Can surrounding landscapes be predictive of in-field pest infestation?
Abstract: Lygus hesperus is a key pest in the cotton Integrated Pest Management system of theSan Joaquin Valley of California, USA. By legal regulation, fields must remain free of any cottonplants from December until planting in March which prohibits arthropods from using cotton as anoverwinter site. L. hesperus is required to annually immigrate and a cotton field must rebuild itsentire arthropod food web during the production season, March until September. We proposeusing community mapping approaches to understand the risk of L. hesperus infestation to anindividual cotton field based on surrounding crop mosaic. In 2011, we sampled arthropodpopulations from selected cotton fields and mapped surrounding crops to a distance of 3.2km.Using spatial tools, we sliced concentric rings of 0.8, 1.2 and 3.2km around the cotton field andcalculated the frequency of crops within each ring. Comparing the abundance of known cropswhich act as sources or sinks of L. hesperus to the maximum infestation in and number ofinsecticide applications to a field, patterns emerged to indicate relative risk of crop assemblages.Understanding such patterns in the landscape creates the opportunity for a community to developplanned landscapes to mitigate this key pest.