Host range trials are underway with the flower weevil on melaleuca a fungus, a wasp, a thrips, two moths, and a beetle on Brazilian peppertree a stem- boring moth on Lygodium a weevil on hydrilla and a flea beetle and a primitive leaf-rolling weevil on the Chinese tallow tree. Methods for colonizing and testing a melaleuca flower weevil were developed and refined.
The genetics work coupled with leaf nutritional analyses showed that a Brazilian peppertree thrips that failed to develop on Florida plants had been collected from the wrong variety of Brazilian peppertree in its home range. Genetic studies also show that worldwide waterlettuce populations comprise at least three distinct groups: South American, African/European, and Southeast Asian. Molecular genetics studies comparing Florida and overseas populations helped identify the origins of lobate lac scale (Malaysia), feathered mosquitofern (Australia), and Brazilian peppertree. Quarantine and overseas host range studies helped eliminate from further consideration as biological controls a Japanese flea beetle on skunk vine, and three weevils and three moths on Brazilian peppertree. Petitions have been submitted requesting the release of an air potato beetle and a Lygodium sawfly. Surveys in the US and Argentina found several fungi that may have potential as biocontrols of fan wort, a submersed weed. The Lygodium moth and the melaleuca stem-gall fly are persisting, increasing in numbers, and dispersing from field release sites. Melaleuca seedlings exposed to these biological control agents had lower survival and slower growth than seedlings protected from them. Surveys show that the melaleuca weevil occurs in 71% and the melaleuca psyllid 78% of the plant�s range in Florida. Long-term monitoring shows melaleuca forests damaged by biological controls have more open canopies, reduced population densities, and are being reinvaded by native plants. During FY09, we conducted research with 12 weed species, 8 biological control agents, 26 potential agents, several fungal isolates, and 1 invasive insect. Significant Activities that Support Special Target Populations This report documents progress that Invasive Plant Research Laboratory staff and collaborators have made toward the biological control of invasive plant and insect species. Survey water bodies in Connecticut for presence of troublesome aquatic weeds. Identify ways to incorporate biological control agents into IPM strategies. Study biological control agents' impact on competition between target weeds and non-target native plants. Study their roles as insect feeding attractants/deterrents, effects on biological control agents' nutritional and reproductive physiology, and possible use in host-specificity protocols. Approach (from AD-416) Survey foreign nations for potential biolgical control agents, determine host-specificity of candidate species, release approved agents into natural and agricultural ecosystems, and evaluate influence of agents on target weed and non-target species population dynamics. To achieve this goal we will address the following areas: prioritizing and evaluating suitable target species for control conducting surveys to discover natural enemies studying the ecology of target species and determining the impact of their suppression on ecosystems conducting risk analysis of potential biological control organisms and releasing, establishing, evaluating, and transferring biological control agents against target species. Progress 10/28/04 to 10/19/09 Outputs Progress Report Objectives (from AD-416) The environmentally safe, sustainable suppression of exotic invasive species which threaten natural agricultural and urban ecosystems in the US with an emphasis on weeds.
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