AbstractBACKGROUNDThe corn leafhopper (Dalbulus maidis) has caused significant losses to corn crops, mainly due to the transmission of pathogens of the corn stunt complex. Therefore, our study aimed to estimate the costs of insecticides for controlling this pest. For this purpose, we used primary data from the Paraná Agribusiness Defense Agency, including information on products applied exclusively in the management of the leafhopper. Our estimates were based on the volume of insecticides applied, multiplied by the respective market price, for each agricultural year and municipality, covering the period from 2015–2016 to 2020–2021. To identify spatial patterns, Exploratory Spatial Data Analysis (ESDA) was performed using a first‐order queen‐type contiguity matrix. The techniques applied included Global Moran's I and Local Indicator of Spatial Association (LISA), allowing the identification of spatial patterns and clusters in the state of Paraná.RESULTSBetween the agricultural years 2015–2016 and 2018–2019, insecticide expenditures (GCC) in most municipalities in Paraná were up to US$ 10.00 ha−1. However, in the agricultural years 2019–2020, 2020–2021, and 2021–2022, GCC increased, exceeding US$ 120.00 ha−1 in some municipalities. High‐High clusters were identified in the northwest and central regions of Paraná, with displacement to the south and southeast regions in the final year analyzed.CONCLUSIONThe largest GCC were recorded in small cultivation areas, suggesting limitations in technology and technical assistance. Despite the increase in the number of products used, expenditures remained concentrated in a few chemical compositions throughout the analyzed period. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.