Location: Invasive Plant Research Laboratory
2010 Annual Report
Survey of melaleuca invaded sites in Miami-Dade County showed varying densities of biological control insects such as weevil and psyllid and an adventive foliar rust fungus (Puccinia psidii) inciting damages to the melaleuca population trees. Most of the melaleuca stands in Chekika areas of the Everglades National Park appeared to have lower densities of these natural enemies. Similarly, many melaleuca stands spotting undeveloped public and private lands south of Homestead-Miami Speedway and around Old-Dixie Highway (Old Card Sound Road) areas were virtually devoid of psyllids though a very low level of weevil damage was observed. Therefore, these sites were primarily targeted for psyllid and weevil redistribution during 2009-2010; these sites and others in selected areas that are deemed to have lower densities will be targeted during 2010-2011 also. During this 2009-2010 reporting period, we made a total of 34 releases totaling over 799,494 psyllids and 4,522 weevils within various melaleuca stands in these areas of Miami-Dade County. During this reporting year we concluded a long-term study designed to assess possible effect of melaleuca litter biomass on its native community invading potential and determined that slow decomposing rate of melaleuca leaves compared to sawgrass may be resulting in an accumulation of excessive amount capable of impeding recruitment of native plants. Also, we have been continuing to monitoring research sites maintained to determine the recovery of melaleuca sites and increasing site dominance by other plant species.
The biological control agent production, release, and establishment activities are directly monitored by ADODR thru one to two visits (per month) of psyllid production facility and release sites. Miami-Dade DERM’s continued financial support towards melaleuca biocontrol efforts of this laboratory has been extremely valuable.