| Popis: |
Background: The Culex quinquefasciatus Say is an important vector of many diseases of public health and veterinary importance. Environmental pollution, resistance development and health hazards associated with the use of synthetic insecticides have led to explore eco-friendly and cost effective management methods for mosquitoes. Methods: In our study, simple water extracts from leaves and bark of three tree species; Eucalyptus camaldulensis, Azadirachta indica (Neem), and Moringa oleifera, were tested to explore their potential negative effects on the oviposition behavior and fitness of Cx. quinquefasciatus. Results: Oviposition bioassays showed a significant delay in onset of 1st oviposition in the all treatments as compred to control. Number of egg rafts and fecundity were significantly lower in all treatments compared to control. Larval emergence was significantly less in the all treatments as compared with the control except Moringa bark. Highest pupation was observed in control as compared to all other treatments. Importantly, no adult emerged in Eucalyptus leaf, bark and in Neem bark extracts. In case of toxicity bioassays, median lethal time (LT50) was lower at higher concentrations and higher at lower concentrations. At highest tested concentration of every botanical extract, LT50 was highly age dependent that is higher for elder larvae and vice versa. Conclusions: Therefore, it could be concluded that simple water extrcats, made locally, from trees may have a great potential to be incorporated in the mosquito control programs. |
