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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Host/parasite interactions between Solenopsis invicta (Hymenoptera: Formicidae) and Thelohania solenopsae (Microsporida: Thelohaniidae)

Hale, Michael Walker 17 September 2007 (has links)
Thelohania solenopsae Knell, Allen and Hazard is a microsporidian pathogen that infects the red imported fire ant Solenopsis invicta Buren. This five part study examined the effects that T. solenopsae has on constructs of colony fitness in field mounds and adoption rates, how T. solenopsae spores are affected by different stable temperatures. This study also examined the effects on T. solenopsae spores due to centrifugation out of the host cell, pH of the solution the spores are kept, and food classes that could be ingested by S. invicta. For the first study, a total of 29 colonies were collected, 16 infected, and 13 uninfected. The study concluded significantly lower brood production in uninfected field colonies when compared to infected field colonies. Additionally, the total number of queens per colony is significantly greater in T. solenopsae infected mounds with 35.4±31.9 queens for infected mounds and 15.5±11.2 queens for uninfected mounds, demonstrating a possible host response to parasite infection. In the study examining stable temperature effects on T. solenopsae spore growth and spore type, a stable temperature of 31°C induced greater production of binucleate free spores in worker S. invicta. There was an overall decrease of T. solenopsae octospores at 16°C, 26°C and 31°C. The studies concerning extraction of T. solenopsae spores, and inclusion in food infusions demonstrated viable spore recovery after centrifugation, verified by using Calcofluor M2R and Sytox Green dual staining. This study demonstrated significant decreases in spore viability over a 10 week period. The study concerning pH demonstrated significant effects of differing pH parameters with the best viable spore recovery at pH 4 and no spore recovery at pH 1 and pH 2. The least viable spore recovery occurred at pH 6 and pH 12 after 24 hours of emersion verified by using Calcofluor M2R and Sytox Green dual staining.
2

Host/parasite interactions between Solenopsis invicta (Hymenoptera: Formicidae) and Thelohania solenopsae (Microsporida: Thelohaniidae)

Hale, Michael Walker 17 September 2007 (has links)
Thelohania solenopsae Knell, Allen and Hazard is a microsporidian pathogen that infects the red imported fire ant Solenopsis invicta Buren. This five part study examined the effects that T. solenopsae has on constructs of colony fitness in field mounds and adoption rates, how T. solenopsae spores are affected by different stable temperatures. This study also examined the effects on T. solenopsae spores due to centrifugation out of the host cell, pH of the solution the spores are kept, and food classes that could be ingested by S. invicta. For the first study, a total of 29 colonies were collected, 16 infected, and 13 uninfected. The study concluded significantly lower brood production in uninfected field colonies when compared to infected field colonies. Additionally, the total number of queens per colony is significantly greater in T. solenopsae infected mounds with 35.4±31.9 queens for infected mounds and 15.5±11.2 queens for uninfected mounds, demonstrating a possible host response to parasite infection. In the study examining stable temperature effects on T. solenopsae spore growth and spore type, a stable temperature of 31°C induced greater production of binucleate free spores in worker S. invicta. There was an overall decrease of T. solenopsae octospores at 16°C, 26°C and 31°C. The studies concerning extraction of T. solenopsae spores, and inclusion in food infusions demonstrated viable spore recovery after centrifugation, verified by using Calcofluor M2R and Sytox Green dual staining. This study demonstrated significant decreases in spore viability over a 10 week period. The study concerning pH demonstrated significant effects of differing pH parameters with the best viable spore recovery at pH 4 and no spore recovery at pH 1 and pH 2. The least viable spore recovery occurred at pH 6 and pH 12 after 24 hours of emersion verified by using Calcofluor M2R and Sytox Green dual staining.
3

Mating flight initiation and nutritional status of Solenopsis invicta (Hymenoptera: Formicidae) alates infected with Thelohania solenopsae (Microsporida: Thelohaniidae)

Overton, Katherine Jane 17 February 2005 (has links)
Thelohania solenopsae Knell, Allen and Hazard, is a microsporidian pathogen that infects the red imported fire ant Solenopsis invicta Buren. This four part study examined the effects that T. solenopsae had on fire ant queens as they matured for their mating flights. For the first study, a total of 878 alates were collected at two timed intervals during a nuptial flight and after to determine if T. solenopsae affected their ability to initiate a mating flight. Infection rates in alates that left the colony early during a flight were 23.75% while alates that did not leave the colony were 66.16%. Two other studies examined whether T. solenopsae affected protein and lipid stores in future queens. Protein stores were not significantly different in infected and uninfected ants, while lipid stores were significantly less in alates that were infected with T. solenopsae (10.69% in infected versus 13.98% in uninfected). The final analysis was done with all of the combined data, which showed that alates infected with T. solenopsae were significantly smaller than uninfected alates.
4

Mating flight initiation and nutritional status of Solenopsis invicta (Hymenoptera: Formicidae) alates infected with Thelohania solenopsae (Microsporida: Thelohaniidae)

Overton, Katherine Jane 17 February 2005 (has links)
Thelohania solenopsae Knell, Allen and Hazard, is a microsporidian pathogen that infects the red imported fire ant Solenopsis invicta Buren. This four part study examined the effects that T. solenopsae had on fire ant queens as they matured for their mating flights. For the first study, a total of 878 alates were collected at two timed intervals during a nuptial flight and after to determine if T. solenopsae affected their ability to initiate a mating flight. Infection rates in alates that left the colony early during a flight were 23.75% while alates that did not leave the colony were 66.16%. Two other studies examined whether T. solenopsae affected protein and lipid stores in future queens. Protein stores were not significantly different in infected and uninfected ants, while lipid stores were significantly less in alates that were infected with T. solenopsae (10.69% in infected versus 13.98% in uninfected). The final analysis was done with all of the combined data, which showed that alates infected with T. solenopsae were significantly smaller than uninfected alates.
5

Invasive interactions of Monomorium minimum (Hymenoptera: Formicidae) and Solenopsis invicta (Hymenoptera: Formicidae) infected with Thelohania solenopsae (Microsporida: Thelohaniidae)

Keck, Molly Elizabeth 16 August 2006 (has links)
Thelohania solenopsae Knell, Alan, and Hazard is an internal microsporidian that parasitizes the red imported fire ant, Solenopsis invicta Buren. This experiment studied the invasive interactions between the native United States ant, Monomorium minimum (Buckley), and S. invicta colonies infected with T. solenopsae and S. invicta colonies free of parasites. This study utilized S. invicta colonies of 100, 300, 600, 800, and 1000 workers to determine the ability of 1000 M. minimum workers to invade each S. invicta colony size. There was a significant difference in the time for M. minimum to invade S. invicta when comparing S. invicta colonies of 1000 workers infected with T. solenopsae to S. invicta colonies that were uninfected. It was also determined that there was a significant difference in the time for M. minimum to invade smaller uninfected S. invicta colonies as opposed to larger uninfected S. invicta colonies. There was no significant difference in the ability of M. minimum to invade smaller S. invicta colonies infected with T. solenopsae as opposed to larger infected S. invicta colonies. It was therefore concluded that S. invicta colonies infected with T. solenopsae were not able to defend their colony or prevent competing ants from invading as well as uninfected S. invicta colonies. This study also demonstrated that M. minimum is a significantly more invasive species when compared to S. invicta, invading S. invicta territories in every situation and doing so in a significantly shorter period of time than S. invicta colonies invaded M. minimum colonies.
6

Pathophysiology and transmission of Thelohania solenopsae in the red imported fire ants, Solenopsis invicta

Chen, Johnny Shou-Chung 01 November 2005 (has links)
Thelohania solenopsae are intracellular pathogens found in the red imported fire ant, Solenopsis invicta. These pathogens cause detrimental effects to their fire ant hosts. The present study revealed that the midgut and the meconium materials from pupating fourth instar larvae were possible vehicles for the horizontal transmission of the disease. The pathogen was further found to cause a reduction of humeral proteins. In SDS-PAGE stained with silver, several proteins were observed only in controls but not in infected fire ant queens. Different queens were found to have variable proteins reduced due to infection of this pathogen. Furthermore, vitellogenin titers were found to be significantly reduced in infected fire ant queens, although the infection rates of the fat body cells was found to be less than 20%. Finally, although the pathogens did not directly induce apoptosis in infected cells, there were more infected cells undergoing apoptosis than uninfected cells. There was no evidence to support the idea that infected fat body cells became more resistant to apoptosis inducers.
7

Pathophysiology and transmission of Thelohania solenopsae in the red imported fire ants, Solenopsis invicta

Chen, Johnny Shou-Chung 01 November 2005 (has links)
Thelohania solenopsae are intracellular pathogens found in the red imported fire ant, Solenopsis invicta. These pathogens cause detrimental effects to their fire ant hosts. The present study revealed that the midgut and the meconium materials from pupating fourth instar larvae were possible vehicles for the horizontal transmission of the disease. The pathogen was further found to cause a reduction of humeral proteins. In SDS-PAGE stained with silver, several proteins were observed only in controls but not in infected fire ant queens. Different queens were found to have variable proteins reduced due to infection of this pathogen. Furthermore, vitellogenin titers were found to be significantly reduced in infected fire ant queens, although the infection rates of the fat body cells was found to be less than 20%. Finally, although the pathogens did not directly induce apoptosis in infected cells, there were more infected cells undergoing apoptosis than uninfected cells. There was no evidence to support the idea that infected fat body cells became more resistant to apoptosis inducers.

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