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1.
Parasite ; 28: 84, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34928206

RESUMO

Mosquito-borne infections have considerable consequences for public health. The mere presence of a single case of vector-borne disease (VBD) introduces a risk to the local community particularly when associated with the compatible vector, host, and suitable environmental factors. Presently, there is no well-established vector control and surveillance programme in Qatar; therefore, the likelihood of VBDs spreading is undetermined. As a result, there is a pressing need to address this gap and enable successful management of VBDs. This study presents the results of three consecutive field surveys conducted between 2017 and 2019 with the aim of defining the types and distribution of mosquitoes that are of public health importance in Qatar. The results of the adult mosquito trappings show that the southern house mosquito Culex quinquefasciatus is the most widespread and abundant mosquito species, followed by Cx. perexiguus, both species representing a risk of West Nile virus transmission. All sampling methods show that the malaria vector Anopheles stephensi is widespread including in urbanised areas, suggesting a risk of local malaria transmission. The wetland mosquito Aedes caspius is also widespread, representing a risk of Rift Valley fever virus transmission. The dengue vector Ae. aegypti was not detected and can be considered neither widespread nor abundant, suggesting a minimal risk for local transmission of dengue, chikungunya and Zika viruses. Interestingly, the study detected Culiseta longiareolata for the first time in Qatar. Regular field studies are needed to further address the knowledge gaps in terms of distribution, ecology, and biting habits of different mosquito species currently present in Qatar to accurately assess the risk of mosquito-borne diseases.


Title: Identification et caractérisation des moustiques de différents sites du Qatar en 2017­2019. Abstract: Les maladies transmises par les moustiques posent de considérables risques en santé publique. La simple présence d'un cas de maladie à transmission vectorielle (MTV) introduit un risque pour la communauté locale lorsque associé à un vecteur, un hôte et des facteurs environnementaux compatibles. À ce jour il n'y a pas de programme de surveillance et de contrôle des vecteurs bien établi au Qatar, et de ce fait la probabilité de diffusion de MTV est indéterminée. C'est pourquoi il existe un besoin pressant de combler ce vide et de permettre une gestion effective des MTV. Ce travail présente les résultats de trois études de terrain successives conduites entre 2017 et 2019, dans l'objectif de caractériser les moustiques d'importance en santé publique et leur distribution au Qatar. Les résultats des piégeages d'adultes révèlent que le moustique domestique méridional Culex quinquefasciatus est l'espèce la plus répandue et abondante, suivie de Cx. perexiguus, les deux espèces présentant un risque pour la transmission du virus West Nile. L'ensemble des échantillonnages montrent que le vecteur du paludisme Anopheles stephensi est largement répandu y compris dans les zones urbanisées, ce qui suggère un risque de transmission locale du paludisme. Le moustique des zones humides Aedes caspius est également largement répandu, présentant un risque pour la transmission du virus de la fièvre de la Vallée du Rift. Le vecteur de la dengue Ae. aegypti n'a pas été détecté et peut être considéré ni répandu ni abondant, ce qui suggère un risque minimal de transmission locale des virus dengue, chikungunya et Zika. Il est intéressant de noter que cette étude a détecté la présence de Culiseta longiareolata pour la première fois au Qatar. Des études de terrain régulières sont nécessaires pour mieux combler les lacunes de connaissances en termes de distribution, écologie et comportement trophique des différentes espèces de moustiques présentes au Qatar, et d'évaluer plus précisément le risque de maladies transmises par les moustiques.


Assuntos
Anopheles , Culex , Malária , Infecção por Zika virus , Zika virus , Animais , Mosquitos Vetores , Catar/epidemiologia
2.
Front Public Health ; 9: 628799, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34956995

RESUMO

West Nile virus infections have surged across the globe. South Texas, located on the path of bird migration, with Culex quinquefasciatus and other Culex species, and biotic primers that predispose the area to epidemics (floods, amplifying hosts, and lack of mosquito control and prevention) remains a highly endemic area for arbovirus spread. West Nile virus infection ranges from mild febrile illness to severe central nervous system involvement. The purpose of this report is to highlight complex presentations of WNV and how confounding presenting symptoms delay diagnosis. The secondary goal is to describe how pandemics, such as SARS-CoV-2, can overwhelm the system and result in medical decision bias errors.


Assuntos
COVID-19 , Culex , Febre do Nilo Ocidental , Vírus do Nilo Ocidental , Animais , Humanos , SARS-CoV-2 , Febre do Nilo Ocidental/diagnóstico
3.
Parasit Vectors ; 14(1): 606, 2021 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-34895318

RESUMO

BACKGROUND: Entomological surveillance is an important means of assessing the efficacy of insect vector management programs and estimating disease transmission thresholds. Among baited traps, Biogents' BG-Sentinel (BGS) trap baited with BG-Lure is considered to have the most similar outcome to, and be a possible replacement for, human-landing catches for the epidemiologically relevant monitoring of adult Aedes aegypti and Culex quinquefasciatus. In contrast to the BGS trap, the Black Hole ultraviolet (UV) light trap, which is widely used to catch nocturnal flying insects, is not baited with synthetic human odor-mimicking lures. METHODS: We evaluated the L-lactic acid-based Kasetsart University (KU)-lures nos. 1-6 as novel candidate chemical lures for the diurnal species Ae. aegypti and the nocturnal species Cx. quinquefasciatus using two commercial traps (the BGS trap and the Black Hole UV light trap) in a semi-field screen (SFS) house. Firstly, we optimized the dose of each KU-lure in an SFS house (140 m3). Secondly, six different candidate KU-lures were screened by comparing their percent attraction using a single discriminating dose (0.5 g). Finally, we evaluated the synergism of the KU-lures selected in this way with commercially available traps. RESULTS: BGS traps baited with KU-lure no. 1 exhibited the greatest percent attraction for Ae. aegypti (29.5% ± 14.3%), whereas those baited with KU-lure no. 6 most strongly attracted Cx. quinquefasciatus (33.3% ± 10.7%). Interestingly, BGS traps treated with 10 g BG-Lure did not significantly attract more Ae. aegypti or Cx. quinquefasciatus than the untreated BGS traps. CO2 at a flow rate of 250 ml/min most strongly attracted both Ae. aegypti and Cx. quinquefasciatus (42.2% ± 14.2% and 75.1% ± 16.9%, respectively). BGS and Black Hole UV light traps with KU-lure no. 6 exhibited a stronger attraction for Cx. quinquefasciatus than untreated traps, and the percent attraction did not differ between the treated traps. CONCLUSIONS: Synergistic effects of KU-lures nos. 1 and 6 with the mosquito traps were demonstrated for both the diurnal and nocturnal species in the SFS house assays. However, further studies are urgently needed for the development of species-specific lures to increase trap efficacy in the field for local vector mosquitoes in Thailand.


Assuntos
Aedes/efeitos dos fármacos , Anopheles/efeitos dos fármacos , Culex/efeitos dos fármacos , Ácido Láctico/farmacologia , Mosquitos Vetores/efeitos dos fármacos , Aedes/efeitos da radiação , Animais , Anopheles/efeitos da radiação , Culex/efeitos da radiação , Feminino , Humanos , Ácido Láctico/química , Masculino , Mosquitos Vetores/efeitos da radiação , Raios Ultravioleta
4.
Braz J Biol ; 83: e248122, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34932614

RESUMO

Being vector of West Nile Virus and falariasis the control of Culex quinquefasciatus is likely to be essential. Synthetic insecticide treatment is looking most effective for vectors mosquito control. However, these products are toxic to the environment and non-target organisms. Consequently, ecofriendly control of vectors mosquito is needed. In this regard botanical insecticide is looking more fruitful. Therefore, the present research aimed to investigate the effectiveness of methanolic extract and various fractions, including, n-hexane, ethyl-acetate, chloroform, and aqueous fraction, obtained from methanolic extract of Ailanthus altissima, Artemisia scoparia, and Justicia adhatoda using separating funnel against larval, pupal, and adult stages of Culex quinquefasciatus. The larvae and pupae of Culex quinquefasciatus were exposed to various concentrations (31.25-1000 ppm) of methanolic extract and its fractions for 24 hours of exposure period. For knock-down bioassay (filter paper impregnation bioassay) different concentration of the methanolic extract and its various fractions (i.e. 0.0625, 0.125, 0.25, 0.5 and 1mg/mL) were applied for 1 hour exposure period. The results were statistically analysed using standard deviation, probit analysis, and linear regression. The R2 values of larvae, pupae, and adult range from 0.4 to 0.99. The values of LC50 (concentration causing 50% mortality) for late 3rd instar larvae after 24 hours exposure period range from 93-1856.7 ppm, while LC90 values range from 424 -7635.5ppm. The values of LC50for pupae range form 1326.7-6818.4ppm and and values of LC90 range from 3667.3-17427.9ppm, respectively. The KDT50 range from 0.30 to 2.8% and KDT90 values range from1.2 to 110.8%, respectively. In conclusion, Justicia adhatoda may be effective for controlling populations of vector mosquito.


Assuntos
Anopheles , Culex , Inseticidas , Animais , Inseticidas/farmacologia , Larva , Mosquitos Vetores , Extratos Vegetais/farmacologia , Folhas de Planta
5.
J Agric Food Chem ; 69(51): 15530-15537, 2021 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-34914386

RESUMO

Naturally occurring avermectins are allosteric modulators of glutamate-gated chloride channels (GluCls) and possess exceptionally potent anthelmintic, acaricidal, and insecticidal activities. Here, we develop photoswitchable azobenzene-avermectin (ABAVM) derivatives, which can be photoactivated upon ultraviolet irradiation. After illumination, the best compound p-AB4″AVM had a 1.88-fold and 2.74-fold insecticidal activity enhancement toward Culex pipiens pallens and Mythimna separata larvae, respectively. p-AB4″AVM allows for optical regulation of dorsal unpaired median neuron membrane potential with a 2.15-fold fluorescence intensity decrease after illumination. p-AB4″AVM and p-AB5AVM enable optical modulation of the behavioral response of Culex pipiens pallens larvae with 1- and 4-fold reduced mobility upon irradiation, respectively. The ABAVMs could be used to reversibly manipulate GluCls with light and may be useful for the mechanistic study of macrocyclic lactone insecticides.


Assuntos
Culex , Inseticidas , Mariposas , Animais , Compostos Azo , Insetos , Inseticidas/farmacologia , Ivermectina/análogos & derivados , Larva
6.
PLoS One ; 16(12): e0260253, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34919572

RESUMO

Microbial synthesis of silver nanoparticles is more advantageous and is eco-friendly to combat the various vectors that cause diseases in humans. Hence, in the present study a Bacillus strain is isolated from marine habitat and is evaluated for its ability to synthesize silver nanoparticles (AgNPs) and its efficacy evaluated against the immature stages of selected mosquito species. The effective candidate was confirmed to be Bacillus marisflavi after 16S rRNA sequencing. The synthesis of AgNPs was confirmed by UV-Vis spectrophotometer. Atomic Force Microscopic (AFM) analysis showed spherical nanoparticles. Size analysis using Scanning Electron Microscope (SEM) showed particles of nano size averaging 78.77 nm. The diameter of the particles analyzed by Dynamic Light Scattering (DLS) showed 101.6 nm with a poly-dispersive index of 0.3. Finally the elemental nature of the nanoparticles was identified by Fourier-transform infrared spectroscopy (FTIR). LC50 and LC90 values for the ovicidal, larvicidal and pupicidal efficacy of the AgNPs against the egg, larvae and pupae of Aedes aegypti, Culex quinquefasciatus and Anopheles stephensi respectively were evaluated. The present study revealed that the nanoparticles have an excellent toxic effect against the disease transmitting vector mosquitoes. Hence, the rapid synthesis of AgNPs would be an appropriate eco-friendly tool for biocontrol of vector mosquitoes.


Assuntos
Aedes/efeitos dos fármacos , Anopheles/efeitos dos fármacos , Bacillus/química , Culex/efeitos dos fármacos , Inseticidas/farmacologia , Mosquitos Vetores/efeitos dos fármacos , Prata/farmacologia , Aedes/fisiologia , Animais , Anopheles/fisiologia , Organismos Aquáticos , Bacillus/genética , Bacillus/metabolismo , Culex/fisiologia , Química Verde , Concentração Inibidora 50 , Inseticidas/química , Larva/efeitos dos fármacos , Larva/fisiologia , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Controle de Mosquitos/métodos , Mosquitos Vetores/fisiologia , Tamanho da Partícula , Pupa/efeitos dos fármacos , Pupa/fisiologia , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Prata/química , Zigoto/efeitos dos fármacos , Zigoto/fisiologia
7.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 33(5): 510-512, 2021 Oct 25.
Artigo em Chinês | MEDLINE | ID: mdl-34791850

RESUMO

OBJECTIVE: To investigate the distribution and density of Culex mosquito populations and the resistance of Culex pipiens pallens to insecticides in Jiangsu Province in 2018 and 2019. METHODS: During the period from June to October in 2018 and 2019, six counties (districts, cities) were sampled in southern, northern and central Jiangsu Province as surveillance sites. The density of Culex mosquitoes was measured overnight using the light trapping technique. In addition, Culex pipiens pallens mosquitoes were collected from Hai'an of Nantong City and Yandu District of Yancheng City, central Jiangsu Province, and the sensitivity of female first filial generations to dichlorodiphenyltrichloroethane (DDT), malation, proposur, beta cypermethrin and deltamethrin was tested using the standard WHO insecticide susceptibility test assay. RESULTS: A total of 104 423 Culex mosquitoes were captured in six surveillance sites of Jiangsu Province in 2018 and 2019, and Culex quinquefasciatus (49.11%), Culex pipiens pallens (28.38%), and Culex tritaeniorhynchus (21.04%) were predominant species. The density of Culex mosquitoes started to increase since early June, peaked in July and tended to be low in late October. Culex pipiens pallens mosquitoes captured from Hai'an was susceptible to malation, while those from Yandu District were moderately resistant to malation. Culex pipiens pallens mosquitoes from both Yandu and Hai'an were moderately resistant to proposur, and were resistant to DDT, beta cypermethrin and deltamethrin. CONCLUSIONS: Culex quinquefasciatus, Culex pipiens pallens and Culex tritaeniorhynchus are predominant Culex species in Jiangsu Province. Culex pipiens pallens is resistant to DT, beta cypermethrin and deltamethrin in central Jiangsu Province.


Assuntos
Culex , Culicidae , Inseticidas , Piretrinas , Animais , Bioensaio , Feminino , Resistência a Inseticidas , Inseticidas/farmacologia , Piretrinas/farmacologia
8.
Indian J Med Res ; 154(1): 132-140, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34782539

RESUMO

Background & objectives: An infective stage specific reverse transcriptase-polymerase chain reaction (RT-PCR) assay utilizing the abundant larval transcript-3 (Alt-3) gene of Wuchereria bancrofti was developed at ICMR-VCRC, Puducherry and found to be stage specific, and sensitive upon validation in the laboratory. This study was aimed at independently evaluating this assay for its utility as a monitoring/surveillance tool in the operational programme for elimination of lymphatic filariasis (LF) by four national research laboratories. Methods: Evaluation of the assay was carried out in a multi-centric mode in three phases. In phase I, a workshop was conducted to impart hands-on training to the scientists from the collaborating centres on the RT-PCR assay and in Phase II the assay was evaluated for specificity and sensitivity in detecting the infective (L3) stage larvae of W. bancrofti in its vector, Culex quinquefasciatus, using 50 coded pooled samples. Phase III evaluation was done on wild-caught mosquito vectors from selected endemic areas of Assam and Bhubaneswar States and Andaman Nicobar islands. Results: Phase I data indicated that the assay was able to detect all the pools of mosquito samples contaning L3 stage larvae of W. bancrofti as positive, even in the presence of other vector stages of the parasite indicating its stage specificity (100%). The assay was found highly sensitive (100%), detecting all the infected pools as positive and specific detecting all uninfected pools as negative. The results of phase II showed inter-laboratory variation. Phase III evaluation from all the centres suggested that the infectivity rate determined for pooled mosquitoes by the RT-PCR assay (0.5%) was comparable to that by dissection method (1.2%) (95% confidence interval overlaps). Interpretation & conclusions: Overall, the results from three of the four participating centres indicated that the assay is at least as sensitive and stage specific as the conventional mosquito dissection technique, and hence, may be useful as a xenomonitoring tool for Transmission Assessment Survey in Mass Drug Administration programmes for LF.


Assuntos
Culex , Filariose Linfática , Animais , Filariose Linfática/diagnóstico , Filariose Linfática/epidemiologia , DNA Polimerase Dirigida por RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Wuchereria bancrofti/genética
9.
Zootaxa ; 5027(4): 515-545, 2021 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-34811156

RESUMO

An updated checklist of the mosquitoes (Diptera: Culicidae) of Algeria based on records published from 1903 to 2021 is presented. Fifty-three species belonging to seven genera are known with reasonable confidence to occur in the country, including Aedes (15 species), Anopheles (15), Coquillettidia (2), Culex (14), Culiseta (5), Orthopodomyia (1) and Uranotaenia (1). Two additional species, Culex simpsoni Theobald, 1905 and Uranotaenia balfouri Theobald, 1904, are provisionally regarded as present in Algeria. Published records are listed for each species, with indication of synonymous usage and variant spelling of names where applicable. The type locality of Aedes biskraensis Brunhes, 1999 is restricted to Seriana in Sidi Okba District in Biskra Province. Problematic species and doubtful occurrence records based on apparently misidentified specimens and confused taxonomy are discussed. Notes on taxonomy and medical importance are provided for the more important species.


Assuntos
Aedes , Anopheles , Culex , Argélia , Animais , Idioma
10.
Epidemiol Prev ; 45(5): 401-410, 2021.
Artigo em Italiano | MEDLINE | ID: mdl-34738457

RESUMO

The relevant ecological changes due to the anthropological pressure on the planet is causing reactions in the biological systems, which we must understand and characterize at the local scale to assist the adoption of suitable decisions in the public health risk management. The project presented in this paper is focused on the vector-borne diseases, mainly transmitted by mosquitoes. The species of mosquito currently playing an active role of public health importance in Italy are Aedes albopictus, as a vector of Chikungunya, Dengue and Zika viruses, as well as Culex pipiens, as a vector of West Nile and Usutu viruses. Predictive models are indicating the risk of introduction and establishment in the Mediterranean basin of Aedes aegypti, which is causing a mayor concern. The project has been conducted by the Emilia-Romagna, Piemonte, Veneto, Marche and Sicilia Regions, together with the Italian National Health Institute. The aim was to develop and pilot testing new approaches and technological tools possibly assisting the public health system in the management of the risk. The activities have been organized on six specific objectives: 1. Development and field testing of guidelines for the surveillance of invasive mosquito species; 2. Creation of risk maps for Chikungunya, Dengue and Zika viruses based on the quantitative monitoring of Aedes albopictus populations; 3. Shaping web platform models assisting the sharing of data from/to actors involved in the integrated surveillance of West Nile at the regional level; 4. Developing communication formats dealing with vector borne diseases addressing citizen and specific categories; 5. Approaching the cost-benefit analysis in the view to assist decision makers; 6. Sero-surveillance on arboviruses not included in the Ministry directive (Tick Borne Encephalitis and Toscana virus). The achieved results are presented and the acquired experience is made available to promote the adoptions on a larger scale of the approaches and methods to be certainly adapted in the specific contexts. The one health approach seems suitable to address the necessities emerging in this field by taking into consideration the different triggers shaping the dynamics we are observing.


Assuntos
Aedes , Febre de Chikungunya , Culex , Dengue , Infecção por Zika virus , Zika virus , Animais , Febre de Chikungunya/epidemiologia , Febre de Chikungunya/prevenção & controle , Dengue/epidemiologia , Dengue/prevenção & controle , Humanos , Itália/epidemiologia , Mosquitos Vetores , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/prevenção & controle
11.
J Insect Sci ; 21(5)2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34605546

RESUMO

To evaluate whether the presence of clear incandescent light was attractive or refractive to host-seeking mosquitoes in northern Colorado, a Bayesian hierarchical model was created to measure differences in trap effectiveness based on presence or absence of phototactic cues. A total of eight CDC miniature light traps (with and without light) were set weekly across four locations in northern Colorado between Weeks 23 and 32 of year 2020. Culex mosquitoes (Diptera: Culicidae) accounted for 81% of all collections in this study with two vectors of West Nile virus being represented. The probability of catching both Culex tarsalis Coquillett and Culex pipiens Linnaeus was reduced when traps were equipped with light, but the difference was not statistically significant for Culex tarsalis. The clear reduction in the number of Culex pipiens caught when these traps were equipped with light indicates negative phototactic behavior and underestimation with current surveillance strategies. Removal of light from these traps may aid our understanding of these species' distribution within the environment, improve collection efficiency, and help guide implementation of targeted control measures used in public health mosquito control.


Assuntos
Culex , Controle de Mosquitos/métodos , Animais , Colorado , Mosquitos Vetores , Estados Unidos , Febre do Nilo Ocidental/transmissão
12.
Artigo em Inglês | MEDLINE | ID: mdl-34639837

RESUMO

Currently, medical and stored grain pests are major concerns of public health and economies worldwide. The synthetic pesticides cause several side effects to human and non-target organisms. Copper nanoparticles (CuNPs) were synthesized from an aqueous extract of Metarhizium robertsii and screened for insecticidal activity against Anopheles stephensi, Aedes aegypti, Culex quinquefasciatus, Tenebrio molitor and other non-target organisms such as Artemia salina, Artemia nauplii, Eudrilus eugeniae and Eudrilus andrei. The synthesized copper nano-particles were characterized using, UV-vis spectrophotometer, Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Energy Dispersive X-Ray analysis (EDaX), High Resolution Scanning Electron Microscope (HR-SEM) and Atomic Force Microscope (AFM) analysis. Insects were exposed to 25 µg/mL concentration produced significant mortality against larvae of A. stephensi, A. aegypti, C. quinquefasciatus and T. molitor. The lower toxicity was observed on non-target organisms. Results showed that, M. robertsii mediated synthesized CuNPs is highly toxic to targeted pests while they had lower toxicity were observed on non-target organisms.


Assuntos
Aedes , Culex , Inseticidas , Nanopartículas Metálicas , Praguicidas , Animais , Cobre/toxicidade , Humanos , Inseticidas/toxicidade , Larva , Nanopartículas Metálicas/toxicidade , Metarhizium , Extratos Vegetais , Folhas de Planta , Prata
13.
Braz J Biol ; 83: e240842, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34550279

RESUMO

This research aimed to investigate various mosquitocidal activities of Chenopodium botrys whole- plant n-hexane extract against Culex quinquefasciatus. The extract showed remarkable larvicidal, pupicidal, adulticidal, oviposition deterrent and adult emergence inhibitory activities against Cx. quinquefasciatus. During the larvicidal and pupicidal activities, the 24-hour lethal concentration (LC50) of extract against 2nd instar larvae, 4th instar larvae and pupae were 324.6, 495.6 and 950.8 ppm, respectively. During the CDC (Centers for Disease Control and Prevention) bottle bioassay for adulticidal activity, the median knockdown times (KDT50) at 1.25% concentration was 123.4 minutes. During the filter paper impregnation bioassay for adulticidal activity, the KDT50 value at 0.138 mg/cm2 concentration was 48.6 minutes. The extract was fractionated into 14 fractions through silica gel column chromatography which were then combined into six fractions on the basis of similar retention factor (Rf) value. These fractions were screened for adulticidal activity by applying CDC bottle bioassay. The fraction obtained through 60:40 to 50:50% n-hexanes-chloroform mobile phase with 0.5 Rf value showed 100% adulticidal activity at 0.2% concentration. During oviposition deterrent activity, the highest concentration (1000 ppm) showed 71.3 ± 4.4% effective repellence and 0.6 ± 0.1 oviposition activity index. During adult emergence inhibition activity, the median emergence inhibition (EI50) value was 312.3 ppm. From the outcome of the present investigation, it is concluded that the n-hexane extract of C. botrys whole- plant possesses strong larvicidal, pupicidal, adulticidal, oviposition deterrent and adult emergence inhibitory activities against Cx. quinquefasciatus.


Assuntos
Chenopodium , Culex , Inseticidas , Animais , Hexanos , Inseticidas/farmacologia , Larva , Extratos Vegetais/farmacologia , Folhas de Planta
14.
Sci Rep ; 11(1): 17474, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34471175

RESUMO

Emergence of vector borne diseases has continued to take toll on millions of lives since its inception. The use of insecticides began as vector control strategy in the early 1900's but the menace of insects is still prevalent. Additionally, the inadequate use of organophosphates and carbamates which target acetylcholine esterase (AChE), are known to develop resistance amongst vectors of transmission and are toxic to humans. In this study, extensive computational screening was performed using homology modelling, molecular docking, molecular dynamics (MD) simulation and free energy change calculation, which highlighted curcumin as a lead molecule out of ~ 1700 phytochemicals against Culex pipiens AChE. In vivo larvicidal activity was carried out along with in vivo and in vitro AChE inhibition assay to determine the biochemical efficacy of curcumin. Our study reveals that curcumin induces mortality in Cx. pipiens at an early stage of its life cycle by AChE inhibition. This also underlines the use of curcumin as a coming-age natural product insecticide.


Assuntos
Acetilcolina/metabolismo , Acetilcolinesterase/química , Inibidores da Colinesterase/farmacologia , Culex/enzimologia , Curcumina/farmacologia , Sequência de Aminoácidos , Animais , Simulação de Acoplamento Molecular , Conformação Proteica , Homologia de Sequência
15.
J Am Mosq Control Assoc ; 37(3): 179-181, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34407164

RESUMO

Over the course of 2019 and 2020, 7 larvicide formulations for use in catch basins were evaluated using a standardized pass/fail protocol. A comparison between 1- and 2-pouch doses of VectoLex® water-soluble pouches (WSP; 10 g per pouch) and 20 g of VectoLex FG (loose granules) suggests that the WSP formulation may have a shorter duration than the FG formulation. Results also suggest that 20 g doses of each of 2 larvicides, Duplex™-G and Sumilarv® 0.5G, may have a minimum effective duration in basins for approximately 40 days. A 20 g dose of Altosid® XR-G and a single briquet Altosid XR each had an observed minimum effective duration of 20 days. Sustain MBG had an observed duration of only 7 wk posttreatment. These observations provide evidence that, in some locations, 20 g granular applications may have a longer effective duration than a single briquet. This work highlights the utility of applying a standardized protocol for routine quality control assessments of the thousands of catch basin larvicide applications performed seasonally by mosquito abatement districts.


Assuntos
Culex , Inseticidas , Animais , Illinois , Larva , Controle de Mosquitos
16.
J Am Mosq Control Assoc ; 37(3): 132-142, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34407172

RESUMO

Mosquito surveillance is the cornerstone for determining abundance, species diversity, pathogen infection rates, and temporal and spatial distribution of different life stages in an area. Various methods are available for assessing adult mosquito populations, including mechanical trap devices using different forms of attractant cues (chemical and visual) to lure mosquitoes to the trap. So-called "light traps" use various electromagnetic wavelengths to produce a variety of visible spectral colors to attract adult mosquitoes. However, this type of trapping technology has not been widely used in Thailand. This study compared the efficacy of 4 light-emitting diodes (LEDs) (blue, green, yellow, and red) and 2 fluorescent (ultraviolet [UV] and white) lights for collecting mosquitoes in urban Bangkok. Using a Latin square experimental design, 6 light traps equipped with different lights were rotated between 6 trap site locations within the Kasetsart University (KU) campus. Each location received 6 replicate collections (6 consecutive trap-nights represented 1 replicate) over 36 collection nights for a total of 216 trap-nights. Traps were operated simultaneously (1800 to 0600 h), with captured mosquitoes removed at 3-h intervals. In total, 2,387 mosquitoes consisting of 11 species across 5 genera (Aedes, Anopheles, Armigeres, Culex, and Mansonia) were captured. Collectively, Culex species represented the predominant group sampled (2,252; 94.4%). The UV light source captured 1,544 (64.7%) of the total mosquitoes collected, followed by white 389 (16.3%), with the 4 LED sources collecting between 6.8% (blue) and 1.9% (yellow). Traps equipped with UV light were clearly the most effective for capturing nocturnally active mosquito species on the KU campus.


Assuntos
Aedes , Anopheles , Culex , Animais , Humanos , Luz , Controle de Mosquitos , Tailândia
17.
Parasitol Res ; 120(9): 3083-3090, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34338859

RESUMO

Mosquitoes (Diptera: Culicidae) are the largest group of blood-feeding insects that disturb not only humans but also other mammals and birds. This study reports the presence of native mosquito species in the regional unit of Thessaloniki and the monitoring of their population. In total, 13 mosquito species belonging to four genera were identified. The most dominant species was Culex pipiens, followed by Aedes caspius. In the present study, we report for the first time the presence of Ae. vittatus in Greece and of Anopheles plumbeus in the regional unit of Thessaloniki. Regarding the seasonal variation, species of the genus Aedes were the ones that first appeared in late March, followed by Culex species at the end of April and finally species of the genus Anopheles in July. Species of the Aedes genus were found to be the most abundant in the first quarter of the year (late March to early April). Population of Cx. pipiens remained at high levels from late April to late September. Species of the genus Anopheles were found in high densities from early August to October. The current study contributes to the knowledge of the mosquito species composition and their relative abundance in an area where West Nile virus caused severe epidemic outbreaks.


Assuntos
Aedes , Culex , Animais , Grécia , Mosquitos Vetores , Saúde Pública , Estações do Ano
18.
Parasite ; 28: 60, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34374642

RESUMO

Between 2016 and 2020, the Medical and Veterinary Entomology unit of the Institut Pasteur du Cambodge collected over 230,000 mosquitoes. Based on this sampling effort, a checklist of 290 mosquito species in Cambodia is presented. This is the first attempt to list the Culicidae fauna of the country. We report 49 species for the first time in Cambodia. The 290 species belong to 20 genera: Aedeomyia (1 sp.), Aedes (55 spp.), Anopheles (53 spp.), Armigeres (26 spp.), Coquillettidia (3 spp.), Culex (57 spp.), Culiseta (1 sp.), Ficalbia (1 sp.), Heizmannia (10 spp.), Hodgesia (3 spp.), Lutzia (3 spp.), Malaya (2 spp.), Mansonia (5 spp.), Mimomyia (7 spp.), Orthopodomyia (3 spp.), Topomyia (4 spp.), Toxorhynchites (4 spp.), Tripteroides (6 spp.), Uranotaenia (27 spp.), and Verrallina (19 spp.). The Cambodian Culicidae fauna is discussed in its Southeast Asian context. Forty-three species are reported to be of medical importance, and are involved in the transmission of pathogens.


Assuntos
Aedes , Culex , Culicidae , Animais , Camboja , Lista de Checagem , Mosquitos Vetores
19.
Pest Manag Sci ; 77(12): 5599-5607, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34402165

RESUMO

BACKGROUND: Harnessing insect ecology for insect control is an innovative concept that seeks to exploit, among others, insect-microbe ecological interactions for improved control of pest insects. Microbe-produced cheese odour attracts several dipterans, including host-seeking mosquitoes, but this phenomenon has not been thoroughly explored for mosquito control. Here we tested the hypothesis that attraction of mosquitoes to cheese odour can be exploited as an ecological trap for mosquito control. RESULTS: In laboratory and/or field experiments, we show that (i) each of five cheese varieties tested (Raclette, Pecorino, Brie, Gruyere, Limburger) strongly attracts female Aedes aegypti and Culex pipiens; (ii) cheese infusions, or headspace odourant extracts (HOEs) of cheese infusions, significantly affect oviposition choices by mosquitoes, (iii) HOEs contain at least 13 odourants; (iv) in field settings, cheese infusions more effectively stimulate mosquito oviposition than positive bluegrass infusion controls, and also capture (by drowning) the spotted wing Drosophila, Drosophila suzukii; and (v) home-made cheese infusions modulate oviposition choices by mosquito females and affect the survivorship of their offspring larvae. CONCLUSION: Our data show that microbial metabolites associated with cheese are attractive to mosquito females seeking hosts and oviposition sites and are likely toxic to mosquito larvae. These microbes and their metabolites could thus be co-opted for both the attract, and the kill, function of 'attract & kill' mosquito control tactics. Implementation of customizable and non-conventional nutritional media as microbe-based ecological traps presents a promising concept which exploits insect ecology for insect control. © 2021 Society of Chemical Industry.


Assuntos
Aedes , Queijo , Culex , Animais , Drosophila , Feminino , Controle de Mosquitos , Oviposição
20.
J Insect Physiol ; 134: 104295, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34411585

RESUMO

The mosquito microbiome is critical to multiple facets of their biology, including larval development and disease transmission. For mosquitoes that reside in temperate regions, periods of diapause are critical to overwintering survival, but how the microbiome impacts this state is unknown. In this study, we compared the midgut microbial communities of diapausing and non-diapausing Culex pipiens and assessed how a reduced midgut microbiome influences diapause preparation. High community variability was found within and between non-diapausing and diapausing individuals, but no specific diapause-based microbiome was noted. Emergence of adult, diapausing mosquitoes under sterile conditions generated low bacterial load (LBL) lines with nearly a 1000-fold reduction in bacteria levels. This reduction in bacterial content resulted in significantly lower survival of diapausing females after two weeks, indicating acquisition of the microbiome in adult females is critical for survival throughout diapause. LBL diapausing females had high carbohydrate levels, but did not accumulate lipid reserves, suggesting an inability to process ingested sugars necessary for diapause-associated lipid accumulation. Expression patterns of select genes associated with mosquito lipid metabolism during diapause showed no significant differences between LBL and control lines, suggesting transcriptional changes may not underlie impaired lipid accumulation. Overall, a diverse, adult-acquired microbiome is critical for diapause in C. pipiens to process sugar reserves and accumulate lipids that are necessary to survive prolonged overwintering.


Assuntos
Culex/microbiologia , Diapausa de Inseto , Metabolismo dos Lipídeos , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Metabolismo dos Carboidratos , Culex/metabolismo , Culex/fisiologia , Feminino , Genes Bacterianos , Sequenciamento de Nucleotídeos em Larga Escala , Interações entre Hospedeiro e Microrganismos , Proteínas de Insetos/metabolismo , Metagenômica/métodos , Microbiota , RNA Ribossômico 16S , Reação em Cadeia da Polimerase em Tempo Real/métodos
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