Distribution, Field Recognition and Implications of Phytophagous Mite Species on Cynodon Spp. (Bermudagrass) and Pennisetum Clandestinum (Kikuyugrass) in Australia

In Australia, infestations of warm-season turfgrasses by plant-feeding (phytophagous) mites have been known for more than 80 years, but the identities and a full list of the mite species involved has remained unresolved. There had long been an underlying assumption among turf managers (based mainly on overseas literature) that mites of the family Eriophyidae were likely responsible for the distorted growth frequently seen and attributed to mite damage on Cynodon spp. (bermudagrasses) and Pennisetum clandestinum (kikuyugrass). A national survey during the 2010/11 growing season followed by opportunistic sampling over the next 5 years has revealed the presence of at least two eriophyoid mites: Aceria cynodoniensis, hitherto assumed to be the sole species involved based on US literature, and Abacarus cynodonis, a species not previously recorded outside of the Middle East. Importantly, the tenuipalpid species, Dolichotetranychus australianus, was also confirmed as a substantial contributor to mite damage symptoms seen on Cynodon dactylon and C. dactylon X transvaalensis. A newly described tarsonemid species, Steneotarsonemus hippodromus, was found extensively in both turf and pasture plantings of P. clandestinum. Additionally, grass-webbing spider mites, Oligonychus araneum and Oligonychus digitatus (Tetranychidae), also occasionally affect these and a wide range of other warm-season grasses non-selectively in Australia. This paper describes the field and laboratory sampling procedures used to identify the various mites, to describe their associated field symptoms for identification purposes, and to determine their distribution within Australia. It also discusses the putative origin of each mite species, their international distribution (including some related species), and implications for warm-season turf producers and facility managers, both in Australia and worldwide.