مختصر البحث:
ABSTRACT In this study, the efficacy of (hot and cold) water extracts and organic
solvent extracts (ethyl alcohol, ethyl acetate, and hexane) of Melia azedarach L
(Sapindales: Meliaceae) leaves was assessed as a larvicide for Culex pipiens L.
(Di…
ABSTRACT In this study, the efficacy of (hot and cold) water extracts and organic
solvent extracts (ethyl alcohol, ethyl acetate, and hexane) of Melia azedarach L
(Sapindales: Meliaceae) leaves was assessed as a larvicide for Culex pipiens L.
(Dipera: Culicidae). Hot water extract was more potent than cold water extract in larval
mortality. Average mortality of first, second, third, and fourth larval instars was 56.7,
52.2, 47.7, and 44.5%, respectively, after 24 h of exposure. The average mortality of the
same larval stages from the cold water was 51.1, 45.5, 37.8, and 36.7%, respectively.
Significant difference was found in pupal mortality as well. The average mortality
of pupae was 34.43% and 41.11% due to cold and hot water extracts, respectively.
Similarly, hexane, ethyl acetate, and ethyl alcohol extracts were toxic to pupae and
mortality recorded was 32.6, 27.95, and 28.36%, respectively. Hexane extract was
comparatively more toxic to larvae than ethyl acetate and ethyl alcohol extracts. The
results of the present study emphasize the importance of using toxic components
extracted from the plant to control the main vector of many detrimental diseases as
well as finding environmentally-friendly and sustainable biopesticides. Furthermore,
the results suggested that biocontrol programs should take into consideration the focus
on larval stages of C. pipiens when aiming to control this medically important insect.
However, further investigation is required to determine the efficacy of M. azedarach
leaves extracts on fitness of adult mosquitoes such as female longevity and fecundity
and egg hatching rate, especially those developed from larvae and pupae exposed to
M. azedarach extracts.
