Sodium chloride (NaCl) and detergent solution have been evaluated for mosquito larvae in la
boratory studies but there is no evaluation for powdery salt and detergent. Therefore, this current 
study evaluated the response of Anopheles coluzzii and Culex quinquifasciatus larvae to salt and 
detergent powders in semi-field experiments. Anopheles and Culex larvae were collected from 
the wild fields. Twenty larvae were introduced into 100ml of water with 1g, 2.5g, 5g, 10g & 15g 
of salt and detergent. These corresponded to 0.01g/ml, 0.025g/ml, 0.05g/ml, 0.1g/ml &0.15g/ml 
respectively. The experiment was replicated into ten. Analysis of variance test was used for sig
nificance and Probit model analysis was used to predict lethal concentrations for 50% and 95%. 
Mean toxicity of larvae increased as concentration increased in all the treatments. Cx. quin
quifasciatus and  exposed to 10g and 15g of salt and detergent recorded complete toxicity. The 
differences between Culex and Anopheles mosquitoes exposed to salt and detergent were signifi
cant (p<0.05). Complete mortality was recorded in all but at different time. Complete mortality 
in Culex and Anopheles exposed to 15g of salt and detergent was after 10 minutes. Irrespective 
of the species, lethal time for 50% of mosquitoes ranged from 5.0 to 1560.8 minutes whereas 
LT95 range from 6.3 to 1893.3 minutes for salt and detergent exposure. Culex exposed to deter
gent recorded the lowest lethal time. So, the salt and detergent at best concentrations were effec
tive and treated abandoned mosquito breeding site.