Browsing by Subject "Fire ants"
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Item A faunistic survey of the organisms associated with ant colonies of West Texas (especially Solenopsis spp.)(Texas Tech University, 1980-12) Neece, Kenneth CharlesNot availableItem A survey for pathogens associated with the ants of West Texas (especially the Solenopsis spp.)(Texas Tech University, 1980-05) Beckham, Richard D.Representative samples of 113 different ant species from west Texas (west of the l00th Meridian) were examined for the occurrence of indigenous pathogens. Samples of the red imported fire ant, Solenopsis invicta Buren, taken from the south central and south eastern part of Texas were also examined for indigenous pathogens. This survey was conducted to lay the groundwork studying the possible suppression by pathogens of the red imported fire ant in its westward movement. Samples were taken at 404 locations throughout the study areas. In the examination of 2,525 samples for the presence of bacteria, viruses, fungi and protozoa, only an occasional occurrence of a pathogen was detected. It appears that the potential for using pathogens presently associated with ant species to inhibit the westward migration of the red imported fire ant is small and that alternate methods of control must be investigated.Item Alginate pellet formulation of Beauveria bassinana pathogenic to the red imported fire ant(Texas Tech University, 1995-12) White, Hershel E,Not availableItem Digital image processing and spatial frequency analysis of Texas roadway environment(Texas Tech University, 1999-12) Tang, ZhenA report presented on the acquisition, storage, processing and analysis of digital images of both fireants activities and small target visibility, beginning with the general introduction of background knowledge in digital image representation, covering acquisition, storage, enhancement and finally development of methods to extract information of interest from the digital images. Fast Fourier transform and digital image processing techniques are reviewed and utilized.Item Effect of red imported fire ants on reproduction, health, and survival of northern bobwhites(Texas Tech University, 1999-08) Mueller, James MichaelThe red imported fire ant affects northern bobwhite by killing pipping chicks (Mitchell 1989) and altering activity of young chicks Pedersen et al. 1996). In addition, the red imported fire ant may dramatically alter the abundance of invertebrates, an important component of northem bobwhite diets, when it colonizes an area (Porter and Savignano 1990). However, there is no evidence northem bobwhite populations are significantly impacted by these particular effects. The red imported fire ant could affect northem bobwhite populations through other means, such as by altering growth or reproduction of northem bobwhite through physiological effects of envenomation. This study evaluated potential mechanisms by which red imported fire ants impact northern bobwhite reproduction, survival, and health. The objectives were to determine the effects of red imported fire ants on hatching success, growth, immunocompetence, and survival of northern bobwhite chicks.Item Effect of Solenopsis invicta buren territoriality on native ants of central Texas(Texas Tech University, 1985-08) Claborn, David MNot availableItem Feeding, clutch sizes, and the population dynamics of the Texas horned lizard, Phrynosoma cornutum(Texas Tech University, 2000-05) Fagan, Jesse F.This thesis includes the development of a population dynamics model on the Texas Horned Lizard and in addition, a prey model involving interaction between the Texas Horned Lizard's main food source, harvester ants, and the non-native fire ant. The goal of this work is to understand the population dynamics of the Texas Horned Lizard, the horned lizard's relationship with its prey, and the effects of fire ants on the biological complexity of this population.Item Foraging and recruitment abilities of Solenopsis invicta Buren, compared with other ant species indigenous to Texas(Texas Tech University, 1985-05) Jones, Stanley RSince its accidental introduction into Mobile, Alabama, the red imported fire ant, Solenopsis invlcta Buren, has become an economic pest of much of the southern United States. Each year this ant continues to expand its range. Why S. invicta is able to successfully colonize areas previously inhabited by multifarious ant species is not understood. Possible explanations include its aggressive behavior, large colony size, and foraging efficiency. This study was conducted to compare the foraging efficiency of S. invicta to three ant species native to south central Texas. Native ants studied include Pheidole dentata Mayr, Monomorium minimum (Buckley) , and Forelius foetidus (Buckley) . Temporal recruitment and food retrieval patterns were recorded and compared for all four species held at equal colony strengths. Results indicate that interspecific differences in recruitment patterns do occur. However, these differences are subtle and do not suggest that S. invicta is a more efficient forager under laboratory conditions, than the other three species.Item Ice-nucleating active bacteria: a novel approach to the management of the red imported fire ant(Texas Tech University, 1995-08) Landry, Camille EmmaOverwintering strategies are important in the survival of insects, and one such strategy involves the regulation of temperatures at which they freeze. Although all insects exhibit some degree of cold tolerance, they can generally be classified as either freeze tolerant or intolerant. Many freeze-intolerant insects seasonally depress their supercooling points, thereby increasing their cold-hardiness in preparation for winter. This study was conducted to assess the influence of cold acclimation on the supercooling ability of the red imported fire ant, Solenopsis invicta Buren. Colonies were consecutively exposed for seven days to decreasing temperatures of 10°, 5°, and O^C (treatments). At the end of each seven-day interval, a thermocouple probe was used to determine whole body supercooling points of randomly selected worker ants from each colony. In addition, head capsule widths and whole body weights were measured. Analysis of variance indicated a significant difference among supercooling points and acclimation temperatures (£ < 0.05). In the 1970's, ice-nucleating active bacteria, a new category of biological ice-nucleators, were discovered among other epiphytic bacteria living on the surface of plants. These ice-nucleating bacteria have the capacity to catalyze ice formation at - 1° to -2°C. I therefore studied the effects of topical mist application of the ice-nucleating active bacteria Pseudomonas syringae (American Type Culture Collection 39254) on the freezing point of minor and media worker ants. My results showed that treatment with P. syringae increased the temperature at which the red imported fire ant froze, thus decreasing its supercooling ability (NOVA; P < 0.05).Item In vitro cultivation of ovaries and ovarian tissue from the red imported fire ant, Solenopsis invicta Buren(Texas Tech University, 1983-12) Kral, Robert MardenA method for in vitro cultivation of ovaries and ovarian cells from Solenopsis invicta has been developed. Whole ovaries were kept alive, in Schneider's Dropsophila medium (pH 6.7) and Hink’s THH-FH medium (pH 6.1, 7.0), for up to six weeks without refeeding. Cells from physically and chemically dissociated ovaries were kept alive for up to 15 days. Very little evidence of mitosis was observed in cell cultures. TNM-FH, pH 7.0, supported cell cultures which were superior to those obtained in the other tested media. The addition of fetal bovine serum, bovine serum albumin, chick embryo extract, whole egg ultra filtrate, and glycylhistidyl-lysine to this medium did not induce growth or longevity greater than that observed in control media, which contained only fetal bovine serum. Overnight refrigeration of whole ovaries in 0.5 mg/ml collagenase solution, followed by 60 minutes incubation at 28o C and physical dissociation, gave a cell yield which was superior to that obtained by other methods of tissue disruption.Item Integrating prescribed burning and insecticide to reduce Fire ant impacts on Bobwhite chicks(Texas Tech University, 2003-12) Norton, Amy AllieneThe red imported fire ant (RIFA) has caused extensive damage to wildlife populations in Texas since its infestation. Northern bobwhite quail in particular have felt the negative impacts of RIFA. RIFA can cause severe injury to bobwhite chicks, rendering them unable to forage for food or escape predators. Observational and experimental evidence has shown that hatching bobwhite chicks experience a low survival rate when exposed to a significant number of foraging RIFA. Control and management of RIFA in Texas is important in protecting bobwhite habitat and potentially increasing bobwhite chick survival and nest success. We initiated a study in Victoria and Goliad counties to examine integrated control methods for RIFA in bobwhite quail habitat. Our research objective was to determine if a reduced rate of insecticide and/or prescribed burning could decrease the foraging activity of RIFA below the threshold that causes mortality of northern bobwhite chicks. Eight research sites were established in early 2002. Each site was divided into a burned and unburned plot. Individual burned and unburned plots randomly received one of four rates of insecticide treatment: 0, 50, 75 or 100% of the recommended label rate of Amdro®. Bait cup sampling of RIFA was conducted immediately prior to, four weeks, eight weeks, and twelve weeks after insecticide treatment. Treatments and sampling were repeated on six plots in 2003 on previously untreated sites in Calhoun County, Texas. Differences in RIFA foraging activity were analyzed among treatments. Differences were assessed using a two-factor repeated measures analysis of variance. RIFA foraging activity was responsive to Amdro® insecticide treatments. As the rate of Amdro® applied increased, foraging activity of RIFA declined. Data from 2002 and 2003 revealed a difference in mean number of foraging RIFA in insecticide treated plots versus control plots (P<0.05) when testing for the main effect of insecticide treatment. In both years, the mean number of foraging RIFA collected in bait cups in burned plots was not different from nonburned plots (P>0.05).Item Response of the red imported fire ant (Solenopsis Invicta Buren) to electricity and magnetism(Texas Tech University, 1995-12) Slowik, Ted J.The phenomenon of red imported fire ant (Solenopsis invicta Buren; Hymenoptera: Formicidae) attraction to electricity and electrical equipment has recently come under scrutiny because of an increasing economic impact (MacKay et al. 1989). Researchers have focused on elucidating the reasons behind ant accumulation in active circuitry and electrical apparatuses in an effort to prevent the resulting ant damage. The results of the research suggested that the electric fields generated in and by the equipment attract ants (MacKay et al. 1989, 1992a, 1992b). However, experimentation has also shown that ant contact with bare, active conductive material (MacKay 1992b) is essential in eliciting the characteristic response to the electricity, suggesting another interaction between ants and electrical current. Taken together, these recent findings about this ant behavior do not clarify, identify, or define the sole cause or interacting factors which cause the attraction of ants to electricity. Therefore, an examination of the importance of electric fields and electric current in generating ant response to active circuitry and an observation of ant behaviors at the electrical site will be conducted in Study One of this thesisItem Selected economic impacts of the red imported fire ant in Texas(Texas Tech University, 1999-08) Polk, M. WadeGiven the economic impacts of RIFA in Texas, procedures need to be developed to determine the precise impacts of RIFA on agricultural crop production, wildlife populations, and electrical and communication equipment. There are several procedures and strategies that are currently utilized to diminish and deter RIFA in Texas, but issues such as the environmental impacts and effectiveness of their control increase the need for further analysis and examination of economically viable approaches for RIFA control. New products and procedures such as electric protection devices, biological control formulations, and creative methods to protect wildlife populations have only recently been developed. Accurate estimates ofthe economic impacts of RIFA on agricultural crop production, wildlife populations, and electrical and communication equipment are necessary to accurately evaluate the effectiveness of the new products and procedures being tested.Item Temporal and spatial components of the yeast flora of the red imported fire ant (hymenoptera: formicidae)(Texas Tech University, 1994-05) Ba, Amadou SidikiFew investigations have examined the relationship between Solenopsis complex and its internal microflora. Most investigations on the red imported fire ant are either control oriented or emphasize the species' negative impact on ecosystems. Therefore, the objective of this research were (1) to isolate and identify yeasts from the red imported fire ant (Solenopsis invicta (2) to determine the impact of associated yeasts on red imported fire ant colony vigor, and (3) to clarify the significance of the association by obtaining and comparing sterol profiles of the yeast flora and the red imported fire ant. Colonies were collected from five locations in Texas: Beaumont, Huntsvllle, Waco, Stephenville, and Abilene. These sites represent a transect along a decreasing moisture gradient from the southeastern to the northwestern region of the state. Colonies were randomly collected during the winter of 1992, and the spring, summer, and fall months of 1993. Physiological and morphological tests showed that the 327 yeast isolates from Solenopsis invicta haemolymph represent five yeast species: Candida parapsilosis (168 Isolates), Candida lipolytica (123 isolates), Candida guillermondii (18 isolates), Candida rugosa (9 Isolates), and Debaryomyces var hansenii (9).Item The effects of red imported fire ants on white-tailed deer fawns(Texas Tech University, 2000-05) Brown, Wayne EvinSince being accidentally imported into the United States in the 1930's, the red imported fire ant [{Solenopsis invicta Buren); RIFA] has had a definable impact on wildlife, agriculture, and industry. A study in the Texas Coastal Prairie demonstrated a significant decrease in white-tailed deer {Odocoileus virginianus) fawn recruitment in RIFA infested areas. Our objective was to test whether mechanisms exist whereby RIFA could affect white-tailed deer fawn survival. We tested whether deer fawns exhibit behaviors that would preclude or reduce direct mortality due to RIFA stings. We hypothesized that RIFA presence would increase fawn movements during the first days after birth, increasing the susceptibility of fawns to predation. Red imported fire ant stings may also alter other fawn behaviors, including increasing licking rate and decreasing nursing rate, which could potentially reduce fawn survival. Red imported fire ants were chemically removed from four enclosures, while four others contained naturally occurring densities of RIFA colonies. We observed behavior of 19 fawns in 1998 and 17 in 1999 from birth to 28 days old and monitored RIFA-fawn encounter intensity in all enclosures using bait cups. No RIFA-induced fawn mortality occurred. Fawns moved to avoid RIFA stinging when irritated, although frequency of fawn movement was not significantly altered in the presence of RIFA. Increased licking and decreased nursing was evident. At the colony density tested, RIFA do not appear to pose a threat to fawn survival at the population level. However, isolated instances of altered fawn behavior due to RIFA stings such as erratic running, jumping, head shaking and bleating did occur that would increase the risk of predation in uncontrolled environments.Item The temperature regime in the Solenopsis invicta mound and its effect on behavior(Texas Tech University, 1980-05) Pinson, Carla KayeThe fire ant mound provides a unique environment for its inhabitants. This mound habitat allows for greater changes in temperature than would be available if nests were constructed below the surface. There is a significant difference in temperature regimes in mound soil and undisturbed soil adjacent to the mound. Significant temperature differences exist within the mound on a vertical plane. Surprisingly, a much less significant horizontal mound temperature change was noted. The temperature characteristics have an important impact on ant behavior and data suggest that they migrate in response to mound temperature changes. The S. invicta workers showed the greatest degree of migration, followed by the pupae and larvae. Reproductives and eggs showed less definite patterns of movement.Item Vitellogenin Receptor and Neuropeptide Receptors Involved in Reproduction of the Red Imported Fire Ant (Solenopsis invicta Buren)(2012-02-14) Lu, Hsiao LingSocial insects have complex forms of social organization. Molecular mechanisms involved in the regulation of their reproduction are not fully understood. This dissertation investigated the vitellogenin receptor (VgR), short neuropeptide F (sNPF) receptor, and two insulin receptors (InRs) in the red imported fire ant Solenopsis invicta, focusing on their possible roles in the regulation of queen reproduction. Knowledge of these receptors may provide novel ways to manipulate either reproductive castes or overall reproductive outcome, diminishing the fire ant impact as invasive pest. Fire ant virgin queens have more abundant VgR (SiVgR) transcripts than newly-mated queens, but limited egg formation. To elucidate whether queen maturation involved changes in SiVgR expression, we investigated both virgin and mated queens. In both queens, immunofluorescence analysis of ovaries revealed differential SiVgR localization in early and late stage oocytes; however, mated queens showed higher SiVgR expression than virgin queens. In virgin queens, the SiVgR signal was first observed at the oocyte membrane beginning at day 12 post-emergence, coinciding with the maturation period required before a mating flight. SiVgR silencing in virgins through RNA interference abolished egg formation, demonstrating that SiVgR is involved in queen ovarian development pre-mating. The sNPF and insulin signaling pathways have been implicated in the regulation of food intake and body size, and these peptides also play a gonadotropic role in the ovaries of some insect species. To elucidate the sites of action of the sNPF peptide(s), the sNPF receptor tissue expression and cellular localization were analyzed in the queen brain, subesophageal ganglion (SEG), and ovaries by immunofluorescence. Results suggest that the sNPF signaling cascade may be involved in diverse functions, and the sNPF peptide(s) may act in the brain and SEG as neurotransmitter(s) or neuromodulator(s), and in the ovaries as neurohormone(s). In addition, to elucidate the role of insulin signaling pathway in the fire ant, two putative InRs were cloned. Transcriptional expression analyses show that the receptor abundance was negatively correlated with body size and nutrition status in fire ant immatures. In queens, the expression of InRs in different queen tissues correlates with tissue requirements for queen reproductive physiology and behaviors.