This research evaluated the new red imported fire ant (RIFA) bait Advion™. Advion™ contains the active ingredient indoxacarb which, following ingestion, must be metabolized into an N-decarbomethoxyllated metabolite known as JT333 in order to become acutely toxic. Laboratory experimentation was conducted to determine the most effective chemical form and concentration of indoxacarb, as well as the most appropriate grit size, for use in Advion™. The results indicated that Advion™ containing indoxacarb was more effective than Advion™ containing JT333, that 0.10%, 0.06%, and 0.045% were the most effective concentrations of indoxacarb, and that standard sized grit (~2 mm) was more effective than small sized grit (<1 mm). Field experimentation was conducted to determine the most effective concentration and quantity of Advion™, as well as the most effective placement of the bait, for obtaining maximum control of RIFA colonies via individual mound treatments. The results indicated that 10 g (2 Tbsp) of 0.045% Advion™ placed around the mound in a circle with a radius of 0.5-3.0 m was the most effective manner in which to treat individual RIFA mounds. Field experimentation was also conducted to compare the effectiveness of label-rate broadcast treatment with Advion™ to the effectiveness of both label-rate broadcast treatment with Amdro® and pre-baiting broadcast treatment with Advion™. Both pre-baiting broadcast treatment and label-rate broadcast treatment with Advion™ ultimately resulted in 98-99% RIFA colony mortality, which was significantly greater than the 87% colony mortality resulting from broadcast treatment with Amdro®. The 6.2 d LT90 for label-rate broadcast treatment with Advion™ was nearly one half that of the LT90 for pre-baiting broadcast treatment. Laboratory experimentation was conducted to determine whether RIFA workers were capable of metabolizing indoxacarb into the toxic metabolite, and the results clearly indicated that they were. Finally, field experimentation was conducted to evaluate the effectiveness of label-rate broadcast treatment with Advion™ at controlling multiple ant species. The results indicated that label-rate broadcast treatment with Advion™ resulted in control of the RIFA and Pogonomyrmex barbatus for at least 7 wk, and Monomorium pharaonis and Dorymyrmex pyramicus for some period of time between 3 and 7 wk.

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.

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

Orientadores: Woodruff Whitman Benson, Jose Roberto Trigo / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-06T14:03:47Z (GMT). No. of bitstreams: 1 Dall'Aglio-Holvercem_ChristianeGoncalves_D.pdf: 1459643 bytes, checksum: 5ed521529fb7303e231df7d9f2ebbda3 (MD5) Previous issue date: 2006 / Resumo: Este trabalho discute alguns aspectos da ecologia da formiga lava-pés Solenopsis invicta e seus parasitóides, as moscas do gênero Pseudacteon (familia Phoridae), e da taxonomia de S. invicta e S. saevissima, ambas nativas da América do Sul. A alometria de colônias de S. invicta no sudeste do Brasil foi estudada através de medições das dimensões do ninho acima do solo, seguidas por escavação e medida da profundidade, biomassa e número de operárias da colônia, assim como da largura média da cabeça das operárias. Análise de regressão dos dados para 28 colônias forneceu novas relações alométricas que podem ser usadas para estimar o volume do ninho (acima e abaixo da superfície do solo), a biomassa de formigas, e o número de operárias a partir do volume do ninho acima do solo. A biomassa de formigas por unidade de volume do ninho, o número de operarias por unidade de volume do ninho, o peso médio por operária, e a largura média da cabeça das operárias foram essencialmente independentes do tamanho da colônia. Em contraste, estas quatro quantidades aumentam com o tamanho da colônia entre colônias de S. invicta na América do Norte. O ciclo sazonal e abundância de moscas parasitóides do gênero Pseudacteon na vizinhança de colônias de S. invicta no sudeste do Brasil foi observado ao longo de um período de 3 anos em li áreas de gramíneas nos arredores de Campinas. O número médio N de forídeos atraídos para um ninho de formigas lava-pés ao longo de um período padrão de observação (15 min) foi usado como uma medida da abundância de forídeos. As dimensões do ninho e algumas variáveis meteorológicas foram também registradas em cada ninho de formigas lava-pés. Pseudacteon tricuspis foi a espécie mais comum (70.4%), seguido por P. curvatus (23.8%), P. obtusus (1.9%) e P.litoralis (3.9%). As características mais notáveis das flutuações sazonais da abundância de Pseudacteon são picos abruptos com duração aproximada de um mês (valores máximos de N entre 4 e 10 forídeos/ninho), que ocorreram em abril e junho de alguns anos; para comparação, valores típicos de N estavam entre 0.2 e 2 forídeos/ninho. As populações de forídeos parecem ser destruídas por incêndios e inundações, mas recuperam-se em uma escala de tempo da ordem de meses. Nenhuma correlação significativa foi encontrada entre a abundância de Pseudacteon e variáveis meteoro lógicas, densidade, ou volume de ninhos de S. invicta, sugerindo que a abundância de Pseudacteon não está diretamente ligada a abundância de S. invicta. Flutuações quase idênticas em abundância de Pseudacteon foram observadas ao longo de um período de 6 meses em duas áreas de estudo separadas por cerca de 3 km, o que pode ser causado por dispersão de forídeos e conseqüente uniformização de densidades sobre áreas de vários quilômetros quadrados. Os números de forídeos atraídos pelos vários ninhos de S. invicta incluídos neste estudo seguiram uma distribuição de Poisson em baixas abundâncias de Pseudacteon (N < 0,5 forídeos/ninho); a distribuição tornava-se mais e mais contagiosa com o aumento da abundância de Pseudacteon (até o máximo observado, de N = 10 forídeoslninho). Esta observação sugere que a atratividade de um ninho de formigas lava-pés aos parasitóides aumenta com o número de forídeos que foram previamente atraídos para o ninho. Critérios quantitativos eficientes foram desenvolvidos para distinguir entre S. invicta e S. saevissima, que são morfológicamente muito similares e cujas distribuições geográficas na América do Sul se sobrepõe significativamente. Estes critérios resultaram da análise de 68 amostras de formigas lava-pés de 9 localidades espalhadas pelo estado de São Paulo (sudeste do Brasil) através de cromatografia gasosa e espectrometria de massa. 22 hidrocarbonetos cuticulares e 18 alcalóides piperidínicos foram identificados nas amostras estudadas, e suas abundâncias relativas foram analisadas utilizando análises de componentes principais e de funções discriminantes. Estas análises mostraram uma separacão nítida entre as duas espécies em um plano com certas coordenadas (P,Q), que são funções das abundâncias relativas dos hidrocarbonetos cuticulares. As amostras provenientes de uma das localidades (São José do Rio Preto) têm uma composição de hidrocarbonetos que é claramente diferente de todas as outras amostras consideradas neste estudo, mas também apresentam algumas caracteristicas em comum com cada uma das duas espécies. Uma possibilidade é que esta população constitua um hibrido de S. invicta e S. saevissima. As duas espécies também exibem uma separação razoavelmente nítida em um plano com coordenadas (R$), que são funções das abundâncias relativas de alcalóides piperidínicos. Os resultados das identificações de espécies baseados nestes critérios de separação quimica concordam com os resultados baseados em um critério morfológico, a presença ou ausência do dente clipeal mediano. A população "anômala" de São José do Rio Preto é morfologicamente classificada como S. invicta / Abstract: This work discusses some aspects of the ecology of the fire ant species Solenopsis invicta and its phorid parasitoid flies ofthe genus Pseudacteon, and ofthe taxonomy of S. invicta and S. saevissima, both of which are native to South America. The allometry of S. invicta colonies in southeast Brazil was studied by measurement of mound (aboveground) dimensions, followed by excavation and measurement of the colony depth, biomass, number of workers, and mean worker head width. Regression anaIysis of data for 28 colonies yielded new allometric relationships which can be used to estimate nest volume (above and below ground), ant biomass, and number ofworkers ITom mound (aboveground) volume. Ant biomass per unit nest volume, number of workers per unit nest volume, mean worker weight, and mean worker head width were nearly independent of colony size. In contrast, these four quantities increase with colony size among S. invicta colonies in North America. The seasonal cycle of abundance of Pseudacteon phorid flies in the vicinity of S. invicta colonies in southeast Brazil was observed over a 3-year period in 11 grass-covered areas in the outskirts of Campinas. The average number N of phorids attracted to a fire ant nest over a standard observation period (15 min) was used as a measure of phorid abundance. Mound dimensions and meteorological variables were also recorded at each fIre ant nest. Pseudacteon tricuspis was the most common species (84.2%), followed by P. curvatus (12.6%), P. obtusus (2.7%) e P. litoralis (0.5%). The most remarkabIe featores of the seasonal fluctuations of Pseudacteon abundance are sharp month-Iong peaks (peak N values between 4 and 10 phorids/nest) which occurred in Abril and June of some years; for comparison, at other times N was typically between 0.2 and 2 phorids/nest. Phorid populations seem to be destroyed by rifes and floods, but recover on a time scale of months. No significant correlation was found between Pseudacteon abundance and meteorological variables, density, or volume of S. invicta nests, suggesting that Pseudacteon abundance is not determined by, and does not determine, the abundance of S. invicta. Almost identical fluctuations in Pseudacteon abundance were observed over a 6-month period in two study areas separated by about 3 km, which may be due to phorid dispersaI and consequent density uniformization over areas of several square kilorneters. The nurnbers of phorids attracted by the various S. invicta nests inc1uded in this study followed a Poisson distribution at 10w Pseudacteon abundances (N < 0.5 phorids/nest), becoming more and more contagious at high Pseudacteon abundances (up to N= 10 phorids/nest). This observation suggests that the attractiveness oftire ant nests to phorid parasitoids increase with the nurnbeer ofphorids which have been previously attracted to the nest. Efficient quantitative criteria were developed for distinguishing between S. invicta and S. saevissima, which are morphologically very similar and whose geographical ranges in South Arnerica significantly overlap. These criteria resulted from the analysis of 68 tire ant samples from 9 localities across São Paulo state (southeast Brazil) via gas chromatography/mass spectrometry. 22 cuticular hydrocarbons and 18 piperidine alkaloids were identified in the studied samples, and their relative abundances were analyzed using principal component and discrirninant function analyses. These analyses showed a sharp separation between the two species in a plane with certain coordinates (P,Q), which are functions of the relative abundances of cuticular hydrocarbons. The fire ant samples from one of the localities (São José do Rio Preto) had a hydrocarbon composition which was markedly different from ali other samples considered in this study, but had some features in common with each ofthe two species. One possibility is that this population constitutes a hybrid of S. invicta and S. saevissima. The two species also show a reasonably sharp separation in a plane with coordinates (R,S), which are functions of the relative abundances of piperidine alkaloids. The species identification results based on these chernical separation criteria agree with those based on a morphological criterion, the presence or absence of the median clypeal tooth. The "anomalous" population from São José do Rio Preto is rnorphologically c1assified as S. invicta / Doutorado / Ecologia / Doutor em Ecologia

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

Plants and insects are some of the most biodiverse groups in the world and are constantly interacting. One unique interaction that has been observed occurs between carnivorous plants and insects; some plant species are capable of capturing and digesting insects for nutrients. Despite preying on these insects, there are cases where such interactions can been viewed as mutualistic. For instance, a nectar reward is produced by the plant to attract insects, and during visitation insects may fall prey to these plants. Additionally, carnivorous myrmecophytic plants may receive an added indirect benefit in the form of reduced herbivory, since ants have the ability to indirectly protect and drive off herbivores from the plant. However, this type of indirect defensive benefit has been rarely observed in carnivorous plants. To determine the nature of the relationship between carnivorous plants and ants, a predator-exclusion experiment was performed in situ using a natural population of the hooded pitcher plant, Sarracenia minor. The presence of the red imported fire ant, Solenopsis invicta, was manipulated in the pitcher plant population to determine if the presence of this non-native ant affects the survival and growth of this carnivorous pitcher plant. From June-November 2014 mean pitcher height and width, number of pitchers, and proportion of pitchers with herbivory present was recorded monthly. Results indicated that pitcher width (p = .042) and the number of pitchers (p = .038) was significantly lower when the presence of S. invicta was reduced. Specifically, the limited presence of S. invicta led to a 21% reduction in mean number of pitchers and a 2.2% reduction in mean pitcher width. This indicated that this non-native ant does provide a direct nutritional benefit for the plant. However, the presence of the ant had no effect on pitcher height and the proportion of pitchers with herbivory present. But, when the proportion of pitchers with herbivory present was compared to a previous native ant study, herbivory proportions where similar or lower when taking the number of ants present into account. This suggests that this non-native ant and native ants equally provide defensive benefits for this native threatened species. Overall, this studied illustrated that carnivorous plants may exhibit similar multiple benefits from a single interaction with a non-native insect that is both prey and provides defense against herbivores.