Effect of the density and release time of Trichogramma sp on Spodoptera frugiperda in the corn crop in the San Marcos community

Abstract

The use of natural enemies to control insect pests such as Spodoptera frugiperda in maize cultivation is a viable alternative that considerably reduces the negative environmental impact of modern agriculture, characterized by the extensive use of agrochemicals. The objective of this study was to evaluate the efficiency of Trichogramma sp in the control of Spodoptera frugiperda in maize crops. The experiment was installed in the San Marcos commune in the Hércules hybrid maize crop, an experimental design was established in completely randomized blocks with a 2x3 bifactorial arrangement, where one factor was the density of the parasitoid (100,000 ind∙ha^-1 (D1) and 200,000 ind∙ha^-1 (D2)) and the second the release times (LT) 30, 45 and 60 days after germination (DDG), with four repetitions. The data obtained were analyzed by the statistical program SISVAR, the means compared by Tukey's test with 95% confidence. Among the variables to be evaluated, the percentage of plants affected (PPA), degree of affectation by armyworm (GAC) and mass of parasitized eggs (MHP) were considered. The results obtained show that the release time directly affects the PPA and GAC variables. While the MHP variable is related to the release time and type of concentration. In the three variables studied, early release always stands out and the effect is intensified when accompanied by higher densities.