Submitted to: Journal of Eukaryotic Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/7/2000
Publication Date: N/A
Interpretive Summary: Naturally occurring protozoan parasites (Microsporidia) of mosquitoes are under study by USDA/ARS scientists who are evaluating and developing these disease causing organisms as biological control agents. Microsporidian parasites cause mortality in mosquitoes worldwide. Recent advances in our knowledge of fundamental aspects of their life cycles and modes of transmission have led to renewed interest in these pathogens as microbial control agents. The research described in this article, which employed both light and electron microscopy, is about the life cycle of a new microsporidian parasite in its mosquito host, it also documents the involvement of a copepod intermediate host. This new information contributes to our understanding of microsporidia and will be valuable for the evaluation and development of these parasites as biocontrol agents.
Technical Abstract: The life cycle of Amblyospora camposi n. sp. is described from the mosquito Culex renatoi and the copepod Paracyclops fimbriatus fimbriatus collected in the leaf axils of the plant Eryngium cabrerae in Argentina. Meiospores of A. camposi (5.8 X 4.1 micrometers) were infectious per os to female adults of the copepod P. f. fimbriatus. All developmental stages in the copepod had unpaired nuclei, with sporulation involving the formation of a sub- persistent sporontogenic interfacial envelope and the production of a second type of uninucleate spore. These spores, formed in the ovaries of P. f. fimbriatus, were large, pyriform, and measured 10.7 X 3.85 micrometers. They infected C. renatoi larvae when ingested to initiate a sequence that involves schizogony and gametogony and ends with plasmogamy and nuclear association to form diplokaryotic meronts. Oblong ovate binucleate spores (7.86 X 2.96 micrometers) are formed in the adult mosquito and are responsible for vertical transmission to the filial generation. This is the first report of an Amblyospora species from a mosquito that inhabits phytotelmata.