ABSTRACT
The protection of crops and harvests has been a historic preoccupation of mankind since the first steps in agriculture 10,000 years ago. Plant extracts were used to protect stored grain well before our era and techniques of biological control were already in use in citrus orchards in China in the 8th Century. The scientific bases of the discipline of agronomy are more recent and are still incomplete despite the development of the natural sciences, which provided an initial description and identification of pest species associated with crops and foodstuffs, and later an understanding of their biology and of their role in the functioning of ecosystems. For example, 1889 is a historic date in the use of beneficial insects, when ladybirds from Australia and New Zealand were released into orange groves in California to control outbreaks of scale insects. The discovery of synthetic pesticides in the 4th decade of the 20th Century was another epic event!
