About varroa mite
Varroa mite are small, oval-shaped reddish-brown mites that parasitise adult honey bees and the brood. The mites weaken and kill honey bee colonies and can also transmit honey bee viruses.
Varroa can quickly spread when uninfected bees contact infected bees, hive products, plant material, hives and contaminated beekeeping equipment.
It is estimated that establishment of Varroa in Australia could result in losses of over $70 million a year.
There are strict quarantine requirements in place to protect the Australian honey bee industry.
What do I look for?
Varroa mites are oval-shaped, around 1.1mm long and 1.5mm wide (slightly larger than a poppy seed). Mites are easily identifiable to the naked eye and are a reddish-brown colour.
Under the Australian Honey Bee Industry Biosecurity Code of Practice, all beekeepers are required to check at least one hive per apiary for external parasites, twice per year, i.e. in autumn and spring. Varroa are very difficult to detect during regular brood inspections, therefore beekeepers are required to use one of the following mite surveillance methods:
- Sugar shaking (factsheet, video)
- Alcohol washing (factsheet, video)
- Drone uncapping (factsheet, video)
Sugar shaking in non-destructive to bees, while alcohol washing and drone uncapping is fatal to the tested bees. Sugar shake kits can be bought from beekeeping supply stores or made at home.
How does varroa mite survive and spread?
Inside a colony, varroa mites reproduce on honey bee brood (larvae and pupae). When a parasitised larva or pupae becomes an adult, they can carry 1-3 mature female mites. These mites will disperse to other adult bees before seeking out a larva in the brood to reproduce on. The reproductive rate of varroa mites increases with the availability of drone brood.
Varroa spreads to uninfected bees through contact with infected bees, hive products, plant material, hives and contaminated beekeeping equipment. This can occur naturally when bees are foraging, swarming, drifting between hives, or robbing weaker colonies, as well as during standard beekeeping practices.
If varroa mites were to establish in eastern Australia they could potentially arrive in Western Australia, although the geographic isolation of our state is an advantage. With the help of volunteer beekeepers, DPIRD operates a network of sentinel beehives at WA ports to detect new incursions of exotic bees and bee pests.
Visit the Plant Health Australia website to learn more about the National Bee Pest Surveillance Program.
Local beekeepers should regularly check hives for mites and report anything unusual to the Exotic Plant Pest Hotline 1800 084 881.
Status in Western Australia
Varroa destructor (Anderson & Trueman, 2000 ) and Varroa jacobsoni (Oudemans, 1904) are absent from Western Australia and both are quarantine pests.
Western Australia's Pest Freedom for varroa mite is supported by general and specific surveillance, and specific import requirements to prevent its entry.
A person who finds or suspects the presence of varroa mite must report it to DPIRD.
Report signs of varroa mite
Early detection and eradication will help protect Western Australian horticultural industries. Please make a report on MyPestGuide or contact the Pest and Disease Information Service (PaDIS) to report this pest.