Introduction:

Aedes aegypti is the main vector of dengue, chikungunya, yellow fever and Zika in the world, chemical control is the most used for its prevention, attacking the reproduction of the mosquito vector, mainly through the application of synthetic insecticides in their breeding places. However, the use of synthetic insecticides has generated resistance in mosquitoes and several ecological problems. The extracts of natural plants with insecticidal function are used as an alternative for vector control. The objective of the present study was to evaluate the larvicidal activity of the Acacia farnesiana pod extract against fourth stage larvae of Ae. aegypti.

Method:

The study was developed in the Laboratory of the Instituto Tecnológico Superior de San Pedro Coahuila, and in the ejido Mayran, San Pedro, Coahuila Mexico. The extract we prepared according to the methodology proposed by INIFAP-CENID-RASPA 1997. The extracts were used in bioassays with fourth instar larvae of Ae. aegypti for 168 hours. Groups of 20 larvae were transferred into plastic cups with 50 mL of water, then 1 mL of each treatment of Acacia farnesiana was applied with final concentrations of 15 % (T1), 25 % (T2), 35 % (T3) and 70 % (T4). For the chemical control Abate® 1SG (Temephos) at 25 % was used. No treatment was applied to the blank. To compare mortality, a one actor analysis of variance was performed for each study (laboratory and field) and an analysis of repeated measures over time for the field phase. A Tukey mean comparison test was developed. The analysis were carried out using the statistical computer program IBM.SPSS 18, with a significance level of P ≤ 0.05.

Results:

In the laboratory, the extract of A. farnesiana at 35% concentration showed greater toxicity against larvae of Ae. aegypti obtaining an average mortality of 15.66 (78.3 %) 72 hours after treatment application (P ≤ 0.05). In the same way, under field conditions, the 35 % treatment turned out to be the most effective, reaching an average of 19.04 (95.2 %) dead larvae.

Discussion or Conclusion:

The extract of A. farnesiana showed insecticidal activity against Ae. aegypti larvae, being more effective at 35 % concentration in laboratory and field conditions. The larvicidal effect of the A. farnesiana extract can be used as a feasible and sustainable alternative to control Ae. aegypti in rural areas. However, it is necessary to do more studies to identify the active ingredients and the action mechanism present in A. farnesiana pods for vector control.