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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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Phenotypic characteristics ofAttalea butyraceaand population abundance ofRhodnius prolixus. Association between phenotypic characteristics of Attalea butyracea palm trees and population abundance of Rhodnius prolixus (n = 150 palm trees). DBH, diameter at breast height.
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Fig2: Phenotypic characteristics ofAttalea butyraceaand population abundance ofRhodnius prolixus. Association between phenotypic characteristics of Attalea butyracea palm trees and population abundance of Rhodnius prolixus (n = 150 palm trees). DBH, diameter at breast height.

Mentions: Relative density of R. prolixus according to A. butyracea physiognomy: The 14-hectare natural forest of A. butyracea has an estimated density of 1265 palm trees/hectare. According to the regression analysis for the data of the 150 palm trees of the first sampling, the relative density of R. prolixus in A. butyracea natural forests is positively associated with the palm crown size (p < 0.0001; r2 = 0.41), number of leaves (p < 0.0001; r2 = 0.23) and palm tree height (p < 0.0001; r2 = 0.193). Palm trees with heights ranging from 2 to 20 meters were sampled and triatomines were collected in palm trees up to 2.9 meters. R. prolixus were also collected from palm trees with a number of leaves in the crown ranging from nine to 27 leaves. Conversely, the DBH of the palm tree has no influence on the population relative density (p = 0.25; r2 = 0.0088) (Figure 2). A multiple regression analysis carried out with the variables that presented an association with the R. prolixus relative density showed a high significance (p = 0.000; r2 = 0.64). This result confirms that the palm tree crown structure affects the relative population density of R. prolixus.Figure 2


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)

Phenotypic characteristics ofAttalea butyraceaand population abundance ofRhodnius prolixus. Association between phenotypic characteristics of Attalea butyracea palm trees and population abundance of Rhodnius prolixus (n = 150 palm trees). DBH, diameter at breast height.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Fig2: Phenotypic characteristics ofAttalea butyraceaand population abundance ofRhodnius prolixus. Association between phenotypic characteristics of Attalea butyracea palm trees and population abundance of Rhodnius prolixus (n = 150 palm trees). DBH, diameter at breast height.
Mentions: Relative density of R. prolixus according to A. butyracea physiognomy: The 14-hectare natural forest of A. butyracea has an estimated density of 1265 palm trees/hectare. According to the regression analysis for the data of the 150 palm trees of the first sampling, the relative density of R. prolixus in A. butyracea natural forests is positively associated with the palm crown size (p < 0.0001; r2 = 0.41), number of leaves (p < 0.0001; r2 = 0.23) and palm tree height (p < 0.0001; r2 = 0.193). Palm trees with heights ranging from 2 to 20 meters were sampled and triatomines were collected in palm trees up to 2.9 meters. R. prolixus were also collected from palm trees with a number of leaves in the crown ranging from nine to 27 leaves. Conversely, the DBH of the palm tree has no influence on the population relative density (p = 0.25; r2 = 0.0088) (Figure 2). A multiple regression analysis carried out with the variables that presented an association with the R. prolixus relative density showed a high significance (p = 0.000; r2 = 0.64). This result confirms that the palm tree crown structure affects the relative population density of R. prolixus.Figure 2

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