[Predatory capacity of Macrobrachium tenellum on Aedes aegypti larvae in lab conditions]

Abstract

INTRODUCTION: in the last few years, a lot of importance has been given to natural predators against Aedes aegypti. Several organisms have been studied both in lab and in the field so as to find out their capacity to devour mosquito larvae. High densities of Macrobrachium tenellum are found in natural conditions, it is not aggressive and may stand wide ranges of temperature, rates of salinity and oxygen concentrations. OBJECTIVE: to evaluate the predatory capacity of Macrobrachium tenellum on Aedes aegypti larvae in lab conditions. METHODS: very young Macrobrachium tenellum prawns measuring A(3.0-3.5cm) and B (4.5-5 cm) were used. The mosquito larvae were obtained after hatching of egss from adult females kept in entomological cages. Five, ten, fifteen and twenty Aedes aegypti larvae were placed per treatment per rank, whereas the second bioassays adjusted the number of larvae to 30, 40, 50 and 80 larvae per treatment per rank. RESULTS: Macrobrachium tenellum showed high rate of larval consumption for the two ranks and treatments. In the highest density (80 larvae), the consumption was 95% of larvae at 24 hours for rank A and 100% for rank B. CONCLUSIONS: Macrobrachium tenellum may be considered as a potential biological control agent, due to its abundant presence in natural conditions, its resistance to different environmental conditions and to its voraciousness seen in this study.