Varrox Evaporator Instruction Leaflet
as Re-Written by Dave Cushman

General license and distribution:
Andermatt BioVet AG. Stahlem1stten 6,
CH-6146.Grossdietwil
Phone ++ 41 62 917 51 10
Fax ++41 62 917 5111
sales@biovet.ch
www.varrox.com

Leaflet issue date... March 2002

1. Appliance

The VARROX-evaporator consists of a heater, a metallic support and 3 .m of lead with 2 battery- clips. It has an output or 150 W. The power source can either be a 12v car battery of 40 Ah or more, other type of accumulator, or a car cigarette lighter used with a seven metre extension lead.

Please note safety precautions ! Wear a protective mask !
Minimum dimension of the entrance: 14 mm high and 90 mm broad
Minimum distance between bottom board and frames: 20 mm

2. Mode of action

A measured quantity of oxalic acid crystals are placed in the pan, then the appliance is inserted through the entrance of the hive, into the middle of the bottom of the hive, keeping the pan horizontal to prevent spillage of crystals. The insertion should be far enough so that the hexagonal metallic support is fully inside the entrance. If bees are clustered over the pan, they must be strongly encouraged to disperse into the interior of the hive by using smoke. The power is switched on and the heating action of the pan causes the oxalic acid to vaporise. The oxalic acid vapour pervades the hive and all the exterior of the bees and hive surfaces are covered by a deposit of a very thin layer of oxalic acid crystals. These fine crystals are tolerated well by the bees, but have a deadly effect on varroa mites.

3. Treatment

Time
The treatment should only be be given when the majority of bees are within the hive, at a time when the bees have no heavy nectar flow, but the temperature should not be cool enough for the bees to be clustered, ie, below + 2°C. The VARROX-vaporiser is particularly suitable for use after the crop has been removed and the bees have ceased rearing brood.

Dosage

The dose varies according to how strong the hive is... one gram of oxalic acid-dihydrate per full sized brood box. The measuring spoon supplied with Each VARROX-vaporiser, if filled with loosely and without compaction, corresponds to one gram of Oxalic acid-dihydrate. So use one spoonfull per brood box. In the case that a hive comprises a brood and a half arrangment of one brood box plus a super, then one and a half sponsful would appear to be a good compromise.

Placing the VARROX-vaporiser
The appropriate amount of oxalic acid-dihydrate is placed into the VARROX evaporator. Take care that the oxalic acid is not spilled when holding the VARROX-vaporiser at an angle or by twisting it. Afterwards, the appliance is Minimum dimensions of the entrance: 14 mm high and 90 mm broad. If insertion through the entrance is not possible because of the construction of the hive, use the opening of the diagnosis drawer where possible. In that case, the entrance of the hive must be shut tightly.

Hint:  Depending on the height of the entrance and the bottom of the hive, it is recommended to fit the VARROX-vaporiser in evenly by bending down both sides of the metallic support a few millimetres. The distance between the bottom of the hive and the heating element can be increased and the source of the heat is taken off the bottom.

Attention:  Due to the heating action of the pan, there is a danger of melting plastified varroa bars and synthetic hives. The VARROX-vaporiser reaches temperatures of up to 300°C and can create patches of heat on the bottom and frames.

Sealing up the hive
Seal the whole entrance (or diagnosis drawer) around the handle of the VARROX-vaporiser using strips of foam or cloth. Open floors should be shut tightly on the whole surface.

Duration of the treatment
After the hive is sealed up, the vaporiser should be switched on for 2 ½ minutes. As a rule, 2 ½ minutes are enough for the vaporisation of the oxalic acid. In the first colony that has to be treated, the heating time may be longer, because the vaporiser is still cold. An extra minute heating is required if using the extension lead.
One of the battery-clips of the lead should be constantly connected with the source of power using the contact of the second clip to switch the appliance on and off. It makes no difference if the plus or minus-poles are connected accordingly or not-the function of the heating is not reduced.
After switchIng off the VARROX-vaporiser, wait for about 2 minutes before the appliance is pulled out, so that the oxalic acid-vapour can settle down. Once removed, ensure that the entrance of the hive is shut tightly again and left shut for another 15 minutes. After taking out the VARROX-vaporiser, it should be cooled in a bucket of water, so that with the next use, no vaporisation begins before the appliance is inserted into the hive.

Hint:  With the use of several VARROX-vaporisers, bigger apiaries can be treated more time-effectively.

4. Oxalic acid-dihydrate (Oxalic acid-crystals) Oxalic acid is an unhealthy, toxic and corrosive substance. When filling the VARROX-vaporiser and during the treatment, it is absolutely necessary to wear protective glasses, a protective mask (FFP 3 S/L), gloves and long-sleeved clothes.

Working safety

Handling of oxalic acid

• Oxalic acid can cause damage to health With both skin contact and if swallowed. Avoid contact with eyes and skin.
• Vapours and dusts of the oxalic acid should not be inhaled.
• Keep oxalic acid out of the reach of children.
• Oxalic acid must be stored in its original container (with law-concurring labelling) in a safe place.

In the case of eye contact. immediately wash the acid out with water. If ingested immediately go to a doctor.

Working safety during the treatment

• Treatments on colonies in a beehouse must only be made from outside through the entrances of the hives. During the treatment, the beehouse must be well ventilated. No person must be inside the beehouse.
• WIth treatments of apiaries in the open, take care that the wind blows any escaping oxalic acid away from the user. The whole length of the lead should be used and the user should stay away rrom the hive.
• The foam material used for sealing the hive must be handled with gloves. This avoids contact with the acid where it may have condensed on the inner side of the foam. The foam material must be washed out carefully with water before putting away.
• After the treatment in the winter, oxalic acid-crystals are found on the bottom of the hive. This can be due to the absence of bee cleaning activity as found in the summer. Caution is therefore needed if mite fall is controlled after a treatment in the winter. Gloves and a protective mask should be worn. The rest of the oxalic acid will break down to water and carbon dioxide and will be cleaned by the bees in spring.
• The VARROX-vaporiser is a powerful heater that generates high temperatures. The vaporisor must not be used near easily inflA. m. melliferaable materials. Always put the vaporiser on a sheet of non-flA. m. melliferaable material (i.e. metal). Never touch the metallic part of the vaporiser when in use. Caution: metallic parts may be hot for a long time after use. The vaporiser must never be switched on without supervision.