A molecular look at bees' gut may show the way to stop their decline in Latin America

The first large-scale standardized survey of colony losses of managed honey bees and stingless bees across Latin America has just been presented.  1736 beekeepers and 165 meliponiculturists participated in the 2-year study (2016–2017 and 2017–2018). On average, 30.4% of honey bee colonies and 39.6% of stingless bee colonies were lost annually across the region. 

These are figures that alarm those who study anthophilous insects in the region. Bees on our continent have the same economic importance as the rest of the world: they pollinate crops and produce honey. However, Latin America has a great diversity of native, stingless bees, which also produce honey and pollinate crops and, on top of that, maintain South American megadiversity by allowing the reproduction of its plant species. Meliponiculture, the management of these diverse and native colonies, is more than an economic activity: it has a profound social impact, and its loss implies damage to cultural diversity.    

UNU-BIOLAC has co-financed academic activities that address this problem from a metagenomic and microbiological perspective. The course "Hands-on Molecular Approaches for Honey Bee Research in Health and Disease" is coming up. We wanted to talk with Karina Antunez, its coordinator, about what is behind the scientific effort to address the loss of colonies.    

Dr. Antunez explains that this Latin American scientific interest has been led since 2016 by a network of researchers called SOLATINA, which, in its eight years of activity, is already made up of more than 300 associates coming from all areas of science, who move to find the answers to two urgent questions: What is the rate of loss of honey bee and stingless bee hives in Latin America, and what are the leading causes of this loss? SOLATINA has been able to identify three probable culprits:

• The loss of habitat and biodiversity (which reduces the availability of pollen and nectar food for bees).
• The use of pesticides.
• Infection by pests and pathogens (Viruses, bacteria, fungi, and mites).     

The use of molecular biology techniques and metagenome analysis is a valuable tool for studying this last problem. These technologies allow, among other things, to identify pathogens whose clinical symptoms are common to several agents. However, the biotechnological approach of Dr. Antunez and other partners in the region is important for the problem as a whole because it provides a way to study the intestinal microbiota of insects.

Like any animal, the community of microorganisms that live in the bees' digestive system is fundamental for their nutritional and immunological adaptive response. It manifests rapid changes in the face of external alterations, whether nutritional, toxicological, or pathological.

The microbiome is, then, a starting point both for early diagnoses (before the development of clinical symptoms of the hive) and for adaptation to the challenges proposed by human activity, which are not limited only to the establishment of monocultures and use of pesticides, but involve the additional complexity of climate change.

The knowledge generated in this way will be fundamental for the design of management strategies.

Latin America plays an important role in the global food supply. Major food-producing countries (Argentina, Brazil, Chile, Mexico and Uruguay) contribute together about 228.1 million tons of food that is attributable directly to insect pollination, and 28% of the world's honey comes from this region. Dr. Antunez reflects on the importance of building capacities locally: It will not only secure incomes and livelihoods, but it is also a matter of protecting local diversity, both biological and cultural, in a region whose heterogeneities make large-scale surveys and public policies challenging to implement.  

Be sure to check out SOLATINA's series of videos on the subject!