Laboratory Comparison of Feeding Success Among Triatoma infestans, T. guasayana, and T. sordida (Hemiptera: Reduviidae)

Abstract

Success in obtaining a blood meal and rapid access to hiding places after feeding are the principal requirements triatomines have as they colonize artificial ecotopes. Feeding success and postfeeding location of 3rd and 5th instars of Triatoma sordida (Stål), of T. guasayana Wygodzinsky & Abalos, and T. infestans (Klug) were studied in an experimental box in which triatomines and a chicken were left to interact overnight. The bird was enclosed in a glass cube, slightly raised to allow triatomines to get in and out, turning the space outside into an extensive refuge area. Four bunches of dry corn husks and a wooden panel were also offered as shelters. The number of live and dead insects and their locations at the end of the experiment were recorded. Predation--as the percentage of missing insects--and success--as the percentage of insects alive and fed--were calculated. Interactions with the host were different among species and sometimes also between individuals of different life stages of the same species. Predation was always > 20%. T. sordida was the best exploiter of the blood source, because 3rd instars were more successful and 5th instars were as successful as the corresponding T. infestans stages. Performance of T. guasayana was equivocal because survival and feeding success were different for both instars. T. infestans showed a pronounced tendency to climb, and 3rd instars of T. guasayana were equally distributed in the upper half of the box and in the corn husks, whereas the majority of T. sordida and 5th instars of T. guasayana sheltered in the husks.

Alteration of the social and spatial organization of the vector of Chagas disease,Triatoma infestans, by the parasiteTrypanosoma cruzi

“…We know very little about the distribution of triatomines inside a dwelling. Even if all the stages are found in the upper part of the walls 17,28 , our results suggest that males and females rest in a stratified manner on the walls, males being above of females. Domestic cockroaches have a similar way of life than triatomines, except the feeding habits.…”

“…Animals can exhibit locomotion that is gravitationally directed vertically down or up (positive or negative geotaxis, respectively). Geotaxis in triatomine has been poorly described, T. infestans was just reported as being more concentrated in the upper half of the walls in houses or chicken houses 17,28 . Moreover, to our knowledge, no studies were conducted to analyze the synergy or conflict between gregariousness and geotaxis in triatomines.…”

Alteration of the aggregation and spatial organization of the vector of Chagas disease, Triatoma infestans, by the parasite Trypanosoma cruzi

“…In studies about the vertical distribution of T. infestans in Brazilian dwellings, adults, nymphs, and eggs of this species tended to be concentrated in the upper half of the wall 24 . In northern Argentina, 58.3% of a domestic T. infestans population obtained after the demolition of a house were in the roof, and eggs were aggregated at the top of the walls, decreasing gradually towards the floor (in 36 ). In experiments using an artificial chicken house, T. infestans assembled at the upper part of the walls (in 36 ).…”

“…Animals can exhibit locomotion that is gravitationally directed vertically down or up (positive or negative geotaxis, respectively). Geotaxis in triatomine has been poorly described, T. infestans was just reported as being more concentrated in the upper half of the walls in houses or chicken houses 24,36 . Moreover, to our knowledge, no studies were conducted to analyze the synergy or conflict between gregariousness and geotaxis in triatomines.…”

Comparative population dynamics of the bug Mepraia spinolai, a sylvatic vector of Chagas’ disease, in different hosts

“…Crocco & Catalá (1997), comparing insects fed on doves and rodents, found that meal average weight was greater for insects feeding on rodents. However, the relationship between weight changes and the quantity of blood ingested has not yet been established (Wisnivesky‐Colli et al , 1995; Pereira et al , 1998; Guarneri et al , 2000b; Soares et al , 2000). The most immediate question concerns the differences between these two host mammal species that might explain the present results.…”