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Carvalho DO, Morreale R, Stenhouse S, Hahn DA, Gomez M, Lloyd A, Hoel D. A sterile insect technique pilot trial on Captiva Island: defining mosquito population parameters for sterile male releases using mark-release-recapture. Parasit Vectors 2022; 15:402. [PMID: 36320036 PMCID: PMC9628054 DOI: 10.1186/s13071-022-05512-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 09/20/2022] [Indexed: 11/06/2022] Open
Abstract
Background The sterile insect technique (SIT), which involves area-wide inundative releases of sterile insects to suppress the reproduction of a target species, has proven to be an effective pest control method. The technique demands the continuous release of sterilized insects in quantities that ensure a high sterile male:wild male ratio for the suppression of the wild population over succeeding generations. Methods For these releases, it is important to determine several ecological and biological population parameters, including the longevity of the released males in the field, the dispersal of the released males and the wild pest population size. The Lee County Mosquito Control District initiated a study in a 47-ha portion of Captiva Island (Florida, USA), an island with a total area of 230 ha, to define biological SIT parameters for Aedes aegypti (L.), an invasive disease-vectoring mosquito known to be difficult to control due to a combination of daytime biting activity, use of cryptic breeding habitats that are difficult to target with conventional night-time ultra-low volume methods, and emerging resistance to commonly used insecticides. Another goal was to assess patterns of dispersal and survival for laboratory-reared sterile Ae. aegypti males released over time in the pilot site. These parameters will be used to evaluate the efficacy of a SIT suppression program for Ae. aegypti on Captiva Island. Results Over the course of seven mark-release-recapture studies using single- and multiple-point releases, 190,504 sterile marked males were released, for which the recapture rate was 1.5% over a mean period of 12 days. The mean distance traveled by sterile males of the local strain of Ae. aegypti that has colonized Captiva Island was 201.7 m from the release point, with an observed maximum traveled distance of 404.5 m. The released sterile mosquitoes had a probability of daily survival of 0.67 and an average life expectancy of ~ 2.46 days. Conclusions These data together with the population size estimate and sterile:wild ratio provide a solid basis for planning the SIT operational phase which is aimed at mosquito population suppression. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05512-3.
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Affiliation(s)
- Danilo O. Carvalho
- grid.420221.70000 0004 0403 8399Insect Pest Control Subprogramme, Department of Nuclear Sciences and Applications, Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, 1400 Vienna, Austria
| | - Rachel Morreale
- Lee County Mosquito Control District, 15191 Homestead Road, Lehigh Acres, FL 33971 USA
| | - Steven Stenhouse
- Lee County Mosquito Control District, 15191 Homestead Road, Lehigh Acres, FL 33971 USA
| | - Daniel A. Hahn
- grid.15276.370000 0004 1936 8091Department of Entomology and Nematology, University of Florida, 1881 Natural Area Drive, Gainesville, FL 32611 USA
| | - Maylen Gomez
- grid.420221.70000 0004 0403 8399Insect Pest Control Subprogramme, Department of Nuclear Sciences and Applications, Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, 1400 Vienna, Austria
| | - Aaron Lloyd
- Lee County Mosquito Control District, 15191 Homestead Road, Lehigh Acres, FL 33971 USA
| | - David Hoel
- Lee County Mosquito Control District, 15191 Homestead Road, Lehigh Acres, FL 33971 USA
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Gu X, Ross PA, Rodriguez-Andres J, Robinson KL, Yang Q, Lau MJ, Hoffmann AA. A wMel Wolbachia variant in Aedes aegypti from field-collected Drosophila melanogaster with increased phenotypic stability under heat stress. Environ Microbiol 2022; 24:2119-2135. [PMID: 35319146 PMCID: PMC9544352 DOI: 10.1111/1462-2920.15966] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 02/15/2022] [Accepted: 03/02/2022] [Indexed: 02/03/2023]
Abstract
Mosquito‐borne diseases remain a major cause of morbidity and mortality. Population replacement strategies involving the wMel strain of Wolbachia are being used widely to control mosquito‐borne diseases. However, these strategies may be influenced by temperature because wMel is vulnerable to heat. wMel infections in Drosophila melanogaster are genetically diverse, but few transinfections of wMel variants have been generated in Aedes aegypti. Here, we successfully transferred a wMel variant (termed wMelM) originating from a field‐collected D. melanogaster into Ae. aegypti. The new wMelM variant (clade I) is genetically distinct from the original wMel transinfection (clade III), and there are no genomic differences between wMelM in its original and transinfected host. We compared wMelM with wMel in its effects on host fitness, temperature tolerance, Wolbachia density, vector competence, cytoplasmic incompatibility and maternal transmission under heat stress in a controlled background. wMelM showed a higher heat tolerance than wMel, likely due to higher overall densities within the mosquito. Both wMel variants had minimal host fitness costs, complete cytoplasmic incompatibility and maternal transmission, and dengue virus blocking under laboratory conditions. Our results highlight phenotypic differences between Wolbachia variants and wMelM shows potential as an alternative strain in areas with strong seasonal temperature fluctuations.
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Affiliation(s)
- Xinyue Gu
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Vic, Australia
| | - Perran A Ross
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Vic, Australia
| | - Julio Rodriguez-Andres
- Peter Doherty Institute for Infection and Immunity and Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Melbourne, Vic, 3000, Australia
| | - Katie L Robinson
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Vic, Australia
| | - Qiong Yang
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Vic, Australia
| | - Meng-Jia Lau
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Vic, Australia
| | - Ary A Hoffmann
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Vic, Australia
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3
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Analysis of the invasion of a city by Aedes aegypti via mathematical models and Bayesian statistics. THEOR ECOL-NETH 2022. [DOI: 10.1007/s12080-022-00528-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Da Re D, Montecino-Latorre D, Vanwambeke SO, Marcantonio M. Will the yellow fever mosquito colonise Europe? Assessing the re-introduction of Aedes aegypti using a process-based population dynamical model. ECOL INFORM 2021. [DOI: 10.1016/j.ecoinf.2020.101180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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5
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Balaji S, Jayachandran S, Prabagaran SR. Evidence for the natural occurrence of Wolbachia in Aedes aegypti mosquitoes. FEMS Microbiol Lett 2020; 366:5380775. [PMID: 30869785 DOI: 10.1093/femsle/fnz055] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Accepted: 03/13/2019] [Indexed: 12/12/2022] Open
Abstract
Wolbachia, a Gram-negative bacterium, is widely known to be present in arthropods and nematodes. Of late, great impetus is given to employ this intracellular bacterium, as an alternative to conventional biocontrol agents for the control of mosquitoes because of its inherent ability to induce sperm-egg incompatibility, feminisation etc. By employing molecular tools, we have shown the presence of Wolbachia from Aedes aegypti mosquito population collected from Coimbatore, India by PCR amplifying the Ae. aegypti mosquito genome with Wolbachia specific 16S rRNA, wsp and ftsZ gene primers. The phylogenetic analysis of these gene sequences incorporating MLST and GenBank reference sequences has confirmed the occurrence of Wolbachia supergroup B in Ae. aegypti. In addition, qRT-PCR results have shown the dynamics of Wolbachia across the developmental stages of mosquito. The absence of Wolbachia in tetracycline-treated Ae. aegypti mosquitoes evidenced by transmission electron microscopy reinforced our finding conclusively. After confirming their persistence through generations, we have designated Wolbachia from Ae. aegypti as wAegB. In our considered view, wAegB could play a dynamic role in impeding mosquito multiplication and consequently impinging transmission of the dreadful dengue.
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Affiliation(s)
- Sivaraman Balaji
- Molecular Microbiology Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore - 641046, Tamil Nadu, India
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6
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Garcia GA, Hoffmann AA, Maciel-de-Freitas R, Villela DAM. Aedes aegypti insecticide resistance underlies the success (and failure) of Wolbachia population replacement. Sci Rep 2020; 10:63. [PMID: 31919396 PMCID: PMC6952458 DOI: 10.1038/s41598-019-56766-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 12/05/2019] [Indexed: 12/12/2022] Open
Abstract
Mosquitoes that carry Wolbachia endosymbionts may help control the spread of arboviral diseases, such as dengue, Zika and chikungunya. Wolbachia frequencies systematically increase only when the frequency-dependent advantage due to cytoplasmic incompatibility exceeds frequency-independent costs, which may be intrinsic to the Wolbachia and/or can be associated with the genetic background into which Wolbachia are introduced. Costs depend on field conditions such as the environmental pesticide load. Introduced mosquitoes need adequate protection against insecticides to ensure survival after release. We model how insecticide resistance of transinfected mosquitoes determines the success of local Wolbachia introductions and link our theoretical results to field data. Two Ae. aegypti laboratory strains carrying Wolbachia were released in an isolated district of Rio de Janeiro, Brazil: wMelBr (susceptible to pyrethroids) and wMelRio (resistant to pyrethroids). Our models elucidate why releases of the susceptible strain failed to result in Wolbachia establishment, while releases of the resistant strain led to Wolbachia transforming the native Ae. aegypti population. The results highlight the importance of matching insecticide resistance levels in release stocks to those in the target natural populations during Wolbachia deployment.
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Affiliation(s)
- Gabriela A Garcia
- Laboratório de Transmissores de Hematozoários, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (IOC/FIOCRUZ), Rio de Janeiro, Brazil
| | | | - Rafael Maciel-de-Freitas
- Laboratório de Transmissores de Hematozoários, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (IOC/FIOCRUZ), Rio de Janeiro, Brazil
| | - Daniel A M Villela
- Programa de Computação Científica, Fundação Oswaldo Cruz (PROCC/FIOCRUZ), Rio de Janeiro, Brazil.
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Koyoc-Cardeña E, Medina-Barreiro A, Cohuo-Rodríguez A, Pavía-Ruz N, Lenhart A, Ayora-Talavera G, Dunbar M, Manrique-Saide P, Vazquez-Prokopec G. Estimating absolute indoor density of Aedes aegypti using removal sampling. Parasit Vectors 2019; 12:250. [PMID: 31113454 PMCID: PMC6528352 DOI: 10.1186/s13071-019-3503-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 05/14/2019] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Quantification of adult Aedes aegypti abundance indoors has relied on estimates of relative density (e.g. number of adults per unit of sampling or time), most commonly using traps or timed collections using aspirators. The lack of estimates of the sensitivity of collections and lack of a numerical association between relative and the absolute density of adult Ae. aegypti represent a significant gap in vector surveillance. Here, we describe the use of sequential removal sampling to estimate absolute numbers of indoor resting Ae. aegypti and to calculate calibration coefficients for timed Prokopack aspirator collections in the city of Merida, Yucatan State, Mexico. The study was performed in 200 houses that were selected based on recent occurrence of Aedes-borne viral illness in residents. Removal sampling occurred in 10-minute sampling rounds performed sequentially until no Ae. aegypti adult was collected for 3 hours or over 2 consecutive 10-minute periods. RESULTS A total of 3439 Ae. aegypti were collected. The sensitivity of detection of positive houses in the first sampling round was 82.5% for any adult Ae. aegypti, 78.5% for females, 75.5% for males and 73.3% for blood-fed females. The total number of Ae. aegypti per house was on average ~5 times higher than numbers collected for the first sampling round. There was a positive linear relationship between the relative density of Ae. aegypti collected during the first 10-min round and the absolute density for all adult metrics. Coefficients from the linear regression were used to calibrate numbers from 10-min collections into estimates of absolute indoor Ae. aegypti density for all adults, females and males. CONCLUSIONS Exhaustive removal sampling represents a promising method for quantification of absolute indoor Ae. aegypti density, leading to improved entomological estimates of mosquito distribution, a key measure in the assessments of the risk pathogen transmission, disease modeling and the evaluation of vector control interventions.
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Affiliation(s)
- Edgar Koyoc-Cardeña
- Unidad Colaborativa de Bioensayos Entomológicos, Campus de Ciencias. Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
| | - Anuar Medina-Barreiro
- Unidad Colaborativa de Bioensayos Entomológicos, Campus de Ciencias. Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
| | - Azael Cohuo-Rodríguez
- Unidad Colaborativa de Bioensayos Entomológicos, Campus de Ciencias. Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
| | - Norma Pavía-Ruz
- Centro de Investigaciones Regionales "Dr. Hideyo Noguchi", Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
| | - Audrey Lenhart
- Entomology Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Guadalupe Ayora-Talavera
- Centro de Investigaciones Regionales "Dr. Hideyo Noguchi", Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
| | - Mike Dunbar
- Department of Environmental Sciences, Emory University, Atlanta, GA, USA
| | - Pablo Manrique-Saide
- Unidad Colaborativa de Bioensayos Entomológicos, Campus de Ciencias. Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
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8
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Garcia GDA, Sylvestre G, Aguiar R, da Costa GB, Martins AJ, Lima JBP, Petersen MT, Lourenço-de-Oliveira R, Shadbolt MF, Rašić G, Hoffmann AA, Villela DAM, Dias FBS, Dong Y, O’Neill SL, Moreira LA, Maciel-de-Freitas R. Matching the genetics of released and local Aedes aegypti populations is critical to assure Wolbachia invasion. PLoS Negl Trop Dis 2019; 13:e0007023. [PMID: 30620733 PMCID: PMC6338382 DOI: 10.1371/journal.pntd.0007023] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 01/18/2019] [Accepted: 11/26/2018] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Traditional vector control approaches such as source reduction and insecticide spraying have limited effect on reducing Aedes aegypti population. The endosymbiont Wolbachia is pointed as a promising tool to mitigate arbovirus transmission and has been deployed worldwide. Models predict a rapid increase on the frequency of Wolbachia-positive Ae. aegypti mosquitoes in local settings, supported by cytoplasmic incompatibility (CI) and high maternal transmission rate associated with the wMelBr strain. METHODOLOGY/PRINCIPLE FINDINGS Wolbachia wMelBr strain was released for 20 consecutive weeks after receiving >87% approval of householders of the isolated community of Tubiacanga, Rio de Janeiro. wMelBr frequency plateued~40% during weeks 7-19, peaked 65% but dropped as releases stopped. A high (97.56%) maternal transmission was observed. Doubling releases and deploying mosquitoes with large wing length and low laboratory mortality produced no detectable effects on invasion trend. By investigating the lab colony maintenance procedures backwardly, pyrethroid resistant genotypes in wMelBr decreased from 68% to 3.5% after 17 generations. Therefore, we initially released susceptible mosquitoes in a local population highly resistant to pyrethroids which, associated with the over use of insecticides by householders, ended jeopardizing Wolbachia invasion. A new strain (wMelRio) was produced after backcrossing wMelBr females with males from field to introduce mostly pyrethroid resistance alleles. The new strain increased mosquito survival but produced relevant negative effects on Ae. aegypti fecundity traits, reducing egg clutche size and egg hatch. Despite the cost on fitness, wMelRio successful established where wMelBr failed, revealing that matching the local population genetics, especially insecticide resistance background, is critical to achieve invasion. CONCLUSIONS/SIGNIFICANCE Local householders support was constantly high, reaching 90% backing on the second release (wMelRio strain). Notwithstanding the drought summer, the harsh temperature recorded (daily average above 30°C) did not seem to affect the expression of maternal transmission of wMel on a Brazilian background. Wolbachia deployment should match the insecticide resistance profile of the wild population to achieve invasion. Considering pyrethroid-resistance is a widely distributed phenotype in natural Ae. aegypti populations, future Wolbachia deployments must pay special attention in maintaining insecticide resistance in lab colonies for releases.
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Affiliation(s)
- Gabriela de Azambuja Garcia
- Laboratório de Mosquitos Transmissores de Hematozoários, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil
| | - Gabriel Sylvestre
- Laboratório de Mosquitos Transmissores de Hematozoários, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil
| | - Raquel Aguiar
- Serviço de Jornalismo e Comunicação, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil
| | | | - Ademir Jesus Martins
- Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM)/CNPq, Rio de Janeiro, Brazil
| | - José Bento Pereira Lima
- Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM)/CNPq, Rio de Janeiro, Brazil
| | - Martha T. Petersen
- Laboratório de Mosquitos Transmissores de Hematozoários, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil
| | - Ricardo Lourenço-de-Oliveira
- Laboratório de Mosquitos Transmissores de Hematozoários, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM)/CNPq, Rio de Janeiro, Brazil
| | - Marion F. Shadbolt
- School of BioSciences, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Gordana Rašić
- School of BioSciences, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Ary A. Hoffmann
- School of BioSciences, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia
| | | | | | - Yi Dong
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, Australia
| | - Scott L. O’Neill
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, Australia
| | - Luciano A. Moreira
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM)/CNPq, Rio de Janeiro, Brazil
- Instituto de Pesquisas René Rachou, Belo Horizonte, Fiocruz, Minas Gerais, Brazil
| | - Rafael Maciel-de-Freitas
- Laboratório de Mosquitos Transmissores de Hematozoários, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM)/CNPq, Rio de Janeiro, Brazil
- * E-mail:
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9
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Lang BJ, Idugboe S, McManus K, Drury F, Qureshi A, Cator LJ. The Effect of Larval Diet on Adult Survival, Swarming Activity and Copulation Success in Male Aedes aegypti (Diptera: Culicidae). JOURNAL OF MEDICAL ENTOMOLOGY 2018; 55:29-35. [PMID: 29029298 PMCID: PMC5850809 DOI: 10.1093/jme/tjx187] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Indexed: 05/23/2023]
Abstract
Control of Aedes aegypti (L.) (Diptera: Culicidae) populations is vital for reducing the transmission of several pervasive human diseases. The success of new vector control technologies will be influenced by the fitness of laboratory-reared transgenic males. However, there has been relatively little published data on how rearing practices influence male fitness in Aedes mosquitoes. In the laboratory, the effect of larval food availability on adult male fitness was tested, using a range of different fitness measures. Larval food availability was demonstrated to be positively correlated with adult body size. Larger males survived longer and exhibited greater swarming activity. As a consequence, larger males may have more mating opportunities in the wild. However, we also found that within a swarm larger males did not have an increased likelihood of copulating with a female. The outcome of the mating competition experiments depended on the methodology used to mark the males. These results show that fitness assessment can vary depending on the measure analyzed, and the methodology used to determine it. Continued investigation into these fitness measures and methodologies, and critically, their utility for predicting male performance in the field, will increase the efficiency of vector control programs.
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Affiliation(s)
- Bethan J Lang
- Grand Challenges in Ecosystems and Environment, Department of Life Sciences,
Imperial College London, United Kingdom
| | - Stefano Idugboe
- Grand Challenges in Ecosystems and Environment, Department of Life Sciences,
Imperial College London, United Kingdom
- Department of Animal and Environmental Biology, University of Benin, Benin
City, Nigeria
| | - Kirelle McManus
- Grand Challenges in Ecosystems and Environment, Department of Life Sciences,
Imperial College London, United Kingdom
| | - Florence Drury
- Grand Challenges in Ecosystems and Environment, Department of Life Sciences,
Imperial College London, United Kingdom
| | - Alima Qureshi
- Grand Challenges in Ecosystems and Environment, Department of Life Sciences,
Imperial College London, United Kingdom
| | - Lauren J Cator
- Grand Challenges in Ecosystems and Environment, Department of Life Sciences,
Imperial College London, United Kingdom
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10
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de Oliveira S, Villela DAM, Dias FBS, Moreira LA, Maciel de Freitas R. How does competition among wild type mosquitoes influence the performance of Aedes aegypti and dissemination of Wolbachia pipientis? PLoS Negl Trop Dis 2017; 11:e0005947. [PMID: 28991902 PMCID: PMC5648260 DOI: 10.1371/journal.pntd.0005947] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 10/19/2017] [Accepted: 09/08/2017] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Wolbachia has been deployed in several countries to reduce transmission of dengue, Zika and chikungunya viruses. During releases, Wolbachia-infected females are likely to lay their eggs in local available breeding sites, which might already be colonized by local Aedes sp. mosquitoes. Therefore, there is an urgent need to estimate the deleterious effects of intra and interspecific larval competition on mosquito life history traits, especially on the duration of larval development time, larval mortality and adult size. METHODOLOGY/PRINCIPAL FINDINGS Three different mosquito populations were used: Ae. aegypti infected with Wolbachia (wMelBr strain), wild Ae. aegypti and wild Ae. albopictus. A total of 21 treatments explored intra and interspecific larval competition with varying larval densities, species proportions and food levels. Each treatment had eight replicates with two distinct food levels: 0.25 or 0.50 g of Chitosan and fallen avocado leaves. Overall, overcrowding reduced fitness correlates of the three populations. Ae. albopictus larvae presented lower larval mortality, shorter development time to adult and smaller wing sizes than Ae. aegypti. The presence of Wolbachia had a slight positive effect on larval biology, since infected individuals had higher survivorship than uninfected Ae. aegypti larvae. CONCLUSIONS/SIGNIFICANCE In all treatments, Ae. albopictus outperformed both wild Ae. aegypti and the Wolbachia-infected group in larval competition, irrespective of larval density and the amount of food resources. The major force that can slow down Wolbachia invasion is the population density of wild mosquitoes. Given that Ae. aegypti currently dominates in Rio, in comparison with Ae. albopictus frequency, additional attention must be given to the population density of Ae. aegypti during releases to increase the likelihood of Wolbachia invasion.
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Affiliation(s)
- Suellen de Oliveira
- Fundação Oswaldo Cruz, Fiocruz-RJ, Instituto Oswaldo Cruz, Laboratório de Mosquitos Transmissores de Hematozoários, Rio de Janeiro, Brazil
| | | | | | - Luciano Andrade Moreira
- Fundação Oswaldo Cruz, Fiocruz-MG, Instituto René Rachou, Mosquitos vetores: Endossimbiontes e Interação Patógeno-Vetor, Rio de Janeiro, Brazil
| | - Rafael Maciel de Freitas
- Fundação Oswaldo Cruz, Fiocruz-RJ, Instituto Oswaldo Cruz, Laboratório de Mosquitos Transmissores de Hematozoários, Rio de Janeiro, Brazil
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11
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Ross PA, Axford JK, Richardson KM, Endersby-Harshman NM, Hoffmann AA. Maintaining Aedes aegypti Mosquitoes Infected with Wolbachia. J Vis Exp 2017. [PMID: 28829414 DOI: 10.3791/56124] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Aedes aegypti mosquitoes experimentally infected with Wolbachia are being utilized in programs to control the spread of arboviruses such as dengue, chikungunya and Zika. Wolbachia-infected mosquitoes can be released into the field to either reduce population sizes through incompatible matings or to transform populations with mosquitoes that are refractory to virus transmission. For these strategies to succeed, the mosquitoes released into the field from the laboratory must be competitive with native mosquitoes. However, maintaining mosquitoes in the laboratory can result in inbreeding, genetic drift and laboratory adaptation which can reduce their fitness in the field and may confound the results of experiments. To test the suitability of different Wolbachia infections for deployment in the field, it is necessary to maintain mosquitoes in a controlled laboratory environment across multiple generations. We describe a simple protocol for maintaining Ae. aegypti mosquitoes in the laboratory, which is suitable for both Wolbachia-infected and wild-type mosquitoes. The methods minimize laboratory adaptation and implement outcrossing to increase the relevance of experiments to field mosquitoes. Additionally, colonies are maintained under optimal conditions to maximize their fitness for open field releases.
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Affiliation(s)
- Perran A Ross
- School of BioSciences, Bio21 Institute and University of Melbourne;
| | - Jason K Axford
- School of BioSciences, Bio21 Institute and University of Melbourne
| | | | | | - Ary A Hoffmann
- School of BioSciences, Bio21 Institute and University of Melbourne
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Villela DAM, Garcia GDA, Maciel-de-Freitas R. Novel inference models for estimation of abundance, survivorship and recruitment in mosquito populations using mark-release-recapture data. PLoS Negl Trop Dis 2017. [PMID: 28650962 PMCID: PMC5501687 DOI: 10.1371/journal.pntd.0005682] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Background Experiments involving mosquito mark-release-recapture (MRR) design are helpful to determine abundance, survival and even recruitment of mosquito populations in the field. Obstacles in mosquito MRR protocols include marking limitations due to small individual size, short lifespan, low efficiency in capturing devices such as traps, and individual removal upon capture. These limitations usually make MRR analysis restricted to only abundance estimation or a combination of abundance and survivorship, and often generate a great degree of uncertainty about the estimations. Methodology/Principal findings We present a set of Bayesian biodemographic models designed to fit data from most common mosquito recapture experiments. Using both field data and simulations, we consider model features such as capture efficiency, survival rates, removal of individuals due to capturing, and collection of pupae. These models permit estimation of abundance, survivorship of both marked and unmarked mosquitoes, if different, and recruitment rate. We analyze the accuracy of estimates by varying the number of released individuals, abundance, survivorship, and capture efficiency in multiple simulations. These methods can stand capture efficiencies as low as usually reported but their accuracy depends on the number of released mosquitoes, abundance and survivorship. We also show that gathering pupal counts allows estimating differences in survivorship between released mosquitoes and the unmarked population. Conclusion/Significance These models are important both to reduce uncertainty in evaluating MMR experiments and also to help planning future MRR studies. Mosquito-borne diseases such as dengue and malaria impose a global burden with recurrent outbreaks. Recently, emergence of arboviral diseases caused by Zika and chikungunya viruses has also become a global concern. Knowledge about the ecology of mosquito populations under natural conditions may provide significant aid to help designing more effective vector control strategies. Quantitative metrics such as the abundance of mosquito populations are difficult to be measured in the field without resorting to experiments with markers. There are, however, limitations to these kinds of experiments such as short mosquito lifespan, marking limitations due to small body size, low efficiency in capturing devices such as traps, and once-only individual capture. Due to these limitations most methods estimate either only abundance or a combination of abundance and survivorship. In this work, we present statistical methods designed to estimate abundance, survivorship and recruitment using inference models and information such as counts of pupae. Results indicate that having low capture efficiencies as often observed in field assays still permits good estimation. Also, low number of released mosquitoes compromise density and survival estimations. We expect these methods to be helpful to people collecting mosquito field data and for health analysts to evaluate possible outcomes of control interventions.
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Affiliation(s)
| | - Gabriela de Azambuja Garcia
- Laboratório de Transmissão de Hematozoários, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Rafael Maciel-de-Freitas
- Laboratório de Transmissão de Hematozoários, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
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Ross PA, Wiwatanaratanabutr I, Axford JK, White VL, Endersby-Harshman NM, Hoffmann AA. Wolbachia Infections in Aedes aegypti Differ Markedly in Their Response to Cyclical Heat Stress. PLoS Pathog 2017; 13:e1006006. [PMID: 28056065 PMCID: PMC5215852 DOI: 10.1371/journal.ppat.1006006] [Citation(s) in RCA: 148] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 12/07/2016] [Indexed: 11/18/2022] Open
Abstract
Aedes aegypti mosquitoes infected with Wolbachia bacteria are currently being released for arbovirus suppression around the world. Their potential to invade populations and persist will depend on interactions with environmental conditions, particularly as larvae are often exposed to fluctuating and extreme temperatures in the field. We reared Ae. aegypti larvae infected with different types of Wolbachia (wMel, wAlbB and wMelPop-CLA) under diurnal cyclical temperatures. Rearing wMel and wMelPop-CLA-infected larvae at 26-37°C reduced the expression of cytoplasmic incompatibility, a reproductive manipulation induced by Wolbachia. We also observed a sharp reduction in the density of Wolbachia in adults. Furthermore, the wMel and wMelPop-CLA infections were not transmitted to the next generation when mosquitoes were exposed to 26-37°C across all life stages. In contrast, the wAlbB infection was maintained at a high density, exhibited complete cytoplasmic incompatibility, and was transmitted from mother to offspring with a high fidelity under this temperature cycle. These findings have implications for the potential success of Wolbachia interventions across different environments and highlight the importance of temperature control in rearing.
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Affiliation(s)
- Perran A. Ross
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
- * E-mail:
| | - Itsanun Wiwatanaratanabutr
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
- Department of Plant Production Technology, Faculty of Agricultural Technology, King Mongkut's Institute of Technology Ladkrabang, Bangkok, Thailand
| | - Jason K. Axford
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Vanessa L. White
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Nancy M. Endersby-Harshman
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Ary A. Hoffmann
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
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Masi M, Cala A, Tabanca N, Cimmino A, Green IR, Bloomquist JR, van Otterlo WAL, Macias FA, Evidente A. Alkaloids with Activity against the Zika Virus Vector Aedes aegypti (L.)-Crinsarnine and Sarniensinol, Two New Crinine and Mesembrine Type Alkaloids Isolated from the South African Plant Nerine sarniensis. Molecules 2016; 21:molecules21111432. [PMID: 27801807 PMCID: PMC6273414 DOI: 10.3390/molecules21111432] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 10/17/2016] [Accepted: 10/19/2016] [Indexed: 11/29/2022] Open
Abstract
Two new Amaryllidaceae alkaloids, belonging to the mesembrine- and crinine-types, named crinsarnine (1) and sarniensinol (2), were isolated from the dried bulbs of Nerine sarniensis together with bowdensine (3), sarniensine (4), hippadine (5) and 1-O-acetyl-lycorine (6). Crinsarnine (1) and sarniensinol (2) were characterized using spectroscopic and chiroptical methods as (1S,2S,4aR,10bS)-2,7-dimethoxy-1,2,3,4,4a,6-hexahydro-5,11b-ethano[1,3]dioxolo-[4,5-j]phenanthridin-1-yl acetate and (6-(3aR,4Z,6S,7aS)-6-methoxy-1-methyl-2,3,3a,6,7,7a-hexa-hydro-1H-indol-3a-yl)benzo[d][1,3]dioxol-5-yl)methanol, respectively. Furthermore, the complete spectroscopic characterization of bowdensine (3) is reported for the first time. Compounds 1–6 were evaluated against the Orlando reference strain of Aedes aegypti. None of compounds showed mortality against 1st instar Ae. aegypti larvae at the concentrations tested. In adult topical bioassays, only 1 displayed adulticidal activity with an LD50 = 2.29 ± 0.049 μg/mosquito. As regards the structure-activity relationship, the pretazettine and crinine scaffold in 2 and 4 and in 1 and 3 respectively, proved to be important for their activity, while the pyrrole[de]phenanthridine scaffold present in 5 and 6 was important for their reactivity. Among the pretazettine group compounds, opening of the B ring or the presence of a B ring lactone as well as the trans-stereochemistry of the A/B ring junction, appears to be important for activity, while in crinine-type alkaloids, the substituent at C-2 seems to play a role in their activity.
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Affiliation(s)
- Marco Masi
- Department of Chemical Sciences, University of Naples "Federico II", Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126 Napoli, Italy.
| | - Antonio Cala
- Department of Chemical Sciences, University of Naples "Federico II", Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126 Napoli, Italy.
- Allelopathy Group, Department of Organic Chemistry, School of Science, Institute of Biomolecules (INBIO), University of Cádiz, C/República Saharaui 7, 11510 Puerto Real, Cádiz, Spain.
| | - Nurhayat Tabanca
- Department of Entomology and Nematology, Emerging Pathogens Institute, University of Florida, Gainesville, FL 32610, USA.
- U.S. Department of Agriculture-Agricultural Research Service, Subtropical Horticulture Research Station, 13601 Old Cutler Rd., Miami, FL 33158, USA.
| | - Alessio Cimmino
- Department of Chemical Sciences, University of Naples "Federico II", Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126 Napoli, Italy.
| | - Ivan R Green
- Department of Chemistry and Polymer Science, University of Stellenbosch, Private Bag X1, Matieland, 7602 Stellenbosch, South Africa.
| | - Jeffrey R Bloomquist
- Department of Entomology and Nematology, Emerging Pathogens Institute, University of Florida, Gainesville, FL 32610, USA.
| | - Willem A L van Otterlo
- U.S. Department of Agriculture-Agricultural Research Service, Subtropical Horticulture Research Station, 13601 Old Cutler Rd., Miami, FL 33158, USA.
| | - Francisco A Macias
- Allelopathy Group, Department of Organic Chemistry, School of Science, Institute of Biomolecules (INBIO), University of Cádiz, C/República Saharaui 7, 11510 Puerto Real, Cádiz, Spain.
| | - Antonio Evidente
- Department of Chemical Sciences, University of Naples "Federico II", Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126 Napoli, Italy.
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