A research led by Macquarie University (Australia) and published in Royal Society Open Science reveals that clortalonil, one of the most widely used fungicides in global agriculture, seriously affects the reproduction of beneficial insects. Even at the lowest doses commonly found in fruits and vegetables.
The study, which used the fruit fly (Drosophila melanogaster) as an experimental model, found a 37% reduction in egg production in individuals exposed to the chemical during their larval development.
Furthermore, negative effects were recorded in both male and female fertility, which could have medium-term population consequences.
“Even the lowest concentrations had a great impact,” explained Darshika Dissawa, the lead author of the study and a doctoral candidate in Natural Sciences at Macquarie. The trial was supervised by Professor Fleur Ponton, who described the magnitude of the observed effects as “surprising.”
A common fungicide with little-known effects
Clortalonil is used to prevent fungal diseases such as mildew and leaf blight, and is present in mass-consumed crops such as blueberries, grapes, citrus fruits, and leafy vegetables. Although it has been banned in the European Union, it is still widely used in Australia and other countries, without specific restrictions on its persistence in food.
D. melanogaster, widely used as a model organism in science, was chosen for its basal position in the food chain. “It serves as an indicator because many other insects present in agricultural environments could be facing similar effects,” Dissawa warned.
One of the most relevant findings is that larvae ingested the contaminated food without modifying their behavior, ruling out the possibility of taste aversion reducing exposure.
Implications beyond the laboratory
Although the study was conducted under controlled conditions, its results raise questions about the real impact of clortalonil on pollinator species and the entire agroecosystem food web.
Insects such as bees, wasps, butterflies, and other dipterans could be suffering similar physiological damage, with cumulative effects on the ecosystem services they provide.
In a context of global crisis due to the decline in pollinators, the study suggests the need to review the use of compounds that, although not neurotoxic or lethal, affect reproductive capacity and population balance.
