The finding opens up a new strand of research into the relationship between insects and fungi, and the impact on colony health. Some of the bees can survive without consuming the fungus; this, however, is a rare event.
The finding was an accident. The research team involved were looking into the growth and development of the Brazilian stingless bee (Scaptotrigona depilis) under laboratory conditions. It was observed that a fungus grew close to the queen and became out of control, killing the bee.
Initially it was thought the fungus was an invasive pathogen. However, when researchers studied bee colonies they found the white, furry-like fungus to be present in smaller quantities. This indicated that in the hive — the natural environment — the behaviour of bees kept the fungus under control. The fungus was found to be associated with the material the bees collected to make brood cells. This material is recycled between nests, creating a reproducible system.
Further study showed the fungus was present for a reason: it provided a food source for bee larvae. The levels of the fungus increased and then dropped as the bees consumed it.
This led to studies back in the laboratory where bee larva were raised with and without the fungus. Those larvae raised with the fungus had an 8 out 10 survival rates. Whereas, those larvae raised without the fungus had only a 1 in 10 survival rate.
The new research does pose an ecological problem. The widespread use of fungicides for agricultural spoilage control can inadvertently harm insects like the stingless bee.
The study was carried out by the Brazilian Agricultural Research Corporation (EMBRAPA). The findings are published in the journal Current Biology. The research paper is titled “Brazilian Social Bee Must Cultivate Fungus to Survive.”
