I'm not one to use pesticides, they're fairly harmful to the environment. For me, the only toxic chemical I have used that works, mind you works way too well, is imidacloprid.

Seemingly harmless to plants in mild doses, but highly toxic to every insect. This stuff works as a water additive, where the plant will take the toxin up into its leaves and stems and even the fruit.

It acts as a repellent and doubles as an insecticide, anything that decides to bite the plant dies in mere seconds, I have seen some instances of bees dropping dead while pollinating the treated plants.

It's extremely destructive, and I advise anyone thinking of using it not to. A healthy plant won't be attacked by pests. They go for sick plants first.