Suitability of Creeping Bentgrass and Bermudagrass Cultivars for Black Cutworms and Fall Armyworms (Lepidoptera: Noctuidae).

The black cutworm, Agrotis ipsilon Hufnagel, and fall armyworm, Spodoptera frugiperda Smith (Lepidoptera: Noctuidae), are common turfgrass pests of golf courses in the southeastern United States. Heat-tolerant bentgrass (Agrostis stolonifera L.) cultivars are expanding the range of bentgrass further south, but these cultivars have not been studied for their potential host plant resistance to black cutworm or fall armyworm. The goals of the study were to investigate feeding response of black cutworm and fall armyworm to these newer heat-tolerant creeping bentgrass cultivars, as well as commonly used cultivars of bermudagrass [Cynodon dactylon (Loppers.)]. Choice and no-choice feeding assays and fecundity tests were conducted in the laboratory and greenhouse to evaluate performance and preference of the two insects. When given a choice, neither black cutworm nor fall armyworm showed a preference for the majority of new cultivars tested. There were no differences in leaf area consumption or insect development for either pest in no-choice feeding assays. Black cutworm females preferred laying eggs in bentgrass compared with bermudagrass, but will oviposit onto bermudagrass, suggesting that both turf species are suitable hosts of this pest. The broad host ranges of generalist caterpillar pests of turfgrass hinder the application of host plant resistance in integrated pest management on golf courses.