Location: Invasive Species and Pollinator Health
Project Number: 2030-30400-002-000-D
Project Type: In-House Appropriated
Start Date: May 13, 2026
End Date: May 12, 2031
Objective:
Objective 1: Discover, develop, and evaluate candidate biological control agents of intractable invasive species.
Sub-objective 1.A: Assess the microbiome associated with invasive cheatgrass populations and a co-occurring native grass species across spatial and temporal gradients.
Sub-objective 1.B: Native-range collection of candidate BCAs and exploration for natural enemies of targeted invasive species.
Sub-objective 1.C: Establish laboratory colonies and evaluate candidate BCAs for host-specificity and impact on targeted invasive species.
Objective 2: Develop integrated protocols to assess and optimize the release, establishment, and impact of biological control agents of invasive species.
Sub-objective 2.A: Demonstrate proof-of-concept for a novel genetic drive mechanism in a model plant species.
Sub-objective 2.B: Test the role of microbial interactions driving the efficacy of established and novel microbial bioherbicides in the genus Pseudomonas for cheatgrass control.
Sub-objective 2.C: Monitoring of establishment and impact of released biological control agents.
Approach:
For Objective 1, ARS scientists will conduct paired sampling of invasive cheatgrass and a co-occurring native grass species, Elymus elymoides, in five western states to assess the microbiome associated with both species across spatial and temporal gradients. They will collect natural enemy species of targeted invasive weeds in the home range of the weed species, describe or identify the natural enemies to species using traditional and molecular techniques, establish experimental colonies in the ARS-Albany quarantine laboratory, and evaluate them for host-specificity and impact on targeted invasive species. In addition, several insect species that are known to parasitize important and emerging agricultural insect pests of the Pacific West region will be evaluated for their host-specificity and impact on the targeted pest insects.
For Objective 2, ARS scientists will design a novel genetic drive based on a eukaryote-derived transposon to produce super-Mendelian inheritance when transformed into Arabidopsis thaliana with a marker-gene cargo as a proof of concept for a strategy to deploy female-sterility genes in similar contructs to control intractable invasive weed species. They will test the role of locally adapted microbes in driving the efficacy of established and novel microbial bioherbicides for cheatgrass control by culturing Pseudomonas isolates collected from soils at seven sites in five states. They will also monitor the establishment and impact of several released biological control agents on targeted weeds and insect pest species using classical and novel molecular protocols.