Corn leafhopper incidence continues to rise in SC

The state average incidence of corn leafhoppers has been increasing weekly in the state of Santa Catarina. “As producers are starting their second planting, the leafhopper tends to migrate from old plantings, which are already being harvested, to new plants, concentrating populations in the off-season areas and increasing the proliferation of the insect,” warns Maria Cristina Canale Rappussi da Silva, a researcher at Epagri responsible for monitoring.

Although the absence or low detection of insects with spiroplasma is observed, phytoplasma has been appearing more frequently in the state's crops. Therefore, producers planning second-crop corn must be attentive to the initial management of the crop to prevent infected insects from migrating from older plantations and transmitting the pathogens in the initial stages of the second-crop corn. "We noticed that, if management is carried out, there is even a decrease in infected insects," comments the researcher.

She emphasizes the importance of all producers in a region carrying out chemical control of newly planted crops up to V8 – V10, as these stages are critical in case of transmission. “The symptoms of stunt disease are silent and will only be observed and quantified during the crop development phase,” says Maria Cristina.

The researcher also emphasizes that producers should pay attention to the bulletins produced by the Monitora Milho SC program. “It is necessary to observe the color change in each location. Each color represents a different incidence range. We see that several locations are in red, or even black. This means that there are places with more than 31 leafhoppers found per week. Others indicate that more than 120 leafhoppers were detected in the traps.”

Corn Monitor Program

The attack of leafhoppers infected with the pathogens of corn stunt can substantially compromise the production of corn crops. To monitor the situation, the Monitora Milho SC program was created in 2021. It is an initiative of the Action Committee against Corn Leafhopper and Associated Pathogens, composed of Epagri, Udesc, Cidasc, Ocesc, Fetaesc, Faesc, CropLife Brasil and the State Secretariat of Agriculture and Livestock.

Monitoring consists of traps installed in crops throughout the state, in order to represent the reality of corn-producing regions. The traps capture leafhoppers, which are analyzed in a laboratory to detect their infection by pathogens that cause diseases of the corn stunt complex. 

To help the production chain monitor and control this insect in Santa Catarina, Epagri developed the Monitora Milho SC app. The app, available for free download, allows producers and technicians to monitor the incidence of the corn leafhopper in Santa Catarina to make more accurate decisions about management. This tool also provides information on the infectivity of the leafhopper with pathogens of the corn stunt complex.