THE development of a pesticide to fight the Varroa Destructor Mite could well bring the end to the mite’s intrusion into the country. Australian grower-owned research corporation Hort Innovation has recently announced it will be working alongside the University of Sydney to develop a world-first hormone-based pesticide that is safe for honeybees but fatal to Varroa mite. As part of the $1.2 million initiative the scientists aim to create molecules that selectively bind to and interfere with the hormone receptors of Varroa mite as well as the small hive beetle.
This will target reproduction, development and behavioural receptors that are absent from vertebrates, making it theoretically safe for other animals in the environment. Until recently Australia was the last known inhabited continent in the world that was not permeated by Varroa mite.
Varroa mites cause weakness in honeybee colonies by feeding on larvae and pupae. They can also live on adult honeybees, transmitting viruses. Chemical control methods exist but research shows Varroa mites globally are building up tolerances and some treatments aren’t suitable for the Australian environment. After the mite was discovered in Newcastle in late June containment zones were established and the destruction of beehives within affected areas began.
Approximately 1800 beehives have been destroyed with the number increasing drastically with every new detection. Continued discoveries of the mite in New South Wales have meant growing containment zones and further concern of a transmission interstate. At the beginning of this week there had been 43 detections of the mite. Biosecurity Tasmania says it remains vigilant to any potential risks or carriers of the mite into the state.
“Biosecurity Tasmania staff have increased vigilance for bee equipment and bee-related products entering Tasmania and for container and shipping movements from NSW,” a Biosecurity spokesperson said. “A biosecurity alert industry notice has been sent to registered beekeepers notifying them of the situation in NSW and actions taken in Tasmania. “The Department of Natural Resources and Environment Tasmania will continue to monitor the situation and work with mainland counterparts to understand any risk to pollination in agriculture if the mite cannot be eradicated. “Tasmania has strong honey and agriculture sectors so has robust biosecurity rules in place to protect the state from unwanted pests and diseases.
“Queen bees may be imported with appropriate protocols, health certification and inspection on arrival, however, Biosecurity Tasmania will review conditions relating to queen bee imports from NSW and other states that may trans-ship queens. “Tasmanian beekeepers should remain vigilant in closely monitoring their colonies for any signs of the varroa mite.”
Hobart-based beekeeper Peter Norris experienced the Varroa outbreak in the UK in the 1990s and said the outbreak may come quite differently. “Historically it takes a couple of years to build up numbers to the level it becomes detectable,” Mr Norris said. “It may be different in Australia where the broods don’t shut down. “The mites need broods to multiply and that may be why it’s been slow to detect.”
He encouraged Tasmanian beekeepers to restrict hive and queen movements to and from the mainland and encouraged the internal breeding of queen bees. “It may not be commercially viable to raise queens in Tasmania because of our shorter seasons but it is viable to raise them for your own operation. “Especially if you’re only running your own hives, 10 or 15 bees over a couple of years is not hard work. It’s not hard to learn and there is a community out there to learn from.”
Used apiary equipment, packaged bees and comb honey are already prohibited from entry to Tasmania due to the risk of small hive beetle which is present in most mainland areas but not present in Tasmania. Biosecurity Tasmania routinely tests sentinel hives and catch boxes but will conduct additional surveillance for Varroa mite on sentinel hives and guard hives maintained as part of the National Bee Pest Surveillance Program at Burnie, Devonport, Bell Bay and Hobart.
Currently there is no movement of queen bees from NSW as part of the restrictions that have been put in place. An $18 million compensation support package was recently announced for registered beekeepers affected by the Varroa mite outbreak by the New South Wales and Federal governments.
Anything suspicious should be reported to Biosecurity Tasmania on 6165 3777.