Colombia has hundreds of species of bees, but many have been hard hit by pesticide use and Colombian entomologist Diana Obregon has been trying to find out the role pesticides play in the decline of the bees that pollinate Lulo, an iconic fruit in Colombia.
Obregon, who is now a PhD student in entomology at Cornell University and a Fulbright scholar, says that without bees the production of Solanum quitoense fruits (known as lulo) would be reduced by 51 percent. Given the widespread popularity of the fruit in Colombia and other countries in Latin America, that gives a strong incentive to understand what impact pesticide use and forest loss have on bees.
“Using drones, we characterized the landscape surrounding the crop fields to quantify the amount of forest remaining and we correlated these areas with the amount of pesticide residues found in lulo flowers and the diversity and abundance of bees visiting the crop,” she said,”We discovered, very highly toxic pesticides for bees in lulo flowers, and as the pesticide residues increased in the farms, the diversity and abundance of bees drastically decreased.”
Encouragingly, Obregon and her colleagues also found when farms are surrounded by high proportions of forested area, this natural habitat helps to offset the negative effects of pesticides.
“But this buffer effect is lost when the residues are very high,” she said, adding that to protect bees and to maintain a sustainable lulo production it is necessary to protect natural areas around farms but also to reduce the excessive use of pesticides.
“In the tropics, there is an immense diversity of native bees that must be studied and preserved,” she said, “The results of my research provide information on ecosystems and crop systems which have been less studied, but which are economically relevant for the region.”
Obregon says she hopes her work contributes to the development of actions and policies which diminish the negative impact of the deforestation and insecticides on pollinators in tropical areas like Colombia’s Andes mountain region.
Obregon grew up in a low-middle income family in the Colombian capital of Bogota, the daughter of a dressmaker and an auto-parts seller.
“Neither my parents’ work nor our daily routine was related to nature, but I remember that they took us many times to visit relatives outside the city,” she said, “For me it was the most exciting time of the year, and the opportunity to be in the country, enjoy the river, the trees, and the animals which made it very special for me.”
This passion for nature led her to apply to the National University of Colombia to study agronomic engineering –the technology and techniques involved in crop production.
In her first semester, she planted strawberries for a class project and learned how important bees were for good fruit production.
“From then on, I continued my career always trying to learn and understand more about the relationship between bees and plants.”
After finishing her master’s degree, Obregon would go on to teach practical skills about fruit production and insect management to students from parts of Casanare, in eastern Colombia heavily impacted by Colombia’s decades-long civil conflict.
“From this experience, I understood the dilemmas that farmers must face while managing the crops, in particular, I was very interested in the difficulty of controlling pests without affecting pollinators,” she said,” This was later my main motivation to study more and to try to understand how pesticides are affecting bee populations.
Obregon isn’t the only researcher from Bogota whose work was inspired by Colombia’s wildlife. Colombian researcher Bibiana Rojas says her life changed forever when she got to meet a poison frog in real life.
Rojas, who is from Bogota, Colombia and is now an Academy of Finland Research Fellow at the University of Jyväskylä in central Finland says she started getting interested in frogs in university and now studies a range of brightly colored frogs and moths and how they interact with predators.