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United States Department of Agriculture

Agricultural Research Service

Research Project: Search, Identify and Export Natural Enemies of Schinus Terebinthifolius, Pistia Stratiotes, Salvinia Molesta, and Eichhornia Crassipes

Location: Invasive Plant Research Laboratory

2013 Annual Report


1a.Objectives (from AD-416):
1. To search for and identify natural enemies of Schinus terebinthifolius Raddi (Anacardiaceae), Pistia stratiotes L. (Araceae), Salvinia molesta D.Mitch. (Salviniaceae), and Eichhornia crassipes (Mart.) Solms (Pontederiaceae) in Argentina and evaluate their potential use as biocontrol agents in the USA. When promising biocontrol agents are found, the following host range studies will be conducted: a) surveys of plant use under natural condition in the native range; and b) laboratory host specificity tests.

2. To export biological control agents of S. terebinthifolius, P. stratiotes, S. molesta, and E. crassipes to IPRL.


1b.Approach (from AD-416):
Collecting permits for the natural enemies of S. terebinthifolius, P. stratiotes, S. molesta, and E. crassipes will be obtained at the respective Provincial Fauna Directions. The insects will be collected mainly individually with aspirator or collecting the whole plant and will be held in plastic containers during the trip and provided fresh foliage until arrival to FUEDEI. Cultures of promising biocontrol agents will be established and data will be obtained on their biology: longevity, fecundity, duration of larval instars, etc. Host specificity tests: Adults of the candidates will be tested with feeding tests and with ovipositions test on the target weeds and on related plants. Test plants will be selected by phylogeny and environmental association. In addition, host specificity test will be performed o inmatures instars if necessary.


3.Progress Report:

This research relates to in-house objectives: 2. Elucidate the ecology and population dynamics of targeted weeds and their potential insect and pathogen biological control agents, and investigate the impact of weed suppression on community and ecosystem structure and function. 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. It is intended to establish an official relationship between IPRL and FuEDEI in Argentina. As a result of establishing this non-funded SCA, we have obtained an export permit, the first issued since 2008, which resulted in the importation and colonization of L. pistiae, a new potential biological control agent for P. stratiotes. Together, in collaboration with the Argentinean foundation FuEDEI, we have also been developing biological control agents of Brazilian peppertree, Schinus terebinthifolius. This is an invasive weed from Brazil, Argentina, and adjacent countries that infests the natural and agricultural areas of south Florida and Hawaii. During the past 12 months we have worked together compiling and organizing the list of herbivore species associated with this plant in its native South American range. This list totals 104 species that include caterpillars (50 spp), beetles (27 spp), bugs (10 spp) and diseases (4 spp). Of these, there remain 26 species that have not been studied and that represent groups that might be suitable for biological control. These species will be the focus of future surveys and quarantine testing. Species accumulation curve analysis that monitors the progress of new species discovery with each survey indicates that additional species will be discovered with continued surveys. These results suggest that continued surveys are justified and will recover new species to be considered for biological control.


Last Modified: 9/20/2014
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