Toxicity of the phenolic extract from jabuticabeira (Myrciaria cauliflora (Mart.) O. Berg) fruit skins on Spodoptera frugiperda

Abstract

Fall armyworm, Spodoptera frugiperda J.E. Smith, 1797 (Lepidoptera: Noctuidae) is the main pest of maize, besides attacking sorghum and cotton crops. The control of this pest has been accomplished mainly with the use of synthetic insecticides but, due to the growing concern about the environment and food quality, phenolic compounds have shown their potential for the biological control of this insect. Thus, the objective of the present study was to evaluate the efficiency of the extract of jabuticabeira, Myrciaria cauliflora [Mart.] O. Berg (Myrtaceae) fruit skin flour in the control of S. frugiperda. Skins of M. cauliflora Sabará genotype were dried at 45 °C in a forced air oven. In order to obtain the extract, 1.0 g flour was mixed with 10 mL acetone: water solution (7:3 v/v). Forty-eight-hour-old S. frugiperda caterpillars were placed in glass tubes with an artificial diet containing the extract at concentrations of 0, 250, 500, 1000, and 2000 mg L-1. The extract, in which the phenolic compounds gallic acid, gallocatechin, catechin, epicatechin, ellagic acid, and salicylic acid were identified at a concentration of 2000 mg L-1, in average, increased mortality rates by 150% in the larval stage, duration of larval stages by 60%, and pupal by 17%, and decreased amount of females by 55%. On the other hand, the extract at 1000 mg L-1 only increased duration of larval period by 24%. It was concluded that the extract is harmful to this insect, probably due to the presence of phenolic compounds.