In India, about 68 per cent of the total population depends upon agriculture for livelihood. There is loss of agricultural products worth Rs. 5000 crore every year due to pests and insects.
This amounts to about 18 per cent of the total food production. Our country spends more than 700 crores every year on the import of chemical pesticides. About three lakhs farmers suffer pesticide poisoning in India due to unsafe handling, storage and application of the pesticides.
Agriculture is so important in India that a serious setback in this field can break the backbone of our economy.
To guard the agricultural produce from the pests, variety of pesticides are in use at present and most of them are toxic chemicals and broad-spectrum pesticides. They kill the enemy, i.e., the target pest but also harm the ecosystem seriously by killing a variety of desirable organisms, thus badly impairing predator-prey relationship.
These directly poison the persons who come in direct contact with them and cause serious health problems in humans who eat traces of pesticides in food items. Most of these pesticides are persistent or non-biodegradable. Hence these exhibit biological magnification by accumulating at higher concentrations in the top organisms of the food chain.
There are reports that even mother's milk and human tissues contain traces of certain pesticides these days. It is clear that once used, pesticides exist somewhere causing serious harm to the mankind and to the ecosystem.
There are reports that pesticides like DDT and industrial compounds like Polychlorinated Biphenyls (PCB's) can act as weak estrogen (the female sex hormone), which may lead to breast cancer in women and impotence in men. In fact, by importing the deadly pesticides, we are bringing in the severe problems associated with them.
Insecticides have helped health officials save millions of lives by killing insects that carry microorganisms causing diseases such as malaria, typhus, dengue fever etc. to name a few. On the other hand, however, malaria control through spray of DDT has caused so much environmental concern that it was banned in USA in 1972.
The usage of biopesticides is being encouraged all over the world. Many old practices pest and insect control are being reconsidered now. Some other old methods have paved the way for the isolation of certain chemicals and preparations of extracts that can be used effectively! Has been demonstrated that biopesticides are capable of destroying only the target pest with harming other live forms or disturbing the ecological balance to a great extent.
They are complete, biodegradable and do not cause any pollution of the environment. Most of the biopesticides % very specific in their action
So, usually pests and insects cannot acquire immunity against these pesticides. On t contrary, with the toxic chemical pesticides in use now, many pests develop genetic resisted and hence the dosage has to be increased every time or different pesticides have to be develop Many a time, elimination of one kind of pest may create other organisms as new pests. The scenario shifts from the bad to the worse.