Insecticide resistance continues to be a major problem for the cotton grower. It also is the focus of much of the research into the use and management of transgenic plants. At times, the jargon associated with resistance can be vague or misleading, not only to the cotton grower or consultant but also to specialists in pest management. Terms such as resistance factors, resistance levels and resistance frequencies are all used to connote the seriousness of resistance. The distinction among the three terms is not always clear and they are sometimes used interchangeably