Ecologia de Solenopsis invicta Buren (Hymenoptera: Formicidae) em um agroecossistema diversificado sob manejo org?nico

• Ano de defesa: 2007
• Autor(a) principal: Almeida, F?bio Souto de
• Orientador(a): Queiroz, Jarbas Mar?al de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal Rural do Rio de Janeiro
• Programa de Pós-Graduação: Programa de P?s-Gradua??o em Ci?ncias Ambientais e Florestais
• Departamento: Instituto de Florestas
• País: Brasil
• Palavras-chave em Português: formiga-lava-p?; moscas decapitadoras; fatores bi?ticos; fatores abi?ticos
• Palavras-chave em Inglês: fire ant; decapitating fly; biotic factors; abiotic factors
• Área do conhecimento CNPq: Recursos Florestais e Engenharia Florestal
• Link de acesso: https://tede.ufrrj.br/jspui/handle/tede/447

The ant Solenopsis invicta Buren (Hymenoptera: Formicidae) (fire ant) is native from South America, but today occurs in Central America, North America and Oceania. The species is usually considered a serious pest because it can reach extremely high densities, is aggressive, can cause a painful sting, wich often cause allergenic reactions in the human being. Moreover, S. invicta can eliminate competitively other ant species in the ecosystems. However S. invicta workers are voracious consumers of arthropods and are among the most active and abundant predators in many crops. Among the natural enemies of S. invicta, parasitoid species of Pseudacteon Coquillett (Diptera: Phoridae) are candidates to be agent of biological control of this ant species in invaded regions. The goal of this study was to determinate the spatial distribution of S. invicta nests in an organic agroecosystem, to evaluate the influence of some abiotic factors (pH, soil density, air and soil temperature, air and soil humidity) on the population density of this ant species; the influence of its population density on the species richness of other ants; and to evaluate the influence of some biotic and abiotic factors on the abundance of Pseudacteon flies, parasitoids of S. invicta. The study was conducted in four plots of 3,500 m2, cultivated with different crop species, in the Sistema Integrado de Produ??o Agroecol?gica (SIPA), Seropedica, Rio de Janeiro, Brazil. The nest distribution of S. invicta was significantly aggregated. The density of S. invicta was significantly related with soil and air temperatures. There was not significant relationship between the density of S. invicta and average species richness of others ants. Among the parasitoid species colected, Pseudacteon obtusus Borgmeier was the most frequent and abundant species on S. invicta disturbed nests, followed by Pseudacteon litoralis Borgmeier, Pseudacteon tricuspis Borgmeier and Pseudacteon solenopsidis Schmitz. The parasitoids species had different patterns of diurne activity. A higher number of individuals P. litoralis and P. obtusus was collected under mild temperatures, whereas on high temperatures the fly activity was decreased. Bigger nests attracted greater number of parasitoids of all species.