Resumen

CAZORLA PERFETTI, Dalmiro José  y  MORALES MORENO, Pedro. Histopathological and ultraestructural study of Beauveria bassiana (Ascomycota) infection on Rhodnius prolixus (Triatominae). Bol Mal Salud Amb [online]. 2011, vol.51, n.1, pp.71-79. ISSN 1690-4648.

A histopathological and ultrastructural study was used to describe the mode of interaction between a native isolate (LF14) of entomopathogenic fungus Beauveria bassiana (Ascomycota, Hypocreales) and nymphs/adults of Rhodnius prolixus (Hemiptera, Reduviidae, Triatominae). Conidia germinate on the surface of triatomine bugs and immediately begin penetration of the cuticle and spiracles by germinal tube. Once invade the haemocele, the fungus multiplies extensively whole insect tissues and organs, leading to triatomine death. When insect cadaver is in mummification stage, outgrowths of fungal hyphae occur first and most extensively in the intersegmental regions of triatomines, emerging at the surface, where they initiate sporulation process. Electron Transmission Microscopy (ETM) studies revealed abundant growth of fungal hypahe and micelar into haemocele, with haemocytic infiltration during fagocitation, encapsulation and melanization process of fungal structures. Areas of low electron-density were frequently observed, suggesting the secretion of enzymes by hyphae to weaken and penetrating cuticle and tissues.

Palabras clave : Biological control; entomopathogenic fungus; histopathology; electron microscopy; Triatomines.