INVESTIGADORES
GORLA David Eladio
artículos
Título:
Interactions between T. infestans and T. sordida. Competition effects on mortality and fecundity rates
Autor/es:
OSCHEROV B; DAMBORSKY M; BAR ME; GORLA DE
Revista:
MEDICAL AND VETERINARY ENTOMOLOGY
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2004 vol. 18 p. 323 - 328
ISSN:
0269-283X
Resumen:
Interspecific competition between two species of triatomine bugs
(Hemiptera: Reduviidae), vectors of Chagas disease, was assessed for
16 months through comparative fecundity and mortality of experimental
populations in chicken nests, maintained indoors with ambient
conditions. Triatoma sordida (Stål), the secondary vector in north-eastern Argentina, was compared with Triatoma infestans
(Klug) the more widespread domestic vector in the southern cone of
South America. Both species populations originated from females
collected in 1995 from the community of Empedrado, Corrientes,
Argentina. Three population units were monitored: T. infestans alone, T. sordida
alone and both species together in equal proportions. Each population
started with six male and six female adults, 116 eggs, and nymphal
instars I to V numbering 82, 48, 16, 11 and 19, respectively. Numbers
and weight of individual bugs were recorded monthly (August 1995 to
December 1996). The pure populations of T. infestans and T. sordida
showed temporal changes in abundance, rising in summer and falling in
winter, similar to the typical trends under normal field conditions. In
the mixed population, however, T. sordida fell to extinction after 6 months, whereas T. infestans reached similar abundance to the pure (control) population. For each nymphal instar of T. sordida,
the mean body weight was significantly less and mortality rate was
higher in the mixed population compared to the pure population, but
there were no significant differences of adult longevity or fecundity
between the pure and mixed populations of T. sordida. The apparent competitive displacement of T. sordida by T. infestans
was attributed to the latter species having better ability to obtain
bloodmeals. This might explain the rarity of mixed populations where
these two species occur in sympatry.