Controlling mosquitoes naturally and safely to avoid mosquito-borne diseases is an urgent need. Plant oils are a promising
source for mosquito control. The larvicidal effects of 18 oils were evaluated against the early 4th
larvae, Culex pipiens. All
oils showed larvicidal activity (55 to 100%, 24 h post-treatment with 2000 ppm for 24 h). The efficacy of oils was classified
as the highly effective group (H group) inducing 95-100% mortalities, including six oils: Azadirachta indica, Cyperus alternifolius,
Lupinus luteus, Lactuca sativa, M. alternifolia, and Persea americana (MO% = 98.33, 100, 98.33, 98.33, 100, and
95%, respectively). Their LC50
values were 588.31, 496.96, 677.45, 611.60, 445.28, and 646.34 ppm, respectively; whereas
their LC99
values were 1601.14, 1331.06, 1953.29, 1667.27, 1342.56, and 1725.94 ppm, respectively. The moderately effective
group (83-93% mortalities) included Syzygium aromaticum, Capsicum annuum, Aloe vera, Nigella sativa, Phyllanthus
emblica, Citrullus colocynthis, Daucus carota, Carthamus glaucus, Ocimum basilicum, and Triticum aestivum. Their LC50
values ranged from 762.39 (S. aromaticum) to 1043.59 ppm (T. aestivum). The least effective group included P. armeniaca
(55%) and Allium cepa (78%). The novel larvicidal activity of seven oils (C. glaucus, C. alternifolius, D. carota, L. sativa, M.
alternifolia, P. armeniaca and T. aestivum) against larvae of Cx. pipiens was reported for the first time in this investigation.
Our findings demonstrate the potential of M. alternifolia, and C. alternifolius followed by A. indica, L. luteus, or L. sativa
as the most potent larvicides that could be used for integrated mosquito control programs. |
