A research group from the Department of Biodiversity and Experimental Biology (DBBE) of the Faculty of Exact and Natural Sciences of the University of Buenos Aires (Exactas UBA) designed a series of experiments to find out if bees can find a way to avoid exposure to agrochemicals. The results, obtained by the team of Catalina Hunkeler, Rocío Lajad, Walter Farina, and Andrés Arenas, are described in a paper recently published in the journal Scientific Reports. According to the Argentine News Agency, via the Exactas UBA information service, the researchers did not have to induce the bees to do anything. For this, they designed another experiment that consisted of placing the bees that had gone through the previous experience in boxes containing the two types of pollen (canola and yellow flower), but this time, without any contaminants. "When we presented the two pollens without contamination to the different groups of bees that had gone through different previous experiences, they showed that they had a memory that made them go towards the pollen they had known as more suitable. That is, they had learned that the pollen from the other plant was contaminated and avoided it," revealed Arenas. According to the researcher, the fact that young bees are in charge of feeding the larvae suggests that this mechanism would reduce exposure to environmental contaminants inside the hive, which would enhance the insect's ability to adapt and survive in ecosystems altered by human activity. Simply, they were exposed to contaminated and uncontaminated pollen, after which they chose which one to consume on their own. In one case, the contaminant was glyphosate, a synthetic herbicide that affects the bee's intestinal flora, causing symptoms associated with microbiota imbalance, such as diarrhea. They placed young bees in transparent acrylic boxes where they were offered contaminated and uncontaminated pollen, varying the contaminant or the type of pollen. Each box had about 80 bees that could choose between one of the two types of pollen, one of which was contaminated with one of the two pesticides. Both pesticides were used in concentrations similar to those found in the environment. "We observed that, at first, the individuals consumed the contaminated and uncontaminated pollen indiscriminately. But, after a while, they could discriminate which pollen was contaminated, possibly because it made them feel bad, so to speak, and then they skewed their consumption towards the other pollen," explained Arenas. Memory was still to be determined if the bees had learned to avoid the contaminated pollen, that is, if they had acquired a memory. In another case, the pollen was contaminated with imidacloprid, an artificial insecticide with neurotoxic effects that "affects the taste sensitivity, learning, memory, and orientation of the individual," explained Arenas. In this way, pollen from two types of flowering plants was used: canola and yellow flower, which have different organoleptic characteristics (smell, taste, and color).
