Experimental evidence indicates that native freshwater fish outperform introduced Gambusia in mosquito suppression when water temperature is below 25°C

Abstract

In a series of laboratory trials, we compared the mosquito larvae predation efficacy of four endemic fish species and the introduced Gambusia holbrooki at different temperatures. Galaxias occidentalis and Galaxias truttaceus, consumed more mosquito larvae at 15 and 20°C and were equally effective consumers of mosquito larvae as G. holbrooki at 25°C. Nannoperca vittata and Bostokia porosa were equally as effective at consuming mosquito larvae as G. holbrooki at 15, 20 and 25°C. G. occidentalis in particular warrant further investigation as a mosquito control agent, not only due to their high consumption of mosquito larvae, but also due to their propensity to kill, but not consume more mosquito larvae than the other four fish species at both 15 and 20°C. For this species, stomach size and digestion rate do not appear to limit the number of mosquito larvae killed. These results indicate that endemic fish species may be more successful than the introduced G. holbrooki at mosquito control.