03140naa a2200181 a 450000100080000000500110000800800410001910000250006024501840008526000090026952023780027865000310265665000340268765000320272170000210275370000230277477301610279711360682025-10-23       2025    bl uuuu     u00u1 u    #d1 aANDRADE, M. V. S. de  aINCIDENCE OF DALBULUS MAIDIS AND ITS NATURAL INFECTION WITH THE CORN STUNT COMPLEX PATHOGENS OVER EARLY AND LATE PLANTINGS OF THE 2023/24 AGRICULTURAL YEAR.h[electronic resource]  c2025  aMaize is a key global crop, with Brazil as the third-largest producer. Despite its economic importance, maize faces major phytosanitary threats, including the severe corn stunt disease complex. This complex is caused by pathogens of the Mollicutes class, represented by the maize bushy stunt phytoplasma (MBSP), and the corn stunt spiroplasma (CSS). Additionally, two viruses, maize rayado fino virus (MRFV) and maize striate mosaic virus (MSMV), have been associated with the disease. The corn leafhopper, Dalbulus maidis (DeLong & Wolcott, 1923) (Hemiptera: Cicadellidae), serves as a persistent vector for these pathogens, facilitating their spread in crops. A comprehensive epidemiological investigation was conducted to determine the occurrence of D. maidis and natural infection in Santa Catarina, Brazil, attending the "Programa Monitora Milho SC". Monitoring was conducted for approximately 38 weeks from July to April during the 2023/24 crop year in 10 crops across the State. Yellow sticky traps were placed at each field edge, and captured D. maidis specimens were counted, and analyzed for infectivity individually or in batches (3 replicates of up to 5 insects). The population fluctuation of D. maidis varied throughout the weeks. The presence of the D. maidis was more intense between weeks 10 and 30, with a population peak between weeks 26 and 29 (January and February). The insect population increased progressively from the early maize growth stages (VE-V2), reaching its peak in the reproductive stages (VT-R1-R3/R4-R6) for both early and late plantings. After harvest, a sharp decline in the insect population was observed. Natural infection of D. maidis with MBSP, CSS, MRFV, and MSMV varied throughout the maize development cycle (Positive samples over the assessment: 42.29, 6.72, 31.97 and 42.41% respectively). During the off-season, MSMV exhibited the highest infection rates (64%). Infection with MBSP progressively increased, peaking in the reproductive stages (VT-R1-R3/R4-R6), coinciding with an increase of CSS and MRFV. After harvest, MBSP and CSS remained detectable in the D. maidis population. The monitoring program provides weekly reports that help farmers track D. maidis incidence and infection status. Continuous monitoring and integrated management strategies are essential for reducing pathogen spread and mitigating yield losses.  aEpidemiological monitoring  aVector population fluctuation  aVector-borne phytopathogens1 aMANICA, M. A. P.1 aSILVA, M. C. C. R.  tIn: INTERNATIONAL SYMPOSIUM OF PLANT VIRUS EPIDEMIOLOGY, 16., 2025, S??o Paulo, SP. Proceedings [...]. S??o Paulo, SP: Instituto Biol??gico, 2025. p. 88-88.