Epizootiological studies of Amblyospora camposi (Microsporidia: Amblyosporidae) in Culex renatoi (Diptera:Culicidae) and Paracyclops fimbriatus fimbriatus (Copepoda:Cyclopidae) in a bromeliad habitat

MICIELI M. V.; BECNEL J.J.; MARTI G.A; TRANCHIDA M. C.; GARCIA J.J.

University of Warwick, Coventry, United Kingdom

Simposio; 41st Annual Meeting of the Society for Invertebrate Pathology and the 9th International Conference on Bacillus thuringiensis; 2008

Society for Invertebrate Pathology (SIP)

The epizootiology of Amblyospora camposi was studied in a natural population of Culex renatoi, a bromeliad-inhabiting mosquito, and its intermediate host, Paracyclops fimbriatus fimbriatus, over a 2-year period. Twenty Eryngium cabrerae plants were sampled monthly and the prevalence of A. camposi in P. f. fimbriatus and Cx. renatoi populations was determined. The monthly prevalence rates of meiospore infections in Cx. renatoi larvae never exceeded 5,5% and was detected in 50% of the monthly samples. Meiospores were available in plants over the course of the study at a mean concentration of 2 x 10 4 meiospores/ml. Within each plant the parasite was maintained by horizontal transmission. P. f. fimbriatus with vegetative stages and mature spores were found regularly in bromeliads suggesting efficient meiospore infectivity to field copepod populations. The mean concentration of spores from copepods found in plants was 8 x 10 2 spores/ml. Infections in copepods were detected in 54% of the monthly samples with a prevalence rate ranging from 0,55 to 17,4% and an overall average of 5,1%. Vegetative stages in fourth instar mosquito larvae (probably derived from the horizontal pathway via spores formed in copepods) were detected in 12.5% of the monthly samples with an overall prevalence rate of 1,1%. Infections in female and male adults were detected in 20,8% of the monthly samples with an overall average of 4,1% and 6,8% respectively. The host – parasite relationship of A. camposi could be yet another example of how a microsporidium has adapted to the ecological parameters of its hosts and the specialized habitat where they are found in nature to ensure long term survival.