Abstract

FIMIA DUARTE, Rigoberto et al. Depredatory action of Mesocyclops aspericomis (Daday,1906) on Culex quinquefasciatus larvae (Say, 1823). Rev Cubana Med Trop [online]. 2008, vol.60, n.3. ISSN 0375-0760.

OBJECTIVE: to evaluate whether the predation efficiency of copepods Mesocyclops aspericomis depends on their density or on that of their preys that are Culex quinquefasciatus in this case. METHODS: Two experiments about the preying of copepod Mesocyclops aspericomis upon first stage Culex quinquefasciatus larvae were made in a 24h-interval. The first experiment assessed the preying capacity of different numbers of copepods (5, 10, 15, 20 and 25 in one liter of unchlorinated water) upon 120 larvae, with 10 replications. The second one evaluated the influence of larval density over the predation efficiency; to this end, the quantity of larvae changed (40, 60, 80,100 and 150 in one liter of water) exposed to 10 copepods, with 10 replications too. Statistical package STATGRAPHIC 5.0 allowed data processing. RESULTS: Killed larva mean showed strong dependence on the density of predators, there were significant differences in all the cases since 25 copepods achieved 87 % larval mortality whereas for 5 copepods, mortality rate was 22.16 %. During the second experiment, the killed larva mean after the 2 first treatments (40 and 60 larvae) significantly differed between them and from the rest of treatment, but from 80 larvae on, no significant differences were found. CONCLUSIONS: Mesocyclops aspericornis increased their predatory efficiency depending on their density in numbers lower or equal to 25 copepods/L, and the predation efficiency rises to 1 copepod/8 larvae ratio, which evinced a type-2 functional response.

Keywords : Copepods; biocontrol; Culex quinquefasciatus; Mesocyclops aspericornis.