The Creator created many kinds of creatures on earth. Among them, man is the best creature of creation, he has created many kinds of insects.

Well, that's your believe, and I respect that.

However, as a scientist I consider evolution as the power which 'created' every single organism which nowadays is existing on this planet by using the two methods mutation and recombination of genes (which for example is also the reason why children differ from their parents).

Furthermore, I wonder how you define "the best"?
Insects were living on this earth long before humans even existed ... and probably will still be here when we have already disappeared again (for example due to pollution of the environment, wars, epidemics or the climate change). If that happens the class Insecta would have clearly proved to be more successful than the species Homo sapiens. :)

Different types of pesticide powders are available in the market as wood resistant insect repellent.

In that case I hope for the inhabitants that the chemicals are less dangerous for human health than the repelled insects had been ...