Larvicidal activity of Hippocratea excelsa extracts against larvae: Aedes aegypti, Culex quinquefasciatus, and Anopheles albimanus (Diptera: Culicidae)

This study evaluated the larvicidal activity of hexanic, acetonic, and methanolic extracts obtained from the fruits-seeds and stems of Hippocratea excelsa against larvae of Aedes aegypti, Culex quinquefasciatus, and Anopheles albimanus. Acute toxicity bioassays were conducted under in vitro conditions using a completely randomized design. Major chemical compounds were identified by gas chromatography-mass spectrometry (GC-MS). The results showed that the hexanic extracts from the stem and fruit-seed at concentrations of 20-200 ppm caused 100% larval mortality in all three mosquito species after 12 h of exposure. The hexanic stem extract showed LC₅₀ values of 4, 4, and 3 ppm at 12 h for Ae. aegypti, Cx. quinquefasciatus, and An. albimanus, respectively. Similarly, the hexanic fruit-seed extract showed LC₅₀ values of 3.7, 3.7, and 3.4 ppm at 12 h for the same species. GC-MS analysis of the hexane stem extract identified hexadecanoic acid ethyl ester (1), 5-cyclohexyl-1-pentene (2), 2-methyloctacosane (3), eicosane (4), squalene (5), β-amyrone (6), and friedelan-3-one (7). These findings suggest that hexanic extracts from the stem and fruit-seeds of H. excelsa possess larvicidal potential for the control of Ae. aegypti, Cx. quinquefasciatus, and An. albimanus larvae.