Damage caused by castor seed oil and its ethanol extracts on Anopheles arabiensis Larvae, Gezira State, Sudan
Mutaman A.A. Kehail, Abdalla Ibrahim Abdalla, Nasir A. Ibrahim
Anopheles mosquitoes are considered as vector of malaria disease and some other endemic diseases in the world. There are some methods already been used for controlling mosquito; of which is natural products. This study was conducted at Laboratories of Faculty of Engineering and Technology, University of Gezira, to evaluate the damage caused by Castor seed raw-oil and its ethanol extract on Anopheles arabiensis mosquito larvae. The Castor seeds were collected from Wad Medani City, whereas, the mosquito larvae were collected from the breeding sites at Tayba village, Gezira State, Sudan. The Castor seeds were shade dried away from the direct sunlight, grounded and then kept separately in small plastic sacks. The raw oil (extracted from the castor seeds) was applied at a concentration of 1.67 ml/L (0.50 ml oil/ 300 ml water) while its ethanol extract was applied at concentration of 30.53 mg/L. The standards of WHO for testing the toxic compound against mosquito larvae was followed. The mortality in A. arabiensis larvae were 95% and 100%, respectively, for the ethanol extract and raw oil, after 24 hours. The results also showed the damage caused by each treatment on the dead larvae and on the survived larvae. The damage involved changes in skin color, formation of larval-pupal intermediate form, swelling, separation in digestive tract, separation of body hairs and decapitation. The study recommends adding these castor seeds as potential natural products for Anopheles larval control, and also running more sensitive tests on human, environmental resources and on the aquatic fauna.