Diversity, composition, and freedom to choose drive effects of St. Augustinegrass cultivar blends on an herbivorous insect

Abstract

Warm-season turfgrasses are conventionally produced and maintained as cultivar monocultures, which leaves them less resilient to pest attack than more diverse plantings. Recent evidence has indicated that mixing St. Augustinegrass [ Stenotaphrum secundatum (Walter) Kuntze] cultivars can provide pest management benefits compared with cultivar monocultures. Research in other systems has shown that the effects of plant diversity on herbivores often depends on the number and identity of plant species present. Host plant diversity can affect herbivore fitness via post-consumptive physiological effects or before consumption by influencing herbivore behavior or plant defenses. To investigate the mechanisms by which St. Augustine-grass cultivar diversity and composition affect an insect herbivore, six cultivars were mixed to create two levels of cultivar diversity,