• If used according to European recommendations,
  there is no risk of problems with honey.

Rademacher and Imdorf 2004
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Methods of application

• Oxalic acid is applied by spraying, trickling or
  evaporating
• Trickling is the preferred application in Europe
• Effectiveness greater than 90
• Mechanism of acaricidal action has not been
  investigated in detail.

Rademacher and Imdorf 2004
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Trickle method
Trickling a solution of water-sugar-oxalic acid
is a promising method to keep Varroa levels
down. 100 parts water and100 parts sugar by
weight 75 g Oxalic-1 liter water- 1 kg sugarwill
make 1,66 liter solution that is enough for 50
hives. This mixed up solution will keep for a
few weeks only and should be used at once. Use
20 to 35 ml solution for each hive depending on
the size of the treated colony.
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Easy Access

                                                                                                   
On a 2 box hive the solution is distributed
according to the amount of bees in each box. The
top box normally holds more bees and is given 70
of the solution
The bottom box is given 30 of the total
solution.
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• The solution is distributed evenly in the gap
  between the top bars, so it will drip down and
  reach as many bees as possible.
• (5-6ml between each frame)
• Time per hive 1,5 min.

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Spray Method

• Not necessary to remove individual frames
• Spray top and bottom cluster
• Quick and effective.

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Vaporizers

• Russian
• Gas
• Battery 12volt

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Efficiency from the Oxalic Acid evaporation in a
different dosage
Test result Without treatment water Oxalic Acid evaporation (g/Beehive   0,5g       1,0g    2,0g     3,0g 5,0g Oxalic Acid evaporation (g/Beehive   0,5g       1,0g    2,0g     3,0g 5,0g Oxalic Acid evaporation (g/Beehive   0,5g       1,0g    2,0g     3,0g 5,0g Oxalic Acid evaporation (g/Beehive   0,5g       1,0g    2,0g     3,0g 5,0g Oxalic Acid evaporation (g/Beehive   0,5g       1,0g    2,0g     3,0g 5,0g
Lowest effect 0,0 1,3 51,7 93,2 91,7 98,1 99,0
Average effect 1,2 4,8 82,8 96,0 97,2 99,0 99,2
Highest effect 2,7 11,5 96,0 99,2 99,6 99,7 99,8
Beehives per test 6   8   12   10   13   11   5
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European Guidelines

• Make a solution by dissolving 35g OA in 1 liter
  of lukewarm solution sugar water (11 solution)
• Recommended dose is 5-6 ml per occupied frame
  space
• Treat in Autumn or early winter
• Most effective in broodles colonies
• Treat when temperature. Is 32-55F
• Wear glves and safety goggles

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The physical properties

• of oxalic acid may be of interest in
  thisconnection. The stuff one buys is usually
  oxalic acid dihydrate, which is acrystal which
  has two water molecules attached to each oxalic
  acid molecule.
• The CRC Handbook of Chemistry and Physics gives
  the following propertiesfor oxalic acid
  dihydrateOn heating1) The water of
  hydration leaves at 101.5 degrees C. The water
  boils offleaving anhydrous oxalic acid
  crystals.2) At 157 degrees C the oxalic acid
  starts to sublime (goes directly fromsolid to
  gas)3) At 189 degrees C the oxalic acid which
  has not yet sublimed decomposes toformic acid
  and carbon monoxide.

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Treatment Considerations

• Mix fresh
• Store unused material in refridgerator
• Safety equipment
• Trickle
• Acid resistant gloves
• Goggles
• Spray or fumigation
• As above as well as
• Acid rated respiratory cartridge

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Results

• Spray treatment reduces varroa infestation by 92
  when compared to untreated (mean)
• Trickle treatment reduced varroa infestation by
  87
• Effectiveness of spray and trickle treatments are
  not significantly different

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No Oxalic Acid resistant possible.

• It works by destroying the mite's suction
  ability, stopping it from feeding from the bee.
  Effectively, the mite starves to death.  

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Essential advantages over the actual usually
fighting methods are

• no delays in the honey, beeswax and propolis
• very good bee compatibility 
• high degree of effectiveness , up to 99 in brood
  free colonies
• no early ageing of the bees (important to
  population of the bees in spring)
• outside any time of honey-collection usable
• very user kind for the beekeeper.

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Caution 

• Oxalic acid in its crystalline form is poisonous
  and should be handled carefully. It should not be
  allowed to contact the skin and it is essential
  that the dust is not inhaled
• Weigh and mix outdoors, preferably in a light
  breeze to take any dust away from you. In the
  solution given above it is safe to handle with
  rubber gloves. 
• Oxalic acid is not dangerous if precautions are
  taken. Wear rubber gloves and be careful not to
  let the acid touch your skin or eyes. Wear old
  clothes, use protective mask, and glasses.

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Annual Bee meeting York

• Oxalic Acid can only be used by requiring a
  prescription from the vet
• It can only be used as a hive cleanser
• All beekeepers have to keep records of all
  medicines used as a treatment for bees
• If not! It carries a two year jail sentence

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Thank You!Credits Dr Marion EllisNebraska
University