The cornerstone of most pest management programs world-wide is the "Economic Threshold" concept which is based on the principle of controlling a pest only if it is economically prudent to do so i.e. the cost of control is less than the value of yield loss caused by the pest. To implement this concept effectively three key criteria must be met. Firstly it must be possible to estimate the abundance of the pest accurately, secondly a rapid curative control must exist, such as an insecticide or miticide, and finally the relationship between the abundance of the pest and reductions in the economic value of the crop must be known. All of these criteria are now met for mites on cotton in Australia.