An ecological pilot project for the control of Triatoma dimidiata allowed a new evaluation four and five years after environmental modifications in the peridomestic areas of 20 households. It was verified that the two groups of houses, 10 case-houses and 10 control-houses, were free of insects after those periods of time. In the first group, the owners started a chicken coop in the backyard and a colony of bugs was found there without infesting the house. In the second group, the inhabitants of one house once again facilitated the conditions for the bugs to thrive in the same store room, reaffirming that man-made ecotopes facilitates colonization. This ecological control method was revealed to be reliable and sustainable and it is recommended to be applied to those situations where the vectors of Chagas disease can colonize houses and are frequent in wild ecotopes.

En la población de Los Chiles. Provincia de Alajuela, Costa Rica, cerca de la frontera con Nicaragua, se recolectó un total de 167 ejemplares (ninfas y adultos) de Rhodnius pallensces, encontrados en la base de las hojas muertas de dos palmeras (Attalea butyracea). La especie había sido reportada previamente de Panama y Colombia colonizando la misma palmera. El examen de 32 insectos reveló que todos estaban infectados con Trypanosoma cruzi y no fue posible demostrar la presencia de T. rangeli en la hemolinfa de 24 insectos. La inoculación en ratones Balb/c con heces de los insectos infectados, mostró una moderada parasitemia y una típica miocarditis aguda con numerosos grupos de parásitos en las fibras cardíacas. Se analiza la distribución geográfica de R. pallescens, así como su posible presencia en los países centroamericanos y en México, en donde la especie es aún desconocida, en coincidencia con la distribución de la misma especie de palmera. Asimismo, se discute el potencial de R. pallescens de adaptarse a ecotopos domésticos y las implicaciones epidemiológicas del fenómeno.

A total of 167 nymphs and adults of Rhodnius pallescens was collected from the basal parts of dead fronds of two palm trees (Attalea butyracea) in the town of Los Chiles, province of Alajuela, Costa Rica, close to the Nicaraguan border. Previous records of this species in the same habitat come from Panama and Colombia. A group of 32 insects examined for Trypanosoma cruzi revealed that all were infected. By examining their hemolymph, none of 24 of the insects was found infected with T. rangeli. Balb/c mice inoculated with the T. cruzi strain from infected insects showed a typical acute myocarditis reaction with numerous groups of parasites among the heart fibers at autopsy. The geographical distribution of R. pallescens as well as its possible presence in other Central American countries and in Mexico where it is still unknown, coinciding with the distribution of the same species of palm tree, is discussed. Likewise, the potential of R. pallescens in becoming adapted to domestic environments is analyzed in light of recent information, and the epidemiological implications of the phenomenon are also discussed.