Larvicidal potency of selected xerophytic plant extracts on Culex pipiens (Diptera: Culicidae)

Journal Article
مستخلص المنشور: 

Chemical insecticides released into the environment may have adverse biological
effects. Therefore, there is a need for ecofriendly insecticides for mosquito control.
Xerophytic plant extracts that may provide more ecofriendly active component were
evaluated against Culex pipiens 4th instars. Plant extracts prepared using different
solvents with a Soxhlet apparatus and different concentrations were tested against
Culex pipiens larvae. The effects were observed at 24 h and 72 h intervals and LD50
and LD90 values determined. Chloroform (CHCl3) and ethyl acetate (EtOAc) extracts
of Althaea ludwigii were the most effective against Cx. pipiens 4th instars, but were
highly dependent on extract concentrations and exposure time. Results suggest that
A. ludwigii extracts contain bioactive compounds, such as phenols and saponins, that
may provide effective Cx. pipiens larval control. However, the extract was found to be
toxic to zebrafish larvae, and may be toxic to other aquatic fauna. Further studies to
determine the active components and toxicity to other fauna are needed.