Experiments were conducted to determine the predatory activity of Helobdella triserialis lineata (Hirudinea: Glossiphonidae) on eggs, larvae and pupae of Aedes fluviatilis and Culex quinquefasciatus (Diptera: Culicidae) in the laboratory, The influence of the leeches on selection, of ovipositing sites by the females of both species of mosquitoes, as well as the role of salinity and water depth in relation to predation were investigated. Larvae and pupae of both species of mosquitoes were efficiently predated, but eggs were not touched. A significantly lower number of eggmasses of Cx. quinquefasciatus were deposited on water containing leeches, but the same did not occur with Ae. fluviatilis. The different depths of water investigated did not interfere with predation and only at concentrations above 3% NaCl was predation considerably diminished.
Helobdella triserialis lineata; Aedes fluviatilis; Culex quinquefasciatus; Biological control
