You can minimize insect damage in your farm or garden without any chemical sprays by installing yellow insect traps which could be a piece of yellow plastic sheet as in photo.
If it is not the commercial yellow insect trap that is already sticky, you can spray vegetable oil or even used motor oil on both sides. Then install the same where your plants are. You can install two or three in a 200-square meter lot. The insects are attracted to the yellow color and in the process they get stuck in it. This practice is now becoming more popular, especially among those who are into organic farming.