Thesis (M.S.)--Eastern Illinois University, 2008. / Includes bibliographical references (leaves 33-35).

One of the most popular methods for achieving control of the Red Imported Fire Ant, Solenopsis invicta Buren, is through the use of broadcast baits. Several factors contribute to bait efficacy, one of which may be particle size. The goals of these laboratory studies were to determine particle size and bait preference using Advance Select Granular Ant Bait and Advance Carpenter Ant Scatter Bait, determine the effect of starvation on bait removal and recruitment to Carpenter Ant Scatter Bait, and determine if any correlation existed between head capsule width and particle size selected. Experimental colonies removed significantly more 1400-2000 μm particles of Select Granular Ant Bait, while ants foraging on Carpenter Ant Scatter Bait preferred 1000-1400 μm particles. Mean number of ants present at bait mirrored results from bait removal test. Ants displayed a preference for Carpenter Ant Scatter Bait based on mean number of ants present at bait for the 10-d foraging period. For starvation assays, significant differences in bait removal and number of ants present occurred in the 0-d group. Ants starved for 5 d removed significantly more bait of all particle sizes, and removed greater amounts of 1000-1400 μm Carpenter Ant Scatter Bait than other sizes. Head width reliably predicted particle size selected, but the linear model explained very little of the observed variation for ants foraging on Select Granular Ant Bait (R2 = 0.043) or Carpenter Ant Scatter Bait (R2 = 0.047). This study supported the significant role of bait size and starvation period in S. invicta bait preference, and demonstrated how size preference may vary depending on bait type.

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.

Invasive species are often implicated in population declines of native species through competition and predation. Red imported fire ant (Solenopsis invicta) predation of songbird nestlings and eggs has been documented. I conducted a replicated manipulative experiment to determine the magnitude of the decrease in nest survival caused by S. invicta in addition to other predators. I conducted mensurative experiments to quantify the frequency of S. invicta foraging near active songbird nests and factors that influence the susceptibility of songbird nests to S. invicta predation. I hypothesized that predation by S. invicta reduced nest survival by 10%, potentially biologically significant, and that songbird nests would be more susceptible to S. invicta predation that were located: (1) closer to the ground, (2) closer to an edge, (3) closer to disturbed soils, and (4) initiated later in the breeding season. I monitored 235 songbird nests including 45 black-capped vireo (Vireo atricapilla), 67 white-eyed vireo (V. griseus), and 123 northern cardinal (Cardinalis cardinalis) nests on 9 patches of 36–103 ha each on private land in east-central Texas, USA in 2006–2007. I found preventing S. invicta from preying upon songbird nests increased nest survival 20% for white eyed vireos and 1% for black-capped vireos. I detected S. invicta near songbird nest on 60% of food lures on the ground and 7% of food lures 1 m high in vegetation (n = 122). Vireo nests <2 m high and <4 m from an edge were more susceptible to S. invicta predation indicating potential threshold conditions, below which songbird nests may be more susceptible. If my results are applicable to other areas then songbird populations of some species nesting below 2 m may have substantially lower nest survival in areas occupied by S. invicta. I suggest the negative impacts of S. invicta on songbird nest survival may be reduced by applying integrated pest management methods and increasing woody vegetation cover in breeding areas of songbird species susceptible to S. invicta nest predation.

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.

Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2017-09-04T12:29:53Z No. of bitstreams: 1 texto completo.pdf: 4835241 bytes, checksum: dae5f55b5996a614610ecd148a75c650 (MD5) / Made available in DSpace on 2017-09-04T12:29:53Z (GMT). No. of bitstreams: 1 texto completo.pdf: 4835241 bytes, checksum: dae5f55b5996a614610ecd148a75c650 (MD5) Previous issue date: 2016-11-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O gênero Solenopsis tem aproximadamente 195 espécies que são popularmente conhecidas como formigas de fogo ou formiga lava-pé. Este gênero possui uma taxonomia difícil a nível morfológico, estando entre as mais complicadas dentre as formigas. Algumas espécies deste gênero, conhecidas como “thief ant”, são predadoras de larvas de S. invicta e poderiam ser usadas em seu controle, mas isso não é possível devido à dificuldade na sua identificação. O objetivo principal deste estudo foi descrever citogeneticamente o gênero Solenopsis. Para isso, foram analisados 30 ninhos utilizando técnicas da citogenética clássica (como coloração convencional com Giemsa, banda C e coloração sequencial com DAPI/CMA 3 ) e citometria de fluxo. Dentre os ninhos analisados foram encontrados 13 morfoespécies. Por meio da citogenética clássica, encontramos 7 números diploides e 11 diferentes fórmulas cariotípica. Quatro dos sete números de cromossomos são descritos pela primeira vez neste estudo para Solenopsis (2n = 24, 26, 28 e 42 cromossomos). Os dados de banda C mostraram que o aumento da quantidade de heterocromatina segue o aumento do número diploide, e essa diferença é mais evidente quando se compara os extremos (2n = 22 e 2n = 42 cromossomos). A identificação das regiões ricas em CG usando CMA 3 possibilitou a identificação uma possível inversão pericêntrica e de uma translocações. A citometria de fluxo foi utilizada para compreender se as células poliploides apresentadas pelas espécies do gênero Solenopsis são naturais e se o número de células poliploides se mantém constante durante o desenvolvimento. Para tanto, determinou-se a ploidia de células do gânglio cefálico de 4 diferentes estágios de desenvolvimento da espécie Solenopsis saevissima (larvas, pré-pupas jovens, pré-pupas velha e pupas) com base na medição do conteúdo de DNA nuclear. Os dados mostraram a presença de células diploides e tetraploides, e estas células apresentaram diferentes proporções dependendo da fase de desenvolvimento analisada. As células tetraploides apresentaram uma diminuição na sua representatividade com a evolução do desenvolvimento da formiga, sugerindo que elas não são permanentes no tecido neural e, provavelmente, não estarão presentes neste tecido em formigas adultas. Esse comportamento difere do que acontece com as células diploides, que tem o seu pico de proliferação no estágio de pré-pupa jovem e em seguida apresentaram uma redução progressiva no número de células em divisão. / The genus Solenopsis has approximately 195 species that are popularly known as „fire ants‟. This genus has a complex taxonomy at the morphological level, figuring among the more complicated among ant species. Some species in this genus, known as „thief ants‟, are predators of S. invicta‟s larvae and could be used in the control of this pest, but this is not possible due difficulty in its identification. The main objective of this study was to describe, cytogenetically, the genus Solenopsis. For this, we used techniques of the classic cytogenetics (such as conventional staining with Giemsa, C band, and sequential staining with DAPI/CMA 3 ) and flow cytometry. We collected a total of 30 nests belonging to 13 morphospecies. By the classic cytogenetics, we found 7 diploid numbers and 11 different karyotypes formulae. Four out of seven chromosome numbers are described for the first time in this study for Solenopsis (2n = 24; 26; 28 e 42 chromosomes). C-banding data showed that the increase in the amount of heterochromatin follows the increase in diploid number, and this difference is more evident when comparing the extreme (2n = 22 and 2n = 42 chromosomes). The recognition of the region rich in CG using CMA3 became possible the identification one inversion pericentric, beyond possible translocations. The flow cytometry was used to understand whether the polyploid cells presented by species of the genus Solenopsis in the classic cytogenetic research are natural and if the number of polyploid cells keeps constant during development. For this, we determined the DNA ploidy of cephalic ganglion cells of workers in 4 different development stages (larvae, young prepupae, old prepupae and pupae) based on the measurement of nuclear-DNA content. The data showed the presence of diploid and tetraploid cells, and these cells presented different proportions depending of the development stage analysed. The tetraploid cells presented a decrease in its representativity with the advance of the ant development, suggesting that they are not permanent in the neural tissue and, probably, will not be present in this tissue of the adult ants. This is different to what happens with diploid cells that had its proliferation peak in young prepupae stage, and then presents a significant progressive reduction in the number of cells during division.

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.

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.

Thesis--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (p.57-63).

Receptors that transport vitellogenin into oocytes are of vital importance to egg-laying species because they promote oocyte development. In this study, we describe the cloning of the first hymenopteran vitellogenin receptor (VgR) cDNA. Using reverse transcription polymerase chain reaction (RT-PCR) and both 5’- and 3’- rapid amplification of cDNA ends (RACE), cDNA fragments encompassing the entire coding region of a putative VgR from fire ant (= SiVgR) were cloned and sequenced. The complete SiVgR cDNA has a length of 5764 bp encoding a 1782-residue protein with a predicted molecular mass of 201.3 kDa. The deduced amino acid sequence of the SiVgR revealed that it encoded a protein belonging to the low-density lipoprotein receptor superfamily. The number and arrangement of modular domains of SiVgR are the same as those of mosquito and fruit fly VgRs, except there are only four Class A cysteine-rich repeats in the first ligand binding domain of SiVgR compared to five in the mosquito and fruit fly. The deduced amino acid sequence of the SiVgR exhibited 35% and 31% identity to those of the mosquito and fruit fly VgRs, respectively. Northern blot analysis demonstrated that the 7.4-kb SiVgR mRNA was present only in Northern blot analysis demonstrated that the 7.4-kb SiVgR mRNA was present only in ovaries of reproductive females − both alates (virgins) and queens (mated) and was more abundant in alates. The developmental profile of transcriptional expression was determined by semiquantitative RT-PCR. It showed that the SiVgR transcript increased 6-fold from 0- to 10-days after mating, then remained constant through 30 days. It also showed that the SiVgR transcripts increased with age in alate virgin females. The transcriptional expression of the SiVgR was up-regulated more than two-fold by methoprene, a juvenile hormone analog, as determined by using an in vitro system. This suggested the SiVgR gene is JH regulated.