Assessment of the predatory capacity on mosquito larvae of Jenynsia multidentata (Anablepidae) in presence of vegetation under laboratory conditions

Larvivorous fish have been studied as potential biocontrol agents of mosquito larvae and pupae through their trophic interactions. The use of native fish for mosquito control may have benefits for both aquatic biodiversity and human health. Evaluating the effect of vegetation on the predatory efficacy is fundamental to determine if this species can be used as a biocontrol agent. With the aim of evaluating Jenynsia multidentata (Jenyns, 1842) as a biocontrol agent of Culex pipiens Linnaeus, 1758, we tested its predatory capacity in the presence or absence of aquatic vegetation under laboratory conditions. Two independent experiments were conducted. Larval consumption at a density of 60 larvae (6 larvae/l) was significantly reduced with the vegetation increased. On the other hand, when the larval density was 120 (12 larvae/l), the predatory capacity of J. multidentata did not vary in the presence or absence of vegetation. This result indicated that vegetation effect on consumption could be related to prey density, since at the higher density of prey the probability of predator-prey encounter might be increased. Jenynsia multidentata is a good consumer in presence of vegetation and could be used as a potential biocontrol agent of mosquito larvae in natural environments with similar characteristics to the ones tested in these experiments.