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United States Department of Agriculture

Agricultural Research Service

Research Project: QUARANTINE RISK ASSESSMENT OF BIOLOGICAL CONTROL CANDIDATES FOR DOWNY ROSE MYRTLE, RHODOMYRTUS TOMENTOSA

Location: Invasive Plant Research Laboratory

2013 Annual Report


1a.Objectives (from AD-416):
1. To determine the laboratory host range of agents selected for assessment, the first being Idiophantis sp.

2. To assess the data and discern the safety of releasing agents in Florida for biological control.

3. To prepare and release permitted insects for distribution and field evaluation in Florida.


1b.Approach (from AD-416):
The methods for determining the laboratory host range of agents will follow the guidelines for experimental methodology and analysis in the Reviewer’s Manual for the Technical Advisory Group [TAG] for Biological Control Agents of Weeds (http://www.aphis.usda.gov/import_export/plants/manuals/ports/downloads/tag.pdf). Specifically no-choice (starvation) tests to determine whether agents will complete development on nontarget species will be conducted. Should development occur, further tests of whether species will sustain agents for multiple generations will be made. If the laboratory host range of an agent is specific, then a petition for its release will be prepared and submitted to USDA APHIS PPQ for review by TAG. Approved agents will be transferred to scientists in Ft. Lauderdale for field release and evaluation.


3.Progress Report:

This research relates to in-house objectives: 3. Conduct faunistic and floristic inventories to discover natural enemies that may serve as biological control agents for target weeds including, but not limited to Brazilian pepper, lygodium, downy rose myrtle, skunk vine and Chinese tallow.

Additional biological control agents will be sought for species for which some control has been achieved, including melaleuca; and 4. Conduct risk analysis to determine environmental safety of new and existing potential biological control agents for weeds such as air potato, melaleuca, Brazilian pepper, lygodium, downy rose myrtle, Chinese tallow, waterlettuce and skunk vine.

Quarantine research at the USDA ARS Invasive Plant Research Lab located at the FDACS DPI Florida Biological Control Laboratory, Gainesville received approval from APHIS PPQ to resume full operation in early December 2012. Meanwhile, surveys for host specific natural enemies of R. tomentosa in China (mainland and Hong Kong) resulted in the discovery and importation (to the Fort Lauderdale facility) of four lepidopteran species: Carea varipes, Neostauropus alternus, Metanastria gemella and Arna bipunctapex. Multiple generations of all species were reared on R. tomentosa in a quarantine laboratory, demonstrating that the plant is a developmental host. However, none of the species demonstrated sufficient host specificity to be considered for biological control of R. tomentosa in the USA. In March and April of 2013, a total of 168 Rhodomrytus woody stems potentially harboring lepidopteran or cerambycid stem boring larvae, and 8 species of lepidopteran leaf feeding larvae were contained in the shipments. Rearing of the leaf feeding larvae is nearly completed but rearing of the stem boring larvae will be ongoing for some time due to their long life cycles. Ongoing research focuses on rearing and initiating host range testing of these species.


Last Modified: 8/22/2014
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