Triatoma yelapensis sp. nov. (Hemiptera: Reduviidae) from Mexico, with a Key of Triatoma Species Recorded in Mexico.

Thirty-four species of Triatominae (Hemiptera, Reduviidae) are recorded in Mexico, Triatoma Laporte, 1832 the most speciose genus in this country. Here, we describe Triatoma yelapensis sp. nov. from the Pacific coast of Jalisco (Mexico). The most similar species to T. yelapensis sp. nov. is T. recurva (Stål, 1868), but they differ in head longitude, the proportion of labial segments, coloration pattern of corium and connexivum, spiracles location, and male genitalia. To provide statistical support for the morphological distinctiveness of the new species, we performed a geometric morphometric analysis of T. yelapensis sp. nov., T. dimidiata s.s. (Latreille, 1811), T. gerstaeckeri (Stål, 1859), and T. recurva (Stål, 1868), considering head morphology. We also provide an updated key of the genus Triatoma for species recorded in Mexico.

The Triatoma phyllosoma species group (Hemiptera: Reduviidae: Triatominae), vectors of Chagas disease: Diagnoses and a key to the species.

The Triatoma phyllosoma species group includes 17 species of kissing bugs, most of them implicated in the transmission of Chagas disease in the Americas. The species of this group are T. bassolsae Alejandre-Aguilar, Nogueda-Torres, Cortz-Jmenez, Jurberg, Galvo Carcavallo, 1999, T. brailovskyi Martnez, Carcavallo Pelaez, 1984, T. dimidiata (Latreille, 1811), T. gerstaeckeri (Stl, 1859), T. gomeznunezi Martnez, Carcavallo Juberg, 1994, T. hegneri Mazzotti, 1940, T. huehuetenanguensis Lima-Cordn, Monroy, Stevens, Rodas, Rodas, Dorn Justi, 2019, T. indictiva Neiva, 1912, T. longipennis Usinger, 1939, T. mazzottii Usinger, 1941, T. mexicana (Herrich-Schaeffer, 1848), T. mopan Dorn, Justi, Dale, Stevens, Galvo, Lima-Cordn Monroy, 2018, T. pallidipennis (Stl, 1872), T. phyllosoma (Burmeister, 1835), T. picturata Usinger, 1939, T. recurva (Stl, 1868), and T. sanguisuga (LeConte, 1855). The validity of some species of the group was uncertain, because of both cryptic species and hybrid occurrence. Species exhibiting these particularities were formerly classified in the T. dimidiata and T. phyllosoma complexes. Although we recognize the historical value of these species complexes, we do not recommend their further use. Instead, we recognize the T. phyllosoma species group here reviewed, considering the current knowledge of the systematics and reproductive behavior of the group. We implement the cohesion species concept, validating the species status of T. bassolsae, T. longipennis, T. mazzottii, T. pallidipennis, T. phyllosoma, and T. picturata. We also provide diagnoses, photographs and a taxonomic key including the recently described species.

[Diversity of Triatominae (Hemiptera: Reduviidae) in Santander, Colombia: Epidemiological implications].

INTRODUCTION: Domestic and wild triatomines in the department of Santander have an epidemiological impact, as recently they have been linked to outbreaks of acute Chagas disease. The analysis of their diversity and temporal variation contributes to the understanding of their biology and ecology in one of the most endemic areas of the country. OBJECTIVES: To analyze triatominae diversity in two regions of Santander. MATERIALS AND METHODS: We analyzed the triatomine records for Santander contained in the CINTROP-UIS entomology lab database. We grouped the information for two regions: the Middle Magdalena area and the Andean region, and for each one we designed species accumulation and range-abundance curves, we calculated diversity and equality indices, and we analyzed colonization and temporal variation or persistence of the community. RESULTS: Ninety five percent of triatomines came from the Andean area and 4.57% from Magdalena Medio, with nine and ten species each. The dominant species in the Andean area were Rhodnius prolixus and Triatoma dimidiata while in Magdalena Medio they were Rhodnius pallescens and Panstrongylus geniculatus. We found a greater diversity and richness in Middle Magdalena compared to the Andean area. The temporal variation showed persistence of communities over time. CONCLUSIONS: Results revealed differences in the diversity of the two regions and the potential of wild species to occupy artificial ecotopes. Triatomines intrusion and the recent involvement of wild species in the transmission of Trypanosoma cruzi emphasize the need to further investigate the ecology of these vectors in order to guide population control strategies.

[Risk of transmission of Chagas disease by intrusion of triatomines and wild mammals in Bucaramanga, Santander, Colombia].

INTRODUCTION: Notice of triatomines in dwellings of some neighborhoods in Bucaramanga motivated the realization of this study.Objetive: To evaluate the intrusion of triatomines and mammals, as well as some risk factors in urban dwellings. MATERIALS AND METHODS: Triatomines were collected in a neighborhood in Bucaramanga, Santander, on a monthly basis during one year with participation of the community. Collection included manual search in lamp posts, use of light traps, animal bait, and chemical attractants in nearby forests. Reservoirs were collected with bait traps. Insects and mammals were identified and examined in order to determine their natural infection. Risk factors in homes were assessed by means of a social-environmental survey. RESULTS: Eleven adult specimens of Pastrongylus geniculatus, as well as 63 of Rhodnius pallescens were collected in the forest, recreational peridomiciliary areas, and houses. Even two females and 21 nymphs of R. pallescens were found in bedrooms. Two specimens of Didelphis marsupialis were captured in neighboring forests. Out of the eleven P. geniculatus captured, nine were examined. Of these, five were positive for Trypanosoma cruzi. It was not possible to establish a significant risk factor;however, the dwellings with report of triatomines were located nearer to the adjacent forest. CONCLUSIONS: The finding of intrusive triatominae species and mammals with T. cruzi in intradomiciliary and peridomiciliary areas and periurban forests prove the potential risk to acquire infection from these populations that dwell in urban housing adjacent to these ecotopes where the sylvan cycle is kept.

Diversidad de Triatominae (Hemiptera: Reduviidae) en Santander, Colombia: implicaciones epidemiológicas / Diversity of Triatominae (Hemiptera: Reduviidae) in Santander, Colombia: Epidemiological implications

Resumen Introducción: Los triatominos domiciliados y silvestres constituyen un problema de impacto epidemiológico en el departamento de Santander, pues se han asociado recientemente con brotes agudos de la enfermedad de Chagas, por lo cual el análisis de su diversidad y variación temporal contribuye al conocimiento de su biología y ecología en una de las áreas más endémicas del país. Objetivo: Analizar la diversidad de triatominos en dos regiones de Santander. Materiales y métodos: Se analizó la información de la base de datos del Laboratorio de Entomología del Centro de Investigaciones en Enfermedades Tropicales de la Universidad Industrial de Santander (CINTROP-UIS), la cual contiene registros de triatominos en Santander. La información se separó en dos regiones, el Magdalena Medio y la zona andina, para cada una de las cuales se diseñaron curvas de acumulación de especies y de rango de abundancia, se calcularon los índices de diversidad y de igualdad, se analizó la colonización y se evaluó la variación temporal o persistencia de la comunidad. Resultados: El 95 % de los triatominos provenía de la zona andina y, el 4,57 %, del Magdalena Medio, con nueve y diez especies, respectivamente. Se encontró mayor diversidad y riqueza en el Magdalena Medio en comparación con la zona andina. Las especies dominantes en la zona andina fueron Rhodnius prolixus y Triatoma dimidiata, mientras que en Magdalena Medio fueron Rhodnius pallescens y Panstrongylus geniculatus. La variación temporal mostró persistencia de las comunidades en el tiempo. Conclusiones:. Los resultados evidenciaron diferencias en la diversidad de las dos regiones, además del potencial de las especies silvestres para ocupar ecótopos artificiales. La intrusión de triatominos y la reciente incriminación de especies silvestres en la transmisión de Trypanosoma cruzi, indican la necesidad de un mayor conocimiento de la ecología de estos vectores para orientar las estrategias de control.

Abstract Introduction: Domestic and wild triatomines in the department of Santander have an epidemiological impact, as recently they have been linked to outbreaks of acute Chagas disease. The analysis of their diversity and temporal variation contributes to the understanding of their biology and ecology in one of the most endemic areas of the country. Objectives: To analyze triatominae diversity in two regions of Santander. Materials and methods: We analyzed the triatomine records for Santander contained in the CINTROPUIS entomology lab database. We grouped the information for two regions: the Middle Magdalena area and the Andean region, and for each one we designed species accumulation and range-abundance curves, we calculated diversity and equality indices, and we analyzed colonization and temporal variation or persistence of the community. Results: Ninety five percent of triatomines came from the Andean area and 4.57% from Magdalena Medio, with nine and ten species each. The dominant species in the Andean area were Rhodnius prolixus and Triatoma dimidiata while in Magdalena Medio they were Rhodnius pallescens and Panstrongylus geniculatus. We found a greater diversity and richness in Middle Magdalena compared to the Andean area. The temporal variation showed persistence of communities over time. Conclusions: Results revealed differences in the diversity of the two regions and the potential of wild species to occupy artificial ecotopes. Triatomines intrusion and the recent involvement of wild species in the transmission of Trypanosoma cruzi emphasize the need to further investigate the ecology of these vectors in order to guide population control strategies.

Riesgo de transmisión de la enfermedad de Chagas por intrusión de triatominos y mamíferos silvestres en Bucaramanga, Santander, Colombia / Risk of transmission of Chagas disease by intrusion of triatomines and wild mammals in Bucaramanga, Santander, Colombia

Introducción: La notificación de triatominos en las viviendas de algunos barrios de Bucaramanga motivó la realización de este estudio. Objetivo: Evaluar la intrusión de triatominos y mamíferos, así como algunos factores de riesgo para la enfermedad de Chagas en viviendas urbanas. Materiales y métodos: En un barrio de Bucaramanga, Santander, se recolectaron triatominos mensualmente durante un año con participación comunitaria mediante búsqueda manual en el alumbrado público, y el uso de trampas de luz, cebo animal y atrayentes químicos en el bosque cercano. Los reservorios se recolectaron con trampas cebadas. Los insectos y mamíferos se determinaron y examinaron para establecer su infección natural. Los factores de riesgo de las viviendas se midieron mediante una encuesta sobre factores sociales y ambientales. Resultados: Se recolectaron 11 adultos de Panstrongylus geniculatus y 63 de Rhodnius pallescens en el bosque, en zonas de recreación en el peridomicilio y en el domicilio, incluidas dos hembras y 21 ninfas de R. pallescens en dormitorios. Se capturaron dos ejemplares de Didelphis marsupialis en el bosques adyacente. De los 11 individuos de P. geniculatus capturados, se examinaron nueve, de los cuales cinco fueron positivos para Trypanosoma cruzi (56 %); de los 63 individuos de R. pallescens capturados, se examinaron ocho, cuatro de los cuales fueron positivos para T. cruzi (50 %). De dos especímenes de D. marsupiales capturados, uno fue examinado y se encontró que era positivo para T. cruzi. No se pudo establecer un factor de riesgo significativo, sin embargo, las viviendas con reporte de triatominos se encontraban más cerca del bosque adyacente. Conclusiones: El hallazgo de especies de triatominos intrusivas y de mamíferos con T. cruzi en el domicilio y el peridomicilio, así como en los bosques periurbanos, demuestra el riesgo de infección en las poblaciones que habitan en viviendas urbanas adyacentes a los ecótopos donde se mantiene el ciclo silvestre.

Abstract Introduction: Notice of triatomines in dwellings of some neighborhoods in Bucaramanga motivated the realization of this study. Objetive: To evaluate the intrusion of triatomines and mammals, as well as some risk factors in urban dwellings. Materials and methods: Triatomines were collected in a neighborhood in Bucaramanga, Santander, on a monthly basis during one year with participation of the community. Collection included manual search in lamp posts, use of light traps, animal bait, and chemical attractants in nearby forests. Reservoirs were collected with bait traps. Insects and mammals were identified and examined in order to determine their natural infection. Risk factors in homes were assessed by means of a social-environmental survey. Results: Eleven adult specimens of Pastrongylus geniculatus, as well as 63 of Rhodnius pallescens were collected in the forest, recreational peridomiciliary areas, and houses. Even two females and 21 nymphs of R. pallescens were found in bedrooms. Two specimens of Didelphis marsupialis were captured in neighboring forests. Out of the eleven P. geniculatus captured, nine were examined. Of these, five were positive for Trypanosoma cruzi. It was not possible to establish a significant risk factor; however, the dwellings with report of triatomines were located nearer to the adjacent forest. Conclusions: The finding of intrusive triatominae species and mammals with T. cruzi in intradomiciliary and peridomiciliary areas and periurban forests prove the potential risk to acquire infection from these populations that dwell in urban housing adjacent to these ecotopes where the sylvan cycle is kept.

On palms, bugs, and Chagas disease in the Americas.

Palms are ubiquitous across Neotropical landscapes, from pristine forests or savannahs to large cities. Although palms provide useful ecosystem services, they also offer suitable habitat for triatomines and for Trypanosoma cruzi mammalian hosts. Wild triatomines often invade houses by flying from nearby palms, potentially leading to new cases of human Chagas disease. Understanding and predicting triatomine-palm associations and palm infestation probabilities is important for enhancing Chagas disease prevention in areas where palm-associated vectors transmit T. cruzi. We present a comprehensive overview of palm infestation by triatomines in the Americas, combining a thorough reanalysis of our published and unpublished records with an in-depth review of the literature. We use site-occupancy modeling (SOM) to examine infestation in 3590 palms sampled with non-destructive methods, and standard statistics to describe and compare infestation in 2940 palms sampled by felling-and-dissection. Thirty-eight palm species (18 genera) have been reported to be infested by ∼39 triatomine species (10 genera) from the USA to Argentina. Overall infestation varied from 49.1-55.3% (SOM) to 62.6-66.1% (dissection), with important heterogeneities among sub-regions and particularly among palm species. Large palms with complex crowns (e.g., Attalea butyracea, Acrocomia aculeata) and some medium-crowned palms (e.g., Copernicia, Butia) are often infested; in slender, small-crowned palms (e.g., Euterpe) triatomines associate with vertebrate nests. Palm infestation tends to be higher in rural settings, but urban palms can also be infested. Most Rhodnius species are probably true palm specialists, whereas Psammolestes, Eratyrus, Cavernicola, Panstrongylus, Triatoma, Alberprosenia, and some Bolboderini seem to use palms opportunistically. Palms provide extensive habitat for enzootic T. cruzi cycles and a critical link between wild cycles and transmission to humans. Unless effective means to reduce contact between people and palm-living triatomines are devised, palms will contribute to maintaining long-term and widespread, albeit possibly low-intensity, transmission of human Chagas disease.

Comparación de métodos para la captura de triatominos (Hemiptera: Reduviidae) en palmas Attalea butyraceaen los Llanos Orientales de Colombia / Comparison of methods for the capture of triatomines (Hemiptera: Reduviidae) in Attalea butyracea palms in the Eastern Plains of Colombia

Introducción. El estudio de los triatominos en sus ecótopos naturales tiene gran significado en la epidemiología de la enfermedad de Chagas. La recolección de insectos vivos y su establecimiento en insectarios permite realizar incontables estudios. Por ello se necesitan métodos efectivos para la captura de triatominos silvestres, especialmente especies intrusas como Rhodnius prolixus. Objetivo. Comparar cuatro métodos para la captura de triatominos en palmas para medir su efectividad. Materiales y métodos. El estudio se llevó a cabo en la localidad de Maní, departamento de Casanare, Colombia, con predominio de Attalea butyracea. Se compararon cuatro metodologías en 67 palmas: trampas con cebo vivo, búsqueda directa en palmas, tala y disección. Resultados. Los métodos fueron efectivos para recolectar ejemplares juveniles y adultos. La tala y la búsqueda manual mostraron los mayores índices de infestación (100 % y 83,33 %). La trampa Angulo mostró mayores índices de hacinamiento (4,93), densidad (3,76), rango de abundancia (1-13) e índice adulto/ninfa (0,22). La tala y la disección fue el método que significativamente recolectó más triatominos en comparación con los otros (p<0,002), seguido de la trampa Angulo. No se observaron diferencias en la captura de los estadios de ninfas entre los métodos evaluados (p>0,05). Conclusiones. Aunque la tala fue el mejor método para la recolección del mayor número de triatominos, los métodos con el cebo vivo con adhesivos o refugios para atrapar los insectos, fueron una buena alternativa. Entre ellos, la trampa Angulo mostró mejores resultados y evitó la exposición del investigador al riesgo y la intervención de ecotopos naturales.

Introduction: Studying triatominae in their natural ecotopes has great significance in the epidemiology of Chagas disease. Gathering live insects and the establishment of insectaries allows countless studies. Therefore, effective methods are needed for capturing wild triatomines, especially intrusive species such as Rhodnius prolixus. Objective: To compare four methods of capturing triatomines in palms to measure their effectiveness. Materials and methods: Our study was conducted in Maní, department of Casanare, Colombia, with a predominance of A. butyracea. We compared four methodologies in 67 palms: live-bait traps, direct search in the palms, felling and dissection. Results: The methods were effective to collect juveniles and adults. Felling and manual search showed the highest infestation rates (100% and 83.33%). Higher indexes of overcrowding (4.93), density (3.76), abundance range (1-13) and adult/nymph index (0.22) were obtained with the Angulo trap. Felling and dissection was the method which significantly collected a greater number of triatomines compared with the other methods (p <0.002); it was followed by the Angulo trap. We did not find any differences in the collection of the nymphal stages among the evaluated methods (p> 0.05).Conclusions: Even though felling was the best method for collecting the highest number of triatomines, live-bait with adhesives or shelters to trap insects were a good alternative to collect the insects in palms. Among them, the Angulo trap showed better results and it prevents the risk of exposure of the researcher and the intervention of natural ecotopes.

[Comparison of methods for the capture of triatomines ( Hemiptera: Reduviidae ) in Attalea butyracea palms in the Eastern Plains of Colombia]. / Comparación de métodos para la captura de triatominos (Hemiptera: Reduviidae) en palmas Attalea butyracea en los Llanos Orientales de Colombia.

INTRODUCTION: Studying triatominae in their natural ecotopes has great significance in the epidemiology of Chagas disease. Gathering live insects and the establishment of insectaries allows countless studies. Therefore, effective methods are needed for capturing wild triatomines, especially intrusive species such as Rhodnius prolixus . OBJECTIVE: To compare four methods of capturing triatomines in palms to measure their effectiveness. MATERIALS AND METHODS: Our study was conducted in Maní, department of Casanare, Colombia, with a predominance of A. butyracea . We compared four methodologies in 67 palms: live-bait traps, direct search in the palms, felling and dissection. RESULTS: The methods were effective to collect juveniles and adults. Felling and manual search showed the highest infestation rates (100% and 83.33%). Higher indexes of overcrowding (4.93), density (3.76), abundance range (1-13) and adult/nymph index (0.22) were obtained with the Angulo trap. Felling and dissection was the method which significantly collected a greater number of triatomines compared with the other methods (p <0.002); it was followed by the Angulo trap. We did not find any differences in the collection of the nymphal stages among the evaluated methods (p> 0.05). CONCLUSIONS: Even though felling was the best method for collecting the highest number of triatomines, live-bait with adhesives or shelters to trap insects were a good alternative to collect the insects in palms. Among them, the Angulo trap showed better results and it prevents the risk of exposure of the researcher and the intervention of natural ecotopes.

[Attalea butyracea palms adjacent to housing as a source of infestation by Rhodnius prolixus (Hemiptera: Reduviidae)]. / Attalea butyracea próximas a las viviendas como posible fuente de infestación domiciliaria por Rhodnius prolixus (Hemiptera: Reduviidae) en los Llanos Orientales de Colombia.

INTRODUCTION: The presence of Rhodnius prolixus in palms on the eastern plains area of Colombia provide a high risk for infection with Trypanosoma cruzi. Intensive surveillance of the palm tree habitat are necessary to confirm the presence of bugs and provide evidence that this habitat is a source of house infestations. OBJECTIVE: The infestation by R. prolixus in the palm, Attalea butyracea, was investigated near homes for assessment of risk. MATERIALS AND METHODS: Palms were examined for Rhodnius bugs adjacent to rural housing in the eastern plains provinces of Casanare and Arauca, Colombia. Bait traps were used as well as an active search by the investigators and a community watch program to collect intradomiciliary triatomine bugs. Collected species were identified by morphological criteria,and natural T.cruzi infections in the triatomine bugs were detected by the PCR technique. RESULTS: In 111 of 172 (64.5%) palms (A. butyracea) inspected, 529 nymphs and adults of R. prolixus and 5 nymphs of Eratyrus mucronatus were collected. The A. butyracea were located within 500 m of housing. In the same period, 132 R. prolixus and specimens of the triatomine species Psammolestes arthuri,Cavernicola pilosa, Triatoma maculata, Panstrongylus geniculatus were collected inside houses. Twenty nymphs of E. mucronatus were found in a pile of bricks on the porch of a home. Natural infection of T. cruzi was detected in 28.8% of R. prolixus from palm trees and 30.0% inside houses. CONCLUSIONS: A new epidemiological scenario of transmission of Chagas disease was revealed, characterized by high rates of infestation of R. prolixus in palms near houses with frequent intrusion into houses. In designing measures to prevent Chagas disease, the association of palm trees, triatomine bugs and housing proximity is a significant consideration.

[New trap for the capture of triatomines in wild and peridomestic habitats]. / Nueva trampa para la captura de triatominos en hábitats silvestres y peridomésticos.

INTRODUCTION: Wild triatomines have become increasingly important in the transmission of Chagas disease because of their frequent house entry behavior. Knowledge of their biology is limited, and few tools are available for their collection. These needs led to the design of a new trap for live triatomines. OBJECTIVES: The characteristics are described of a new bait trap designed for collecting triatomines. Trap usage and preliminary results are described for collections in several regional natural habitats in Colombia. MATERIALS AND METHODS: The trap houses a live animal as bait and provides a shelter for triatomines that are attracted by the bait. RESULTS: The trap was very effective for collecting Rhodnius prolixus, Triatoma dimidiata and Rhodnius pallescens in the natural habitats of each species. Triatomine density ranged widely in palm environments in each of two regions, and a relatively higher density in areas surrounding dwellings in the Andean region. CONCLUSIONS: The new trap for collecting triatomines proved successful in collecting live wild triatomines, using live bait native to the study areas. It is easy to transport and place, it is functions well in a variety of habitats, and it is more effective than other traps using live bait.

Nueva trampa para la captura de triatominos en hábitats silvestres y peridomésticos / New trap for the capture of triatomines in wild and peridomestic habitats

Introducción. Los triatominos silvestres han incrementado su importancia en la transmisión de la enfermedad de Chagas por su frecuente intrusión en la vivienda, los pocos conocimientos sobre su biología y la escasez de herramientas para su recolección y estudio, motivaron el diseño de una nueva trampa para obtener insectos vivos. Objetivo. Describir las características, forma de utilización y resultados preliminares de uso, de una nueva trampa con cebo vivo, diseñada para recolectar triatominos en sus hábitats naturales en diferentes regiones de Colombia. Materiales y métodos. Se describen las características físicas de una trampa que aloja un animal vivo como cebo y un refugio para los triatominos que se acercan atraídos por el cebo. Resultados. Se demostró una gran eficacia para la recolección de Rhodnius prolixus, Triatoma dimidiata y Rhodnius pallescens en sus hábitats silvestres en las regiones estudiadas. Se encontró un mayor rango de densidad en palmas en las dos regiones y un mayor promedio de triatominos por hábitat positivo en el peridomicilio en la región andina. Conclusiones. La nueva trampa para triatominos demostró ser útil en la recolección de triatominos silvestres vivos en las regiones de estudio; utiliza un cebo vivo que se obtiene en las mismas zonas; es fácil de transportar y colocar; evita la intervención de los hábitats, y muestra una mayor eficacia que la encontrada con otras trampas que utilizan cebo vivo.

Introduction. Wild triatomines have become increasingly important in the transmission of Chagas disease because of their frequent house entry behavior. Knowledge of their biology is limited, and few tools are available for their collection. These needs led to the design of a new trap for live triatomines. Objectives. The characteristics are described of a new bait trap designed for collecting triatomines. Trap usage and preliminary results are described for collections in several regional natural habitats in Colombia. Materials and methods. The trap houses a live animal as bait and provides a shelter for triatomines that are attracted by the bait. Results. The trap was very effective for collecting Rhodnius prolixus, Triatoma dimidiata and Rhodnius pallescens in the natural habitats of each species. Triatomine density ranged widely in palm environments in each of two regions, and a relatively higher density in areas surrounding dwellings in the Andean region. Conclusions. The new trap for collecting triatomines proved successful in collecting live wild triatomines, using live bait native to the study areas. It is easy to transport and place, it is functions well in a variety of habitats, and it is more effective than other traps using live bait.

[Antennal phenotype variation in sylvatic, peridomestic and domestic populations of Triatoma dimidiata (Hemiptera: Reduviidae) from Santander, Colombia]. / Variación del fenotipo antenal de poblaciones del domicilio, peridomicilio y silvestres de Triatoma dimidiata (Hemiptera: Reduviidae) en Santander, Colombia.

INTRODUCTION: Triatoma dimidiata is one of the widely distributed triatomines in Colombia. The phenotype of the antenna is a characteristic of populations that can differ among habitats and can give information concerning its biology and behavior. This information in turn can be used in the development of new methodological proposals for its control. OBJECTIVE: The behavior of populations of Triatoma dimidiate was studied in several different habitats, using the antennal phenotype. MATERIALS AND METHODS: A mechanoreceptor and three chemoreceptors were compared in the antennae of 60 Triatoma dimidiata adults from several defined habitats in Santander, using unvariate and multivariate analyses. RESULTS: The multivariate analysis differentiated the female populations significantly. These differences were associated with variations in the number of thick-walled trichoids and with the numerical increase of the thin walled trichoids in habitats close to human housing. The males, with a larger number of sensilla and thin walled trichoids, were not differentiated significantly, although, similar tendencies were observed. Sexual dimorphism was clear in these characters in the total population, but less pronounced in the domestic populations. CONCLUSIONS: The antennal sensilla patterns were useful in the intraspecific differentiation of Triatoma dimidiata in different habitats. The differences in the female population shed light on new sensorial arrangements for the exploration of the habitat, in contrast with the male populations that, because of their great capacity for dispersion, were not differentiated in the distinct habitats. The differences in sensilla patterns between females from urban areas and those from rural surroundings may be a simple and efficient marker of the origin of individual Triatominae attempting to colonize new habitats.

Variación del fenotipo antenal de poblaciones del domicilio, peridomicilio y silvestres de Triatoma dimidiata (Hemiptera: Reduviidae) en Santander, Colombia / Antennal phenotype variation in sylvatic, peridomestic and domestic populations of Triatoma dimidiata (Hemiptera: Reduviidae) from Santander, Colombia

Introducción. Triatoma dimidiata es uno de los triatominos más ampliamente distribuidos en Colombia, la caracterización fenotípica antenal de poblaciones de diferentes hábitats proporcionaran conocimientos sobre su biología y comportamiento que podrán ser utilizados en nuevas propuestas metodológicas para su control. Objetivo. Estudiar el comportamiento de poblaciones de Triatoma dimidiata en diferentes hábitats utilizando el fenotipo antenal. Materiales y métodos. Se analizaron un mecanorreceptor y tres quimiorreceptores antenales de 60 individuos de Triatoma dimidiata provenientes de diferentes hábitats en Santander utilizando análisis univariados y multivariados. Resultados. Los análisis multivariados diferenciaron significativamente las poblaciones de las hembras, estas diferencias estuvieron asociadas a variaciones en el número de tricoides de pared gruesa, con aumento de los tricoides de pared fina en hábitats cercanos al domicilio humano. Los machos con mayor número de sensilla y de tricoides de pared fina, no se diferenciaron, sin embargo tendencias similares fueron apreciadas. Se observó dimorfismo sexual entre todas las poblaciones y fue menor en el del domicilio. Conclusiones. El fenotipo de sensilla antenal fue útil en la diferenciación intraespecífica de Triatoma dimidiata en diferentes hábitats. Las diferencias en hembras ponen de manifiesto nuevos arreglos sensoriales para la explotación del hábitat a diferencia de los machos, que por su mayor capacidad de dispersión, no se diferenciaron entre los ecotopos. La similitud entre hembras de zona urbana, con hembras de peridomicilio rural permite proponer al fenotipo antenal como un sencillo y eficiente indicador para la determinación del origen de triatominos que intentan colonizar nuevos hábitats.

Introduction. Triatoma dimidiata is one of the widely distributed triatomines in Colombia. The phenotype of the antenna is a characteristic of populations that can differ among habitats and can give information concerning its biology and behavior. This information in turn can be used in the development of new methodological proposals for its control. Objective. The behavior of populations of Triatoma dimidiate was studied in several different habitats, using the antennal phenotype. Materials and methods. A mechanoreceptor and three chemoreceptors were compared in the antennae of 60 Triatoma dimidiata adults from several defined habitats in Santander, using unvariate and multivariate analyses. Results. The multivariate analysis differentiated the female populations significantly. These differences were associated with variations in the number of thick-walled trichoids and with the numerical increase of the thin walled trichoids in habitats close to human housing. The males, with a larger number of sensilla and thin walled trichoids, were not differentiated significantly, although, similar tendencies were observed. Sexual dimorphism was clear in these characters in the total population, but less pronounced in the domestic populations. Conclusions. The antennal sensilla patterns were useful in the intraspecific differentiation of Triatoma dimidiata in different habitats. The differences in the female population shed light on new sensorial arrangements for the exploration of the habitat, in contrast with the male populations that, because of their great capacity for dispersion, were not differentiated in the distinct habitats. The differences in sensilla patterns between females from urban areas and those from rural surroundings may be a simple and efficient marker of the origin of individual Triatominae attempting to colonize new habitats.

Analysis of antenal sensilla patterns of Rhodnius prolixus from Colombia and Venezuela

Antennal sensilla patterns were used to analyze population variation of domestic Rhodnius prolixus from six departments and states representing three biogeographical regions of Colombia and Venezuela. Discriminant analysis of the patterns of mechanoreceptors and of three types of chemoreceptors on the pedicel and flagellar segments showed clear differentiation between R. prolixus populations east and west of the Andean Cordillera. The distribution of thick and thin-walled trichoids on the second flagellar segment also showed correlation with latitude, but this was not seen in the patterns of other sensilla. The results of the sensilla patterns appear to be reflecting biogeographic features or population isolation rather than characters associated with different habitats and lend support to the idea that domestic R. prolixus originated in the eastern region of the Andes.

Analysis of antenal sensilla patterns of Rhodnius prolixus from Colombia and Venezuela.

Antennal sensilla patterns were used to analyze population variation of domestic Rhodnius prolixus from six departments and states representing three biogeographical regions of Colombia and Venezuela. Discriminant analysis of the patterns of mechanoreceptors and of three types of chemoreceptors on the pedicel and flagellar segments showed clear differentiation between R. prolixus populations east and west of the Andean Cordillera. The distribution of thick and thin-walled trichoids on the second flagellar segment also showed correlation with latitude, but this was not seen in the patterns of other sensilla. The results of the sensilla patterns appear to be reflecting biogeographic features or population isolation rather than characters associated with different habitats and lend support to the idea that domestic R. prolixus originated in the eastern region of the Andes.