P. tricuspis
not annotated - annotated - LINNAEUS only
21526930
Fire ant decapitating fly cooperative release programs (1994-2008): two Pseudacteon species, P. tricuspis and P. curvatus, rapidly expand across imported fire ant populations in the southeastern United States.
Natural enemies of the imported fire ants, Solenopsis invicta Buren S. richteri Forel (Hymenoptera: Formicidae), and their hybrid, include a suite of more than 20 fire ant decapitating phorid flies from South America in the genus Pseudacteon. Over the past 12 years, many researchers and associates have cooperated in introducing several species as classical or self-sustaining biological control agents in the United States. As a result, two species of flies, Pseudacteon tricuspis Borgmeier and P. curvatus Borgmeier (Diptera: Phoridae), are well established across large areas of the southeastern United States. Whereas many researchers have published local and state information about the establishment and spread of these flies, here distribution data from both published and unpublished sources has been compiled for the entire United States with the goal of presenting confirmed and probable distributions as of the fall of 2008. Documented rates of expansion were also used to predict the distribution of these flies three years later in the fall of 2011. In the fall of 2008, eleven years after the first successful release, we estimate that P. tricuspis covered about 50% of the fire ant quarantined area and that it will occur in almost 65% of the quarantine area by 2011. Complete coverage of the fire ant quarantined area will be delayed or limited by this species' slow rate of spread and frequent failure to establish in more northerly portions of the fire ant range and also, perhaps, by its preference for red imported fire ants (S. invicta). Eight years after the first successful release of P. curvatus, two biotypes of this species (one biotype occurring predominantly in the black and hybrid imported fire ants and the other occurring in red imported fire ants) covered almost 60% of the fire ant quarantined area. We estimate these two biotypes will cover almost 90% of the quarantine area by 2011 and 100% by 2012 or 2013. Strategic selection of several distributional gaps for future releases will accelerate complete coverage of quarantine areas. However, some gaps may be best used for the release of additional species of decapitating flies because establishment rates may be higher in areas without competing species.
22182614
Short-Term Population Redistribution of Pseudacteon tricuspis (Diptera: Phoridae) From Point Source Releases.
There is a need for quantitative data on patterns and rates of movement of organisms to understand their movement behavior and predict their rates of spread. Opportunities for studying movement of biological control agents are presented during release programs. However, despite these opportunities, patterns and range of dispersal are often not considered. For example, information about effects of wind on dispersal patterns and heterogeneities in rates of movement is critical to predicting future range expansion of biological control agents and determining proximity of multiple releases. Here, the pattern and range of movement of a fire ant parasitoid, Pseudacteon tricuspis Borgmeier, was investigated by performing a series of mass-release-resighting experiments. Flies were released at a central location surrounded by radial transects containing trays of host ants at variable distances along four axes. Resighted flies were censused at these trays at 30 min intervals, up to 2 h postrelease. The dispersal pattern of P. tricuspis in the short term was consistent with a simple diffusion model. On average, 50% of P. tricuspis dispersed =<10 m, and 95% dispersed =<29 m. Diffusion rates were variable, depending on release densities, but tended to decline over time after release. Drift of dispersing flies was detected in several trials, and was attributed to prevailing wind dynamics. Data from this assessment of the short term redistribution pattern of P. tricuspis could be useful in determining proximity of releases of this, and other fire ant parasitoids.