Multiple Pseudacteon phorid fly species, including P. tricuspis and P. curvatus,
have been released in the southern United States beginning in 1997 and 2003
(respectively) to serve as biological control agents against red imported fire ants
Solenopsis invicta Buren (hereafter referred to as RIFA). Field research in the United
States on phorid/RIFA interactions has addressed establishment and spread of released
species. Additionally, studies are needed on phorid biology and ecology with respect to
spatial distribution and phenology, phorid/habitat associations and phorid-mediated
affects on RIFA foraging patterns.
A suite of manipulative laboratory and field experiments/observations were
conducted to 1) develop a novel phorid sampling device to provide uniform and
repeatable sampling of flies, 2) assess spatial distributions and phenology of
Pseudacteon tricuspis and P. curvatus, 3) assess P. tricuspis and P. curvatus habitat
associations and 4) assess phorid-mediated affects on RIFA foraging patterns and caste
ratios. PTS Traps (developed for this research) are significantly more effective than
previous sampling methods in terms of mean number of flies collected, efficiency of use
and % trap success. Data collected with these traps allowed for the determination of
patterns of species-specific phenology and relative densities through time and speciesspecific
numerical/spatial superiority (Chapter IV). P. curvatus was significantly more
abundant than P. tricuspis in only one of the habitat types sampled (df (160) = 4.57, P <
0.005). P. tricuspis densities did not differ significantly among habitat type.
Llaboratory experiments revealed that phorid-exposed RIFA colonies foraged less
intensively diurnally (df = 1,558; P < 0.05) and more intensively nocturnally (df = 778;
P < 0.05) relative to control colonies. Field data regarding this compensatory nocturnal
foraging shift did not corroborate those of the laboratory work. In the field there was no
significant difference in foraging intensity during nocturnal (df (18) = -0.486, P = 0.633)
and diurnal (df (18) = 1.375 P = 0.186) sampling periods. Lastly, chi-square analysis of
RIFA forager size-classes revealed significant differences between phorid-infested
(treatment) and phorid-free (control) sites (X
2 = 6811.85, df = 3, P < 0.05) with a
significantly greater proportion of small RIFA foragers at the phorid-infested site.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2008-12-148 |
| Date | 14 January 2010 |
| Creators | Puckett, Robert T. |
| Contributors | Harris, Marvin K. |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation |
| Format | application/pdf |
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