Information about Miticide Strips

AHBIC update: 30/07/2022

The Australian Pesticides and Veterinary Medicines Authority (APVMA) is the Australian Government regulator of all agricultural and veterinary chemicals.

To allow the use of chemicals in the beekeeping industry, there must be a registration for use or a use permit.

There are existing permits in place to allow emergency use of miticides to control Varroa, and there are maximum residue limits (MRLs) established to provide an extra level of confidence for beekeepers.

In Australia, the only miticide strips that are available for use are under the emergency use permit held by Plant Health Australia (PHA). This permit includes Mite Away Quick Strips (formic acid), Bayvarol (flumethrin), Apistan (tau-fluvalinate) and Apiguard (thymol). In addition, the Commonwealth Government holds a permit for Apivar (amitraz).

There are permit applications with the APVMA for additional options, but this approval will take time to be reviewed and granted.

There are positives and negatives to each of the available miticide options. The following information is based on the PHA surveillance permits.

Formic Acid Formic acid is an option for organic producers but is extremely harsh on the bees. The use permit is for a 2-week application and must not be applied to hives with 6 frames of bees or less. Formic acid will cause brood mortality and the death of around 1,500 bees per day of treatment. If this product was used on the average strength hive that we would see at almond pollination it is anticipated the hives would come out of the orchard as extremely weak hives.

Thymol Thymol has constraints in its effectiveness due to minimum daily temperatures. The permit states that this product ‘must not be used if the maximum daily temperature is lower than 15oC or when colony activity is low’. The permit also states that ‘honey harvested from the treated hives may have its taste affected’. New Zealand beekeepers have also commented that thymol will ‘taint’ the honey leaving a lingering taste behind. The label also states ‘undiluted honey must not be sold....an acceptable dilution rate is 1:10’.

Tau-fluvalinate (Apistan) This product is a synthetic pyrethroid similar to Bayvarol, but it has a higher concentration of active ingredient (880mg tau-fluvalinate compared to 3.6mg flumethrin) and has a full treatment period of 6 to 8 weeks. The higher active ingredient concentration results in increased residue risk compared to Bayvarol. The label also states that honey must not be sold for human consumption until it is tested to ensure residues are below the MRL. This testing can be done by the honey packer, which could induce an extra cost.

Flumethrin (Bayvarol) Flumethrin is the same active ingredient that is in common household fly sprays. The full treatment time for Bayvarol is 6 weeks. Flumethrin, when used multiple times, does create a residue risk in beeswax. It should be noted that this is an accumulative effect, and there is a low risk with a single treatment. The PHA permit states that treatment should not occur when honey supers are present. On the contrary to that, there is a New Zealand permit that allows treatment with honey supers present, but this permit requires the honey to be tested for residues. There are many studies that have shown the residue risk of Bayvarol residues in honey is low. Anecdotally, New Zealand beekeepers have reported the use of Bayvarol on honey flows with no residues detected.

Resistance Recent genetic testing of the mites sampled from the Newcastle incursion has revealed no genetic markers for resistance to both pyrethroids and amitraz. This supports the results from the Pettis field tests undertaken that also demonstrated mite susceptibility to pyrethroid treatments.

Surveillance permit for Bayvarol for hive movement The NSW DPI is planning to conduct surveillance of hives that have been moved under the hive movement declaration. This will occur in the first instance on the hives moved to almond orchards. Advice from many experts around the world and locally has resulted in a use permit being submitted for Bayvarol. Bayvarol represents the most appropriate miticide that delivers the best efficacy with the lowest risk to beekeepers and residues. The recently approved permit (PER92639) allows for the short application of Bayvarol for surveillance (1-6 days) activities. This permit allows for treatment when honey supers are present, but honey must be tested before it is sold for human consumption. The intention for surveillance is to apply 4 Bayvarol strips for a maximum of 6 days to allow for any mites present to drop onto the sticky mats. The surveillance teams will then remove the mats and strips from the hives and send them to the lab for assessment.

What will happen if they detect mites in hives on almonds? If a mite is detected through surveillance, the infested hives will be euthanised. There is no intention to hold bees on almonds or establish zones around the detection. Any hives deemed to be at risk of mite transfer (ie. apiaries that are placed near infected hives on the same orchard) will be subject to further surveillance.