These last couple months have been full of fantastic exit talks/defenses by my fellow graduating doctors! Today, we heard about the research of my friend and fellow bug enthusiast Carlo Moreno. Carlo received a Fullbright fellowship to study native potatoes and the insects that eat them in the Andes Mountains in Venezuela.
In the last 50 years, the Andean potato farming communities have shifted from growing a diverse variety of native potatoes (check out that photo!) to papas blancas, or white potatoes, that are favored more for export and to make into Lays Potato Chips- I kid you not! The problem is that these new potatoes are grown more and more as monocultures, which means more issues with insects and thus more inputs of pesticides and herbicides. Carlo found that many farmers would tell him that the insects didn’t touch their papas negras, or the main native potato, but that they attacked the new potatoes, the papas blancas, readily.
Carlo wanted to see if this was actually true- were the insects more likely to attack the new potatoes more than the native potatoes? The insect he focused on was the Guatemalan Potato Moth, or GPM. But he didn’t just do any old observational study: Carlo actually became an Andean farmer himself. He negotiated a plot of land where he was able to grow his own potatoes in his own way- a researcher’s way- with carefully structured plots of monocultures and mixed varieties.
After learning how to successfully grow potatoes, Carlo collected his potatoes and instead of feasting, checked them for GPM damage. He found that there was significantly more damage on the new potatoes than the native potatoes, confirming the farmer’s knowledge that the GPMs attack the new potatoes more readily than the native potatoes.
He also checked out what was surrounding the fields and found that those areas surrounded by the beautiful native Paramo vegetation were more likely to have more natural predators, like ground beetles and spiders, that ate up the moths. Also, when he tested whether those natural predators actually made a difference in the amount of damage on the potatoes, he found that they did in fact significantly reduce the percent of damage on each potato.
Conclusions: native potatoes are more resistent to the Guatemalan Potato Moth and conserving the native vegetation around farms reduces the need for pesticides! Carlo did some awesome and important work in an agricultural system that has greatly changed in the last 50 years, perhaps not for the better. In fact, Carlo investigated the potential for sustainable livelihoods in these communities and found that not only is there great potential for sustainable management, but that it can come with massive benefits to farmer livelihoods. Carlo is now working with a Venezuelan scientist and activist to come up with ways to market native potatoes as both sources of food and income.