YOU must have seen grasshoppers and beetles in the countryside or at home. They are common insects that can be easily found in Hong Kong.
But they are also one of many pests that bring damage to crops and affect livelihood of many farmers in developing countries.
Pest damage is therefore an enemy that farmers have to combat in order to grow enough food for their families.
In the old days, farmers had their traditional pesticide to cope with pests. The methods employed were non-chemical and natural, such as crop rotation, planting more than one crop or using 'trap crops' to attract pests away from main crops.
These methods were effective in diversifying the potential threat that pest could bring to the whole yield.
However, under the influence of Western-style intensive agriculture, farmers have abandoned their traditional subsistence farming practice and shifted to growing single cash crops such as cotton, banana and tobacco for export.