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Mougabure-Cueto G, Hernández ML, Gilardoni JJ, Nattero J. Morphometric study of the legs of the main Chagas vector, Triatoma infestans (Hemiptera: Reduviidae). Acta Trop 2024; 255:107219. [PMID: 38649106 DOI: 10.1016/j.actatropica.2024.107219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2024] [Revised: 04/15/2024] [Accepted: 04/16/2024] [Indexed: 04/25/2024]
Abstract
In triatomines, vectors of Chagas disease, active dispersal takes place by walking and flying. Flight has received more attention than walking although the last is the dispersal modality used by nymphs due to their lack of wings and also used by adults, which would facilitate the colonization and reinfestation of houses after vector control actions. The present work studied the morphometrical variation of Triatoma infestans legs, the main vector of Chagas disease the Southern Cone of South America. We described morphometric traits and the natural variation of each leg segment. Different linear, size and shape variables of each component of the three right legs of fifth instar nymphs of T. infestans were analyzed using morphometric tools. We analyzed differentiation, variation and correlation for each segment across the fore-, mid and hind legs using different statistical approaches such as general linear model, canonical variates analysis, test of equality of coefficient of variation and partial least square analysis. We also analyzed variation and correlation between segments within each leg with partial least square and morphometric disparity analyses. Our results showed that the segments differed between legs, as general trends, the dimensions (length, width and/or size) were greater in the hind legs, smaller in the forelegs and intermediate in the mid ones. The femur and tibia (length and/or width) showed differences in morphometric variation between legs and the femur and tibia showed the highest levels of correlation between legs. On the other hand, in the fore- and mid legs, the femur (length or width) showed similar variation with tibia and tarsus lengths, but in the hind legs, the femur showed similar variation with all segments and not with the tibia length, and there were strong correlations between linear measurement within each leg. Our results suggest that the femur and tibia could play a determining role in the coordination between the legs that determines the walking pattern. Considering that these segments would also be linked to the specific function that each leg has, this study suggests a preponderant role of the femur and tibia in the walking locomotion of T. infestans.
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Affiliation(s)
- Gastón Mougabure-Cueto
- Laboratorio de Fisiología de Insectos, Departamento Biodiversidad y Biología Experimental (DBBE), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Instituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA, UBA-CONICET). Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - María Laura Hernández
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina; Unidad Operativa de Vectores y Ambiente (UnOVE), Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos Malbrán, Centro Nacional de Diagnostico e Investigación en Endemo-Epidemias (CeNDIE), Cordoba, Argentina
| | - Juan José Gilardoni
- Laboratorio de Fisiología de Insectos, Departamento Biodiversidad y Biología Experimental (DBBE), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Instituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA, UBA-CONICET). Buenos Aires, Argentina
| | - Julieta Nattero
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales, Departamento de Ecología, Genética y Evolución. Laboratorio de Eco-Epidemiología. Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires. Instituto de Ecología, Genética y Evolución (CONICET-IEGEBA). Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina.
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Ren YS, Zhang B, Zeng Y, Zhu DH. Effects of Flight on Reproductive Development in Long-Winged Female Crickets ( Velarifictorus aspersus Walker; Orthoptera: Gryllidae) with Differences in Flight Behavior. INSECTS 2023; 14:79. [PMID: 36662007 PMCID: PMC9861251 DOI: 10.3390/insects14010079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 01/06/2023] [Accepted: 01/09/2023] [Indexed: 06/17/2023]
Abstract
A trade-off between the capacity for flight and reproduction has been documented extensively in wing polymorphic female insects, thereby supporting the possible fitness gain due to flightlessness. However, most of these studies were conducted without considering the effect of flight behavior. In the present study, we assessed the flight duration by long-winged (LW) females in the cricket species Velarifictorus aspersus on different days after adult emergence and examined the effect of flight on ovarian development in LW females with different flight capacities. Our results showed that the flight capacity increased with age and peaked after 5 days. In addition, the flight capacity varied among individuals, where most LW females could only take short flights (sustained flight time < 10 min) and only a few individuals could take long flights (sustained flight time > 20 min). In LW female crickets demonstrating only short flights, repeated flying for 30 or 60 min significantly promoted reproductive development. However, in those capable of long flights, reproductive development was affected only after a flight of 60 min. The flight muscles degraded after the start of rapid reproduction in those with both short and long flights. Our results indicated that the critical flight time for switching from flight to reproduction varies among LW V. aspersus female crickets with polymorphic flight behavior.
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Lobbia PA, Rodríguez C, Mougabure-Cueto G. Effect of reproductive state on active dispersal in Triatoma infestans (Klug, 1834) (Hemiptera: Reduviidae: Triatominae) susceptible and resistant to deltamethrin. Acta Trop 2019; 196:7-14. [PMID: 31054918 DOI: 10.1016/j.actatropica.2019.05.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/01/2019] [Accepted: 05/01/2019] [Indexed: 11/18/2022]
Abstract
Triatoma infestans (Klug, 1834) is the main vector of the Chagas´ disease in Argentina. The presence of insects in the domestic environment after application of pyrethroid insecticides was reported. The colonization and the evolution of insecticide resistance are processes that can explain these control failures. In both processes, the active dispersal of insects is a determining factor. The aim of the present study was to determine whether the reproductive state modulate the dispersal capacity of females of T. infestans susceptible and resistant to deltamethrin. For this, different variables associated with active dispersal were measured in virgin and copulated females both susceptible and resistant to deltamethrin. The experimental arena was 10 m long and contained two shelters. Groups of 12 females of each experimental group were released in one of the shelters and were able to move during 3 days/nights. The results showed that the females mainly dispersed by walking regardless of the reproductive state and the toxicological phenotype. On the other hand, the copula affected the posterior dispersal capacity in females susceptible and resistant to deltamethrin. The copulated females dispersed more times, leaved more times from the shelters and showed a higher proportion of dispersed individuals than the virgin females. Finally, the insecticide resistance reduced the dispersal capacity of females. The resistant insects showed lower number of dispersal events, a lower proportion of dispersed individuals, and lower exit and entry events from/to shelter than susceptible insects. This is the first report of the effect of copula on the capacity of active dispersion in vectors of Chagas disease susceptible and resistant to insecticides.
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Affiliation(s)
- P A Lobbia
- Laboratorio de Investigación en Triatominos (LIT), Centro de Referencia de Vectores (CeReVe)-Programa Nacional de Chagas-Ministerio de Salud y Desarrollo Social de la Nación, Santa María de Punilla, Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - C Rodríguez
- Cátedra de Introducción a la Biología-Instituto de Investigaciones Biológicas y Tecnológicas-Facultad de Ciencias Exactas, Físicas y Naturales-Universidad Nacional de Córdoba, Córdoba, Argentina
| | - G Mougabure-Cueto
- Laboratorio de Investigación en Triatominos (LIT), Centro de Referencia de Vectores (CeReVe)-Programa Nacional de Chagas-Ministerio de Salud y Desarrollo Social de la Nación, Santa María de Punilla, Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
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Hernández ML, Dujardin JP, Gorla DE, Catalá SS. Can body traits, other than wings, reflect the flight ability of Triatominae bugs? Rev Soc Bras Med Trop 2015; 48:682-91. [PMID: 26676492 DOI: 10.1590/0037-8682-0249-2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 09/16/2015] [Indexed: 11/22/2022] Open
Abstract
INTRODUCTION Insects of the subfamily Triatominae are vectors of Trypanosoma cruzi , the Chagas disease parasite, and their flying behavior has epidemiological importance. The flying capacity is strikingly different across and within Triatominae species, as well as between sexes or individuals. Many Triatoma infestans individuals have wings but no flying muscles. In other Triatominae species, no clear relationships were found between wing length and flying behavior. If wing presence or size is not reflective of the flying behavior, which other parts of the body could be considered as reliable markers of this important function? METHODS The genus Mepraia has exceptional characteristics with invariably wingless females and wingless or winged males. We calculated the porous surface exposed to odorant molecules to estimate the olfactory capacity of Mepraia spinolai . The head shape and thorax size were estimated using the geometric morphometric approach and traditional morphometric techniques, respectively. RESULTS Alary polymorphism in M. spinolai was significantly associated with consistent modification of the thorax size, head shape, and notable change in the estimated olfactory capacity. The macropterous individuals had a larger olfactory surface and thorax size and significantly different head shape compared to those of the micropterous individuals. CONCLUSIONS We concluded that these structural changes could be associated with the flying potential of Triatominae. Thus, morphological attributes not found on wings could help determine the likely flying potential of the bugs.
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Affiliation(s)
- María Laura Hernández
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica, Anillaco, La Rioja, Argentina
| | - Jean Pierre Dujardin
- Unité Mixte de Recherche 177-Interactions Hôte-Vecteur-Parasite-Enrironnement dans les Maladies Tropicales Négligées dues aux Trypanosomatidés, Institut de Recherches pour le Développement, Montpellier, France
| | - David Eladio Gorla
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica, Anillaco, La Rioja, Argentina
| | - Silvia Susana Catalá
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica, Anillaco, La Rioja, Argentina
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Castro LA, Peterson JK, Saldana A, Perea MY, Calzada JE, Pineda V, Dobson AP, Gottdenker NL. Flight behavior and performance of Rhodnius pallescens (Hemiptera: Reduviidae) on a tethered flight mill. JOURNAL OF MEDICAL ENTOMOLOGY 2014; 51:1010-1018. [PMID: 25276931 DOI: 10.1603/me14014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
ABSTRACT Flight dispersal of the triatomine bug species Rhodnius pallescens Barber, the principal vector of Chagas disease in Panama, is an important mechanism for spreading Trypanosoma cruzi, causative agent of Chagas disease. This study measures R. pallescens flight performance using a tethered flight mill both when uninfected, and when infected with T. cruzi or Trypanosoma rangeli. Forty-four out of the 48 (91.7%) insects initiated flight across all treatments, and trypanosome infection did not significantly impact flight initiation. Insects from all treatments flew a cumulative distance ranging from 0.5 to 5 km before fatiguing. The median cumulative distance flown before insect fatigue was higher in T. cruzi- and T. rangeli-infected insects than in control insects; however, this difference was not statistically significant. There was a positive relationship between parasite load ingested and time until flight initiation in T. rangeli-infected bugs, and T. rangeli- and T. cruzi-infected females flew significantly faster than males at different time points. These novel findings allow for a better understanding of R. pallescens dispersal ability and peridomestic management strategies for the prevention of Chagas disease in Panama.
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Almeida CE, Oliveira HL, Correia N, Dornak LL, Gumiel M, Neiva VL, Harry M, Mendonça VJ, Costa J, Galvão C. Dispersion capacity of Triatoma sherlocki, Triatoma juazeirensis and laboratory-bred hybrids. Acta Trop 2012; 122:71-9. [PMID: 22210440 DOI: 10.1016/j.actatropica.2011.12.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Revised: 12/02/2011] [Accepted: 12/03/2011] [Indexed: 10/14/2022]
Abstract
Flight dispersion is recognized as one of the most important mechanisms for triatomine house infestation. Triatoma sherlocki and T. juazeirensis are closely related species that occur within the same ecotope and their possible reproductive boundaries are unknown. T. sherlocki has shorter wings than T. juazeirensis; a characteristic that possibly implies in reduced flight dispersion, however, this species has been found to invade and colonize homes in Bahia, Brazil. Here, we tested the flight potential of T. sherlocki, compared to that of T. juazeirensis and laboratory-bred hybrids. Insects were kept in an apparatus designed to distinguish flyers from nonflyers. Fifty-one and 53% of T. juazeirensis and hybrids were flyers respectively, whereas no T. sherlocki were recorded to fly. Morphometric analysis of the main structures associated with the locomotor abilities showed that hybrids exhibited intermediate size for most of characters. The width of pronotum of both hybrids and T. juazeirensis was significantly larger than T. sherlocki. We suggested that lack of flight ability of T. sherlocki is possibly a result of reduced wing size and distinct shape, combined with undeveloped flight muscles in a shorter thoracic box. The mobility of T. sherlocki might be compensated by its significantly longer legs, and may possibly increase its ability to invade human dwellings by active dispersion. What is more, this study showed that hybrids between T. sherloki and T. juazeirensis have intermediate morphological characters that may give them higher fitness than their parents, and thus may advance the process of house infestation by either fight or walking in case of an eventual natural hybridization.
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Chaves LF. An entomologist guide to demystify pseudoreplication: data analysis of field studies with design constraints. JOURNAL OF MEDICAL ENTOMOLOGY 2010; 47:291-298. [PMID: 20496574 DOI: 10.1093/jmedent/47.1.291] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Lack of independence, or pseudoreplication, in samples from ecological studies of insects reflects the complexity of working with living organisms: the finite and limited input of individuals, their relatedness (ecological and/or genetic), and the need to group organisms into functional experimental units to estimate population parameters (e.g., cohort replicates). Several decades ago, when the issue of pseudoreplication was first recognized, it was highlighted that mainstream statistical tools were unable to account for the lack of independence. For example, the variability as a result of differences across individuals would be confounded with that of the experimental units where they were observed (e.g., pans for mosquito larvae), whereas both sources of variability now can be separated using modern statistical techniques, such as the linear mixed effects model, that explicitly consider the different scales of variability in a dataset (e.g., mosquitoes and pans). However, the perception of pseudoreplication as a problem without solution remains. This study presents concepts to critically appraise pseudoreplication and the linear mixed effects model as a statistical solution for analyzing data with pseudoreplication, by separating the different sources of variability and thereby generating correct inferences from data gathered in studies with constraints in randomization.
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Affiliation(s)
- Luis Fernando Chaves
- Department of Environmental Studies, Emory University, 400 Dowman Drive, Suite E510, Atlanta, GA 30322, USA.
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