Artemisia absinthium-borne compounds as novel larvicides: effectiveness against six mosquito vectors and acute toxicity on non-target aquatic organisms

The eco-friendly control of mosquito vectors is a crucial challenge of public health importance. Here we evaluated the larvicidal potential of Artemisia absinthium essential oil (EO) and its three major chemical constituents against six mosquito vectors: Anopheles stephensi, Anopheles subpictus, Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, and Culex tritaeniorhynchus. The EO was obtained by leaf hydro-distillation. Its chemical composition was analyzed using gas chromatography-mass spectrometry. Major components were (E)-β-farnesene (31.6 %), (Z)-en-yn-dicycloether (11.12 %), and (Z)-β-ocimene (27.8 %). The EO was toxic effect against larval populations of An. stephensi, An. subpictus, Ae. aegypti, Ae. albopictus, Cx. quinquefasciatus, and Cx. tritaeniorhynchus, with LC50 values of 41.85, 52.02, 46.33, 57.57, 50.57, and 62.16 μg/ml. (E)-β-farnesene, (Z)-en-yn-dicycloether, and (Z)-β-ocimene were highly effective on An. stephensi (LC50 = 8.13, 16.24 and 25.84 μg/ml) followed by An. subpictus (LC50 = 10.18, 20.99, and 30.86 μg/ml), Ae. aegypti (LC50 = 8.83,17.66, and 28.35 μg/ml), Ae. albopictus (LC50 = 11.38,23.47, and 33.72 μg/ml), Cx. quinquefasciatus (LC50 = 9.66, 19.76, and 31.52 μg/ml), and Cx. tritaeniorhynchus (LC50 = 12.51,25.88, and 37.13 μg/ml). Notably, the EO and its major compounds were safer to the non-target organisms Chironomous circumdatus, Anisops bouvieri and Gambusia affinis, with LC50 values ranging from 207.22 to 4385 μg/ml. Overall, our results highlight that (E)-β-farnesene, (Z)-en-yn-dicycloether, and (Z)-β-ocimene from the A. absinthium EO represent promising eco-friendly larvicides against six key mosquito vectors with moderate toxicity against non-target organisms.