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Rabinovich JE. Morphology, Life Cycle, Environmental Factors and Fitness – a Machine Learning Analysis in Kissing Bugs (Hemiptera, Reduviidae, Triatominae). Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.651683] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Populations are permanently evolving and their evolution will influence their survival and reproduction, which will then alter demographic parameters. Several phenotypic, life history and environmental variables are known to be related to fitness measures. The goal of this article was to look into the possible types of those relationships in insects of the subfamily Triatominae, vectors of Trypanosoma cruzi, the causative agent of Chagas disease. After an exhaustive literature review of 7,207 records of publications referring exclusively to all possible features of the triatomines, using 15 keywords those records were reduced to 2,968 publications, that were analyzed individually; after deleting those publications that did not have the data in quantitative form as needed for the objective of this article, I found that 171 papers were adequate for the present analysis. From them I compiled a dataset of 11 variables and 90 cases from 36 triatomine species. Those variables included four environmental, two life cycle, and four morphological variables, and one demographic parameter: a fitness measure (the population intrinsic rate of natural increase, r0), used as dependent variable. However, the relationship between T. cruzi and its vector host was not included in this analysis despite triatomine-T. cruzi interactions constitute an important factor in the evolution of triatomine’s life history. I resorted to the Random Forest method as a machine learning approach for the analysis of this dataset, and found that –in addition to the triatomine species themselves– only the two life cycle variables (mean development time from egg to adult, and mean fecundity, expressed as the average number of female eggs laid per female per day) were statistically significant in determining fitness (r0). The machine learning approach used in the analysis provided a similar but deeper insight into these relationships than classical regression. Except for an analysis on senescence, this is the first study in triatomines addressing these questions. These results will be useful for other theoretical optimization approaches (frequency-dependence, density-dependence, evolutionary game theory, and adaptive dynamics), thus contributing to the theoretical framework for interpreting the succession of stages in insect adaptations, a framework yet to be constructed.
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Brito RN, Souza RCM, Abad-Franch F. Dehydration-Stress Resistance in Two Sister, Cryptic Rhodnius Species-Rhodnius prolixus and Rhodnius robustus Genotype I (Hemiptera: Reduviidae). JOURNAL OF MEDICAL ENTOMOLOGY 2019; 56:1019-1026. [PMID: 31220293 DOI: 10.1093/jme/tjz041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Indexed: 06/09/2023]
Abstract
Rhodnius prolixus Stål, a major Chagas disease vector, often colonizes in houses, whereas its sister species, Rhodnius robustus Larrousse genotype I, does not colonize in houses and has little medical relevance. Factors potentially underlying this crucial difference remain largely uncharted. The 'microclimate-adaptation hypothesis' notes that R. prolixus is adapted to the dry microclimate of small-crowned Copernicia palms, whereas R. robustus I exploits the high-moisture microclimate of large-crowned Attalea and Acrocomia. Hence, R. prolixus, but not R. robustus I, would be (pre)adapted to the relatively dry microclimate typical of man-made habitats. This hypothesis predicts that, while severe dehydration should harm both species similarly, R. prolixus should withstand moderate-to-mild dehydration stress better than R. robustus I. To test this prediction, we compared fitness metrics of genotyped R. prolixus and R. robustus I kept at 28°C and under severe (20% relative humidity, RH), moderate (40% RH), or mild dehydration stress (75% RH). Egg-hatching success increased with decreasing dehydration stress in R. robustus I (0% → 19% → 100%), but was high across treatments in R. prolixus (78% → 100% → 100%). Both species underwent high, early mortality under severe dehydration; under moderate and mild stress, R. prolixus experienced less mortality and survived longer than R. robustus I. Our results suggest that adaptation to distinct palm-crown microclimates may partly underlie the so far unexplained differences in house-colonization ability among Rhodnius Stål species. Experimental replication across additional species/populations will be required to further probe this adaptive hypothesis-which, if supported, may also provide insight into the likely responses of Chagas disease vectors to climate change.
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Affiliation(s)
- Raíssa N Brito
- Grupo Triatomíneos, Instituto René Rachou, Fundação Oswaldo Cruz - Fiocruz, Belo Horizonte, Minas Gerais, Brazil
| | - Rita C M Souza
- Grupo Triatomíneos, Instituto René Rachou, Fundação Oswaldo Cruz - Fiocruz, Belo Horizonte, Minas Gerais, Brazil
| | - Fernando Abad-Franch
- Grupo Triatomíneos, Instituto René Rachou, Fundação Oswaldo Cruz - Fiocruz, Belo Horizonte, Minas Gerais, Brazil
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Dworak ES, Araújo SMD, Gomes ML, Massago M, Ferreira ÉC, Toledo MJDO. Sympatry influence in the interaction of Trypanosoma cruzi with triatomine. Rev Soc Bras Med Trop 2017; 50:629-637. [PMID: 29160509 DOI: 10.1590/0037-8682-0219-2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 08/24/2017] [Indexed: 11/22/2022] Open
Abstract
INTRODUCTION Trypanosoma cruzi, the etiologic agent of Chagas disease, is widely distributed in nature, circulating between triatomine bugs and sylvatic mammals, and has large genetic diversity. Both the vector species and the genetic lineages of T. cruzi present a varied geographical distribution. This study aimed to verify the influence of sympatry in the interaction of T. cruzi with triatomines. Methods: The behavior of the strains PR2256 (T. cruzi II) and AM14 (T. cruzi IV) was studied in Triatoma sordida (TS) and Rhodnius robustus (RR). Eleven fifth-stage nymphs were fed by artificial xenodiagnosis with 5.6 × 103 blood trypomastigotes/0.1mL of each T. cruzi strain. Every 20 days, their excreta were examined for up to 100 days, and every 30 days, the intestinal content was examined for up to 120 days, by parasitological (fresh examination and differential count with Giemsa-stained smears) and molecular (PCR) methods. Rates of infectivity, metacyclogenesis and mortality, and mean number of parasites per insect and of excreted parasites were determined. RESULTS Sympatric groups RR+AM14 and TS+PR2256 showed higher values of the four parameters, except for mortality rate, which was higher (27.3%) in the TS+AM14 group. General infectivity was 72.7%, which was mainly proven by PCR, showing the following decreasing order: RR+AM14 (100%), TS+PR2256 (81.8%), RR+PR2256 (72.7%) and TS+AM14 (36.4%). CONCLUSIONS Our working hypothesis was confirmed once higher infectivity and vector capacity (flagellate production and elimination of infective metacyclic forms) were recorded in the groups that contained sympatric T. cruzi lineages and triatomine species.
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Affiliation(s)
- Elaine Schultz Dworak
- Programa de Pós-Graduação em Ciências da Saúde, Universidade Estadual de Maringá, Maringá, PR, Brasil
| | - Silvana Marques de Araújo
- Programa de Pós-Graduação em Ciências da Saúde, Universidade Estadual de Maringá, Maringá, PR, Brasil.,Departamento de Ciências Básicas da Saúde, Universidade Estadual de Maringá, Maringá, PR, Brasil
| | - Mônica Lúcia Gomes
- Programa de Pós-Graduação em Ciências da Saúde, Universidade Estadual de Maringá, Maringá, PR, Brasil.,Departamento de Ciências Básicas da Saúde, Universidade Estadual de Maringá, Maringá, PR, Brasil
| | - Miyoko Massago
- Departamento de Ciências Básicas da Saúde, Universidade Estadual de Maringá, Maringá, PR, Brasil
| | - Érika Cristina Ferreira
- Programa de Pós-Graduação em Ciências da Saúde, Universidade Estadual de Maringá, Maringá, PR, Brasil.,Departamento de Estatística, Universidade Estadual de Maringá, Maringá, PR, Brasil
| | - Max Jean de Ornelas Toledo
- Programa de Pós-Graduação em Ciências da Saúde, Universidade Estadual de Maringá, Maringá, PR, Brasil.,Departamento de Ciências Básicas da Saúde, Universidade Estadual de Maringá, Maringá, PR, Brasil
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Ha YR, Kim JH, Ryu J, Lee SJ. Superb feeding behavior of Aedes albopictus transmitting Zika virus. PLoS One 2017; 12:e0184871. [PMID: 28957351 PMCID: PMC5619709 DOI: 10.1371/journal.pone.0184871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 09/03/2017] [Indexed: 11/18/2022] Open
Abstract
Disease-mediated mosquitoes have been receiving much attention, as the World Health Organization recently declared the Zika virus a global public health emergency. Mosquitoes transmit pathogens that cause various tropical diseases including malaria, dengue fever and yellow fever as well as Zika virus. The vector efficiency of mosquitoes depends on their blood-feeding characteristics and the mechanics of their blood-sucking pump system, but only a few studies have attempted to investigate these key issues. In this study, we demonstrate the rapid and gluttonous liquid-feeding characteristics of Ae. albopictus which transmits Zika virus can be explained by similar proportion of two blood-sucking pumps and accelerated liquid intake driven by fast expanding of pumps. Our results provide insight into the vector efficiency of Ae. albopictus in terms of feeding velocity, pumping frequency, liquid-intake rate, and wall shear stress.
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Affiliation(s)
- Young Ran Ha
- Center for Biofluid and Biomimic Research, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Jun Ho Kim
- Department of Mechanical Engineering, Center for Biofluid and Biomimic Research, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Jeongeun Ryu
- Department of Mechanical Engineering, Center for Biofluid and Biomimic Research, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Sang Joon Lee
- Center for Biofluid and Biomimic Research, Pohang University of Science and Technology, Pohang, Republic of Korea
- Department of Mechanical Engineering, Center for Biofluid and Biomimic Research, Pohang University of Science and Technology, Pohang, Republic of Korea
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Georgieva AY, Gordon ER, Weirauch C. Sylvatic host associations of Triatominae and implications for Chagas disease reservoirs: a review and new host records based on archival specimens. PeerJ 2017; 5:e3826. [PMID: 28948106 PMCID: PMC5609523 DOI: 10.7717/peerj.3826] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 08/29/2017] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND The 152 extant species of kissing bug include important vectors of the debilitating, chronic, and often fatal Chagas disease, which affects several million people mainly in Central and South America. An understanding of the natural hosts of this speciose group of blood-feeding insects has and will continue to aid ongoing efforts to impede the spread of Chagas disease. However, information on kissing bug biology is piecemeal and scattered, developed using methods with varying levels of accuracy over more than 100 years. Existing host records are heavily biased towards well-studied primary vector species and are derived from primarily three different types of observations, associational, immunological or DNA-based, with varying reliability. METHODS We gather a comprehensive and unparalleled number of sources reporting host associations via rigorous targeted searches of publication databases to review all known natural, or sylvatic, host records including information on how each record was collected. We integrate this information with novel host records obtained via attempted amplification and sequencing of a ∼160 base pair (bp) region of the vertebrate 12S mitochondrial gene from the gastrointestinal tract of 64 archival specimens of Triatominae representing 19 species collected primarily in sylvatic habitats throughout the southern United States and Central and South America during the past 10 years. We show the utility of this method for uncovering novel and under-studied groups of Triatominae hosts, as well as detecting the presence of the Chagas disease pathogen via Polymerase Chain Reaction (PCR) of a ∼400 bp sequence of the trypanosome 18S gene. RESULTS New host associations for several groups of arboreal mammals were determined including sloths, New World monkeys, coatis, arboreal porcupines and, for the first time as a host of any Triatominae, tayras. A thorough review of previously documented sylvatic hosts, organized by triatomine species and the type of observation (associational, antibody-based, or DNA-based), is presented in a phylogenetic context and highlights large gaps in our knowledge of Triatominae biology. CONCLUSION The application of DNA-based methods of host identification towards additional species of Triatominae, including rarely collected species that may require use of archival specimens, is the most efficient and promising way to resolve recognized shortfalls.
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Affiliation(s)
- Anna Y. Georgieva
- Department of Entomology, University of California, Riverside, CA, United States of America
| | - Eric R.L. Gordon
- Department of Entomology, University of California, Riverside, CA, United States of America
| | - Christiane Weirauch
- Department of Entomology, University of California, Riverside, CA, United States of America
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Head shape variation in response to diet in Triatoma williami (Hemiptera, Reduviidae: Triatominae), a possible Chagas disease vector of legal Amazônia. ZOOL ANZ 2017. [DOI: 10.1016/j.jcz.2017.04.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Sant'Anna MRV, Soares AC, Araujo RN, Gontijo NF, Pereira MH. Triatomines (Hemiptera, Reduviidae) blood intake: Physical constraints and biological adaptations. JOURNAL OF INSECT PHYSIOLOGY 2017; 97:20-26. [PMID: 27521585 DOI: 10.1016/j.jinsphys.2016.08.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 08/05/2016] [Accepted: 08/09/2016] [Indexed: 06/06/2023]
Abstract
In order to efficiently obtain blood from their vertebrate hosts, bloodsucking arthropods have undergone an evolutionary selection process leading to specialist adaptations in their feeding apparatus (mouthparts and suction pumps) and salivary molecules. These adaptations act to counteract haemostasis, inflammation, and immune responses in their vertebrate hosts. The association of haematophagous arthropods with vertebrate hosts during a blood feed allows the transmission of pathogens between their hosts and vectors in a tripartite interaction. Feeding mechanisms in haematophagous arthropod species have been the subject of studies over at least eight decades worldwide, as a consequence of the importance of vector-borne diseases and their impact on human health. Here we review studies of the feeding mechanisms of triatomine bugs, with a particular focus on factors that influence their feeding performance when obtaining a blood meal from different vertebrate hosts.
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Affiliation(s)
- Maurício Roberto Viana Sant'Anna
- Laboratório de Fisiologia de Insetos Hematófagos, Departamento de Parasitologia, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Campus Pampulha, Belo Horizonte CEP 31270-901, Brazil
| | - Adriana Coelho Soares
- Laboratório de Fisiologia de Insetos Hematófagos, Departamento de Parasitologia, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Campus Pampulha, Belo Horizonte CEP 31270-901, Brazil
| | - Ricardo Nascimento Araujo
- Laboratório de Fisiologia de Insetos Hematófagos, Departamento de Parasitologia, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Campus Pampulha, Belo Horizonte CEP 31270-901, Brazil
| | - Nelder Figueiredo Gontijo
- Laboratório de Fisiologia de Insetos Hematófagos, Departamento de Parasitologia, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Campus Pampulha, Belo Horizonte CEP 31270-901, Brazil
| | - Marcos Horácio Pereira
- Laboratório de Fisiologia de Insetos Hematófagos, Departamento de Parasitologia, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Campus Pampulha, Belo Horizonte CEP 31270-901, Brazil.
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Pavan MG, Corrêa-Antônio J, Peixoto AA, Monteiro FA, Rivas GBS. Rhodnius prolixus and R. robustus (Hemiptera: Reduviidae) nymphs show different locomotor patterns on an automated recording system. Parasit Vectors 2016; 9:239. [PMID: 27121502 PMCID: PMC4848847 DOI: 10.1186/s13071-016-1482-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 03/30/2016] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Circadian rhythms of triatomines, vectors of the etiological agent Trypanosoma cruzi responsible for Chagas disease, have been extensively studied in adults of the two most epidemiologically relevant vector species, Rhodnius prolixus and Triatoma infestans. However, little attention has been dedicated to the activity patterns in earlier developmental stages, even though triatomine nymphs are equally capable of transmitting T. cruzi to humans. Because circadian rhythms may differ even between closely related species, studies that focus on this behavioral trait can also be used to shed light on the taxonomy of controversial taxa, which becomes especially relevant regarding vector species. METHODS We compared the daily locomotor activity patterns of second- and third-instar nymphs of Rhodnius prolixus and Rhodnius robustus in order to unveil possible behavioral differences between these cryptic species. Mitochondrial and nuclear markers were sequenced to confirm species identification. RESULTS Nymphs of both species had a bimodal pattern of locomotion and similar daily activity patterns, but R. prolixus is more active under light/dark cycles and depicts a more pronounced activity rhythm under constant darkness conditions. CONCLUSIONS We describe the implementation of an often-used automated method for the recording of individual locomotor activity to differentiate sibling species of Rhodnius with distinct epidemiological relevance. The higher levels of activity observed in the nymphs of R. prolixus could potentially contribute to increased vector capacity.
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Affiliation(s)
- Márcio G. Pavan
- />Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil
- />Laboratório de Biologia Molecular de Insetos, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil
| | - Jessica Corrêa-Antônio
- />Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil
| | - Alexandre A. Peixoto
- />Laboratório de Biologia Molecular de Insetos, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil
- />Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM)/CNPq, Rio de Janeiro, Brazil
| | - Fernando A. Monteiro
- />Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil
- />Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM)/CNPq, Rio de Janeiro, Brazil
| | - Gustavo B. S. Rivas
- />Laboratório de Biologia Molecular de Insetos, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil
- />Present address: Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil
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Peculiar liquid-feeding and pathogen transmission behavior of Aedes togoi and comparison with Anopheles sinensis. Sci Rep 2016; 6:20464. [PMID: 26839008 PMCID: PMC4738329 DOI: 10.1038/srep20464] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 01/04/2016] [Indexed: 01/12/2023] Open
Abstract
Female mosquitoes transmit various diseases as vectors during liquid-feeding. Identifying the determinants of vector efficiency is a major scientific challenge in establishing strategies against these diseases. Infection rate and transmission efficiency are interconnected with the mosquito-induced liquid-feeding flow as main indexes of vector efficiency. However, the relationship between liquid-feeding characteristics and pathogen remains poorly understood. The liquid-feeding behavior of Aedes togoi and Anopheles sinensis was comparatively investigated in conjunction with vector efficiency via micro-particle image velocimetry. The flow rates and ratio of the ejection volume of Aedes togoi were markedly higher than those of Anophels sinensis. These differences would influence pathogen re-ingestion. Wall shear stresses of these mosquito species were also clearly discriminatory affecting the infective rates of vector-borne diseases. The variations in volume of two pump chambers and diameter of proboscis of these mosquito species were compared to determine the differences in the liquid-feeding process. Liquid-feeding characteristics influence vector efficiency; hence, this study can elucidate the vector efficiency of mosquitoes and the vector-pathogen interactions and contribute to the development of strategies against vector-borne diseases.
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Costa GCA, Soares AC, Pereira MH, Gontijo NF, Sant’Anna MRV, Araujo RN. Physiological characterization of the hematophagy of Ornithodoros rostratus (Acari: Argasidae) on live hosts. J Exp Biol 2016; 219:3656-3664. [DOI: 10.1242/jeb.144246] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 09/07/2016] [Indexed: 01/03/2023]
Abstract
Ornithodoros rostratus is an argasid tick and its importance is based on its hematophagy and the resulting transmission of pathogens such as Rickettsia rickettsii and Coxiella burnetii unto its vertebrate hosts. In the face of a lack of physiological studies related to hematophagy in argasid ticks, this paper aims to identify and characterize the events that occur throughout the feeding by O. rostratus on live hosts. Electrical signals and alterations on the feeding site were monitored using intravital microscopy and electromyography. The analyses allowed for the characterization of four distinct events: suction, salivation, chelicerae movements, and inactivity. Feeding was divided into two distinct phases: 1- penetration of mouthparts (when only salivation and chelicerae movements occurred) and the formation of the feeding pool (salivation and chelicerae movements with the first signs of suction) and 2 - engorgement during which chelicerae movements ceased and blood intake took place in feeding complexes (salivation followed by suction). Variations in patterns of the electrical signals, suction frequency, and salivation showed four distinct sub phases: 2a – Suction with electrical signals of irregular shape, increased suction frequency and decreased salivation frequency throughout blood feeding; 2b – Suction with electrical signals of symmetrical shape, high suction rates (3.8 Hz on average) and feeding complexes lasting for 7.7 seconds; 2c - Suction with electrical signals of irregular shape, high suction frequency and feeding complex lasting 11.5 seconds; 2d - Electrical signals with no profile and longest feeding complexes (14.5 seconds). Blood feeding ended with the withdrawal of the mouthparts from the host's skin.
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Affiliation(s)
- Gabriel Cerqueira Alves Costa
- Laboratório de Fisiologia de Insetos Hematófagos, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos 6627, 31270-901, Belo Horizonte, MG, Brazil
| | - Adriana Coelho Soares
- Laboratório de Fisiologia de Insetos Hematófagos, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos 6627, 31270-901, Belo Horizonte, MG, Brazil
| | - Marcos Horácio Pereira
- Laboratório de Fisiologia de Insetos Hematófagos, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos 6627, 31270-901, Belo Horizonte, MG, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Universidade Federal do Rio de Janeiro, 21941-909, Rio de Janeiro, Brazil
| | - Nelder Figueiredo Gontijo
- Laboratório de Fisiologia de Insetos Hematófagos, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos 6627, 31270-901, Belo Horizonte, MG, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Universidade Federal do Rio de Janeiro, 21941-909, Rio de Janeiro, Brazil
| | - Maurício Roberto Viana Sant’Anna
- Laboratório de Fisiologia de Insetos Hematófagos, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos 6627, 31270-901, Belo Horizonte, MG, Brazil
| | - Ricardo Nascimento Araujo
- Laboratório de Fisiologia de Insetos Hematófagos, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos 6627, 31270-901, Belo Horizonte, MG, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Universidade Federal do Rio de Janeiro, 21941-909, Rio de Janeiro, Brazil
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Soares AC, Araújo RN, Carvalho-Tavares J, Gontijo NDF, Pereira MH. Intravital microscopy and image analysis of Rhodnius prolixus (Hemiptera: Reduviidae) hematophagy: the challenge of blood intake from mouse skin. Parasitol Int 2013; 63:229-36. [PMID: 23886517 DOI: 10.1016/j.parint.2013.07.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2012] [Revised: 06/24/2013] [Accepted: 07/04/2013] [Indexed: 11/20/2022]
Abstract
Hematophagous insects transmit many of the most dangerous parasitic diseases. The transmission usually occurs during hematophagy or just after as this is when the vector and the host are in contact. The contact time is determined by the feeding performance of the insect in each host. In triatomines, feeding performance interferes with both their life cycle and the vectorial competence to transmit the hemoflagellate Trypanosoma cruzi. Triatomine bugs are vessel feeders, obtaining their blood meals directly from the vessels (venules or arterioles) of their vertebrate hosts. The host blood intake rate is not constant during the feeding, and the sucking frequency of triatomines tends to be higher and to contain fewer interruptions in pigeons than in mice. To identify the difficulties encountered by triatomine bugs in obtaining blood meals from mouse skin, we used intravital microscopy techniques associated with electromyograms of the cibarial pump. To monitor the vibration of the cannulated vessels and the blood flow through the head of the insect during the engorgement phase, we introduced a novel method for image analysis. The mean number of vessels used during a Rhodnius prolixus blood meal was 3.4±1.2, and the insects fed more in venules (63%) than in arterioles (37%). An important increase in vascular permeability was observed throughout the feeding. Platelet aggregation, rolling and leukocyte adherence were analyzed on the venular endothelium, showing remarkable increases for some time following the R. prolixus feeding. The reduction in sucking frequency that was observed during insect feeding was likely due to the increased cibarial pump filling time. The monitoring of the vessel wall pulsation also permitted the registration of regurgitation-like movements during blood pumping, with these movements being recorded mostly during the second half of the feeding. The evaluation of blood flow through the head of the insect suggested that the regurgitation-like movements were not true regurgitations and were caused by abrupt difficulties in the function of the cibarial pump. The role of the platelet plugs and the changes in blood viscosity at the R. prolixus feeding site are discussed. The method introduced in the present study to analyze the images brings new insights into the interaction between hematophagous vectors and their hosts, reinforcing the importance of insect saliva throughout the feeding process.
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Affiliation(s)
- Adriana Coelho Soares
- Departamento de Parasitologia, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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Nattero J, Malerba R, Rodríguez CS, Crocco L. Phenotypic plasticity in response to food source in Triatoma infestans (Klug, 1834) (Hemiptera, Reduviidae: Triatominae). INFECTION GENETICS AND EVOLUTION 2013; 19:38-44. [PMID: 23831637 DOI: 10.1016/j.meegid.2013.06.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 06/10/2013] [Accepted: 06/13/2013] [Indexed: 11/19/2022]
Abstract
In the Gran Chaco region of Argentina, Bolivia, and Paraguay, vector transmission of Trypanosoma cruzi, the etiological agent of Chagas disease, is still a severe problem because, among other causes, houses are reinfested with Triatoma infestans, the main vector of T. cruzi in southern South America. A better understanding of adaptation and evolution of T. infestans populations may contribute to the selection of appropriate vector control strategies in this region. Phenotypic plasticity is essential to understand development and maintenance of morphological variation. An experimental phenotypic plasticity study was conducted to assess if blood meal source induced head shape and size variation during development in T. infestans. Eighteen full-sib families were assigned to one of two food sources (pigeon and guinea pig) to examine the effect of food source on head shape and size in all nymph instars and adults. Data were analyzed using geometric morphometric tools and phenotypic plasticity analyses. Significant differences in head shape and size were observed between adults fed on different food sources. Allometric effects at the adult stage were observed. Head size showed significant food source × family interaction for fifth-instar nymphs and adults. For head size, significant differences between food sources were observed at stages and in ontogenetic trajectory. Phenotypic plasticity expression was found for head shape and size in adults; indeed, bugs fed on guinea pigs exhibited greater changes in head shape and larger heads than those fed on pigeon. Full-sib families exhibited different patterns of phenotypic expression in response to food source. Food source × family interaction may indicate that the observed variation in phenotypic plasticity may contribute to changes in head morphometry. These results may contribute to the selection of an appropriate control strategy for T. infestans in the Gran Chaco region, since they provide evidences of morphological plasticity in this species.
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Affiliation(s)
- Julieta Nattero
- Cátedra de Introducción a la Biología, Facultad de Ciencias Exactas Físicas y Naturales, Instituto de Investigaciones Biológicas y Tecnológicas (IIByT) CONICET, Universidad Nacional de Córdoba, Avda. Vélez Sarsfield 299, piso 5, X5000JJC Córdoba, Argentina.
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Nattero J, Rodríguez CS, Crocco L. Effects of blood meal source on food resource use and reproduction in Triatoma patagonica Del Ponte (Hemiptera, Reduviidae). JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2013; 38:127-133. [PMID: 23701617 DOI: 10.1111/j.1948-7134.2013.12018.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Triatoma patagonica (Del Ponte, 1929) (Hemiptera-Reduviidae) is a peridomestic vector of Chagas disease that has been frequently found colonizing peridomestic structures in several localities in Argentina. Studying relationships between feeding and reproductive factors is important because these traits regulate population density and define vectorial capacity. Since T. patagonica can circulate among peridomestic structures taking blood from both bird and mammal hosts, we evaluated the extent to which different blood meal sources affect food resource use and reproductive parameters. We used 5(th) instar nymphs and females that fed on either guinea pigs or pigeons to estimate food resource use. We estimated reproductive parameters in adults that fed on these sources. Nymphs and adults showed differences in blood consumption between feeding sources. Females fed on pigeons ingested more blood and needed a higher amount of blood to produce an egg than females fed on guinea pigs. There were no differences in the number of eggs laid and hatched between insects fed on different feeding sources. The higher amount of blood ingested and consumed by T. patagonica fed on pigeons did not translate into higher fecundity or fertility. The lower amount of guinea pig blood ingested was offset by its high nutritional quality.
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Affiliation(s)
- Julieta Nattero
- Cátedra de Introducción a la Biología, Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas (IIByT) CONICET. Universidad Nacional de Córdoba, Córdoba, Argentina.
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Rabinovich JE, Kitron UD, Obed Y, Yoshioka M, Gottdenker N, Chaves LF. Ecological patterns of blood-feeding by kissing-bugs (Hemiptera: Reduviidae: Triatominae). Mem Inst Oswaldo Cruz 2012; 106:479-94. [PMID: 21739038 DOI: 10.1590/s0074-02762011000400016] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2011] [Accepted: 05/06/2011] [Indexed: 11/21/2022] Open
Abstract
Host use by vectors is important in understanding the transmission of zoonotic diseases, which can affect humans, wildlife and domestic animals. Here, a synthesis of host exploitation patterns by kissing-bugs, vectors of Chagas disease, is presented. For this synthesis, an extensive literature review restricted to feeding sources analysed by precipitin tests was conducted. Modern tools from community ecology and multivariate statistics were used to determine patterns of segregation in host use. Rather than innate preferences for host species, host use by kissing-bugs is influenced by the habitats they colonise. One of the major limitations of studies on kissing-bug foraging has been the exclusive focus on the dominant vector species. We propose that expanding foraging studies to consider the community of vectors will substantially increase the understanding of Chagas disease transmission ecology. Our results indicate that host accessibility is a major factor that shapes the blood-foraging patterns of kissing-bugs. Therefore, from an applied perspective, measures that are directed at disrupting the contact between humans and kissing-bugs, such as housing improvement, are among the most desirable strategies for Chagas disease control.
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Affiliation(s)
- Jorge Eduardo Rabinovich
- Centro de Estudios Parasitológicos y de Vectores, Universidad Nacional de La Plata, La Plata, Buenos Aires, Argentina.
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Barreto-Santana D, Starling J, Gurgel-Gonçalves R, Cuba CAC. [Comparative biology and feeding behavior of Rhodnius neglectus and Rhodnius robustus (Triatominae) under laboratory conditions]. Rev Soc Bras Med Trop 2012; 44:490-5. [PMID: 21860897 DOI: 10.1590/s0037-86822011000400018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Accepted: 04/28/2011] [Indexed: 11/21/2022] Open
Abstract
INTRODUCTION The vector competence of triatomine insects is determined by studying their biology and feeding behavior under field and/or laboratory conditions. Factors including the number of bites, the amount of blood ingested and defecation time have implications for trypanosome transmission. The biological and behavioral parameters of Rhodnius neglectus and R. robustus were compared under experimental conditions to estimate differences in the potential transmission of trypanosomes. METHODS The insects were observed daily to determine the period of nymphal development, mortality, detection of food source, number of bites, time of blood meal intake, amount of blood ingested, time elapsed between the end of the meal and the first defecation and the frequency of defecation. RESULTS Although the nymphal development of R. neglectus (156.4 ± 25.05d) was lower than that of R. robustus (204.7 ± 13.22d), the mortality between species was similar (63.8 and 65% respectively).R. robustus and R. neglectus quickly located the food source, especially in the first instar (2.5 and 1.6 min, respectively). Although the time of blood meal intake was similar between the species, R. robustus ingested a larger amount of blood on average at all stages and exhibited higher values for the fifth instar. Nymphs of R. neglectus bit more frequently, and they defecated faster and more often than those of R. robustus. CONCLUSIONS Under laboratory conditions, R. neglectus has a greater potential for transmission of Trypanosoma cruzi and T. rangeli than does R. robustus, an attribute that should be further evaluated in experimental infections.
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Affiliation(s)
- Daniella Barreto-Santana
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brasília, DF.
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Lahondère C, Lazzari CR. Mosquitoes cool down during blood feeding to avoid overheating. Curr Biol 2011; 22:40-5. [PMID: 22177900 DOI: 10.1016/j.cub.2011.11.029] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Revised: 10/19/2011] [Accepted: 11/14/2011] [Indexed: 10/14/2022]
Abstract
Temperature is one of the most important factors affecting the life of insects [1]. For instance, high temperatures can have deleterious effects on insects' physiology. Therefore, many of them have developed various strategies to avoid the risk of thermal stress [2]. They can seek a fresher environment or adjust their water loss, but hematophagous insects, such as mosquitoes, must confront the issue of thermal stress at each feeding event on a warm-blooded host [3]. To better understand to what extent mosquitoes are exposed to thermal stress while feeding, we conducted a real-time infrared thermographic analysis of mosquitoes' body temperature during feeding on both warm blood and sugar solution. First, our results highlighted differences in temperature between the body parts of the mosquito (i.e., heterothermy) during blood intake, but not during sugar meals. We also found that anopheline mosquitoes can decrease their body temperature during blood feeding thanks to evaporative cooling of fluid droplets, which are excreted and maintained at the end of the abdomen. This mechanism protects the insect itself, probably as well as the sheltered microorganisms, both symbionts and parasites, from thermal stress. These findings constitute the first evidence of thermoregulation among hematophagous insects and explain the paradox of fresh blood excretion during feeding.
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Affiliation(s)
- Chloé Lahondère
- Institut de Recherche sur la Biologie de l'Insecte, UMR CNRS 6035, Université François Rabelais, 37200 Tours, France
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Souza RDCMD, Soares AC, Alves CL, Lorosa ES, Pereira MH, Diotaiuti L. Feeding behavior of Triatoma vitticeps (Reduviidae: Triatominae) in the state of Minas Gerais, Brazil. Mem Inst Oswaldo Cruz 2011; 106:16-22. [PMID: 21340350 DOI: 10.1590/s0074-02762011000100003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Accepted: 08/12/2010] [Indexed: 11/22/2022] Open
Abstract
The objective of this study was to evaluate the feeding behavior of Triatoma vitticeps through the identification of its food sources and the characterization of the blood ingestion process. In addition, we aimed to verify if the saliva of this vector interferes with the perception of the host during the feedings by creating a nervous impulse. Here, we demonstrated that the T. vitticeps saliva reduces, gradually and irreversibly, the amplitude of the compound action potential of the nervous fibre, which helps decrease the perception of the insect by the host. The precipitin reaction demonstrated the feeding eclecticism of this vector, with the identification of eight food sources - most of them found simultaneously in the same insect. The analysis of the electrical signals produced by the cibarial pump during meals demonstrated that the best feeding performance of T. vitticeps nymphs that fed on pigeons is mainly due to the higher contraction frequency of the pump. The longer contact period with the host to obtain a complete meal compared with other triatominae species of the same instar could favor the occurrence of multiple blood sources in T. vitticeps under natural conditions, as it was evidenced by the precipitin test.
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Affiliation(s)
- Rita de Cássia Moreira de Souza
- Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas, Instituto René Rachou, Fiocruz, Belo Horizonte, MG, Brasil, 30190-002
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Paim RMM, Araújo RN, Soares AC, Lemos LCD, Tanaka AS, Gontijo NF, Lehane MJ, Pereira MH. Influence of the intestinal anticoagulant in the feeding performance of triatomine bugs (Hemiptera; Reduviidae). Int J Parasitol 2011; 41:765-73. [PMID: 21447340 DOI: 10.1016/j.ijpara.2011.01.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Revised: 01/27/2011] [Accepted: 01/29/2011] [Indexed: 11/16/2022]
Abstract
Triatomines are haematophagous insects in all post-embryonic life stages. They are vectors of Trypanosoma cruzi, the causative agent of Chagas disease. Their vectorial ability is influenced by their feeding performance, which varies greatly amongst species. Recent work showed that inhibition of the coagulation process in the anterior midgut (crop) environment considerably influences the blood meal size. In this work, we performed a comparative study of the level of anticoagulant activity in the saliva and crop contents of three triatomine species -Triatoma infestans, Triatoma brasiliensis and Rhodnius prolixus - and correlated this with their feeding performance on live hosts. Moreover, the feeding parameters on a large diameter vessel influenced by the crop anticoagulants were evaluated in detail. The anticoagulant activity was significantly higher in the crop contents than in salivary glands, varying from 1.6-fold higher for R. prolixus to 70-fold higher for T. brasiliensis. Amongst the species, T. brasiliensis had the lowest crop anticoagulant activity, the lowest concentration of thrombin inhibitor, and took the longest to feed. Triatoma brasiliensis nymphs that had their intestinal anticoagulant (brasiliensin) knocked down by RNA interference had the lowest capacity to maintain cibarial pump frequency at higher levels throughout the feeding process and consequently a lower ingestion rate (mg/min), even when fed under favourable conditions (large diameter vessel). However, the feeding difficulty for brasiliensin knockdown T. brasiliensis nymphs was reversed by treating the host mice with heparin (a potent systemic anticoagulant) before blood feeding. The results indicate that crop anticoagulant activity influences modulation of the blood-pumping frequency to the intestine and significantly affects the feeding efficiency of triatomine spp. on live hosts.
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Affiliation(s)
- Rafaela M M Paim
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Bloco I4, Sala 177, Av. Antônio Carlos 6627, Belo Horizonte, MG, Brazil
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Guarneri AA, Araujo RN, Diotaiuti L, Gontijo NF, Pereira MH. Feeding performance of Triatoma brasiliensis (Hemiptera: Reduviidae) on habitual hosts: Thrichomys laurentius (Rodentia: Echimyidae) and humans. Vector Borne Zoonotic Dis 2011; 11:443-5. [PMID: 21395421 DOI: 10.1089/vbz.2010.0086] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Triatoma brasiliensis is an important vector of Trypanosoma cruzi in the semiarid zones of Northeastern Brazil where it is commonly found in human dwellings, peridomiciliary areas, and the wild environments. To better understand features that may be influencing the interaction of T. brasiliensis with its hosts, in the present work we compared the feeding performance of sylvatic and domestic populations of T. brasiliensis on humans and on Thrichomys laurentius, a wild rodent found in the natural ecotopes of T. brasiliensis. The analyses were performed using the electronic monitoring of the cibarial pump. The blood sources considerably affected the feeding parameters. Insects fed on T. laurentius had lower ingestion rate, gained less weight, had longer interruption time, remained less time in contact with the host, and had the contractions of the pump in a lower frequency during the feeding process in comparison to insects fed on humans. These results indicate that humans are better blood sources for T. brasiliensis than T. laurentius. The fact that there was no difference between the feeding performance of sylvatic and domestic insects suggests that feeding is not a barrier for the domiciliation. Together, these findings suggest that shelter and faster blood meals are qualities of human dwellings that facilitate the domiciliation of T. brasiliensis.
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Chiang RG, Chiang JA. Feeding through artificial membranes reduces fecundity for females of the blood-feeding insect, Rhodnius prolixus. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2010; 74:103-113. [PMID: 20513058 DOI: 10.1002/arch.20365] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The blood-feeding insect, Rhodnius prolixus, has been raised in the laboratory for close to 100 years. Various feeding techniques have been employed ranging from the use of warm-blooded hosts, to the use of previously collected blood offered through artificial membranes. This study compared the fecundity in mated and unmated females fed rabbit blood directly from the shaved belly of a rabbit to that of females fed defibrinated rabbit blood through an artificial membrane. These results confirm previous reports that this insect's feeding efficacy is reduced using an artificial membrane. It also demonstrates for the first time that the fecundity index, which measures the efficiency of turning the blood meal into eggs, is significantly reduced. We suggest that the natural feeding on a warm-blooded host may provide cues that have the short-term effect of enhancing the act of feeding and the long-term effect of increasing egg production efficiency. Until an artificial feeding method that does not interfere with feeding and fecundity is devised, experiments on reproduction in R. prolixus warrant the use of a warm-blooded host to emulate feeding in its natural setting.
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Affiliation(s)
- R Gary Chiang
- Biology Department, Redeemer University College, Ancaster, ON, Canada.
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Araujo RN, Costa FS, Gontijo NF, Gonçalves TCM, Pereira MH. The feeding process of Cimex lectularius (Linnaeus 1758) and Cimex hemipterus (Fabricius 1803) on different bloodmeal sources. JOURNAL OF INSECT PHYSIOLOGY 2009; 55:1151-1157. [PMID: 19712677 DOI: 10.1016/j.jinsphys.2009.08.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 07/27/2009] [Accepted: 08/17/2009] [Indexed: 05/28/2023]
Abstract
The bedbugs Cimex lectularius and Cimex hemipterus are obligate hematophages in all their nymphal instars as well as in the adult stage. The efficiency with which the insects obtain blood from their hosts is directly related to their population dynamics. In the present study we compared the feeding process and salivary content in individuals of these two species when fed on different blood sources or host sites, using a cibarial pump electromyogram. Females ingested more blood than males but needed longer contact time with the host to complete the meal. The bedbug C. lectularius was more efficient than C. hemipterus in obtaining blood from mice and pigeons. With regard to the feeding site on mice, it was easier for the insects to obtain blood from the skin of the belly than that of the back. Individuals of C. hemipterus were able to maintain the cibarial pump functioning at higher frequencies for longer periods when fed on pigeons treated with anticoagulant. Although saliva from C. lectularius contained more hemeproteins and showed more anti-clotting activity its total protein content was similar to that of C. hemipterus. Overall, C. lectularius obtains a bloodmeal more efficiently from its hosts, which may have enabled this species to reach higher levels of infestation than C. hemipterus.
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Affiliation(s)
- Ricardo N Araujo
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, Brazil
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Araujo RN, Pereira MH, Soares AC, Pereira IDCA, Diotaiuti L, Gontijo NF, Lehane MJ, Guarneri AA. Effect of intestinal erythrocyte agglutination on the feeding performance of Triatoma brasiliensis (Hemiptera: Reduviidae). JOURNAL OF INSECT PHYSIOLOGY 2009; 55:862-868. [PMID: 19524588 DOI: 10.1016/j.jinsphys.2009.06.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Revised: 05/28/2009] [Accepted: 06/04/2009] [Indexed: 05/27/2023]
Abstract
Triatoma brasiliensis is an important vector of Trypanosoma cruzi in Brazil. The feeding efficiency on its hosts depends on several parameters including the maintenance of the ingested blood at low viscosity, which could be modulated by the anterior midgut (crop) anticoagulant and haemagglutinant activities. In the present study, we characterized T. brasiliensis crop haemagglutination activity and evaluated its importance in the feeding process. Soluble crop contents (SCC) of T. brasiliensis were able to agglutinate rat, mouse and rabbit eryhtrocytes, but had no activity on cattle and Thrichomys apereoides, a rodent species commonly associated with T. brasiliensis in the wild. The haemagglutination was characterized by the immediate formation of several clusters of erythrocytes connected by flexible elastic-like fibers. The feeding efficiency of T. brasiliensis on rat (agglutinated by SCC) was almost double that from T. apereoides (not agglutinated by SCC). The influence of haemagglutination on feeding was confirmed by artificially feeding bugs on a diet composed of cattle or rat erythrocytes. The bugs fed on cattle erythrocytes had lower ingestion rates in comparison to those fed on rats. The results indicate that, in addition to other parameters, haemagglutination brought about by SCC has an important role in the feeding efficiency of T. brasiliensis.
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Affiliation(s)
- Ricardo N Araujo
- Departamento de Parasitologia do Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Caixa Postal 486, 31270-901 Belo Horizonte, MG, Brazil
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Falibene A, Gontijo ADF, Josens R. Sucking pump activity in feeding behaviour regulation in carpenter ants. JOURNAL OF INSECT PHYSIOLOGY 2009; 55:518-524. [PMID: 19217950 DOI: 10.1016/j.jinsphys.2009.01.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2008] [Revised: 01/16/2009] [Accepted: 01/26/2009] [Indexed: 05/27/2023]
Abstract
Modulation of liquid feeding-rate would allow insects to ingest more food in the same time when this was required. Ants can vary nectar intake rate by increasing sucking pump frequency according to colony requirements. We analysed electrical signals generated by sucking pump activity of ants during drinking solutions of different sucrose concentrations and under different carbohydrate-deprivation levels. Our aim was to define parameters that characterize the recordings and analyse their relationship with feeding behaviour. Signals showed that the initial and final frequencies of sucking pump activity, as well as the difference between them were higher in sugar-deprived ants. However, these parameters were not influenced by sucrose solution concentration, which affected the number of pump contractions and the volume per contraction. Unexpectedly, we found two different responses in feeding behaviour of starved and non-starved ants depending on concentration. Starved ants drank dilute solutions for the same length of time as non-starved ants but ingested higher volumes. While drinking the concentrated solutions, starved ants drank the same volume, but did so in a shorter time than the non-starved ones. Despite these differences, for each analysed concentration the total number of pump contractions remained constant independently of sugar-deprivation level. These results are discussed in the frame of feeding regulation and decision making in ant foraging behaviour.
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Affiliation(s)
- Agustina Falibene
- Grupo de Estudio de Insectos Sociales, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón II, Ciudad Universitaria (C1428EHA), Buenos Aires, Argentina
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Araujo RN, Soares AC, Paim RMM, Gontijo NF, Gontijo AF, Lehane MJ, Pereira MH. The role of salivary nitrophorins in the ingestion of blood by the triatomine bug Rhodnius prolixus (Reduviidae: Triatominae). INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2009; 39:83-89. [PMID: 18992340 DOI: 10.1016/j.ibmb.2008.10.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2008] [Revised: 09/24/2008] [Accepted: 10/06/2008] [Indexed: 05/27/2023]
Abstract
To assist haematophagy, Rhodnius prolixus produces several bioactive molecules in its saliva which it injects into the host skin. The most abundant of these molecules are the nitrophorins (NPs). In this work, we reduced the expression of NP1-4 in the saliva of R. prolixus by RNAi and evaluated the subsequent feeding performance of the bugs using the cibarial pump electromyogram either on the dorsal skin or on the tail vein of the mice. NPs salivary mRNA was reduced by >99% in comparison to controls. Saliva from knockdown nymphs also presented 82% less haemproteins while the total protein was not reduced. Knockdown nymphs feeding on the skin had lower ingestion rates mainly due to the longer cumulative probing time and lower cibarial pump frequency. Another difference was that knockdown insects bit approximately 5 times more. No differences were observed between groups fed on the tail vein. When the feeding sites were compared, nymphs fed on the tail vein had higher effective ingestion rates. These findings endorse the importance of the NPs for the ability of bugs to complete the meal in a short total contact time with a low number of bites, decreasing the perception of the insect by the host.
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Affiliation(s)
- Ricardo N Araujo
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal Minas Gerais, Bloco I4, Sala 177, Av. Antônio Carlos 6627, Pampulha, CEP 30270-901 Belo Horizonte, MG, Brazil
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Nectar intake rate is modulated by changes in sucking pump activity according to colony starvation in carpenter ants. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2008; 194:491-500. [DOI: 10.1007/s00359-008-0323-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2007] [Revised: 02/20/2008] [Accepted: 02/21/2008] [Indexed: 10/22/2022]
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Josens R, Falibene A, Gontijo ADF. Electrical signals during nectar sucking in the carpenter ant Camponotus mus. JOURNAL OF INSECT PHYSIOLOGY 2006; 52:1234-42. [PMID: 17069844 DOI: 10.1016/j.jinsphys.2006.09.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2006] [Revised: 09/07/2006] [Accepted: 09/11/2006] [Indexed: 05/12/2023]
Abstract
Ants of the same size can vary their intake rate of a given sucrose solution depending on the colony's needs for carbohydrates. As this capacity has not yet been described for another insect, the question of how they can do that was the focus of our work. When viscosity and ant-morphometry remain constant, changes in intake rate can only be attributed to the sucking forces. The aim of this study was to analyze the nectar sucking activity in the ant Camponotus mus. Feeding behavior seems to be under motivational control; therefore, we developed a non-invasive experimental device. We recorded the electrical signal generated during nectar feeding by offering ants sucrose solutions of different concentrations (from 10%w/w to 70%w/w). The signal frequency was between 2 and 12 peaks/s. We could distinguish two different patterns of electrical signal during feeding depending on the solution concentration. Only the more concentrated solutions reached frequencies higher than 7 peaks/s and the signal performance was quite irregular. For the other concentrations (10%, 30% and 50%), signal frequencies were lower than 6 peaks/s and the signal pattern was sinusoidal, regular and decreased with intake in all cases. We discuss the possible implications of these two signal patterns.
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Affiliation(s)
- Roxana Josens
- Departamento de Biodiversidady Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón II, Ciudad Universitaria (C1428 EHA), Buenos Aires, Argentina.
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Pereira MH, Gontijo NF, Guarneri AA, Sant'Anna MR, Diotaiuti L. Competitive displacement in Triatominae: the Triatoma infestans success. Trends Parasitol 2006; 22:516-20. [PMID: 16971183 DOI: 10.1016/j.pt.2006.08.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2006] [Revised: 08/09/2006] [Accepted: 08/30/2006] [Indexed: 11/26/2022]
Abstract
Brazil has just been certificated by Pan American Health Organization as 'free of Chagas disease transmission due to Triatoma infestans'. During the early 1980s, this species of blood-sucking bug alone was considered responsible for approximately 80% of Chagas disease transmission. But it was not always so. The species originally abundant in houses of central and eastern Brazil was Panstrongylus megistus, which seems to have been progressively displaced from houses by T. infestans during the past century. Indeed, T. infestans seems able to displace other Triatominae in artificial environments. Recent studies suggest that it might simply be because T. infestans feeds more efficiently than its Triatominae competitors.
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Affiliation(s)
- Marcos H Pereira
- Departamento de Parasitologia do Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Caixa Postal 486, 31270-901, Belo Horizonte, MG, Brazil.
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Araujo R, Santos A, Pinto F, Gontijo N, Lehane M, Pereira M. RNA interference of the salivary gland nitrophorin 2 in the triatomine bug Rhodnius prolixus (Hemiptera: Reduviidae) by dsRNA ingestion or injection. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2006; 36:683-93. [PMID: 16935217 PMCID: PMC1892898 DOI: 10.1016/j.ibmb.2006.05.012] [Citation(s) in RCA: 167] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2006] [Revised: 05/10/2006] [Accepted: 05/15/2006] [Indexed: 05/06/2023]
Abstract
Mass sequencing of cDNA libraries from salivary glands of triatomines has resulted in the identification of many novel genes of unknown function. The aim of the present work was to develop a functional RNA interference (RNAi) technique for Rhodnius prolixus, which could be widely used for functional genomics studies in triatomine bugs. To this end, we investigated whether double-stranded RNA (dsRNA) can inhibit gene expression of R. prolixus salivary nitrophorin 2 (NP2) and what impact this might have on anticoagulant and apyrase activity in the saliva. dsRNA was introduced by two injections or by ingestion. RT-PCR of the salivary glands showed that injections of 15 microg of NP2 dsRNA in fourth-instar nymphs reduced gene expression by 75+/-14% and that feeding 1 microg/microL of NP2 dsRNA into second-instar nymphs (approx. 13 microg in total) reduced gene expression by 42+/-10%. Phenotype analysis showed that saliva of normal bugs prolonged plasma coagulation by about four-fold when compared to saliva of knockdown bugs. These results and the light color of the salivary gland content from some insects are consistent with the knockdown findings. The findings suggest that RNAi will prove a highly valuable functional genomics technique in triatomine bugs. The finding that feeding dsRNA can induce knockdown is novel for insects.
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Affiliation(s)
- R.N. Araujo
- Departamento de Parasitologia, Instituto de Ciências Biológicas, UFMG, Belo Horizonte, MG, Brazil
| | - A. Santos
- Departamento de Parasitologia, Instituto de Ciências Biológicas, UFMG, Belo Horizonte, MG, Brazil
| | - F.S. Pinto
- Departamento de Parasitologia, Instituto de Ciências Biológicas, UFMG, Belo Horizonte, MG, Brazil
| | - N.F. Gontijo
- Departamento de Parasitologia, Instituto de Ciências Biológicas, UFMG, Belo Horizonte, MG, Brazil
| | - M.J. Lehane
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - M.H. Pereira
- Departamento de Parasitologia, Instituto de Ciências Biológicas, UFMG, Belo Horizonte, MG, Brazil
- Corresponding author. Tel.: +55 31 3499 2867; fax: +55 31 3499 2970. E-mail address: (M.H. Pereira)
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Soares AC, Carvalho-Tavares J, Gontijo NDF, dos Santos VC, Teixeira MM, Pereira MH. Salivation pattern of Rhodnius prolixus (Reduviidae; Triatominae) in mouse skin. JOURNAL OF INSECT PHYSIOLOGY 2006; 52:468-72. [PMID: 16580013 DOI: 10.1016/j.jinsphys.2006.01.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2005] [Revised: 12/27/2005] [Accepted: 01/04/2006] [Indexed: 05/08/2023]
Abstract
The objective of this work was to study the pattern of salivation of triatomines during feeding in mouse skin. Rhodnius prolixus was fed with a solution of the dye acridine orange or fluorescein. The saliva was efficiently labelled with acridine orange, probably due to the difference in pH between the salivary gland (6.0) and the hemolymph (6.5-7.0). This procedure was not effective at labelling the saliva of Triatoma infestans, however, fluorescent labelling of R. prolixus saliva allowed us to demonstrate that salivation occurs during entire feeding process. The saliva is released soon after the bite. In the probing phase, saliva is pumped continuously in the host skin, including around the blood vessels. During the engorgement phase, saliva is observed in a bolus within the blood vessel and some of it is sucked up by the insect, together with blood. The frequency of saliva emission inside the vessels was low (0.51+/-0.18 Hz). The saliva deposition in the microcirculation is continuous and modulated by the frequency of the cibarial pump because, when functioning at high frequency, cibarial pump sucks almost all saliva to the insect gut. This mechanism would determine the quantity of saliva deposited in the microcirculation as necessary, and consequently minimizing the host's immune response to salivary antigens.
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Affiliation(s)
- Adriana Coelho Soares
- Departamento de Parasitologia, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Avenida Presidente Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, Minas Gerais, CEP 31270-901, Brazil
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Guarneri AA, Diotaiuti L, Gontijo NF, Gontijo AF, Pereira MH. Blood-feeding performance of nymphs and adults of Triatoma brasiliensis on human hosts. Acta Trop 2003; 87:361-70. [PMID: 12875930 DOI: 10.1016/s0001-706x(03)00121-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The blood-feeding behaviour of nymphs and adults of Triatoma brasiliensis fed on the forearm of human volunteers was studied by electronic monitoring of the cibarial pump. Parameters of total contact time (TT), initial weight (IW), weight gain (WG), ingestion rate (IR), pump frequency (F), quantity of liquid ingested per cibarial pump stroke (QLC) and non-ingestive time (NIT) (cumulative probing time and pumping interruptions during blood feeding) were measured. Protein profile (SDS-PAGE) and quantity of proteins of salivary gland extracts (QP) were also determined for each stage. The TT reflects the feeding performance of the insects and differed between instars, varying between 18.3+/-2.5 min for the first instar and 33.9+/-2.3 min for the fifth instar. The observed increase in the IR when comparing different instars was related to the increase in the cibarial pump volume inferred from the QLC data. During development, the volume of the cibarial pump grew asymmetrically determining the different contact times observed among the instars. Males and females presented a remarkable sexual dimorphism in respect to the volume of the cibarial pump, females showing a better performance compared to males. Despite the differences, the results show that each of the development stages of T. brasiliensis was able to obtain a relatively fast bloodmeal, with few interruptions and without causing pain, providing further evidence of the capacity of this species to adapt to domestic environments.
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Affiliation(s)
- Alessandra A Guarneri
- Centro de Pesquisas René Rachou, Fiocruz, Caixa Postal 1743, 30190-002, Belo Horizonte, MG, Brazil.
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Martínez-Ibarra JA, Novelo López M, Hernández Robles MDR, Grant Guillén Y. Influence of the blood meal source on the biology of Meccus picturatus Usinger 1939 (Hemiptera: Reduviidae: Triatominae) under laboratory conditions. Mem Inst Oswaldo Cruz 2003; 98:227-32. [PMID: 12764439 DOI: 10.1590/s0074-02762003000200011] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aspects related to hatching, time-lapse between presenting the blood meal and beginning of feeding, feeding time, postfeed defecation delay,life time, mortality and fecundity for each stage of Meccus picturatus, life-cycle were evaluated and compared in two cohorts of M. picturatus fed on hens or rabbits. The hatching rate observed for each of the two studied groups of eggs was 78.1% (n = 2298) on the group fed on hens and 82.1% (n = 2704) on that fed on rabbits, and the average time of hatching was 20 days. Mean time-lapse for beginning feeding was under 3 min in nymphal stages and postfeed defecation delay was under 10 min in all stages, in both cohorts. Mean feeding time was significantly (P < 0.05) shorter in triatomines fed on hens than on rabbits. A similar number of nymphs of each cohort, 69 fed on hens (34.5%) and 68 fed on rabbits (34%), completed the cycle. No significantly (P > 0.05) differences were recorded among the average times from NI to adult in the cohort fed on hens (196.8 15.8 days) and the average time in the cohort fed on rabbits (189.5 22.9). The average span in days for each stage fed on hens was not significantly different to the average span for each stage fed on rabbits. The number of blood meals at each nymphal stage varied from 1 to 6 in both cohorts. The mortality rates were higher on fifth nymphal stage, in both cohorts. No significant (P > 0.05) differences were recorded on mortality rates on most nymphal stages of both cohorts. The average number of eggs laid per female from the cohort fed on hens in a 9-month period was 791.1, whereas the average number of eggs in the cohort fed on rabbits was 928.3.
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Affiliation(s)
- José Alejandro Martínez-Ibarra
- Area de Entomología Médica, Laboratorio de Salud Pública, Centro Universitario del Sur, Universidad de Guadalajara, Jalisco, México.
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