Triatoma rubrovaria (Blanchard, 1843) (Hemiptera-Reduviidae-Triatominae) III: patterns of feeding, defecation and resistance to starvation

Abstract

Data from the Chagas Disease Control Program indicate a growing domiciliary and peridomiciliary invasion of

Triatoma rubrovaria (Blanchard, 1843) (Hemiptera - Reduviidae - Triatominae) IV: bionomic aspects on the vector capacity of nymphs

“…The obtained data support earlier assumption that T. rubrovaria presents bionomic characteristics that may be favorable to acquire infection and transmit the T. cruzi to man (Almeida et al 2003). So, the domiciliary invasion process registered for T. rubrovaria must be continually monitored.…”

“…This same feature was observed for North American species such as T. protracta Ulher (1894), T. rubida (Ulher, 1894) and Paratriatoma hirsuta Barber, 1938, which did not display a defecation pattern conducive to transmission of Chagas disease to man (Wood 1951). Almeida et al (2003) showed that following a post feeding elapsed time of more than 1 min, most of T. rubrovaria specimens had moved more than 3 cm away from the biting site. Based on these results we conclude that T. cruzi transmission may be a potential risk when the insect defecates either during feeding or in less than 1 min after feeding.…”

“…Dias (1956) originally demonstrated that the transmission of Chagas disease depends on the habit of the infected triatomine by Trypanosoma cruzi, in defecating during or shortly after the blood meal. In this context, Almeida et al (2003) stressed that T. rubrovaria reaches similar index to the ones observed for other effective vector species, such as T. infestans.…”

“…Almeida et al (2003) showed that in a regulated fast (20 days of starvation), in the first feeding in each instar, an index of 53.3% (the highest one) of females defecated in less than 1 min after the end of feeding. In this study, 78.2% of N5 displayed its highest index defecating in less than 30" in the first feeding (Fig.…”

What Do We Know About Chagas Disease in the United States?

“…The important Latin American vector species tended to defecate while feeding on the host or within 1-2 minutes of completing a blood meal, which would promote transmission, more often than sylvatic species. [8][9][10] Among the U.S. vectors, Triatoma rubida occasionally defecated during a blood meal or soon after feeding, but the other species studied, Triatoma gerstaeckeri, T. protracta, and T. sanguisuga, rarely or never defecated on the host, and a low percentage within 1-2 minutes of completing the blood meal.…”