Life cycle, feeding and defecation patterns of Rhodnius ecuadoriensis (Lent & León 1958) (Hemiptera: Reduviidae: Triatominae) under laboratory conditions

Abstract

Rhodnius ecuadoriensis is the second most important vector of Chagas Disease (CD) in Ecuador. The objective of this study was to describe (and compare) the life cycle, the feeding and defecation patterns under laboratory conditions of two populations of this specie [from the provinces of Manabí (Coastal region) and Loja (Andean region)]. Egg-to-adult (n = 57) development took an average of 189.9 +/- 20 (Manabí) and 181.3 +/- 6.4 days (Loja). Mortality rates were high among Lojan nymphs. Pre-feeding time (from contact with host to feeding initiation) ranged from 4 min 42 s [nymph I (NI)] to 8 min 30 s (male); feeding time ranged from 14 min 45 s (NI)-28 min 25 s (male) (Manabí) and from 15 min 25 s (NI)-28 min 57 s (nymph V) (Loja). The amount of blood ingested increased significantly with instar and was larger for Manabí specimens (p < 0.001). Defecation while feeding was observed in Manabí specimens from stage nymph III and in Lojan bugs from stage nymph IV. There was a gradual, age-related increase in the frequency of this behaviour in both populations. Our results suggest that R. ecuadoriensis has the bionomic traits of an efficient vector of Trypanosoma cruzi. Together with previous data on the capacity of this species to infest rural households, these results indicate that control of synanthropic R. ecuadoriensis populations in the coastal and Andean regions may have a significant impact for CD control in Ecuador and Northern Peru.

The biology of three Mexican-American species of Triatominae (Hemiptera: Reduviidae): Triatoma recurva, Triatoma protracta and Triatoma rubida

“…The average numbers of blood meals required for moulting to the next instar for T. protracta and T. rubida were similar to the values found for Rhodnius colombiensis (Mejia, Galvão, Jurberg), Rhodnius prolixus (Stål) and Rhodnius ecuadoriensis (Lent and León), whereas the average number of blood meals for T. recurva was higher than the average numbers for these three latter species (Arévalo et al 2007a, Villacís et al 2008). Because an increase in the number of vector-host interactions (for blood feeding) increases the probability of transmission of T. cruzi to hosts (Rocha et al 2001), the three currently studied species could be considered potentially epidemiologically important with respect to T. cruzi transmission to human populations.…”

Demographic fitness of Belminus ferroae (Hemiptera: Triatominae) on three different hosts under laboratory conditions

“…This level of mortality is similar to that obtained in B. ferroae fed on the vertebrate host in the present study (91%). In contrast, the two cohorts of B. ferroae fed on arthropods developed from the egg to adult stage with mortality rates of between 56-60%, which is similar to or even lower than the rates reported for other species of Triatominae fed on their natural vertebrate hosts (Bar et al 2003, Martínez-Ibarra et al 2003, 2007, Villacís et al 2008). …”

Prevalence, Genetic Characterization, and 18S Small Subunit Ribosomal RNA Diversity of Trypanosoma rangeliin Triatomine and Mammal Hosts in Endemic Areas for Chagas Disease in Ecuador

“…However, its capacity to transmit T. rangeli has not been evaluated yet. Recent studies have demonstrated that R. ecuadoriensis is an important threat for Chagas disease transmission due to its wide geographical distribution, high infection rates with T. cruzi, good vector efficiency, and capacity of adaptation to different habitats (Villacis et al 2008, Grijalva and Villacis 2009, SuarezDavalos et al 2010, Grijalva et al 2012, 2014. In this regard, the presence of R. ecuadoriensis, infected with T. rangeli, constitutes an important element to consider when the distribution of trypanosomes is evaluated in Chagas disease endemic areas.…”