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Effect of the physiognomy of Attalea butyracea (Arecoideae) on population density and age distribution of Rhodnius prolixus (Triatominae).

Urbano P, Poveda C, Molina J - Parasit Vectors (2015)

Bottom Line: In its natural forest environment, this triatomine is mainly found in palm tree crowns, where it easily establishes and develops dense populations.The relative population density of R. prolixus on natural A. butyracea groves is associated with the palm's height, number of leaves and crown volume.A higher density of R. prolixus was found as the palm tree height increased and as the distance of the palm with respect to the forest border decreased, especially towards anthropically intervened areas.

View Article: PubMed Central - PubMed

Affiliation: Centro de Investigaciones en Microbiología y Parasitología Tropical - CIMPAT, Universidad de los Andes, Carrera 1 No. 18A-10, Bloque A, Bogotá, Colombia. plurbanus@gmail.com.

ABSTRACT

Background: Rhodnius prolixus Stål, 1859 is one of the main vectors of Trypanosoma (Schyzotrypanum) cruzi Chagas, 1909. In its natural forest environment, this triatomine is mainly found in palm tree crowns, where it easily establishes and develops dense populations. The aim of this study was to evaluate the effect of the physiognomy and reproductive status of Attalea butyracea on the population relative density and age structure of R. prolixus and to determine the vector's population stratification according to the vertical and horizontal profile of an A. butyracea forest.

Methods: Using live bait traps, 150 individuals of A. butyracea with different physiognomy and 40 individuals with similar physiognomy (crown size, number of leaves, palm tree height, diameter at breast height, reproductive status) were sampled for triatomines in Yopal, Casanare-Colombia. Temperature and relative humidity were measured in the crown of the palm tree. Entomological indices and natural infection rates were also determined.

Results: The relative population density of R. prolixus on natural A. butyracea groves is associated with the palm's height, number of leaves and crown volume. The young immature stages were present mostly at the crown's base and the advanced immature stages and adults were present mostly at the crown of the palm tree. This distribution correlates with the temperature stability and relative humidity in the base and the fluctuation of both environmental variables in the palm's crown. A higher density of R. prolixus was found as the palm tree height increased and as the distance of the palm with respect to the forest border decreased, especially towards anthropically intervened areas. A density index of 12.6 individuals per palm tree with an infestation index of 88.9% and a colonization index of 98.7% was observed. 85.2% was the infection index with T. cruzi.

Conclusion: The physiognomy of palm trees affects the relative population density and the distribution of developmental stages of R. prolixus. Therefore, they constitute a risk factor for the potential migration of infected insects from wild environments towards residential environments and the subsequent epidemiological risk of transmission of T. cruzi to people.

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Related in: MedlinePlus

Features of palm trees with similarities in their physiognomic structure (n = 40 palm trees). A) Population density (nymphs and adults) of Rhodnius prolixus by the microhabitat sampled in Attalea butyracea palm tree crowns. B) Stratification density of the developmental stages of Rhodnius prolixus in crowns of Attalea butyracea palm trees. C) Daily variations of the temperature and relative humidity in the three sampling sites on the crown of Attalea butyracea palm tree.
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Fig4: Features of palm trees with similarities in their physiognomic structure (n = 40 palm trees). A) Population density (nymphs and adults) of Rhodnius prolixus by the microhabitat sampled in Attalea butyracea palm tree crowns. B) Stratification density of the developmental stages of Rhodnius prolixus in crowns of Attalea butyracea palm trees. C) Daily variations of the temperature and relative humidity in the three sampling sites on the crown of Attalea butyracea palm tree.

Mentions: Population relative density and age structure of R. prolixus in the palm tree crown: No statistically significant differences between the R. prolixus relative population density were found according to the sampling site in the crown (Kruskal-Wallis, p = 0.54) (Figure 4A). However, the N1, N2 and N3 relative densities were significantly higher in the base and mid-zone of the crown (Dunn, p = 0.001), while the N5 and adult relative densities were significantly higher than the rest of the developmental stages in the crown (Dunn, p = 0.0001) (Figure 4B).Figure 4


Effect of the physiognomy of Attalea butyracea (Arecoideae) on population density and age distribution of Rhodnius prolixus (Triatominae).

Urbano P, Poveda C, Molina J - Parasit Vectors (2015)

Features of palm trees with similarities in their physiognomic structure (n = 40 palm trees). A) Population density (nymphs and adults) of Rhodnius prolixus by the microhabitat sampled in Attalea butyracea palm tree crowns. B) Stratification density of the developmental stages of Rhodnius prolixus in crowns of Attalea butyracea palm trees. C) Daily variations of the temperature and relative humidity in the three sampling sites on the crown of Attalea butyracea palm tree.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4389994&req=5

Fig4: Features of palm trees with similarities in their physiognomic structure (n = 40 palm trees). A) Population density (nymphs and adults) of Rhodnius prolixus by the microhabitat sampled in Attalea butyracea palm tree crowns. B) Stratification density of the developmental stages of Rhodnius prolixus in crowns of Attalea butyracea palm trees. C) Daily variations of the temperature and relative humidity in the three sampling sites on the crown of Attalea butyracea palm tree.
Mentions: Population relative density and age structure of R. prolixus in the palm tree crown: No statistically significant differences between the R. prolixus relative population density were found according to the sampling site in the crown (Kruskal-Wallis, p = 0.54) (Figure 4A). However, the N1, N2 and N3 relative densities were significantly higher in the base and mid-zone of the crown (Dunn, p = 0.001), while the N5 and adult relative densities were significantly higher than the rest of the developmental stages in the crown (Dunn, p = 0.0001) (Figure 4B).Figure 4

Bottom Line: In its natural forest environment, this triatomine is mainly found in palm tree crowns, where it easily establishes and develops dense populations.The relative population density of R. prolixus on natural A. butyracea groves is associated with the palm's height, number of leaves and crown volume.A higher density of R. prolixus was found as the palm tree height increased and as the distance of the palm with respect to the forest border decreased, especially towards anthropically intervened areas.

View Article: PubMed Central - PubMed

Affiliation: Centro de Investigaciones en Microbiología y Parasitología Tropical - CIMPAT, Universidad de los Andes, Carrera 1 No. 18A-10, Bloque A, Bogotá, Colombia. plurbanus@gmail.com.

ABSTRACT

Background: Rhodnius prolixus Stål, 1859 is one of the main vectors of Trypanosoma (Schyzotrypanum) cruzi Chagas, 1909. In its natural forest environment, this triatomine is mainly found in palm tree crowns, where it easily establishes and develops dense populations. The aim of this study was to evaluate the effect of the physiognomy and reproductive status of Attalea butyracea on the population relative density and age structure of R. prolixus and to determine the vector's population stratification according to the vertical and horizontal profile of an A. butyracea forest.

Methods: Using live bait traps, 150 individuals of A. butyracea with different physiognomy and 40 individuals with similar physiognomy (crown size, number of leaves, palm tree height, diameter at breast height, reproductive status) were sampled for triatomines in Yopal, Casanare-Colombia. Temperature and relative humidity were measured in the crown of the palm tree. Entomological indices and natural infection rates were also determined.

Results: The relative population density of R. prolixus on natural A. butyracea groves is associated with the palm's height, number of leaves and crown volume. The young immature stages were present mostly at the crown's base and the advanced immature stages and adults were present mostly at the crown of the palm tree. This distribution correlates with the temperature stability and relative humidity in the base and the fluctuation of both environmental variables in the palm's crown. A higher density of R. prolixus was found as the palm tree height increased and as the distance of the palm with respect to the forest border decreased, especially towards anthropically intervened areas. A density index of 12.6 individuals per palm tree with an infestation index of 88.9% and a colonization index of 98.7% was observed. 85.2% was the infection index with T. cruzi.

Conclusion: The physiognomy of palm trees affects the relative population density and the distribution of developmental stages of R. prolixus. Therefore, they constitute a risk factor for the potential migration of infected insects from wild environments towards residential environments and the subsequent epidemiological risk of transmission of T. cruzi to people.

Show MeSH
Related in: MedlinePlus