Gebresilassie, Araya (PhD)Dugassa, Sisay (PhD)Muhammed, Merdya2021-11-082023-11-092021-11-082023-11-092021-09-21http://etd.aau.edu.et/handle/123456789/28557Mosquitoes that belong to the genus Anopheles are among the major vectors of vector-borne diseases (VBDs). Among VBDs, malaria plays a crucial role in public health challenges worldwide. The use of synthetic insecticides to control malaria vectors causes resistance, environmental toxicity and kills non-target animals. Thus, it is imperative to seek a relatively safe and effective alternative tool to the currently available mosquitocidal products. Natural herbal products with insecticidal properties would play an important role in resolving this problem. Therefore, the current study aimed to assess the effects of crude leaf solvent extracts of Calpurnia aurea, Momordica foetida, and Zehneria scabra against the laboratory colony of larvae and adults of An. stephensi. Fresh leaves of test plants were collected, air dried, and then separately ground to powder. The powders were soaked in aqueous, hexane, and methanol solvents. The extracts were concentrated, and a stock solution was prepared to desired test concentration. For comparison, temephos (larvicide) and untreated solutions were used as the standard and negative controls, respectively. Mortality was observed after 24 hrs recovery period. The statistical analyses were performed using SPSS software (Kruskal-Wallis test), and R software (a generalized linear model was used to determine LC50 and LC90 values of the extracts). Larvicidal activity between treatments, negative control, and standard groups were significant differences (P < 0.05). Among the test extracts, the lowest LC50 and LC90 values were recorded in larvae treated with aqueous extract of M. foetida with 34.61 ppm and 57.61 ppm, respectively followed by Z. scabra (LC50 = 35.85 ppm; LC90 = 68.26 ppm) and C. aurea (LC50 = 38.69 ppm; LC90 = 108.28 ppm). Larval mortality was not observed from the hexane and control treatments, while the temephos achieved 100%. In addition, aqueous extract of Z. scabra showed the most effective adulticidal action in An. stephensi with LC50 and LC90 values of 176.20 ppm and 425.13 ppm, respectively. The results suggest that the leaf extracts of the three test plants have the potential of being used for the control of An. stephensi instead of synthetic mosquitocides. Further studies need to be conducted to identify the active ingredients and their mode of action.enAnopheles StephensiBotanicalsPlants ExtractsAdulticidesLarvicidesThesis