Breakthrough in the fight against dangerous bee parasites
For years, experts have been warning that the bee population is at risk. The Varroa mite is one of the most dangerous enemies of bees worldwide: it can completely exterminate a bee colony within one to three years. German researchers have now discovered a drug against this parasite.
Pesticides and parasites endanger bees
Scientists and beekeepers have been observing massive bee deaths for years. This has fatal consequences for humans, because insects play an essential role in agriculture because they pollinate the flowers of useful plants and thus have a direct impact on the harvest. The cause of bee death is, among other things, certain pesticides. Two insecticides in particular harm queen bees, as an international team of scientists has found out. But a parasite that has been brought in also affects the bees: the Varroa mite. German researchers have now discovered a drug against the dangerous bee pest.
Varroa mite can completely exterminate bee colonies
The Varroa mite is one of the most dangerous enemies of bees worldwide: it can completely exterminate a bee colony within one to three years.
The parasite, originally from Asia, was introduced to Europe about 40 years ago via imported bees.
So far, beekeepers have had to treat hives with aggressive organic acids or chemically manufactured mites, which cause resistance problems and residues.
Researchers at the University of Hohenheim in Stuttgart have now succeeded for the first time in developing a potential drug that can free infected beehives from the dreaded Varroa mite by feeding them with little effort.
The promising substance is readily available lithium chloride. After more than 25 years of research, a new active ingredient is available for the first time in the global fight against the Varroa mite, which acts completely differently than previous means.
Discussions are already underway with companies with the aim of product development and approval. The scientists published their first results in the scientific reports.
Active ingredient discovered against dangerous parasites
A cheap, easy-to-use active ingredient against the dangerous mite, which according to the current state of knowledge of the researchers has no dangerous side effects for bees, beekeepers or consumers and is abundant in nature: This is what the results of the research project promise.
With lithium chloride, the research team has found an active ingredient for such a drug that is easy to obtain and administer. So far, there is also no evidence of a deposit in honey.
“Lithium chloride can be fed to bees dissolved in sugar water. In our experiments, small amounts of the saline solution were enough to kill the mites on the bees within a few days - without side effects for the bees, ”explained Dr. Peter Rosenkranz, head of the State Institute for Apiculture, in a message.
More tests needed
The availability also speaks for the active ingredient: the global stocks of the light metal lithium are estimated at over 40 million tons, as lithium chloride salt it is found in brine, salt lakes and healing springs, and in some cases in astonishingly high concentration.
The salt, which is easily soluble in water, is used, among other things, as a drying agent and deicer solution. It has been used as an antidepressant in human medicine since the mid-20th century.
Before the active substance can be launched on the market as a medication for bees, further tests are still necessary to determine the best dosage and to rule out side effects for bees and users and the risk of residues.
One is currently in talks with companies that want to continue this development.
Discovered by accident
The team around Dr. Rosary takes a much more complex approach:
"Together with the biotechnology startup SiTOOLs Biotech, we tried to specifically switch off certain genes using the RNA interference method, or RNAi method for short. This procedure received the Nobel Prize in Medicine in 2006 and has since been used worldwide to combat diseases. ”
The idea: RNA fragments are fed to the bee and then taken up by the Varroa mite while sucking blood. In the mite, the fragments specifically switch off the parasite's vital genes.
“These RNA fragments are harmless to bees because they only interact with varroa-specific genes. With the Varroa mite, however, central metabolic processes are disturbed and the mite is finally killed, ”says Dr. Rosary.
The approach is successful, but then the scientists noticed something strange: "In control experiments, we were also able to kill the mites with unspecific fragments of RNA, which should not find a genetic target in either the bees or the mites," reports Dr. Rosary.
"The mites did not get anything in our" gene mixture "while the bees were not harmed."
It took almost two years for lithium chloride to be found as the secret weapon against the parasite. The researchers had used the chemical as an aid in the isolation of the RNA fragments, which are used to switch off the genes in the bee body.
A discovery with serious consequences, because the RNAi method would work, but would be expensive and time-consuming. "Lithium chloride, on the other hand, is easy to manufacture, relatively inexpensive, and easy to store." (Ad)