1. Larvicidal oil or larvicide (such as temephos, Bacillus thuringiensis subspecies israelensis etc. ) can be applied to stagnant water directly with dosage according to the label instructions.

2. Depending on the product, larvicide may be applied weekly into the stagnant water until the water has been removed.

3. Higher than required concentration of larvicide or excessive amount of larvicidal oil would not give better result on killing the mosquito larvae.

4. Although larvicide has been distributed in 94 districts since 2002, logistic regression analysis showed no association between the intervention and dengue incidence.

5. Methods The density surveillance was conducted by the spoon method, and 10% beta-cypermethrin and 1% Abate larvicide were deployed on the spot for larval control.