Submitted to: Memorias Do Instituto Oswaldo Cruz
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/23/2003
Publication Date: 11/1/2003
Citation: Micieli, M.V., Garcia, J.J., Becnel, J.J. 2003. Life cycle and epizootiology of amblyospora ferocis (microspora: amblyosporidae) in the mosquito psorophora ferox (diptera, culicidae). Memorias Do Instituto Oswaldo Cruz. 50:171-175. Interpretive Summary: Naturally occurring protozoan parasites (Microsporidia) of mosquitoes are under study by USDA/ARS scientists to evaluate and develop these disease causing organisms as biological control agents. Microsporidian parasites are known to cause mortality in mosquitoes worldwide and recent advances on fundamental aspects of their life cycles and modes of transmission has led to renewed interest in these pathogens as microbial control agents. This article, using both the light and electron microscope, describes the complete life cycle of a new microsporidian parasite in a mosquito host and documents the involvement of a copepod intermediate host. New information obtained here contributes to our basic understanding of these parasites which we hope will assist in the evaluation and development of microsporidia as biocontrol agents.
Technical Abstract: A natural population of Psorophora ferox (Humbold, 1820) infected with the microsporidium Amblyospora ferocis García and Becnel, 1994 was sampled weekly during a seven-month survey in Punta Lara, Buenos Aires Province, Argentina. The sequence of development of A. ferocis in P. ferox larvae leading to the formation of meiospores followed the developmental pathway previously reported for various species of Amblyospora. Natural prevalence of A. ferocis in larval population ranged from 0.4% to 13.8%. Spores were detected in the ovaries of field-collected P. ferox females and were responsible for transovarial transmission of A. ferocis to the next generation of mosquito larvae. These spores were binucleate and slightly pyriform in shape. Prevalence of A. ferocis in the adult population ranged from 2.7% to 13.9%. Preliminary data on effects of the infection on female fecundity showed that infected field-collected adults of P. ferox laid 47.6 ± 6.5 eggs of which 35.8% ± 4.1% hatched. Uninfected field-collected adults of P. ferox laid 82.8 ± 6.8 eggs of which 64.1% ± 5.5% hatched. Six species of copepods living together with P. ferox were fed meiospores from field infected larvae and none became infected. Horizontal transmission of A. ferocis to P. ferox larvae remains unknown.