Location: Invasive Plant Research Laboratory
Project Number: 6032-30400-001-029-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Jul 1, 2025
End Date: Jun 30, 2026
Objective:
Objective 1: Continue field and laboratory host range evaluations of prospective agents like Bagous clarenciensis and Elophila sp., particularly acceptance of North American species of Azolla.
Objective 2: Import Elophila sp. and expand host range testing.
Objective 3: Begin surveys of parasitoids on native Elophila species to gauge possible biotic resistance.
Objective 4: Examine the impacts of Azolla pinnata on freshwater communities (water, plants, invertebrates) in Florida.
Approach:
Objective 1 and 2. We are building the test plant list for Azolla pinnata, but this primarily focuses on no-choice tests using non-target species of floating water ferns (Azollaceae and Salvineaceae). These are not species diverse families, so the host range is relatively brief. No-choice tests are inherently conservative, so any taxa that experience non-target feeding will be added to choice tests and then multi-generational tests to determine long term viability on non-target hosts.
Objective 3. One of the major reasons biological control agents do not establish is due to resistance from the native community. Since we are considering an arthropod with a native congener, it will be important to determine the parasite load on this species and whether they will attack the Australian species. To do this, we are rearing Elophila obliteralis on A. pinnata and A. filiculoides and collecting larvae and pupae to rear through. Any parasitoids collected are preserved for identification.
Objective 4. One of the advantages of having a native congener that is polyphagous, is that we can use it as a proxy for determining impact on A. pinnata and A. filiculoides (it feeds on both). We have set up several mesocosms outside to look at multigenerational impacts on cover and biomass of A. pinnata.