Ecology and field biology of two dominant Camponotus ants (Hymenoptera: Formicidae) in the Brazilian savannah

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Ecology and field biology of two dominant <i>Camponotus</i> ants (Hymenoptera: Formicidae) in the Brazilian savannah

<p><i>Camponotus renggeri</i> and <i>C. rufipes</i> are very abundant in Brazilian cerrado savannah, where they feed extensively on liquid rewards and commonly associate with plants bearing extrafloral nectaries and honeydew-producing insects. Here, we provide a qualitative and quantitative field account on the natural history and ecology of these two ant species. The study was carried out in a cerrado reserve in south-eastern Brazil across a rainy/hot season (summer) and a dry/cold season (winter). The ants were found in two vegetation physiognomies: all nests of <i>C. rufipes</i> were located in the cerrado <i>sensu stricto</i> (scrub of shrubs and trees, 3–8 m tall), whereas <i>C. renggeri</i> occurred mostly in the cerradão (forest with more or less merging canopy, 10–12 m tall). Both species nested in fallen or erect dead trunks, as well as underground. In addition, <i>C. rufipes</i> built nests using dead plant material arranged or not around shrub bases. Colonies of <i>C. rufipes</i> were generally more populous than those of <i>C. renggeri</i>, and both species had colonies with more than one dealated queen. Both species were active mainly at night and foraged for resources near their nests, mainly extrafloral nectar and hemipteran honeydew (aphids and mealybugs). The average size of the home ranges of <i>C. renggeri</i> in cerrado <i>sensu stricto</i> and cerradão varied from ≈ 2.8 to 4.0 m² and apparently were not affected by season. In <i>C. rufipes</i>, however, foraging grounds in cerrado <i>sensu stricto</i> showed a twofold increase from dry/cold (≈ 4.5 m²) to rainy/hot season (≈ 9.8 m²). Our study highlights the importance of natural history data to understand the foraging ecology and role of these ants in cerrado savannah.</p

Prevalência de cárie e necessidades de tratamento em escolares de seis a doze anos de idade, Goiânia, GO, Brasil, 1994 The prevalence of dental caries and necessary treatment in six to twelve years old schoolchildren in Brazil, 1994

OBJETIVO: Investigou-se a prevalência de cárie e necessidades de tratamento em escolares de Goiânia-GO, Brasil, que possui água fluoretada há 9 anos. METODOLOGIA: A amostra foi constituída de 1.400 escolares de 6 a 12 anos de idade que freqüentavam escolas públicas na zona urbana do município estudado. RESULTADOS: Os índices CPO-D e ceo-d encontrados no total da amostra foram 2,19 e 2,86, respectivamente, demonstrando uma redução de 57,1% em relação ao CPO-D verificado na região Centro-Oeste, em 1986. Para os escolares de 12 anos de idade, o CPO-D encontrado foi 4,59, estando acima da meta estabelecida para o ano 2.000 pela FDI/OMS. Verificou-se que a percentagem de escolares livres de cárie foi muito baixa em todas as idades, apresentando-se em torno de 11% para o total da amostra. Houve predomínio do tratamento restaurador na dentição decídua em todas as idades e na permanente a partir dos 9 anos de idade. CONCLUSÃO: A prevalência de cárie em escolares de Goiânia-GO é alta e comparável à situação verificada na maioria dos países da América Latina e nas regiões menos favorecidas de países desenvolvidos. Há necessidade de se implantar medidas educativas e preventivas em saúde bucal que intervenham nos reais determinantes da doença na população.<br>OBJECTIVE: The prevalence of dental caries and needs of treatment among schoolchildren in Goiânia-GO, middle-west of Brazil was assessed. METHODOLOGY: The study population consisted of 6-12-yr-old schoolchildren (n=1,400) attending public schools located in the urban area of the city, where the water-supply had been fluoridated for 9 years. RESULTS: Mean dmf-t and DMF-T for the total sample were 2.19 and 2.86, respectively, showing a reduction of 57.1% in the DMF-T as compared to the regional data from the national survey carried out in 1986. At age 12 DMF-T was 4.59, which is above the acceptable level according to the FDI/WHO goal for the year 2000. Percentage of caries-free schoolchildren was very low at all ages (11% of the total sample). The most significant need was for restorative treatment in the treatment deciduous dentition at all ages and in the permanent dentition from age 9. CONCLUSION: It was concluded that the prevalence of dental caries among schoolchildren in Goiânia-GO is high, comparable to the situation in most Latin American countries and poor regions of developed countries. The results indicate the need for oral health education and preventive programs targeted at the underlying causes of the disease, in the population