Location: Great Basin Rangelands Research
Project Number: 2060-22000-024-44-I
Project Type: Interagency Reimbursable Agreement
Start Date: Oct 1, 2016
End Date: Sep 30, 2021
ARS-Reno and key collaborators will conduct laboratory, greenhouse and field research on the biology, ecology, and genetics of medusahead (Taeniatherum caput-medusae), cheatgrass (Bromus tectorum) and red brome (B. rubens), three annual grass species of Eurasian origin that are invasive in the Great Basin and Intermountain West, with the ultimate goal of discovering and developing effective biological control agents and other novel control strategies for these invasive grasses.
ARS researchers and their collaborators will collect eriophyid mite species and other natural enemies from medusahead, cheatgrass, and red brome plants through native range surveys, followed by taxonomic, genetic and biological (e.g. host-range) study of these natural enemies to assess their suitability as classical biological control agents. Lineages of model eriophyid mite species will be characterized using fine-scale DNA fingerprinting and this data will be correlated with host-range traits and enable rapid screening of field-collected mites. PCR-based genetic markers for the three targeted grass species will be produced and utilized to describe relationships between native and invasive populations, to understand weed invasion dynamics and to identify putative native-range source regions for invasive weed populations; all markers produced will be made available to the public. The endophytic mycoflora of medusahead will be compared between its native and invaded ranges to investigate possible roles of endophytes in the invasion ecology of this grass. Selected target grass species populations will be observed throughout their annual life cycles to identify and compare important mortality trends between the native and invaded ranges.