Presencia de Thielaviopsis paradoxa De Seynes Höhn en el tubo digestivo de Rhynchophorus palmarum Linneo (Coleoptera: Curculionidae)

Abstract

In order to know the role of R. palmarum in the transmission of the fungus Thielaviopsis paradoxa, causal agent of the bleeding coconut stem , a microbiological study of the alimentary canal of this insect was carried out. Adult specimens were colleted from four areas of Miranda state, using innocuous traps with pheromone and host volatiles as attractive. Twenty insects from each area were anesthetized by refrigeration at 5 °C for 15 minutes, and then disinfected in dicofol (0.5%) and sodium hipoclorite (3%) solutions, respectively. Immediately, they were dissected in sterile distilled water, under a stereoscopic microscope. The alimentary canal was extracted and cut into fore-gut, mid-gut and hind-gut. Each section was cultivated in acidified potato glucose agar (APGA), for the determination of fungi. T. paradoxa was identified, in 45% of the processed specimens. The pathogenicity of the fungus was proven in young coconut plants. This study demonstrates the possible role of R. palmarum as a vector of T. paradoxa in commercial plantations of coconut and other palms.