Interações mediadas quimicamente entre Lepidoptera e espécies de Piperaceae

Abstract

The fossil record of the first insects, dating to half of the Carboniferous Period, indicate that these were saprofagus and not herbivorous. The habit of feeding on green plants arose during the coevolution of insects and plants. In response to change in saprophic habit of insects, plants have developed chemical defenses against them by the accumulation of toxic compounds known as secondary metabolites. In an attempt to overcome plant chemical defense, insects developed strategies that allowed them to have a plant tissue diet. So far it is not completely elucidated how this process occurred, but there is evidence that insects have developed the ability to use the biotransformation mechanism to detoxify these plant defense substances. In order to contribute to the understanding of chemical specificity between insects and plants, the present work was directed to elucidate the possible biotransformations of secondary metabolites of Piper species by insects, considering that Piper leaves accumulate compounds as amides and phenylpropanoides, which have allelochemical properties. Leaves of the species Piper aduncum, P. marginatum, P. tuberculatum and P. caldense, which accumulate phenylpropanoids, amides / phenylpropanoids, amides and benzoic acids prenylated were added to the diet of lepidopteran species. The results obtained showed that the piplartin amide, abundant in leaves of P. tuberculatum and known due to its biological potential, including insecticidal activity, was biotransformation during the digestive process of the caterpillars Heraclides brasilienses and Gonodonta sp1 in the respective ester 3,4,5 trimethoxycinnamate. In relation to the phenylpropanoid dilapiol, a potent natural insecticide, found in abundance in P. aduncum, there was no biotransformation during the digestive process of lepidopteran larvae Quadrus u-lucida and Gonodonta fulvidens. As for the major phenylpropanoids Easarone, Z-asarone and dilapiol present in leaves of P. marginatum, no evidence of biotransformation was also found during its metabolism by the Q. u-lucida, H. brasilienses and ENI 1 caterpillars. The same was observed for 3-geranyl-geranyl-4-hydroxybenzoic acid, found in leaves of P. caldense, where no evidence of biotransformation was found during metabolism by the Gonodonta sp2 caterpillar. The results obtained contribute to increase the knowledge about the metabolism of compounds with insecticidal properties of Piper in insects, main object of the systematic study of our research group.