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Fungal diseases get less than they deserve.

They are a major cause of and economic loss for food producers. Huge proportions of like wheat and potato are lost every year to disease. Likewise, fungal infections threaten honey production in honeybees by killing huge numbers of the animal, and likely contributes to (CCD).

Human activity often determines a fungus will spread, because we transport crops and livestock long distances and cram of a together. The plight of the honeybee is a perfect example. In the first episode of the Netflix series “,” honeybees throughout the US are transported en masse every spring to California, where they pollinate . Bringing so many bees together makes the spread of pathogens and disease unavoidable, and beekeepers around the country as a result.

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Fungi can infect hives that are already , and cause disease in . It is possible to treat hives with fungicidal chemicals, but pathogens are . In addition, chemical fungicides can often kill helpful microbes because they are rather indiscriminate, and may even harm bees directly. Pesticides are as a to CCD, although there is much and controversy on this point. Regardless, we desperately need alternatives to chemical pesticides.

In work to the pre-print site bioRxiv, scientists show how Bombella apis, a bacterium that commonly resides in bee hives, can actively help to protect bees against fungal infection. Rather than spray any synthetic chemicals into a hive, these bacteria appear to secrete their own personal anti-fungals.

Biological control — or — is the use of living organisms to protect plants or animals against pests and pathogens. Biocontrol to protect crop plants is a well-established idea. The from India to Mauritius in the 18th century is an early example, as the birds kept down locust populations, protecting crops. Some suggest that biocontrol was also used as early as 4000 years ago in to hunt scavenging rats, and in were used to control citrus pest populations.

In the modern era, ecologist noted in Silent Spring that Bacillus to kill flour moth larvae in Germany in 1911, and to control populations of the Japanese beetle in the Eastern US in the . Bacteria are integral to many newly developed biocontrol technologies, and research shows that we may be able to develop bacterial biocontrol to help honeybees resist fungal disease.

is a bacterium found in honeybee hives, especially in nectar and royal jelly stores, and in the little rooms called where larvae live. Scientists at really , and they are working hard to understand the role of the of the European honeybee. Earlier work that the presence of B. apis is correlated with increased resistance to the that have devastated honeybee hives all around the world. This suggests that the bacterium has a protective effect. 

In , a team led by showed that B. apis can inhibit the growth of two common fungal pathogens, Beauveria bassiana that infects 70 percent of all known insect species and is actually used as a like mites, and the more relevant pathogen Aspergillus flavus that targets honeybee brood and . When B. apis was grown together with either fungus — what microbiologists call co-culturing — the fungi were severely impaired in the ability to form spores. The authors suggest that this not only reduces the occurrence of infection and disease among bees in the hive, but it may also reduce the likelihood that bees who go out foraging could spread the infection to another hive or to other insects.

The protection offered by B. apis to honeybees makes it a solid biocontrol candidate. The population of B. apis within a hive can be increased by delivering more bacterial cells within a sugar solution that bees feed on. Sugar/syrup solutions are used routinely by beekeepers who struggle to gather enough nectar during winter.

In fact, live bacteria are not even needed for this protective effect, according to the study. Molecules the bacterium secretes can be collected and on their own display the same anti-fungal effect observed during co-culture experiments. This is interesting from the perspective of understanding B. apis physiology, as it confirms that the anti-fungal molecules are secreted by bacterial cells. The molecules are likely , a known class of antifungals involved in other symbiotic relationships that confer pest resistance. It’s possible that these secreted molecules can be applied directly to the hive in concentrated form, to help when a hive is under threat.

These findings complement a recent study from the where researchers to drastically improve bee defenses against the virus DWV, which causes deformed wings and an inability to fly, and Varroa mites, both of which are heavily implicated in colony collapse. The for devastating losses in the US honeybee population. The engineered S. alvi bacteria were sprayed into a hive in a sugar solution, so the bees took the new bacterial species into their guts. According to that study, the bacteria induces a bee immune response that kills mites and blocks viral infection. The result was a huge increase in survival rate in mite-infested bees, and an impressive reduction in deaths caused by the virus.

The Texas study shows that we can use modern biotechnology to enhance the innate protective effect of symbiotic bacteria. But the Indiana investigation underlines that there are still some interactions between naturally occurring microbes that we do not yet fully understand, but which impact how we should manage our food ecosystems. We now know that B. apis has a clear beneficial effect for honeybees, so anti-microbial compounds added to a hive to fight infection to avoid damaging the beneficial B. apis population.

Biocontrol is not expected to replace chemical fungicides entirely, but experts believe it can be part of an approach to , along with promoting biodiversity and reducing habitat loss for the animals and microbes that keep ecosystems functioning. We will lose a lot more than honey if colonies continue to collapse.

This article was originally published by . We have republished it with permission.