Distribution and abundance of Simulium spp. in streams of the state of São Paulo (Brazil) with different water quality


  • Andrea de B.P. Viviani Instituto Butantan - Laboratório de Imunologia Viral.
  • Carlos Jose Pereira da Cunha Araújo-Coutinho Instituto Butantan - Laboratório de Imunologia Viral.
  • Rosiane Brito de Moraes Universidade do Estado do Mato Grosso
  • Hélio Benites Gil Instituto Butantan - Laboratório de Imunologia Viral
  • Roberto Leung Universidade do Estado do Mato Grosso
  • Antonio Fernando Monteiro Camargo Universidade do Estado de São Paulo




The aim of this work was to determine the distribution and abundance the species of Simulium: in 5 streams of the north coastal region of the state of São Paulo. Simulium larval and water samples were collected every 2 weeks in summer and winter, 2001. The larval were collected on artificial substrates (triplicate) preserved in alcohol (70%) and after analyzed quantitative and qualitative. From the streams the values of temperature, dissolved oxygen, conductivity, pH and stream discharge were measured. The contents of total nitrogen and dissolved nitrogen, ammoniacal nitrogen, nitrate, nitrite, orthophosphate, dissolved phosphorus and total phosphorus were determined in the laboratory. Water quality has great influence in the distribution and abundance of the species. S. pertinax was more abundant in streams without or with low levels of pollution, S. inaequale in streams more polluted and S. incrustatum in intermediary levels of pollution. S. pertinax was the species more abundant with 57.5% of presence in the samples, the second more abundant was S. inaequale with 42.1% of presence and S. incrustatum was rare with 0.4% of presence. The larval abundance was lower in the polluted environment. 

Key words: Simulium spp, larval population, abiotics aspects.