Evaluación larvicida del extracto etanólico de la semilla de carica papaya sobre larvas del IV estadio de Aedes Aegypti (Diptera : Culicidae) en condiciones de laboratorio

Abstract

The following project aims to evaluate the larvicidal effect of ethanol extract of Carica papaya seeds on Aedes aegypti larvae of IV stage in laboratory conditions, to generate natural alternatives on controlling the dengue vector. In the methodology were conducted six bioassays with different concentrations of ethanol extract of Carica papaya seeds 50, 100, 250, 500, 750 and 1000 PPM with four repetitions each, using 100 specimens by bioassay and a control group that only got dechlorinated water to compare mortality in the larvae subjected to experimental treatments and natural mortality without exposure. Readings were taken at 0, 2, 12, 24, 36, and 48 hours post exposure for the observation of mortality in each of the bioassays. Subsequently it conducted an evaluation of residual effect of C. papaya extract with fortnightly repopulation of specimens in the same initial conditions and thus determine the toxicity decrease of the extract diluted in water with the passage of time. Mortality rates in the bioassays of the ethanolic extracts of Carica papaya seeds in 50, 100, 250, 500, 750 y 1000 PPM after 48 hours were 46%, 87%, 95%, 99%, 100% y 100% respectively. It was determined by the probit model LC50 48.8 ppm and 151.2 LC 90 PPM. For lethal times 50% (TL 50) and 90% (TL90), it was found that TL50 was between 5 to 8 hours and TL90 between 10 to 12 hours , wherein the lethal time decreases by increasing the concentration. Finally it was corroborated through ANOVA analysis of a factor that the concentrations affect the mortality of Aedes aegypti larvae and it is concluded that the extract of Carica papaya has a high larvicidal effectiveness in concentrations above 100 ppm. As for the residual effect the mortalities were lower than initial, with 0%, 8%, 11%, 14%, 19% y 23% respectively to the aforementioned concentrations, therefore the extract degradation is evident with the passage of time, ensuring the use of this in aquatic environments for control of Aedes aegypti.