„With increasing usage of monocrops in some regions, beekeepers have to choose a site even more carefully that offers diverse nutrition resources to keep their bee colonies healthy. Good hygiene control at the site and strong bee colonies with a healthy queen can help to fight chalkbrood.”
Peter Trodtfeld, bee expert and beekeeper at the Bayer Bee Care Center
Chalkbrood, a fungal disease that can infect honey bee larvae, has become more prevalent in recent years in Australia. A LaTrobe University research team based in Melbourne has seen that the fungal pathogen remains active even during hot, dry weather. This suggests the Australian strain of chalkbrood is unique from those found in North America and Europe where the fungal disease is typically found in late spring, during cool, damp conditions, when the temperatures in the brood combs might sink below 35 degree Celsius. Other known factors that trigger the disease are a high level of humidity, colony incest as well as poor bee hygiene behaviors.
Normally, as the weather gets warmer, the conditions are suboptimal for the fungus to grow and it becomes dormant. Still, it remains infectious for many years and may sprout again, once the conditions are optimal. Now, the researchers want to find out why chalkbrood has become more severe in Australia. PhD candidate Jody Gerdts explains that there is a seasonal “lack of pattern” to the newest strain of chalkbrood in Australia.
The fungal spores envelop the honey bee larvae, leading to mummification that is either white or gray-black in color.
Chalkbrood disease was first detected in Australia in the early 1990s. It is known that it is caused by the fungus Ascophaera apis. So far, experts suggest that preventive and acute beekeeping measures seem to be the best defense against the disease. They should also supply colonies a site with high quality nutrition resources to keep them healthy.
Gerdts and her research colleagues are also developing another approach to fighting chalkbrood: they hope to breed “hygienic” honey bees that will clean their own hive, removing infected larvae. Gerdts notes that hygienic bees in North America have been shown to reduce the degree of chalkbrood infection as well as that of other bee fungi.
Learn more about the research at LaTrobe University here.
Also The Australian Government provides detailed information about chalkbrood disease.
Find more information on chalkbrood and other honey bee diseases here or take a look at what one US beekeeper has done in order to breed hygienic bees.