Efeito de anticontaminantes utilizados na dieta artificial de Spodoptera frugiperda sobre o vírus Spodoptera frugiperda Multiple Nucleopolyhedrovirus (SfNPV)

Abstract

Spodoptera frugiperda (J. Smith) 1797 (Lepidoptera: Noctuidae) is the main corn pest and presents great potential for damage due to the difficulty in its control, which has mainly been done with chemical insecticides. Thus, biological control with the baculovirus Spodoptera frugiperda multiple nucleopolyhedrovirus (SfNPV) may be an alternative to the use of agrochemicals. To make feasible studies and tests in the formulation of bioinsecticides, it is necessary to use an artificial diet. In addition to optimal nutrition for insect development, it is also necessary to add antimicrobial, such as formalin, Nipagin and tetracycline, which reduce or prevent contamination by microorganisms in the artificial diet. The objective of this work was to analyze the effect of antimicrobial used in the artificial diet of S. frugiperda on SfNPV. It was made 8 treatments with infected caterpillars by SfNPV, to analyze the influence of antimicrobial on the action of the virus on the caterpillar and 8 treatments with healthy caterpillars to evaluate if there was interference specifically on the caterpillar. Each treatment consisted of 30 replicates and each caterpillar consisted of 1 replicate. The mortality assessment made over 10 days. The mixture of Nipagin + formoldehyde 10% caused a negative effect on the virus, causing the lowest mortality rate in the caterpillars infected by this baculovirus. When all the treatments were compared, it has been found that formaldehyde 10%, it is what appears to cause toxicity to caterpillars and somehow potentiate a virus action. Finally, it was found that Nipagin + tetracycline did not interfere without control by SfNPV and did not cause toxicity to S. frugiperda, being a mixture more suitable to be added to the artificial diet of this insect.