Evaluation of plant extracts on Spodoptera frugiperda (JE Smith, 1797) (Lepidoptera: Noctuidae

Abstract

The fall armyworm (Spodoptera frugiperda) (JE Smith, 1797) leads to large losses in maize production due to the damage it causes as well as the difficult control. Thus, the objective of this study was to evaluate the effect of aqueous extract of Ruta sp. (leaves and branches), Chenopodium ambrosioides (leaves and branches) and Melia azedarach (fruit) on S. frugiperda when incorporated in artificial diet. The experiment consisted of four treatments with 20 repetitions each, with each worm being a repetition. They are: diet + Ruta sp. Diet + C. ambrosioides; diet +M. azedarach and negative control group. The assessed parameters were mortality and weight of larvae and pupae. The data were subjected to variance analysis, with the means compared by Tukey test at 5% significance level. There was a 100% mortality rate of larvae treated with M. azedarach, before the formation of pupae, whose weight was impossible to determine. The larvae fed on C. ambrosoides had significantly lower weight (0.13 ± 0.02) than the other treatments, and the same occurred in relation to the weight of larvae (0.14 ± 0.02). Therefore, the high concentration of the extract in the diet possibly prevented the worms’ feeding and developing, which led to the mortality.