Efeito de extrato aquoso de Strychnos pseudoquina A. St. Hil sobre Spodoptera frugiperda J.E. Smith, 1797 (Lepidoptera: Noctuidae)

Abstract

The fall armyworm (Spodoptera frugiperda (J.E. Smith, 1797)) (Lepidoptera: Noctuidae) is a major pest of maize (Zea mays L.) cultivation. This cereal holds significant economic importance and is a staple in human and animal diets across all continents. In Brazil, controlling this pest has become a challenge for both small and large-scale producers. Botanical extracts are important tools in pest management, offering a sustainable and environmentally friendly approach to safeguarding agricultural crops and preserving biodiversity. The Brazilian flora provides a wide variety of plants that could be important for the production of bioinsecticides. Thus, the aim of this study was to evaluate the insecticidal potential of aqueous extracts from false quina (Strychnos pseudoquina A. St. Hil) on the biology of S. frugiperda fed on an artificial diet and on maize leaves. To achieve this, we tested the hypotheses that "the aqueous extract of S. pseudoquina may be effective in controlling S. frugiperda, with the effects of this extract in an experiment conducted with maize leaves interfering more with the life cycle of this insect than in an experiment with artificial diet." Therefore, experiments were conducted with S. frugiperda subjected to feeding on the diets; we used different concentrations (control, 5%, and 10%) of aqueous extract of S. pseudoquina, where the results obtained from the concentrations of 5% and 10% compared to the control were increased larval longevity, reductions in pupal biomass, feeding, number of days ovipositing, number, and viability of eggs, and consequently, reduction of individuals in the second generation. Therefore, we suggest that the extract of S. pseudoquina may be a viable additional alternative for use in family and organic farming; however, it is recommended that field tests be conducted using other parts of the plant and different extraction methods, which may maximize insecticidal activity as well as allow the assessment of effects on non-target organisms.