Lygus management has become more important in Arizona cotton in the last few years due to a series of factors. Two of these factors, widespread availability of insect growth regulators (IGRs) for whitefly control and transgenic ‘Bt' cotton for lepidopteran control, have resulted in a drastic reduction in the number of Lygus-active insecticides sprayed in our cotton systems (see Ellsworth, this volume). In 1995, an average of 12.5 foliar insecticide sprays for all insects (1.26 directed at Lygus) were made in Arizona cotton, many of which had some degree of Lygus activity (see Williams, 1996–1998). In 1997, this was reduced to 5.33 applications (2.10 directed at Lygus), and about 0.5 of these were IGRs which have no Lygus activity. This reduction in use has effectively opened a window during which Lygus can cause damage and promoted this pest to major status. Another factor that has also raised the prominence of this pest in our landscape is the substantial increase in alfalfa acreage, including some seed alfalfa, in Arizona.