Vol. 3, Issue 1 (2018)
Mosquitocidal potential of Rhodomyrtus tomentosa leaf extracts against Dengue and Zika virus vector, Aedes aegypti
Author(s): Muthu Kasinathan, Jayapal Subramaniam, C Elanchezhiyan, Samivel Kanthammal, Mayakrishnan Vijay
Abstract: Dengue is a mosquito-borne flavivirus found in tropical and sub-tropical regions of the world, mostly in urban and semi-urban areas. Aedes aegypti is primary vector and its day-biting mosquitoes spread disease, 40% of the world’s population living in an area at risk for dengue. The present study explored the effects of Rhodomyrtus tomentosa acetone and methanol leaf extract of R. tomentosaon larvicidal and pupicidal toxicity against dengue and zika virus vector, Aedes aegypti. The R. tomentosa dried plant materials (powder), 300 g of the plant materials was extracted with 1 L of organic solvents of acetone and methanol for using a Soxhlet apparatus boiling point range 60–80°C for 8 h at room temperature (27±2°C). The extracts were concentrated at reduced temperature on a rotary vacuum evaporator and stored at a temperature of 4 °C. The yields of the R. tomentosaacetone and methanol crude extracts were 12.86g and 14.11g, respectively. The larvicidal and pupicidal lethal toxicity was observed after 24 h of exposure; No mortality was observed in the control group. The LC50 and LC90 of R. tomentosa leaf acetone extract (RTAE) against the first to fourth instar larvae and pupae A. aegypti were; the LC50 value of first instar was 312.17, 352.65, 407.21, 471.60 and 523.91 ppm and 722.67, 739.19, 848.42, 944.81 and 1083.29 ppm, respectively.The LC50 and LC90 values of R. tomentosa leaf methanolic extract (RTME) against the first to fourth instar larvae and pupae of A. aegypti were; the LC50 value of LC90 values were; 263.82 ppm (I), 299.43 ppm (II), 331.64 ppm (III), 386.16 ppm (IV) and 419.56 ppm (pupae), respectively. The LC90 value of 1st instar was 609.83 ppm, 2nd instar was 677.22 ppm, 3rd instar was 746.13 ppm, 4th instar was 858.83 ppm, and pupa was 908.72 ppm (pupae), respectively. Overall, highlighted the larvicidal and pupicidal evaluation of acetone and methanolic leaf extract of Rhodomyrtus tomentosa against Dengue and Zika virus vector, Aedes aegypti. This is a new eco-friendly approach for the control of dengue and zika virus vector, Ae. aegypti mosquito as target species. The natural products of biopesticides are eco-friendly for the dengue vector control management programs.