Varroa mite detection in Townsville
Varroa mites (Varroa jacobsoni) have been detected on Asian honey bees in Townsville.
Biosecurity Queensland is undertaking surveillance activities in the Townsville area in response to the detection.
To stop the spread of varroa mites, a Prevention and Control Program is now in place for the Townsville City Council local government area.
The Prevention and Control Program 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 emailing email@example.com 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.
Biosecurity Queensland is asking the public to report Asian honey bees and feral bee nests on 13 25 23.
Beekeepers who conduct their own surveillance on managed hives (sugar shaking, drone uncapping or alcohol washing) should use the managed hive surveillance form 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.
Townsville bird watching groups have also been collecting samples of Rainbow bee-eater pellet that can be analysed to determine the presence or absence of Asian honey bees within the feeding range of the Rainbow bee-eaters. Bird watching groups collecting samples should use the rainbow bee-eater sample pellet collection form to record details of samples collected. These samples are then given to Biosecurity Queensland who will analyse the samples in the laboratory.
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.
Information about bee biosecurity and photos that will help you identify the varroa mite, are available on the Bee Aware website.
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.
Asian honey bee left, European honey bee right with Varroa mite present
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 live with it. Varroa were mainly found in the northern regions of Asia before shifting hosts from AHB to European honey bees (EHB) when they were introduced to North East Asia.
Today the Varroa destructor mite is responsible for the collapse and death of EHB colonies wherever it is present (if untreated) around the world.
Varroa jacobsoni is currently being eradicated from Australia, however Varroa destructor is not present in Australia.
Entry into Australia would likely be from nests or swarms of EHB or AHB arriving via a vessel at an Australian seaport. Once it enters the mainland of Australia, Varroa destructor would be capable of spreading easily throughout the continent, and so it is considered our greatest pest threat to the honey bee industry. This would 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 can only reproduce in the drone (male) brood as bees can detect, groom and remove 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 do not show the grooming behaviour seen in AHB. Varroa mites are obligate parasites of honey bees, meaning they do not survive for long away from their specific host.
One or two female varroa mites enter a brood cell before it is capped (closed) and lay 5-6 eggs each. The newly hatched nymph mites feed on the bee larvae. Once nymphs mature, they mate and the male dies. The females attach themselves to adult bees and feed off their haemolymph (blood).
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 bees in the colony declines until all are dead within one to three years.
What can be done to prevent varroa mite?
The Australian Government's Department of Agriculture and Water Resources 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 and Water Resources on 1800 803 006 or Biosecurity Queensland on 13 25 23 for identification and correct capture procedures.
Under the National Pest Bee Surveillance Program in Queensland, sentinel bee hives are placed near ports and monitored for the presence of mites regularly. Under the program, bait hives and traps are established to attract honey bees that might have left ships undetected. These are routinely monitored and analysed. Any bees detected on wharves are killed and sampled to ensure they are not carrying varroa or other unwanted 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 the mite possible. All beekeepers should monitor their hives and must report unexpected hive deaths, deformed bees or bees with parasites on them, poor brood patterns and dead brood to Biosecurity Queensland.
Bee pupae with a varroa mite. Reproduced with permission from Dr Denis Anderson, CSIRO.
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 and Water Resources on 1800 803 006 or Biosecurity Queensland on 13 25 23 for identification and correct capture procedures.