Varroa mite detection in Townsville
Biosecurity Queensland officers working as part of the National Varroa Mite Eradication Program (NVMEP) are responding to a new incursion of varroa mite (Varroa jacobsoni) found on a nest of feral Asian honey bees at the Port of Townsville on 28 April 2020.
Genetic testing indicates this Asian honey bee detection is not related to any previous incidents in Australia, including those in Cairns, or the subject of the current national eradication program underway in Townsville.
A prevention-and-control and a surveillance program under the Biosecurity Act 2014 remain in place following the detection of varroa mites on a colony of feral Asian honey bee at the Port of Townsville in May 2019.
The NVMEP is funded through a partnership between industry and government and commenced following detection of an Asian honey bee nest infested with varroa mite at the port in June 2016. Response activity implemented by Biosecurity Queensland since that time has wiped out that incursion.
The NVMEP is being led by Biosecurity Queensland and will continue until 30 April 2021.
The movement of live bees is restricted within the Townsville area. Refer to the Prevention and Control Program (PDF, 967.1KB) and the map of the affected area (PDF, 365.2KB), or read the full surveillance program (PDF, 1.6MB).
Townsville residents are urged to report sightings of suspect Asian honey bees and nests to 13 25 23.
Surveillance programs under the Biosecurity Act 2014 provide for specific measures to confirm the presence or absence or to monitor levels of pests, diseases and weeds (or their known carriers), or to monitor compliance with the legislation in relation to such biosecurity risks.
A prevention and control program allows an authorised officer entry to a place to undertake measures to destroy or eradicate the target pest.
The Prevention and Control Program for varroa mites imposes obligations on an occupier of a place where managed hives are kept. Anyone wanting to move live bees, bee hives, or any other item that may contain live bees out of the Townsville City Council area will need to notify Biosecurity Queensland by email at least 7 days prior to the intended movement.
Anyone moving live bees through the Townsville City Council area, that have originated outside the area, must ensure the bees are packaged and sealed in a manner that prevents the escape of live bees while they transit through the area.
Beekeepers who conduct their own surveillance on managed hives (sugar shaking, drone uncapping or alcohol washing) should use the managed hive surveillance form (PDF, 178.0KB) to record details of the surveillance conducted, results obtained and details of any samples collected. The form should be returned to BQ along with any samples requiring laboratory analysis, or can be emailed to BQ to advise of test results if there is not a sample requiring analysis.
Staff from the Townsville National Varroa Mite Eradication Program (NVMEP) have been collecting samples of rainbow bee-eater pellets that can be analysed to determine the presence or absence of Asian honey bees within the feeding range of the rainbow bee-eaters. Bee keepers or members of the public that notice evening roosting sites for the rainbow bee-eater are encouraged to report these sites to Biosecurity Queensland by calling 13 25 23. Please ensure an accurate location is recorded and provide a return contact number to assist NVMEP staff in locating these sites.
Beekeepers are encouraged to inspect their hives regularly for signs of varroa mites and other exotic pests, and to report any suspected symptoms to Biosecurity Queensland on 13 25 23.
Additional information on how to prepare for and reduce the risk of exotic and established pests that could have significant impacts on honey bees is available in the bee industry biosecurity plan.
Honey bees and varroa mites
The varroa mite (Varroa destructor and Varroa jacobsoni) is a well-adapted parasite of the Asian honey bee (AHB). AHB have evolved with varroa and so are able to tolerate infestations, however the mite poses a serious risk to Australia’s European honey bee (EHB) population should it spread.
Varroa jacobsoni is currently being eradicated from Australia. No established infestation of Varroa destructor has been recorded in Australia.
Entry of varroa into Australia would likely be from nests or swarms of EHB or AHB arriving via a vessel at an Australian seaport. Entry to mainland Australia could have a significant impact on honey production and pollination services provided by EHB.
Varroa appearance and biology
The adult female varroa mite is reddish-brown, flattened and oval-shaped - the size of a pinhead (1.0-1.7 mm long x 1.5-1.99 mm wide). They may be seen on the thorax or nestled into the abdominal folds of adult bees. In AHB, varroa only reproduce in the drone (male) brood as increased grooming detects and removes varroa from worker bees and worker brood cells.
On European honey bees (EHB) the varroa mite can reproduce on all types of brood as EHB groom less intensively than AHB. Varroa mites are obligate parasites of honey bees, meaning they cannot survive long away from their honey bee hosts.
Female varroa mites enter a brood cell shortly before it is capped, feed on the pupating larvae and from the third day, lay 1 egg per day.. The adults and newly hatched mite nymphs feed on the bee pupae. As nymphs mature, they mate and the males die. The females leave the cell with the emerging bee, attach themselves to and feed on bees and are carried by the bees to other cells or even other hives.
Information about bee biosecurity and photos that will help you identify varroa mite, are available on the Bee Aware website.
Effect of varroa on European honey bees
Varroa mites usually take some time before being noticed within a hive, sometimes up to two years. Hives with low levels of infestation display few symptoms. Symptoms of hives with medium to high levels of infestation may include:
- spotted-brood pattern with infested brood being removed from their cells
- weak bees that do not live long
- virus infections that would otherwise cause little harm
- stunted wings, missing legs or other deformities in severely attacked colonies
Without chemical treatment, the vitality of the colony declines resulting in colony death within one to three years.
What can be done to prevent varroa mite?
The Department of Agriculture monitors incoming cargo ships entering Australian ports for bees and other unwanted insect pests.
Any swarm of bees found at international port locations, should be reported to the Australian Government's Department of Agriculture on 1800 798 636 or Biosecurity Queensland on 13 25 23 for identification and appropriate capture procedures.
Under the National Pest Bee Surveillance Program in Queensland, sentinel bee hives are placed near ports and monitored regularly for the presence of mites. Under the program, traps are established and regularly monitored to attract honey bees that might have left ships undetected. Any bees detected on wharves are killed and sampled to ensure they are not carrying varroa or other exotic bee pests.
Beekeepers also participate in the National Bee Pest Surveillance Program via their own mite surveillance. This is managed by Biosecurity Queensland in collaboration with the Queensland Beekeeper's Association and regional bee clubs. Samples are collected each year from hives throughout Queensland and tested for exotic mites.
Early detection of varroa mites is essential to make containment of mite incursions possible. All beekeepers should monitor their hives and report unexpected hive deaths, deformed bees, bees with parasites, unexplained poor brood patterns and dead brood to Biosecurity Queensland.
Any colony of bees arriving in Australia must be regarded as a serious threat. Beekeepers and the general public are requested to be aware of bees entering an international sea port or airport and the risk they could pose to the commercial honey bee in Australia.
Ports and surrounding areas are of special interest. Any swarm found at port locations should be reported to the Australian Government's Department of Agriculture on 1800 798 636 or Biosecurity Queensland on 13 25 23 for identification and appropriate capture procedures.