Impact of Edhazardia aedis (Microsporidia: Culicosporidae) on a seminatural population of Aedes aegypti (Diptera: Culicidae)

The effectiveness of the microsporidium Edhazardia aedis (Kudo) to control a seminatural population of Aedes aegypti (L.) was evaluated over a 2-year period. The tests were conducted in a large screened enclosure against an established population of A. aegypti provided caged rabbits as an ad lib. blood supply. In year 1, inoculative release of E. aedis resulted in dispersal of the microsporidium by infected A aegypti females to all containers within the enclosed study site over a 20-week period. In the second year of the study, inundative release of E. aedis produced high larval and adult infections and successfully eliminated the population of A aegypti within 11 weeks of introduction. In both years, a deviation from the typical life cycle that produced horizontally infectious spores was critical for persistence of E. aedis within containers. This study has demonstrated that E. aedis is superbly adapted to A aegypti, having evolved a number of strategies that ensure long-term survival and make it a serious candidate for introduction as a classical biological control agent.