Biopesticides and Integrated Pest Management (IPM) Introduction
while giving information about insect and disease resistant transgenic crops, we discussed about the losses to crop yields caused due to infestation by a variety of pests and diseases. An estimated one third of global agricultural production is destroyed by over 20,000 species of field and storage pests. According to some estimates, the crop losses due to arthropods, diseases and weeds on a world wide basis have increased from 34.49%in 1965 to 42.1% in 1990, despite intensive pest control measures. In terms of money, these losses amount to US $ 300 billion annually. These losses account only for crop production losses, so that if we include post-harvest losses due to storage pests, etc., the total losses in developing countries reach a staggering level of about 60-70%.

In view of the above problems with the use of pesticides, there is a world-wide search for economically acceptable alternatives to the use of these toxic chemicals. One such alternative that was discussed in is the use of insect resistant transgenic crops that carry genes like Cry genes(s) derived from Bacillus thuringiensis or protease inhibitor genes (e.g. cowpea trypsin inhibitor genes (e.g. cowpea trypsin inhibitor gene, CpTI) derived from some legumes. Considerable effort is, however, directed towards the search of other alternatives also. As a result, newer technologies have either already emerged or still emerging. For instance, a number of less hazardous chemicals, as well as less non-toxic biologically based products have been recommended and tried. The strategy has been described as ‘integrated pest management (IPM)’.

This newer approach to deal with crop losses due to pests include biological control, integrated pest management and biotechnology. The approach stresses on a more ecological or ‘system approach’ based on the study of population biology at the local farm level. The approach will thus involve a true integration of renewable technologies such as host-plant resistance and natural biological control, which can be made available to even the most resource-poor farmers. In this ‘integrated pest management (IPM)’ and the ecological system approach’ to control the pests and increase crop production. Major emphasis will be laid on biopesticides as a biotechnological approach, which is only a part of the total system approach.