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FIBKA Guidelines on Varroa Destructor

Beekeepers please note;

(a) only licenced medications may be used legally in Ireland, strictly according to manufacturers’ instructions, and (b) non-standard use of some medications (Bayvarol & related specific agents) will accelerate emergence of resistance in Varroa, with detriment not only to the individual but to the wider beekeeping community. However, non-recommended uses of agents with non-specific actions (thymol, organic acids) just increases risk of ineffective varroa treatment and higher colony loss, impacting only on the beekeepers who do it. Incorrect vaporization also carries significant health risk for the beekeeper her/himself.

Anybody having problems with the medications below after using them correctly ( according to the manufacturers instructions should report the adverse reaction on www.hpra.ie under animal medicinces.

Varroa

Know your enemy before you fight it..
1) What is Varroa?
a) It is a mite which is a parasite on both the adult and the prepupal stage of the honey bee.

2) Why should we be worried about it?
a) It is an exotic mite and the European honey bees have not adapted to it.
b) Because of its feeding on the juvenile stages it has a severe effect on the health and longevity of the emerging bees.
c) It is a vector for several viruses.
d) If the colony is not treated it will die.

3) How can we test for its presence in a colony of bees?
a) The mite is now pandemic in Ireland, it is in every colony.

4) So how do you treat for it?
a) There is no treatment that will kill all the mites within a colony.
b) So the treatments are applied when colony numbers reach a level where the health of the colony will be affected.

5) So this means checking on the level of infestation. How?
a) There are four methods in common use:
i) Open Mesh Floor with monitoring board.
ii) Uncapping drone Brood
iii) Sugar shake.
iv) Alcohol Roll.

OPEN MESH FLOOR:
This is a replacement floor on the hive with the solid boards replaced by a mesh small enough to prevent bees from falling though and large enough to allow mites to fall through freely. There is provision for a monitoring board to be inserted so that the fallen mites can be counted. The depth from the mesh to the monitoring board should be about 50mm (2 inches) which is deep enough to prevent mites from climbing back up into the hive.
To use before any treatment is used place the monitoring board in and return after three or four days. Remove the board and count the mites that have landed on the board, Divide this number by the number of days and this gives you the DAILY NATURAL MITE DROP.
Depending on the time of year this will inform you whether you do not need to treat at present, whether numbers are rising so that some action should be taken or whether the colony is liable to collapse and urgent treatment is needed.

 

 Jan-MarchApr -JulAugustSeptNov
Control not neededLess than 2Less than 1Less than 3Less than 4Less than 8
Light Control NeededLess than 8Less than 8Less than 8Less than 8Less than 8
Urgent Treatment RequiredMore than 8More than 8More than 8More than 8More than 8

Note that these figures are for Natural Mite Fall with no Treatment.
These figures derived from The DEFRA Booklet ‘Managing Varroa’

 6)UNCAPPING DRONE BROOD:

Open hive and find a patch of sealed drone brood. Using an uncapping fork lift out the drone brood and examine for varroa mites. The pupae should be preferably at the pink eye stage as the exoskeleton is strong enough for the pupae to be lifted out. You count the number of pupae with varroa not the number of mites.

About 100 pupae should be removed and a percentage calculated.

 April- May -JunJun -JulyAugust
No ActionLess than2%Less than 3%Less than 5%
Light Action2% – 4%3%-7%5% – 10%
Severe RiskMore than 4%More than 7%More than 10%

You will see that for this test there has to be drone brood in the colony.

It is not advisable to carry out this test on a frequent basis as there is a need for drones to be flying in order to allow for proper mating of the Queen.

7)SUGAR SHAKE:

Sugar ShakeEquipment needed jar with mesh lid, bucket with white base filled with water, icing sugar.

Pour 100ml water into the jar and mark the water level.

Dry the jar thoroughly Shake bees off a brood frame avoid taking the queen, pour the bee into the jar to the marked level. This is about 300 bees. Shake the jar gently. Then shake in about 2 tablespoons of icing sugar. Roll the jar so that the bees are coated in the icing sugar leave for a while and then upend the jar over a white bottomed bucket of water and shake vigorously. The icing sugar will dissolve in the water & the mites will float, the white bottom in the bucket makes it easy to count the mites. The mites will fall through the mesh, the bees will be retained and the sugar dissolves in the water and the mites can be counted.

The bees can be returned to the hive unharmed.

The percentage of mites can be calculated. You used 300 bees so if you got 12 mites you divide by 3 to get the % and in that instance your answer is 12/3 =4%

MONTHMayAugust
Treatment levelMore than 2%More than 3%

8)ALCOHOL ROLL:

A similar test to the sugar shake, but the bees are treated with alcohol instead of sugar and the mites and bees are separated by double sieving~; a coarse sieve to separate the bees and a fine sieve to catch the mite.

THIS TEST KILLS THE BEES

9)TREATMENT OPTIONS:

There are two choices

a)MANIPULATION:

i) Queen Trapping:

Principle is to restrain the queen on specific frames so that all the brood is concentrated. The queen is caged on a frame in the brood nest for nine days, then you remove her from the frame and put a new un-laid frame into the cage with the queen on it to lay it up. On day 18 you again move the queen to another new frame and take away the first one she laid which would now be sealed. On day 27 you can now take the cage out and release the queen to freely move around the brood box again and remove the frame that was put in on day 18. On day 36 you remove the last frame that was put in on day 27.  Mites will enter the brood to breed and when sealed the frame may be removed and mites destroyed by freezing. This can usually be done in June if necessary. Because the bees are not busy rearing brood they will forage for nectar.

A total of three frames are used with the queen being moved from each week to a new frame

Queen Trapping
Queen Trapping

Disadvantage is that there is a lot of work involved.

ii) “Artificial Swam”

Principle is to have all the mites in a colony made ‘phoretic’ by preventing egg-laying and then to use ‘bait frames’ to attract mites.

(1)DAY 1

Move colony with supers to new stand more than 10 feet away.

Place new brood box with clean drawn comb or foundation on old stand.(This is the swarm colony)

Find the old queen and move to the swarm colony, check the old box for queen cells and leave one open queen cell destroying all others.

(flying bees will return to site of old stand forming the swarm colony)

Feed new box if necessary.

(2)DAY 9 

Swarm colony Queen and bees have formed colony eggs are laid and brood is developing

Old colony Cage the queen cell and destroy any other queen cells.

(3)DAY 21 , Remove 2 frames of open brood from the swarm colony and place it in the old colony which will have no brood.

(4)When bait frames are sealed remove from old colony and destroy by freezing

Remove and cull the virgin queen from the old colony and re-unite with the swarm colony

iii)“ Drone Culling”

Drone Culling
Drone Culling

Place a super frame ( or a brood frame with foundation to half depth) in the brood box on the edges of the brood nest.

The bees will draw the bottom part mainly in drone comb.

Wait until the drone cells are sealed and then remove the frames cutting away the drone portion and return the frame to the colony.

Destroy the removed drone brood by freezing.

NOTE: AS THE BEES NEED DRONES FOR MATING THIS SHOULD NOT BE DONE TO EXCESS

CHEMICAL TREATMENTS:

The statutory rules concerning the administration of chemical treatments are covered in

EUROPEAN COMMUNITIES (ANIMAL REMEDIES) (No. 2) REGULATIONS 2007

The important sections are Part VI Section 39, 40 and 42.

In essence: no medication may be administered unless it is licenced for the purpose. The dosage and administration is in accordance with the licence and these must be shown on the label.

The owner must keep an ‘Animal Remedies Record’ of all medications administered and these records must be kept for a period of 5 years.

This Animal Remedies Record shall be of the following form :

Purchase/incoming details—

  • (a) Quantity
  • (b) Authorised name of the animal remedy
  • (c) Date of Receipt
  • (d) Name and address of supplier

Administration/Outgoing details—

  • (a) Date of Administration,
  • (b) Authorised name and quantity of the animal remedy administered,
  • (c) Identity of animal to which the animal remedy was administered
  • (d) Date of expiry of a withdrawal period,
  • (e) Name of person who administered the animal remedy,
  • (f) Name of prescribing veterinary practitioner (if applicable),
  • (g) Quantities of unused or expired animal remedies which were returned shall be of the following form:

In the case of Varroa there are only six medications currently licenced for use in Ireland so anything else not authorized will not be discussed.

  1. Bayvarol
  2. Apiguard
  3. Apibioxal
  4. Mite Away Strips
  5. VarroMed
  6. POLYVAR Yellow

Bayvarol: 

Bayvarol
Bayvarol

A synthetic pyrethroid. It was extremely efficient but acted on a particular synapse and so mites were able to develop resistance to it.

Dosage and use was the insertion of four strips into the brood box for a period of six weeks after which the strips were to be removed and disposed of. (Two strips for a nuc)

It is a contact poison and so mites within the cells were not affected, this is why the dose lasted for the six weeks as this is two brood cycles.

At this stage there is resistance to the chemical and it should not be used.

For anybody still with stocks of it, you should test for pyrethroid resistance before you use it

How do I know if I have Pyrethroid Resistance? 

  1. Cut a 9 x 25 mm piece from an  Apistan strip and staple it to a piece of card 75 x 125 mm. Place it in a 1lb honey jar with the strip facing inwards. Please note that APISTAN is not licenceced in Europe and is not legally available , you cannot use Bayvarol to do this test.
  2. Prepare a 2-3mm mesh cover to close the jar. Plastic greenhouse shading mesh is ideal.
  3. Cut a piece larger than the opening so that it can be folded back over the open end of the jar and secured using a strong elastic band.
  4. Take precautions not to sample the queen. Shake adult bees from 1 or 2 brood combs into a container such as a washing up bowl. Gently scoop up bees with the jar until it is half full.
  5. Place a sugar cube in the jar and seal off using the mesh. Store in the dark at room temperature with the mesh uppermost.
  6. After 24 hours hit the upturned jar with the palm of your hand over white paper and shake 3 times  and the dead mites will fall out. Count the mites knocked out.
  7. Immerse the bees in the jar into a solution of water and washing up liquid (strong washing up strength).
  8. Wash the dead bees to remove any remaining mites. Place the bees in a coarse kitchen sieve that will hold bees but let Varroa mites through. Secure a honey straining cloth or jelly bag under the sieve to retain mites. Place under a fast running tap or tap with a shower fitting to wash any remaining mites off the bees. Count the number of mites washed off.
  9. If the total number of mites is less than 5 discard the results.
  10. Calculate the efficacy as a percentage. Multiply the number of mites knocked down by 100 and divide by the total number of mites i.e. the number knocked down plus those washed off. If the answer is less than 50% it indicates that there is a resistance problem.

A New test for resistance to Bayvarol has been found by Rothamsted Research in Harpenden Hertfordshire , this test identifies the mutation giving the resistance, can be used on dead or live mites and is done on a single mite. This test costs money and can be done on single mites. Basically it is a PCR test.

Apiguard:

Apiguard
Apiguard

Thymol gel in foil sealed trays

Action is general in attacking the mites by vapour and contact.

In use it needs and eke of about 20mm high to allow the bees to make contact with the gel. (An empty Super might be used as an eke if one is not to hand.

Requires the maximum day temperature to exceed 15 degrees. We normally use it in autumn when the supers are taken off, if the bees need feeding, feed your bees a gallon of feed before you put it on because sometimes they spend too much time trying to get it out of the hive that they do  not take down feed

Open one tray and place on top of the brood frames and leave for two weeks.

After the two weeks add the second tray and leave for four weeks or until the tray is empty.

If using open mesh floor make sure the monitoring board is inserted. Due to the more general action in attacking the mites resistance is not likely to be formed. It does not kill the mites with the brood cells. Half the dose is adequate for a nuc

ApibioxalApibioxal:

Active agent is Oxalic acid

Packaging is in 3 quantities 35g, 175g and 350g

Should be used when there is no brood in the colony

May be used in a solution of sugar and water or by vaporizing the dry chemical.

In solution: for the 35g pack

Make a sugar syrup solution of 500g sugar dissolved in ½ litre of water this makes more syrup than required so take ½ litre of the syrup and dissolve the sachet into it.

Treat by tricking 5ml of the solution per seam of bees i.e. about 50ml per colony.

As the chemical will be used in cold weather and poured directly onto bees keep the solution warm before administering.

THE SOLUTION HAS A LOW SHELF LIFE and must be discarded before it discolours.

Apibioxal is now licenced for use all year round in a broodless period

Vaporising: use a commercial vaporising unit e.g. VARROX and follow the instructions on it as regards heating etc. quantity of chemical is 2g of the Apibioxal powder. Caution the use of the vaporiser requires protective equipment to avoid inhalation of fumes.

Maqs
Maqs

MAQS (Mite Away Quick Strips)

Literature states ‘that background colony or health issues may be “exposed” ’

Temperature range for use 29.5 –10 C

Suggested treatment times May or mid-August this would allow for natural queen supersedure. There must be a minimum of 6 frames of brood in the stock.

Full ventilation is needed

Entrance 1 inch high and full width

Maqs 2

Placement is 2 strips over the brood box (the lower brood box if double brood).If there is no super on place empty super above brood box. Do not disturbe the colony during treatment

Use open mesh floor and monitoring board as some of the mites will not be dead and will re-infect bees.Treatment is 7 days but bees may remove the strips.

There is no recommendation on the treatment of nucs from this manufacturer. Caution in some stocks the formic acid in this treatment may affect the queen.

VarroMed 

This is a new product on to the Irish market and consists of a mixture of formic acid and oxalic acid. The ideal time to use is is during a broodless period.

It is drizzeled on beteween the frames of brood as outlined below. Not for use during the honey flow

The dose should carefully be adjusted to the colony size (see dosing table). Determine the colony size and number of occupied bee spaces to be treated, and select the correct amount of product required. The following dosing scheme applies:

No. of bees            VarroMed per ml

5,000 – 7,000                  – 15ml

7,000 – 12,000                -15-30ml

12,000 – 30,000              -30-45ml

> 30,000                        -45ml

The use of VarroMed with the above dosing scheme only applies for hives with vertical frames that can be accessed from the top, as the treatment of bees in other types of hives has not been investigated.

The multi-dose container has a graduated dosing scale for accurate dosing. Product needs to be warmed up before use.

How much to use

Winter one treatement in a broodless period . Do not repeat

Spring 

1x or 3x

Treatment should be conducted at the start of the season with increasing colony population and when the natural mite fall is more than 1 mite per day

The treatment should be repeated twice more (that is to a maximum of 3 treatments), if more than 10 mites are detected on the floorboard within 6 days after the first treatment

Autumn 

up to 5x

possible in late summer/early autumn with decreasing colony population, and when the natural mite fall is more than 4 mites per day.

administrations).

The treatment should be repeated twice more (that is to a maximum of 5 treatments), if more than 150 mites (colonies from the second year) or more than 90 mites (nucleus colonies in the first year) are detected on the floorboard within 6 days

Heat the product to 25-35C before application , use in the evening when the bees have finished flying. Remove any brace comb before applying . Do not open the hive for a week after use.

Shelf life of the product is 2 years unopened , 30 days once opened.

APIVAR

Apivar has recently been made available in Ireland.

Active substance is Amitraz.

For use in a single brood box only , 2 strips per hive, strips must be located in the brood nest with a minimum of 2 frames between strips for a minimum of 6 weeks and a max of 10, relocating the strips to the brood nest if necessary

Manufacture recommmends all brood frames are changed out ( within 3 years) to stop residues building up in wax

Not to be used during a flow , not to be used when honey supers are on

This product must be rotated with the rest above and not used as a sole product

We recommend that the product is rotated and not used again for 2 years

Self life 2 years , once opened the strips start to deteriorate ( do not store once opened) .

SPC available http://www.hpra.ie/img/uploaded/swedocuments/Licence_VPA10383-001-001_26092017161935.pdf

POLYVAR Yellow

There is another product licenced for varroa treatment in Ireland called Polyvar yellow. Each strip contains 275mg of flumetherin. They are yellow plastic strip with 15 holes per strip that are put on at the entrance of the hive and as the bees come into the hives the flumetherin gets on to the bees and is spread around the hive.

Two strips are normally used per hive and they should be left on for at least 9 weeks and not more than 4 months

The SPC can be found at the following location https://www.hpra.ie/img/uploaded/swedocuments/LicenseSPC_10021-076-001_24032017154938.pdf

The product is designed to be rotated with other medications and not flumethrin based medications. The manufacturers are warning of resistance build up to the varroa mite. This treatment cannot be used as a stand alone treatment and would have to be backed up with a winter Apibioxal. The product will be spread around the hive as it catches the mites on the way in; it does not deal with those already in the brood nest under the cappings and will not deal with those that have built up a resistance to Flumetherin.

Updated October 2018