Desenvolvimento de uma emulsão pulverizável de óleo de andiroba a 2% para controle de insetos em pomares.

Abstract

Andiroba (Carapa guianensis Aublet) belongs to the Meliaceae family, in Brazil the species has existence throughout the Amazon Basin. The seeds of this tree store approximately 70% of oil compounds that give limonoids andiroba the power of natural insecticide. An insect that has caused major damage in orchards is the Drosophila suzukii, a small insect that damages fruits thin skin by the action of the female of the species, which pierce the surface of the fruit to lay their eggs and the days the fruits come collapse and end up deteriorating. In order to test insecticidal properties and repellent action of andiroba oil in agricultural pests arises interest in the development of a sprayable formulation which does not damage the fruit and leaves. Emulsions are an alternative dispersing this oil because as colloidal systems, allow the mixture of two immiscible liquids stabilized by adding a surfactant. The purpose of this study was to develop a sprayable emulsion andiroba oil 2% for insect control in orchards; evaluate the physical and chemical stability, perform preflight testing its insecticidal action and effectiveness in the field and in front of the laboratory D. suzukii. The formulation developed was found adequate with the incorporation of 2% of andiroba oil in a stable emulsifier system of the aqueous external phase, providing ease of application in the preparation spraying. Not undergoing significant changes organoleptic characteristics, small variations occur in the pH, the lowest temperature conditions, but within acceptable values. Although the pH changes, the value maintained in the range 6.0 to 7.0, typical for emulsions with vegetable oils. In field studies developed formulation provided a lower incidence of positions in relation to the control and treatment with only one application, there was no presence of larvae in fruit receiving the formulation developed and treated with saline. As andiroba oil application reduced the emergency D. suzukii adults compared to the control. The number of D. suzukii collected in traps sprayed externally with andiroba oil was significantly lower than that obtained in traps without the use of oil (control). In fruit immersed in the formulation developed no emergence of the larvae, while in water-immersed fruit identified larvae. Thus it is concluded that the anbiroba oil promoted the insecticidal action, as well as action against the insect repellency D. suzukii.