Currently Australia has a high concentration of feral honey bee colonies – that is unmanaged hives in the wild—and these helpful insects pollinate many crops. But as overseas experience has shown, if there should be an incursion of the honey bee parasite Varroa destructor in Australia, this invader would kill off unmanaged hives, with the loss of these valuable pollination services.
Since Varroa destructor mites are found in the rest of the world, including New Zealand and our northern neighbours, Australia has to be prepared.
That’s why Plant Health Australia (PHA) has been working on a suite of honey bee biosecurity projects. Some are efforts to prevent an incursion, while others aim to assist our industries, including plant producers, to prepare for the changes that Varroa destructor is likely to bring.
The latest project is a series of videos available on YouTube and the BeeAware website, to explain the threat posed by Varroa destructor to our honey bees, how beekeepers can best protect their apiaries from pests, and the likely implications for plant producers.
According to Dr Jenny Shanks from PHA, there will be two main changes in the event that Varroa establishes.
“The first is that many crop producers will find they need to use managed hives to pollinate crops for best quality and yield. This applies to many horticultural crops including almonds, cherries, strawberries, apples, pears, avocados, summerfruit, melons, some vegetables and plums,” Jenny said.
“The second change is that beekeepers will need to change their beekeeping practices. They will need to visit hives more often to check for mites and to control them, which will put up the cost of pollination services.”
Pollination using managed hives is a complex business.
“The beekeeper and the producer need to consider many factors,” Jenny said.
“When hives are brought in, the number of boxes, their placement, the amount of brood, and whether sugar syrup is added to encourage more pollen collection, are all factors that will affect the pollination rate.”
Jenny urges beekeepers and growers alike to seek more information from the new videos or the pollination section of the BeeAware website, to achieve best results.
The health of the bees also has a major impact. Jenny emphasises that beekeepers must follow good biosecurity practices so that hives function well for producers.
“Clearly if hives are diseased or half empty, a grower is not getting the full benefit from that hive. Growers who hire hives are entitled to inspect them, to make sure they’re getting their money’s worth.”
Recently, PHA developed the Australian Honey Bee Industry Biosecurity Code of Practice in consultation with beekeepers and governments to provide a framework for best-practice biosecurity measures.
Some sections of the Code are already mandatory under existing state and territory legislations. Some parts of the Code apply to all beekeepers; others apply only to beekeepers with 50 or more hives.
All of this will become crucial should Varroa destructor establish here, but producers may find that they benefit from the services of managed hives now. Even if growers are getting good crop yields from feral bees and native pollinators, adding managed hives can often improve pollination rates further and therefore crop yield.
Depending on the crop, it can also produce larger or better quality fruit, and because pollination is more synchronised, it can result in more defined harvest period.
All of the honey bee work that PHA carries out is funded by partnerships between the Australian Government, state and territory governments, the Australian Honey Bee Industry Council and plant production industries through Hort Innovation.
See the honey bee biosecurity short videos at beeaware.org.au/videos
NOTE: Another species of Varroa mite, Varroa jacobsoni was discovered in Townsville in 2016 sparking a national eradication program to prevent it establishing. This mite species is a parasite of Asian honey bees and so poses less threat to European honey bees.