Estimation of the Economic Threshold for the Fall Army Worm Spodoptera frugiperda (Lepidoptera: Noctuidae) in Short Stature Maize, Variety Delfín

Abstract

Spodoptera frugiperda is a key pest in Latin America, capable of causing significant economic losses if management is not timely. Estimation of economic thresholds adapted to local conditions and specific varieties is essential to optimizing control and reducing unnecessary use of insecticides. The objective of this study was to estimate the economic threshold of S. frugiperda in short stature maize, Delfín variety, under field conditions in northern Sinaloa, Mexico. We set up seven treatments with different levels of artificial infestation (0–25%), plus a regional control, in a completely random design. We evaluated the percentage of damaged plants, with an estimated loss of 32.515 kg/ha for each 1% of damage. Considering a US $325 t−1 price of maize and US $127 ha−1 cost of control, we determined an economic threshold of 12.05% damaged plants. This value is a practical tool for better decision-making in S. frugiperda management in Delfín variety maize. We recommend validation in different agroecological contexts and growing seasons.