Thesis (M.S.)--University of Tennessee, Knoxville, 2003. / Title from title page screen (viewed Mar. 16, 2003). Thesis advisor: Bruce E. Tonn. Document formatted into pages (iv, 75 p. : color ill., maps). Vita. Includes bibliographical references (p. 62-74).

The assemblage of bacteria and fungi associated with red imported fire ants (RIFA) Solenopsis invicta Buren was obtained from Hinds, Leake, and Madison Counties (location) along Natchez Trace Parkway in Mississippi. The sites were selected due to the limited presence of RIFA within the park and the more natural, undisturbed ecosystem. Active mounds containing soil, plant debris, and RIFA (substrate) were collected in March, July, and November of 2004 (time). Samples were processed according to standard microbiological protocols, and microorganisms identified using morphological, biochemical and molecular methods. A total of 71 bacteria (2324 isolates) and 50 fungi (1445 isolates) were obtained. The most common bacterium and fungus identified were Bacillus sp. B76(B)Ydz-zz, and Trichoderma aureoviride strain IMI 113135. The fungal entomopathogens Paecilomyces lilacinus and Metarhizium anisopliae var. anisopliae were isolated from mound soil, plant debris, and external tissues of the ants. Patterns of species richness, diversity, and evenness values across substrates were 71, 1.58, and 0.37 for bacteria, and 50, 1.11 and 0.28 for fungi, respectively. Total coefficient of community values for bacteria were 0.74 – 0.89 and 0.79 – 0.92 for fungi indicating uniform communities. No consistent trends were observed by comparing substrate, location, and sampling date. However, fungi species richness and diversity for ant external tissues were significantly higher than internal tissues of the ant. Selected bacteria and fungi were evaluated for their biological control and/or antagonistic potential in vitro and in situ. The most promising isolates studied in vitro included Paenibacillus sp. JA-08, Aspergillus terreus, and Aspergillus sp. HZ-35 with death rates on mound soil surface at 4.4, 5.0, and 4.8. The fungus Metarhizium anisopliae var. anisopliae strain LRC 211 had low death rate (1.8) on mound soil during in vitro trial but showed the greatest biocontrol potential during in situ evaluation. After 14 days in situ evaluation, the living RIFA extracted showed sluggish movement and the fungus was recovered from dead (48.3%) and living (33.3%) RIFA. Since the in situ trials were conducted only at one location and season, additional tests, including microscopic documentation of parasitism/pathogenicity, are needed to confirm the results of this study.

The study was divided into three main sections. In the first section, temporal stability of genetic structure of red imported fire ant populations and effective population sizes were assessed with the help of microsatellites. The second part of the study was focused on the development of new microsatellite markers for the population genetics study of fire ants. The third part of the study was aimed at describing the association of phenotypic and genotypic characters of polygyne hybrid (Solenopsis invicta x richteri) fire ant in a colony and identifying the origin of polygyny in hybrid imported fire ant colony. Meridian, Yazoo City and Crystal Springs in Mississippi and Mobile, Alabama were selected for conducting the study. The overall FST estimates and the pairwise FST estimates between the populations of study, indicated little genetic differentiation and low spatial variation in the nuclear genetic structure of red imported fire ant. Gene flow estimates indicated that there is extensive movement between these populations. From 2006 to 2008 the FST estimates decreased and gene flow estimates increased, indicating that there is no equilibrium between genetic drift and migration in the populations studied. Effective population sizes ranged from 10 -17 in these populations.We have isolated and characterized an additional 11 polymorphic microsatellite loci in the invasive ant S. invicta from a population in Lauderdale County, Mississippi. The observed and effective number of alleles ranged from two to six (average 3.1818 ± S. E. 0.0486). Probability tests indicated significant deviations from the Hardy-Weinberg equilibrium at three loci. The polymorphism information content of the microsatellites ranged from 0.1482 to 0.6208.Identifying multiple inseminated queens in a colony and sequencing the critical region of Gp-9 locus (1600 base pairs) in individuals with the polygyne allele strongly indicate the association of phenotypic and genotypic characters of polygyny in a hybrid imported fire ant colony. A 100% match of Gp-9B and Gp-9b alleles and concordance in the critical amino acid substitutions of the Gp-9 locus in the hybrid fire ant with S. invicta Buren provides the evidence that polygyny in the hybrid imported fire ant colony is derived from S. invicta.

Field trials were conducted in 1988 to evaluate the effectiveness of Steinernema (=Neoaplectana) carpocapsae (Weiser) in controlling the fire ant. Infective juveniles (IJ) of the nematode were applied as drench on 235 and 422 mounds, respectively for 2-month summer and 6-week fall evaluation periods. In comparative trials, amidinohydrazone (Amdro) was applied to 249 (summer) and 65 (fall) active mounds, with 245 (summer) and 78 (fall) untreated active as controls. Nematode treatments resulted in an average of 47% control (Abbott's formula) in summer trials and 19-88% control in the fall trials, compared with 39% and 47% control, respectively with amidinohydrazone. Active mounds treated with nematodes or amidinohydrazone had significantly fewer individuals than control mounds in summer trials.

Dissertation (Ph.D.)--Auburn University, 2006. / Abstract. Includes bibliographic references.

Thesis (M.S.) in Entomology--University of Maine, 2007. / Includes vita. Includes bibliographical references (leaves 46-52).

No description available.

Thesis (Ph.D.)--Mississippi State University. Department of Entomology and Plant Pathology. / Title from title screen. Includes bibliographical references.

Grassland communities represent major biodiversity hotspots across the United States. Among these grassland types is the short-leaf pine savanna, a major historical habitat along the Cumberland Plateau. The Cumberland Plateau’s grasslands are under threat due to land use changes such as urbanization and land conversion to pasture and hardwood forests. This study seeks to better understand the community ecology of ants on the Cumberland Plateau using powerlines as a comparison to degraded and historic habitats. Ants have a preference between open sites and forested sites, a separation of 44.5% on a DCA. The Simpson diversity places the short-leaf pine savanna significantly lower than adjacent forest, (df-3, F=3.56, p-value=0.029; Figure 1.5). Stenamma Westwood, 1839 is a cryptic genus with a Holarctic clade of 44 species, six of which occur in the southeastern United States. This work is a redescription providing an updated key, with images to those species in the southeast.

Red imported fire ant specimens were first collected in Virginia in 1989 from colonies located in Hampton, Va. Now colonies are established throughout the Hampton Roads area of Virginia. Because the fire ant is a new pest information regarding the distribution, biology, and management of the ant in Virgnia are absent. Therefore studies were conducted to compare the efficacies of four broadcast fire ant control products and an individual mound treatment to control fire ants and to determine the impact of Advion and Top Choice on non-target ant species. Additionally, twenty-six fire ant colonies in Virginia were sampled to determine colony social form and to detect biological control organisms. Lastly, the CLIMEX model was used to predict the potential spread of the fire ant in Virginia. Field trials showed that combination applications of Advion and Top Choice provided the fastest and greatest reduction in foraging three days after treatment and the longest residual control of fire ant colonies for one year. Field tests documenting the impacts of Advion and Top Choice on non-target ants indicate treatments do supress ant foraging but ant populations will rebound 10-12 months after treatment. Laboratory PCR assays revealed that colonies in Virginia are primarily polygyne. Also, Kneallhazia solenopsae, Pseudaction spp. parasitoid decapitating phorid flies, and Solenopsis invicta virues (SINV) genetic materials were detected in fire ant samples. CLIMEX model results indicate that fire ants will be able to spread as far east as the Greater Richmond area and as far north as Alexandria in Virginia. / Master of Science in Life Sciences