Survival of Larvivorous Fish Used for Biological Control of <I>Aedes aegypti</I> Larvae in Domestic Containers With Different Chlorine Concentrations

Abstract

The two fish species Betta splendens (Regan) and Poecilia reticulata (Peters) are known predators of Aedes aegypti (L., 1762) larvae. Both species have been used for biological control in northeastern Brazil. However, the feasibility of these fish for the control of Ae. aegypti larvae in domestic containers may be limited by their survival in chlorinated water, as supplied by the public water system. We exposed fish to three different concentrations of chlorine: 1, 1.5, and 2.0 mg/liter. All B. splendens survived at 1.0 mg/liter chlorine concentration; 72.5 and 39.3% of B. splendens survived chlorine concentrations of 1.5 and 2.0 mg/liter, respectively. In contrast, only 4.4% of P. reticulata survived at a chlorine concentration of 1.0 mg/liter. We conclude that B. splendens may be an appropriate species for biological control of Ae. aegypti in domestic water tanks.

Survival of Betta splendens fish (Regan, 1910) in domestic water containers and its effectiveness in controlling Aedes aegypti larvae (Linnaeus, 1762) in Northeast Brazil

“…Assuming that the water for domestic consumption has a lower concentration of organic matter than natural breeding sites, it is probable that this restriction of nutrients is a factor reducing the longevity of Betta fish in domestic water containers. Regarding chlorine, it has been demonstrated that 27.5% of the fish specimens do not resist concentrations of chlorine of 1.5 mg/l (Cavalcanti et al. 2009).…”

“…2007). Specimens of B. splendens survived at 1.0 mg/l concentration of chlorine with no apparent discomfort and 75% of them survived at concentrations of 1.50 mg/l (Cavalcanti et al. 2009).…”

Biological Control of Dengue Vectors

“…The ability to withstand chlorine can be an important characteristic because in many countries chlorine is added to the drinking water, and that is then stored in large tanks by householders. A study comparing the chlorine tolerance of two larvivorous fish, B. splendens and Poecilia reticulata, found that P. reticulata was unable to withstand chlorine concentrations within the limits for human consumption in Brazil (Cavalcanti, et al 2009). Not always but, somehow there are reluctance of certain individuals to use fish in tanks because their presence stinks drinking water.…”

Survival of larvivorous fish used for biological control of Aedes aegypti (Diptera: Culicidae) combined with different larvicides

“…Possible reasons for the fishes' death are high concentrations of chlorine (Cavalcanti et al . ) and interaction with larvicides used in water reservoirs. According to Hurst et al .…”

“…However, in tanks where fish were placed and died later, the risk of infestation by A. aegypti larvae doubled (Oliveira-lima et al 2010). Possible reasons for the fishes' death are high concentrations of chlorine (Cavalcanti et al 2009) and interaction with larvicides used in water reservoirs. According to Hurst et al (2006), most manufacturers of larvicides claim that they are non-lethal to non-target species.…”