Using Formic & Oxalic Acidsfor treatment of Varroa & Tracheal& Honey bee parasitic mitesUsing Formic & Oxalic Acidsfor treatment of Varroa & Tracheal& Honey bee parasitic mites
Michael YoungMichael Young
Institute of Northern Ireland BeekeepersInstitute of Northern Ireland Beekeepers
Oxalic acid in natureOxalic acid in nature
Occurs naturally in plantsOccurs naturally in plants
Carrots contain 500 mg/kgCarrots contain 500 mg/kg
Broccoli contains 900 mg/kgBroccoli contains 900 mg/kg
Rhubarb leavesRhubarb leaves
Occurs naturally in insects.Occurs naturally in insects.
Oxalic acid in honeyOxalic acid in honey
Natural constituent of honeyNatural constituent of honey
Values range between 8 and 300 mg/kg inhoneyValues range between 8 and 300 mg/kg inhoney
Moist vegetables contain much more OAthan honeyMoist vegetables contain much more OAthan honey
Low risk of residues in honey.Low risk of residues in honey.
Bernardini and Gardi 2001
Oxalic acid use in EuropeOxalic acid use in Europe
Recently registered (2005) and extensivelyused in EuropeRecently registered (2005) and extensivelyused in Europe
Maximum residue limits established Dec.2004 at 50 millequivalents of free acidsMaximum residue limits established Dec.2004 at 50 millequivalents of free acids
If used according to Europeanrecommendations, there is no risk ofproblems with honey.If used according to Europeanrecommendations, there is no risk ofproblems with honey.
Rademacher and Imdorf 2004
Methods of applicationMethods of application
Oxalic acid is applied by spraying, tricklingor evaporatingOxalic acid is applied by spraying, tricklingor evaporating
Trickling is the preferred application in EuropeTrickling is the preferred application in Europe
Effectiveness greater than 90%Effectiveness greater than 90%
•Mechanism of acaricidal action has notbeen investigated in detail.•Mechanism of acaricidal action has notbeen investigated in detail.
Rademacher and Imdorf 2004
Trickle methodTrickle method
Trickling a solution of water-sugar-oxalic acid is a promising method tokeep 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 isenough for 50 hives.
This mixed up solution will keep for afew weeks only and should be used atonce.
Use 20 to 35 ml solution for each hivedepending on the size of the treatedcolony.
Easy AccessEasy Access
On a 2 box hive the solution isdistributed according to the amount ofbees in each box. The top boxnormally holds more bees and isgiven 70% of the solution
The bottom box is given 30% ofthe total solution.
The solution is distributed evenly in the gap between thetop bars, so it will drip down and reach as many bees aspossible.The solution is distributed evenly in the gap between thetop bars, so it will drip down and reach as many bees aspossible.
(5-6ml between each frame)
Time per hive 1,5 min.Time per hive 1,5 min.
Spray MethodSpray Method
Not necessary to remove individual framesNot necessary to remove individual frames
Spray top and bottom clusterSpray top and bottom cluster
Quick and effective.Quick and effective.
VaporizersVaporizers
RussianRussian
GasGas
Battery 12voltBattery 12volt
Efficiency from the Oxalic Acidevaporation in a different dosageEfficiency from the Oxalic Acidevaporation in a different dosage
Test result
Without
treatment
water
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 pertest
6
8
12
10
13
11
5
European GuidelinesEuropean Guidelines
Make a solution by dissolving 35g OA in 1 liter oflukewarm solution sugar water (1:1 solution)Make a solution by dissolving 35g OA in 1 liter oflukewarm solution sugar water (1:1 solution)
Recommended dose is 5-6 ml per occupiedframe spaceRecommended dose is 5-6 ml per occupiedframe space
Treat in Autumn or early winterTreat in Autumn or early winter
Most effective in broodles colonies Most effective in broodles colonies
Treat when temperature. Is 32-55°FTreat when temperature. Is 32-55°F
Wear glves and safety gogglesWear glves and safety goggles
The physical propertiesThe 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 acidmolecule.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 acidmolecule.
The CRC Handbook of Chemistry and Physics gives the following propertiesfor oxalic acid dihydrate:On heating:1) 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 sublimeddecomposes toformic acid and carbon monoxide.The CRC Handbook of Chemistry and Physics gives the following propertiesfor oxalic acid dihydrate:On heating:1) 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 sublimeddecomposes toformic acid and carbon monoxide.
Treatment ConsiderationsTreatment Considerations
Mix freshMix fresh
Store unused material in refridgeratorStore unused material in refridgerator
Safety equipmentSafety equipment
TrickleTrickle
Acid resistant glovesAcid resistant gloves
GogglesGoggles
Spray or fumigationSpray or fumigation
As above as well asAs above as well as
Acid rated respiratory cartridgeAcid rated respiratory cartridge
ResultsResults
Spray treatment reduces varroa infestationby 92% when compared to untreated(mean)Spray treatment reduces varroa infestationby 92% when compared to untreated(mean)
Trickle treatment reduced varroainfestation by 87%Trickle treatment reduced varroainfestation by 87%
Effectiveness of spray and trickletreatments are not significantly differentEffectiveness of spray and trickletreatments are not significantly different
No Oxalic Acid resistantpossible.No Oxalic Acid resistantpossible.
It works by destroying the mite's suctionability, stopping it from feeding from thebee. Effectively, the mite starves todeath. It works by destroying the mite's suctionability, stopping it from feeding from thebee. Effectively, the mite starves todeath.
Essential advantages over the actualusually fighting methods are:Essential advantages over the actualusually fighting methods are:
no delays in the honey, beeswax and propolisno delays in the honey, beeswax and propolis
very good bee compatibility very good bee compatibility
high degree of effectiveness , up to 99% inbrood free colonieshigh degree of effectiveness , up to 99% inbrood free colonies
no early ageing of the bees (important topopulation of the bees in spring)no early ageing of the bees (important topopulation of the bees in spring)
outside any time of honey-collection usableoutside any time of honey-collection usable
very user kind for the beekeeper.very user kind for the beekeeper.
Caution: Caution:
Oxalic acid in its crystalline form is poisonous andshould be handled carefully. It should not be allowedto contact the skin and it is essential that the dust isnot inhaledOxalic acid in its crystalline form is poisonous andshould be handled carefully. It should not be allowedto contact the skin and it is essential that the dust isnot inhaled
Weigh and mix outdoors, preferably in a light breezeto take any dust away from you. In the solution givenabove it is safe to handle with rubber gloves. Weigh and mix outdoors, preferably in a light breezeto take any dust away from you. In the solution givenabove it is safe to handle with rubber gloves.
Oxalic acid is not dangerous if precautions aretaken. Wear rubber gloves and be careful not to letthe acid touch your skin or eyes. Wear old clothes,use protective mask, and glasses.Oxalic acid is not dangerous if precautions aretaken. Wear rubber gloves and be careful not to letthe acid touch your skin or eyes. Wear old clothes,use protective mask, and glasses.
Annual Bee meeting YorkAnnual Bee meeting York
Oxalic Acid can only be used by requiringa prescription from the vetOxalic Acid can only be used by requiringa prescription from the vet
It can only be used as a hive cleanserIt can only be used as a hive cleanser
All beekeepers have to keep records of allmedicines used as a treatment for beesAll beekeepers have to keep records of allmedicines used as a treatment for bees
If not! It carries a two year jail sentenceIf not! It carries a two year jail sentence
Thank You!Credits Dr Marion EllisNebraska UniversityThank You!Credits Dr Marion EllisNebraska University