Susceptibility of Aedes albopictus Larvae to the Larvicidal Activity of Three Types of Derris elliptica Extract.

Abstract

<b>Background and Objective:</b> The methanol, ethyl acetate and n-hexane extracts of <i>D. elliptica</i> root have high larvicidal activity against <i>Aedes aegypti</i> larvae, the primary vector of dengue but have not been understood their potential against <i>Ae. albopictus</i> larvae, the secondary vector of dengue that also transmits Chikungunya and Zika viruses. This <i>in vitro</i> study aims to understand the larvicidal activity of the 3 extract types of <i>D. elliptica </i>root against <i>Ae. albopictus</i> larvae. <b>Materials and Methods:</b> The tuba root extract types were obtained from the sequential extraction process with 3 steps of liquid-liquid partition as described in the previous report. Six concentrations were occupied in this experiment ranging of 0.5, 1.0, 2.0, 4.0, 10.0 and 15.0 mg L<sup>1</sup> each concentration was 5 times replicated and placed in 250 mL plastic cups. As many as 20 of 3rd instar larvae of <i>Ae. albopictus</i> were subjected in each treatment cup and larval mortality was observed after 24 and 48 hrs of exposure. <b>Results:</b> Larval mortality rates based on concentration range of 13.75-97.00 and 43,75-100%, 14.00-44.00, 34.00-90.00%, 12.00-47.00 and 28.00-88.00%, with the LC<sub>50</sub> after 24 and 48 hrs of exposure were 2.925 and 0.414, 16.184, 2.900, 15.789 and 4.380 mg L<sup>1</sup>, respectively for methanol, ethyl acetate and n-hexane extracts. <b>Conclusion:</b> The methanol, ethyl acetate and n-hexane extract of tuba root have high larvicidal activity against <i>Ae. albopictus</i> larvae. Further study on prototype formulation of larvicide and elucidation of the specific phytochemical compounds of the extracts were necessarily conducted.