Semisynthetic bis and mono-chalcones semi-synthetic with toxic effects on Spodoptera frugiperda

Abstract

Chalcones are biologically active molecules. They are bactericide, antifungal and insecticidal. The exploration of molecules already selected by nature to play a role in ecological defense appears as an essential starting point to search for new products for pest control.We selected for this test, 6 mono-chalcones: A, B, A001, C001, G001, H001 and 8 bis-chalcones: B1, C1, D1, F1, G1, H1, J1, K1, which were evaluated for their antifeedant, toxic and nutritional effects on larvae of Spodoptera frugiperda.The antifeedant activity was calculated when 50% of the larvae control ate 50% of the diet through the FR factor. Toxicity was assessed through larval, pupal mortality and the emergence of adults and nutritional effects with consumption rates (IC), growth (GR) and consumption efficiency (EIC).The bis and mono-chalcones tested at 100 µg/g of artificial diet, did not cause antialimentary effect on larvae of S. frugiperda. The bis-chalconas C1, G1, H1 and K1, caused lethal effect on S. frugiperda in the first larval stages, being C1 the most toxic (85%). Adults who survived showed malformations and decreased size, which led to death. The larvae fed with aggregate in the bis-chalconas diet: C1, G1 and H1 had the highest percentage of intake and the poorest conversion of nutrient absorption (ECI), which suggests that the larva metabolizes food for energy and results in a decrease of growth and death in early stages.Bis-chalcones showed greater toxicity than mono-chalconas and C1 causes the highest toxicity and nutritional alteration.