The corn leafhopper, considered the main pest of this crop in Brazil, has caused billions in losses to national production. An unprecedented study by the Brazilian Agricultural Research Corporation (Embrapa) calculates that the country lost an average of 22.7% of its corn harvest annually between 2020 and 2024, causing a loss of around US$6.5 billion (the equivalent of R$33.5 billion) annually.
According to Embrapa, over the four harvests evaluated, the accumulated amount of financial losses reached the mark of US$25.8 billion (US$133.1 billion), since around 2 billion 60-kilo bags were no longer produced.
To arrive at these numbers, the researchers analyzed data from the National Supply Company (Conab) referring to historical series of productivity, grain production and corn planted area since 1976 — and estimated the economic losses associated with corn stunting in the main grain producing regions in Brazil.
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The Embrapa study, in partnership with the Agricultural Research and Rural Extension Company of Santa Catarina (Epagri) and the Brazilian Agriculture and Livestock Confederation (CNA), had its conclusions published in the international magazine Crop Protection.
The impact was greater in the first harvest analyzed (2020/2021), with a 28.9% loss in production. In the 2023/2024 harvest, there was a reduction in this index (to 16.7%).
The cost of applying insecticides to control the leafhopper rose 19% in these four harvests, exceeding US$9.00 per hectare, which significantly increased the production cost for the farmer.
“The results indicate that corn stunting led to an average loss of 31.8 million tons per year”, points out Charles Oliveira, researcher at Embrapa Cerrados and author of the study. In around 80% of the locations evaluated, leafhoppers or stunting were identified as a central factor in the decline in productivity.
Impacts
Brazil is the third largest corn producer in the world and one of the main exporters. The estimate for the 2025/2026 harvest is a production of 138.4 million tons, according to data from Conab, and a production value of around US$30 billion.
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According to the research, the two types of stunting – the pale (Spiroplasma kunkelii) and the red (“Candidatus” Phytoplasma asteris) – are today the biggest phytosanitary threat to Brazilian grain production. Both diseases are caused by the corn leafhopper, which also transmits the striate mosaic and corn stripe viruses.
According to the Embrapa researcher, the problem is aggravated by the lack of preventive treatment for these diseases, which can cause total loss, especially of crops grown with susceptible hybrids.
Although the pathogens have been known since the 1970s, epidemic outbreaks have become frequent since 2015. “Changes in the production system that occurred in recent decades, such as the expansion of the off-season and the cultivation of corn almost throughout the year, created a favorable scenario for the survival of the leafhopper and microorganisms”, details Oliveira.
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For Tiago Pereira, technical advisor at CNA, the leafhopper is no longer a localized problem: “We are talking about losses that directly impact the producer’s income, the productive stability and the country’s competitiveness. The difference in this study is transforming this recurring perception into numbers, with a scientific basis.”
How to face the plague
The corn leafhopper has a high capacity for reproduction and dispersal. Present in all regions of the country, it is a difficult species to manage, says Embrapa. Biological control with entomopathogenic fungi, natural enemies of the pest, has proven to be a management alternative to be associated with chemical control and an important option for the system, since some corn leafhopper populations are already resistant to certain groups of insecticides.
Since control based exclusively on chemical insecticides is insufficient, the research recommends the adoption of a set of practices:
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- Elimination of tiguera corn (volunteer plants that appear in the off-season due to the loss of grains during harvesting and transportation): breaks the life cycle of the vector and pathogen.
- Planting synchronization: avoids long sowing windows that favor the dispersion of the leafhopper between crops.
- Use of resistant or tolerant cultivars maintains high levels of productivity even under disease pressure.
- Initial management with application of chemical and biological control in the initial stages of the plant (up to V8): prevents the infection from causing more severe damage.
- Monitoring: implies constant and coordinated surveillance between neighboring producers.
