Influence of the palm tree species on the variability of Rhodnius nasutus Stål, 1859 (Hemiptera, Reduviidae, Triatominae)

Abstract

This work evaluated the occurrence and genetic structure of Rhodnius nasutus sampled in two sites using morphometry and microsatellites. These sites, presented distinct abiotic features and palm trees: (i) nine Attalea speciosa palm trees, so called babaçu, were sampled from the Meruoca Mountain Ridge, a sloping region of reminiscent forest in the state of Ceará, Brazil, and (ii) 17 Copernicia prunifera palm trees, so called carnaúba, were sampled in the scrub savanna region (Sobral district) that surrounds the mountain ridge. Of the twenty-six palm trees dissected, 70.6% of carnauba and 88.9% of babaçu were infested by R. nasutus. The micro-climatic data where R. nasutus were sheltered demonstrated that the babaçu and carnaúba palm trees presented significant differences (p < 0.05) in relation to the external environment, except for temperature and relative humidity regulation, suggesting that the architecture of the babaçu crown keeps a more stable micro-environment. The morphometric studies of the F1 generation demonstrated that insects from the babaçu (A. speciosa) were significantly larger (p = 0.000) than those collected in carnaúba (C. prunifera) palm trees. Also, microsatellite analysis demonstrated a high genetic differentiation between the two groups of R. nasutus (R(st) = -0.77). Our results suggest that the difference in size between the populations is probably related to an incipient process of genetic drift in populations associated to each palm tree, probably also driven by the different climatic features observed in these micro-environments.

Description and characterization of the melanic morphotype of Rhodnius nasutus Stål, 1859 (Hemiptera: Reduviidae: Triatominae)

“…R. nasutus is described as a species of the Triatominae, with a red-brownish body as its general characteristic. This coloring is very similar to the color of the fi bers and stem of the carnaúba palm tree 2,14 , which is considered as the main ecotope for R. nasutus. Thus, this coloration disguises the triatomines, protecting them from predators.…”

Study of the external female genitalia of 14 Rhodnius species (Hemiptera, Reduviidae, Triatominae) using scanning electron microscopy

“…On the other hand, all descriptive studies in the morphology field also have this limitation. For triatomines, morphological variations, not described before, were detected for Rhodnius nasutus in Ceara [25], and Triatoma rubrovaria in Rio Grande do Sul [26]. …”

Eco-epidemiology of Chagas disease in northeastern Brazil: Triatoma brasiliensis, T. pseudomaculata and Rhodnius nasutus in the sylvatic, peridomestic and domestic environments

“…Both species have been captured in peridomestic environments and natural ecotopes in xerophytic semiarid ecosystems, often constituting large colonies with high rates of T. cruzi infection (Sarquis et al 2004). Rhodnius nasutus, a native triatomine of northeastern Brazil which naturally inhabits Carnauba palm trees (Copernicia prunifera), has also been captured in the peridomestic and domestic environments (Sarquis et al 2006;Dias et al 2011). Furthermore, R. nasutus colonizes other wild ecotopes, such as the Licania rigida tree , suggesting that this species presents some ecological eclecticism and may be readapting from its traditional habitat due to anthropic transformations.…”