Spatial distribution and sequential sampling protocol for Spodoptera frugiperda (Lepidoptera: Noctuidae) on commercial maize fields in Sinaloa, Mexico

Abstract Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is the most important pest on maize (Zea mays L.) crops in Mexico and can cause substantial economic losses if left unmanaged. Commonly, growers carry out some control strategies when observe damage caused by S. frugiperda in their crops without considering whether the level of damage is sufficient to warrant any action. Some authors suggest considering as reference a level damage of 20% or more. Nevertheless, the Sinaloa growers lack of a practical method to estimate such damage. Therefore, the objective of this research was to develop a sequential sampling method that can determine the most appropriate time to initiate a control strategy and that can be applied by the producers of Sinaloa, Mexico. Three trials were established to evaluate six different sequential sampling methods, using a probabilistic test based on the presence and absence of damaged plants and an action threshold of 15 %. The results indicate the best option was a sequential sampling plan based on the Taylor method, performing the regression analysis with Log10, with a maximum of 50 sampling units per plot.