What began as isolated reports quickly turned into a mass mortality crisis that has reignited the debate on sustainable agriculture.
In late 2025, beekeepers in Uruguay began reporting that their bees were dying. Some 15,000 hives and more than 85 beekeepers were reportedly affected. Jihmy Fiorelli, president of the Uruguayan Beekeeping Society (SAU), says this could be less than the reality: “That figure could double, as many beekeepers did not want to report it out of fear.”
Typically renting space from landowners, apiarists fear being evicted for complaining.
Those complaints would be aimed at farming methods: in Uruguay, beekeepers set up their hives in soya, maize and rapeseed fields. The variety of flowers and the fertility of the soil on these farms aid steady honey production. Blooming rapeseed fields in Nueva Helvecia, south-west Uruguay. The flora and soil fertility of crop fields like these make them ideal places to set up hives (Image: Peter Giovannini / imageBROKER / Alamy) In 2025, there were 2,200 registered beekeepers in Uruguay and over 550,000 hives, producing approximately 9,000-12,000 tonnes of honey per year. However, this army of beekeepers is increasingly concerned that farmers’ use of pesticide “cocktails” poses a threat to their sector.
The pesticide cocktail
Uruguay’s bee colonies typically lose around 30% of their population each year, due to nutritional stress, and exposure to both agricultural pesticides and other chemicals. However, several researchers tell Dialogue Earth that the latter is an increasingly significant risk factor.
Estela Santos, an entomologist at Uruguay’s University of the Republic (Udelar), says the 2025 die-off could not have been due to natural causes: “We were able to confirm that it was a case of chemical poisoning. It cannot be explained by any disease.”
Insecticides were detected in only two of the 24 samples analysed in Santos’s study. This led the scientists to focus on other pesticides: the cocktail of herbicides and desiccants (drying agents) used in agriculture. They hypothesised these might combine to produce a lethal toxic effect, one not anticipated by analysing each product separately.
Gustavo Fripp is a beekeeper and delegate of the Honorary Commission for the Development of Beekeeping (CHDA) at the Ministry of Livestock, Agriculture and Fisheries (MGAP). He explains that complex mixtures are often prepared to maximise the profitability of agricultural production: “Sometimes six or seven products are mixed together, and then we don’t know what the effect will be.”
Santos also highlights that, although the individual use of chemical inputs is regulated, there are currently no regulations in Uruguay requiring impact assessments for these mixtures. Recommended The MGAP has informed Dialogue Earth that its investigations into the 2025 bee mortality event are so far inconclusive. No chemical molecule has been found that recurs systematically in all affected hives. Agustín Giudice, the ministry’s director general of agricultural services, says they are leaning towards a multi-causal explanation: nutritional, health and management factors, alongside exposure to agrochemicals.
The National Commission for Rural Development (CNFR), a group of family farm businesses, issued a statement in December in response to the deaths, urging that “all relevant investigations be carried out”. It also highlighted the importance of coexistence between beekeeping and agriculture.
Agricultural boom
Over the past decade, Uruguay has seen an expansion of agricultural land devoted to crops, particularly soya and maize, with production reaching record highs.
This growth, however, has been accompanied by a high volume of chemical inputs.
Preliminary data from the MGAP indicates 31 million litres of herbicides were imported in 2024. Paraquat – classified as moderately hazardous by the World Health Organization – was one of the most imported, after glyphosate.
Giudice asserts that these chemicals are necessary to ensure the sector’s competitiveness. According to Santos, however, they have ecological costs that extend beyond bees. He claims they affect the more than 500 species of insects in Uruguay that play a beneficial role in pollination, as well as the decomposition of organic matter. Mangangás , as well as wasps and butterflies, are negatively affected by the agrochemicals used to fumigate farmed soils, say experts (Image: Lucas Ninno / Dialogue Earth) Fiorelli says the impact of soil fumigation with agrochemicals causes a “monstrous ecological imbalance”, affecting wasps, mangangás (large bees native to South America) and butterflies.
Regulation and standards
For Santos, one of the biggest problems is that Uruguay assesses chemicals using “lethal dose 50” (LD50). This metric indicates whether a compound will cause the death of 50% of test organisms under laboratory conditions. LD50 ignores differences in local ecosystems in terms of climate, flora or pollinator behaviour, explains Santos.
These differences, Santos believes, could mean that international chemical standards are insufficient for assessing localised mortality: a specific imported chemical could prove to be more lethal in Uruguayan fields than its label suggests. He expresses regret that this has not yet “caught the attention” of regulatory agencies to prompt an update of impact assessment protocols.
There are also commercial implications. A recent study revealed almost 50% of the active ingredients in pesticides permitted in Latin America are not permitted in the European Union (EU), due to environmental safeguarding. Furthermore, 88% of the pesticide active ingredients that are approved for use in at least one Latin American country, and that are classified as high-risk by the World Health Organization, are not permitted in the EU. In particular, Uruguay has 86 approved active ingredients that are banned in the EU. Recommended A recent legislative amendment also removed the obligation for farmers to report crop spraying. “This led to a sharp drop in the number of reports. Reinstating mandatory reporting is one of the main demands [of beekeepers],” says Fripp.
The agricultural landscape
Although experts and authorities claim intensive agriculture and beekeeping go hand in hand, in practice, the two industries appear increasingly at odds.
Beekeepers operate on farmland via private agreements, but these have become more fragile. According to Fripp, some agricultural associations argue they should have exclusive use of the land to produce, free from bee-friendly restrictions, while beekeepers claim they depend on precisely that same fertile area to carry out their activities.
Alternatives are emerging, such as integrated pest management (IPM) and the use of biological inputs. IPM is a production strategy that aims to reduce reliance on pesticides through systematic crop monitoring technology and the selective use of chemicals. Biological inputs follow the same logic, using products made from plant or insect extracts with less harmful chemicals – or none at all – to control pests and diseases. Recommended Research suggests that training in these types of agroecological practices can reduce pesticide poisoning by up to 73% .
The use of biological inputs has begun in Uruguay, although Fripp points out that “they are more expensive and still represent a very small share of the market”. In any case, he stresses, biological inputs are not a “magic solution”, but must be integrated into a broader management framework.
Santos insists that true coexistence requires “learning to give way in terms of space, time and practices”, such as applying chemicals at night or avoiding spraying during plant flowering periods. These changes can protect pollinators.
Uruguay recently proposed a tax on those pesticides that the World Health Organization and the UN’s Food and Agriculture Organization both consider to be the most dangerous to health.
Fripp says this is “a positive sign” but that the funds raised should go directly to beekeepers. After all, industry estimates place the value of the “free” pollination services they provide at up to USD 400 million a year.
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