Shifting crop landscapes: Implications to IPM in field crops using cotton and Lygus hesperus as a case study

Cotton has dominated the cropping landscape of the San Joaquin Valley in California for over 50 years. IPM for the key pest, Lygus hesperus, has developed with cotton as the dominate crop. In recent years, cotton production has substantially declined and the types of cotton have shifted. Pima cotton (Gossypium barbadense) has increased relative to upland varieties (G. hirsutum). The changes in crops in the landscape result in changes in the source and sink relationships of cotton to other Lygus hosts. The proximity of these crops to cotton fields plays an important role in the severity and duration of Lygus movement into cotton fields. These changes in Lygus population dynamics have created new challenges to IPM in cotton. This case study will illustrate the importance of understanding the role of landscape level systems to IPM.