Intensidade de dano de Aceria guerreronis Keifer (Acari : Eriophyidae) em frutos de coqueiro sob diferentes condições e respostas olfativas de seus predadores

Abstract

Aceria guerreronis Keifer (Acari: Eriophyidae) is widespread in most coconut growing regions of the Americas and Africa and it has been established rapidly in some major producing countries in Asia. It is considered a major coconut pest in the world. Several studies have being carried out to obtain information to control this pest. This study aimed to: (I) investigate the damage intensity of A. guerreronis on coconut fruits in the field under different conditions: (i) plants with removed bunches; (ii) bunches with the distal portion of the spikelets removed; (iii) bunches monthly sprayed with Abamectina (9g/ha); (iv) and control plants; and (II) studing the foraging behavior of the predatory mites Neoseiulus baraki (Athias-Henriot) and Proctolaelaps bickley Bram, evaluating the ability of the predators to identify and differentiate odors from parts of coconut plants infested or not by the eriophyid using Y-tube olfactometer and “T” arenas. The removal of spikelet had no effect the damage level of new bunches emitted bythe plant, but delayed the damage intensity of A. guerreronis in about 1 month. After the removal of all bunches, the intensity of damage was restored in two months to the new bunches emitted. Chemical control with Abamectin, on monthly based application, kept the A. guerreronis intensity of damage at low levels. In olfactometer tests both predators were able to distinguish between the infested plant parts and the air stream. The predators preferred infested parts over their respectivenon-infested ones, and among the infested plant parts, the spikelets promoted greater attraction to predators. In arena tests both predators preferred epidermis’s disc of coconut fruits infested with A. guerreronis over other sources. The results showed that both predators are able locating A. guerreronis by olfactory stimuli.