mr arunkumar
i will tell you the most effective solution, a little costlier, but it ensures nearly ONE YEAR RELEIF from coockroadches

There is a tube ( like some oinment ) named GOODBY ROACHES
costing around QR.45. When I did nto get this, I got it from Dubai. 2-3 drops of this liquid, apply different parts of the house..and forget cockroaches for one full year.

So surprising...I dont know how it works or weans away the insects