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ARS Home » Southeast Area » Fort Lauderdale, Florida » Invasive Plant Research Laboratory » Research » Research Project #441007

Research Project: Biological control of earleaf acacia (Acacia auriculiformis) in Florida

Location: Invasive Plant Research Laboratory

Project Number: 6032-22000-013-090-R
Project Type: Reimbursable Cooperative Agreement

Start Date: Jul 1, 2021
End Date: Aug 30, 2022

The objectives of this project plan are to develop environmentally safe, self-sustaining methods for the management of invasive weeds of exotic origin that threaten ecologically sensitive aquatic and terrestrial ecosystems of the United States, with a focus on the southeastern region. This project is relevant to the NP 304 Action Plan, Component 2 – Weeds; Problem Statement 2B: Biological control and ecosystem research and Problem Statement 2C: Integrated approaches to weed management; Objective 2: Survey native habitats of the candidate weeds in their geographical areas of origin for potential biological control agents. Acquire and characterize biological control agents and conduct thorough host-specificity tests informed by molecular phylogeny to determine fundamental host range. [C2, PS 2B] The objectives specific to this project are: Objective 1: Continue biology studies and host range testing of Calomela beetle populations. Objective 2: Establish rearing protocols for Trichologaster and begin biology studies. Objective 3: Continue regular collections of Calomela intemerata, Macrobathra arrectella, and Trichologaster spp. as needed to replenish laboratory colonies and obtain environmental data for biology studies. Objective 4: Establish colonies of Macrobathra arrectella at IPRL, Fort Lauderdale, and UFIFAS IRREC, Fort Pierce from established colonies at ABCL, Australia Objective 5: Synthesize and compile herbivore surveys on Acacia auriculiformis in Australia.

Since the earleaf acacia project began with feasibility studies in 2015, significant progress has been made towards finding viable biological control agents. We have determined that earleaf acacia is a problematic invasive plant and is in the log phase of expansion, especially in southwest Florida. Foreign surveys for arthropod herbivores and pathogens have yielded several promising candidates, one of which will likely be petitioned for release to the Technical Advisory Group (TAG) for the Biological Control of Weeds. Additional agents, after initial host-specificity screenings, have been established in colonies in Australia and will be transferred to the US for additional host range testing. The initial exploration and testing phase of the earleaf acacia project was funded through FWC cooperative agreements and is concluding. Continued support is needed to see these promising agents to fruition so that we have effective tools to help control the rapidly spreading earleaf acacia invasion. We will continue to obtain related species and test multiple candidates for their potential for biological control.