Composição química e atividade acaricida do óleo essencial das folhas de Syzygium cumini (Myrtaceae).

Abstract

Syzygium cumini, known as purple olive, or jamul, dates back to its healing powers since the beginnings of many societies, today confirmed through its antioxidant, anti-diabetic, anti-fungal properties and reports against different arthropods. The essential oil, extracted from the fresh leaves, through hydrodistillation technique with the aid of a Clevenger type apparatus, had a yield of 0.12%m/m and its chemical characterization, through Gas Chromatography coupled to a Mass Spectrometer (GC-MS), provided as major constituents (Z)-[beta]-ocimene (30.456%), [alfa]-pinene (15.537%) and (E)-[beta]-ocimene (15.177%). The contact bioassays performed, with the objective of identifying the effects of the oil on the spider mite, demonstrated a considerable toxicity of the oil. The residual contact bioassay, which the mites are placed on already treated leaves, presented the LC50 = 7.54uL/mL. While in the spray bioassay, where the mites are sprayed when they are on the leaves, presented a LC50 = 8.69uL/mL. In addition, the oil was also showed an ovicidal property with an estimated LC50 of 0.22uL/mL. this essential oilvshowed similar and promising effects compared to acaricides already marketed, while bioassaysvdemonstrated how different tests act on pest instinct mechanisms.