Ecotopes, Natural Infection and Trophic Resources of Triatoma brasiliensis (Hemiptera, Reduviidae, Triatominae)
Vol. 93(1): 7-13
Jane Costa/+, Josimar Ribeiro de Almeida*, Celia Britto**, Rosemere Duarte**, Verônica Marchon-Silva, Raquel da S Pacheco***
Coleção Entomológica, Departamento de Entomologia ***Departamento de Bioquímica e Biologia Molecular, Instituto Oswaldo Cruz, Av. Brasil 4365, 21045-900 Rio de Janeiro, RJ, Brasil *Departamento de Ecologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil **Departamento de Ciências Biológicas, Escola Nacional de Saúde Pública-Fiocruz, Rio de Janeiro, RJ, Brasil
Triatoma brasiliensis is considered as one of the most important Chagas disease vectors in the northeastern Brazil. This species presents chromatic variations which led to descriptions of subspecies, synonymized by Lent and Wygodzinsky (1979). In order to broaden bionomic knowledge of these distinct colour patterns of T. brasiliensis, captures were performed at different sites, where the chromatic patterns were described: Caicó, Rio Grande do Norte (T. brasiliensis brasiliensis Neiva, 1911), it will be called the "brasiliensis population"; Espinosa, Minas Gerais (T. brasiliensis melanica Neiva & Lent 1941), the "melanica population" and Petrolina, Pernambuco (T. brasiliensis macromelasoma, Galvão 1956), the "macromelasoma population". A fourth chromatic pattern was collected in Juazeiro, Bahia the darker one in overall cuticle coloration, the "Juazeiro population". At the sites of Caicó, Petrolina and Juazeiro, specimens were captured in peridomiciliar ecotopes and in wilderness. In Espinosa the specimens were collected only in wilderness, even though several exhaustive captures have been performed in peridomicile at different sites of this municipality. A total of 298 specimens were captured. The average registered infection rate was 15% for "brasiliensis population" and of 6.6% for "melanica population". Specimens of "macromelasoma" and of "Juazeiro populations" did not present natural infection. Concerning trophic resources, evaluated by the precipitin test, feeding eclecticism for the different colour patterns studied was observed, with dominance of goat blood in household surroundings as well as in wilderness.
Key words: Triatoma brasiliensis - ecotopes - trophic resources - natural infection - different colour patterns
Triatoma brasiliensis Neiva, 1911 has a wide geographical distribution (Alagoas, Bahia, Ceará, Goiás, Minas Gerais, Paraíba, Pernambuco, Piauí, Rio Grande do Norte, Sergipe, Tocantins). It is regarded as one of the most important vectors of Chagas disease in the northeastern region (Silveira et al. 1984). The different melanic forms have been described as subspecies: T. b. brasiliensis Neiva, 1911; T. b. melanica Neiva & Lent, 1941 and T. b. macromelasoma Galvão, 1956. These subspecies were described on the basis of the pronotum, legs and hemelytron chromatic characters (Galvão 1956). Lent and Wygodzinsky (1979) have considered them as synonymous. A fourth chromatic pattern was collected by us in Juazeiro, Bahia, and will be referred to in this study as "Juazeiro population".
In order to broaden bionomic knowledge on T. brasiliensis, field captures were performed at different localities where the distinct chromatic variations were collected: Caicó, Rio Grande do Norte ("brasiliensis population"); Espinosa, Minas Gerais ("melanica population"); Petrolina, Pernambuco ("macromelasoma population") and in Juazeiro, Bahia ("Juazeiro population"). Comparative data among these different melanic forms were obtained regarding ecotopes, trophic resources and natural infection by T. cruzi.
The present study complements morphological (Costa et al. 1997a), biological (Costa & Marchon-Silva 1996, Costa et al. 1996a) and biochemical analysis which have detected phenotypical differences among the distinct chromatic patterns mentioned (Costa et al. 1997b). The aim was to clarify the taxonomic status at intra- or interspecific levels of different populations of T. brasiliensis utilizing multidisciplinary studies.
ACKNOWLEDGMENTS
To Drs Fernando Dias de Avila Pires, Ortrud Monika Barth and Maria Goreti Rosa Freitas-Sibajev for suggestions and for critical reading of the manuscript.
Presented at the XXII Annual Meeting on Basic Research of Chagas Disease, Caxambu, MG, Brazil and supported by Fundação Nacional de Saúde and CNPq.
Table I | Table II | Table III | Table IV | Table V | | Table VI
+Corresponding author. Fax: +55-21-590.3545
Received 2 December 1996
Accepted 5 August 1997
Memórias Home Page | Editorial Office | Subscription Information | Search
Vol. 93(1) - Contents | Instructions to Authors | News and Events | Past Issues | E-mail
