Researchers at the University of Sydney found that the connection between sucking tissue varroa The mite and virulence of the honeybee virus were most likely misunderstood.
The study casts doubt on the long-held belief that parasitic varroa tick – a tick that absorbs the tissues of honeybees – transmits the virus of the deformed wing of honeybees and at the same time changes the virus, making it more virulent and deadly.
A study published today at Proceedings of the Royal Society B: Biological Sciences concludes that this belief is wrong.
“The prevailing wisdom is that the tick selects very virulent strains of the virus,” said Professor Madeleine Beekman of the School of Life and Environmental Sciences at the University of Sydney.
“For this reason, the virus is currently known as a very dangerous virus, and Australian beekeepers insist that the virus should not enter the country. In fact, there is legislation prohibiting the import of any bee products that may contain a virus. ” But our work shows that the virus is likely to be an innocent bystander. ”
Australia is the only country in the world that remains free from varroa mite. This makes Australian honey and wax valuable, as there are no chemical residues used to kill the parasites.
“Australia is the last country on the planet to produce absolutely pure honey,” says Professor Beekman. "But, probably, the tick will arrive in Australia on shipping containers, so we need to understand how the tick and the virus interact."
Prof. Beekman and her team at the Social Insect Conduct and Genetics Laboratory introduced honeybee pupae with a high level of deformed wing virus that is carried by a tick to check whether the virus was highly virulent due to changes in the transmission path that occurred through varroa mite.
In the absence of a tick, the virus must be transmitted to other bees through direct interaction between an infected and non-infected bee. varroa makes the transfer, biting one bee and then another.
The team found the transfer route used varroa The tick virus selects viruses that are much more virulent than the virus of a deformed wing, for example, the Sakbruda virus and the Black Queen's cellular virus. These viruses usually suppress the Virus Deformed Wing. The destruction of the Sacbrood and Black Queencell virus leaves only Deformed Wing Virus, which does not kill the bees.
"Our work therefore changes our understanding of the effect varroa “The virus of the deformed wing and the health of bee colonies,” said Professor Beekman.
“This means that we do not need to be afraid of the virus. Instead, we need to focus on eliminating the tick and reducing its number. ”
The results will also affect how Australian beekeepers can prepare for the arrival. varroa,
“Many countries are actively choosing populations of honey bees that can tolerate varroa tick without treatment. Australian beekeepers would like to import sperm from such populations in order to start preparing their honey bees by the time the tick appears, ”said Professor Bickman.
“But the importation of sperm is currently banned due to the threat of a deformed wing virus, which may be present in bee sperm. Perhaps beekeepers can now convince the authorities that bee sperm is safe. ”
“If we want to protect the bees, now there’s no point in trying to fight the virus,” said Professor Bickman. "Instead, you need to focus again on keeping the number of ticks in honey bee colonies low."
Bee disease riddle
Live transmission by injection affects the competition among RNA viruses in bees, Proceedings of the Royal Society B, rspb.royalsocietypublishing.or… .1098 / rspb.2018.2452