Varroa incursion – impact on native bees

If you live in a Varroa mite emergency zone, do you need to move your stingless bee hives away?

In the July Issue of the Cross-Pollinator, we published an article on the potential impacts of the incursion of the Varroa mite, a pest of honey bees. Among the risks to native bees, we identified the danger of pesticide loaded bait stations (page 6).

The bait stations will generally be laid out in a 3 km grid. The exact locations will not be made public. The stations are expected to remain in place for 12 months.

Bait stations will consist of a sugar syrup attractant with the insecticide fipronil added. The bait stations will contain only sugar solution until they are observed being visited by honey bees. At that time, syrup is replaced with fipronil laced syrup which will be removed by the end of the day. The bait will be monitored for that time to ensure non-target animals such as native bees, will not be exposed to the chemical.

With managed honey bee hives already euthanized in the red zones, the bait stations will depopulate any wild European honey bee populations. It is expected that the insecticide in the dead honey bee colonies will remain active for at least 26 months. This persistent poisoning action increases the likelihood of a honey bee eradication attempt being successful, as the colonies that are not killed in the first round of poisoning may be poisoned by robbing honey containing fipronil from a previously poisoned hive.
There remains a risk that stingless bee colonies will be attracted to the honey or other resources in a dead feral bee colony, collect the resource, transport back to their nest and poison the colony. Although this risk would seem to be low, many beekeepers may decide to play it safe and remove their hives.

ANBA recommends that if you keep colonies of stingless bees within a red zone, that you make plans to move those hives away soon. Expect to have to keep your stingless bee hives out of the red zones for up to three years.

Citation: Tim Heard, James Cook, Amy-Marie Gilpin, Ros Gloag, Dean Haley, Mark Hall, Katja Hogendoorn, Shahid Mehmood, Ben Oldroyd and Tobias Smith. (2022) Varroa incursion – what does it mean for native bees?. The Cross-Pollinator, Issue 34, pp 3 – 7, July 2022.


NSW DPI update, 23 Sep 2022, on the use of bait stations to eradicate feral honey bees in the Varroa eradication zones

NSW Department of Primary Industries (NSW DPI) is continuing efforts in response to the Varroa mite incursion, confirmed as Varroa destructor, found in sentinel hives at the Port of Newcastle.
It is now day 93 since Varroa mite was detected in NSW. The NSW DPI response team has worked to contain, trace and eradicate the bee parasitic mite from zones in NSW.

Beekeepers and the apiary industry have been critical in helping us work towards eradicating Varroa mite. The apiary industry and NSW DPI, Local Land Services, Rural Fire Service, National Parks and Wildlife Service and the Environmental Protection Agency have all partnered together on the national response.
There have been 100 infected premises (or sites) with confirmed Varroa mite in the contained hot spot areas of NSW – in the Hunter, Nana Glen and Narrabri areas.

A 10km radius red eradication zone, and 25 km radius purple surveillance zone are in place around each infected premises, with strict restrictions on management of beehives.
Hives at each infected premises were euthanised and contact tracing was completed to understand how hives had been moved prior to the detection of Varroa mite.

NSW DPI undertook intensive surveillance in surrounding purple notification and yellow surveillance emergency zones – developing a level of confidence that permitted merging the yellow surveillance zone into the rest of NSW (blue general emergency zone).

The response teams are currently working through the red eradication zones, euthanising all European honey-bee managed hives. All hives within red eradication zones are being euthanised to achieve the aim of full eradication of Varroa mite. Euthanising uninfected hives means we are removing any chance of Varroa mite surviving and spreading undetected through potential fu-ture hosts, where incubation of the parasite may be happening.

The next step in each red eradication zone is to destroy any wild European honeybee populations. This will involve using bait stations, which periodically will (not 24/7) include an insecticide to euthanise the bees. More detail on this part of the response will be made available once plans are finalised.
For more information on the NSW DPI Varroa mite emergency response, including the location of the red zones, visit www.dpi.nsw.gov.au/varroa

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