SA reports first case of Varroa mite

South Australia’s Department of Primary Industries and Regions (PIRSA) has reported the first detection of Varroa mite in the state, following a sighting of the pest in a managed beehive located in the Riverland.

The parasitic mite, which has a devastating effect on European honey bees, made its way into Australia in 2022, when it was detected in Newcastle, NSW. Since then, Varroa mite has been detected in Victoria, Queensland and the ACT. CSIRO’s Dr John Roberts has described the pests as “the greatest biological threat to Australia’s honey bee and pollination-dependent plant industries”.

PIRSA Apiary Unit surveillance teams initially identified a suspected detection of Varroa mite in a hive at Pooginook on 2 September. The affected hive is part of a consignment of hives brought into the state from Queensland to support the critical almond pollination season. The detection was made during routine surveillance activities which have been in place since the first discovery of the pest in NSW.

Samples were promptly submitted to the South Australian Research and Development Institute (SARDI), which has since confirmed the presence of Varroa. PIRSA is continuing to carry out further sampling across the consignment.

To support containment, sticky mats and acaricides are being deployed across all hives within the orchard. Acaracides is a highly effective treatment in the destruction of Varroa mite. A movement control has already been applied to ensure bees, hives and associated equipment cannot be moved from the site.

Additionally, a Biosecurity Notice has been issued to beekeepers, and a meeting of the South Australian Varroa Industry Advisory Committee (SAVIAC) has been held.

Since 2023, PIRSA has implemented strict biosecurity conditions for hives entering South Australia from Varroa-positive states, including: detailed movement history and compliance checks; surveillance protocols; and a requirement that hives must not have been within 25 km of a known Varroa outbreak.

The hives from Queensland met these conditions and they were not sourced from the vicinity of a known outbreak, PIRSA said.

PIRSA’s Biosecurity Apiary Unit and Varroa Program Team, including the Varroa Development Officers (VDOs), are working closely with affected beekeepers to define the extent of the detection, slow the spread of Varroa mite and help guide management practices.

Further information is available at https://pir.sa.gov.au/biosecurity/animal_health/animal_species/bees/varroa_mite.

Image credit: iStock.com/Bee-individual