Introduction: A recent study in Kenya highlighted a promising advance in malaria control by demonstrating that infecting mosquitoes with the endosymbiont Microsporidia MB blocks Plasmodium transmission. However, the i...Introduction: A recent study in Kenya highlighted a promising advance in malaria control by demonstrating that infecting mosquitoes with the endosymbiont Microsporidia MB blocks Plasmodium transmission. However, the influence of biotic and abiotic factors such as diet, relative humidity (RH) and temperature on this infection remains poorly studied. This study, aimed to gain a better understanding of this relationship. Methods: To highlight the influence of diet quantity, we defined a range of 3 quantities: 0.00375 g, 0.015 g and 0.09 g. Each quantity was tested on two groups of larvae: a group of 150 larvae infected with Microsporidia MB (MB+), and a group of 150 larvae not infected with Microsporidia MB (MB−) (control group), each divided into three replicates of 50 larvae. Each replicate was fed each morning with the assigned quantity until the pupal stage. In addition to this factor, we investigated the influence of temperature and RH. We defined three temperature-RH combinations: 21˚C-80% RH, 39˚C-50% RH, and 27˚C-75% RH. Each combination was tested on two groups of larvae: a group of 150 MB+ larvae and a group of 150 MB− larvae, each divided into three replicates of 50 larvae. Each replicate was subjected to the assigned combination until pupation. Pupae that had reached the adult stage were tested by PCR to determine their Microsporidia MB infection status for each factor studied. Results: The results showed that only the lowest quantity (0.00375 g) significantly reduced the prevalence of Microsporidia MB compared with the medium quantity (chi-2 test, χ2 = 4.9088, df = 1, p = 0.02672) and the high quantity (chi-2 test, χ2 = 4.7958, df = 1, p = 0.02853). As for temperature and RH, the combination 39˚C-50% RH led to a significant reduction in the prevalence of Microsporidia MB compared with the combination 27˚C-75% RH (chi-2 test, χ2 = 6.3736, ddl = 1, p = 0.01158) and that 21˚C-80% RH (chi-2 test, χ2 = 9.983, ddl = 1, p = 0.00158). Conclusion: This work contributes to a better understanding of some key factors linked to Microsporidia MB infection in mosquitoes. However, further research on several generations is necessary to draw more comprehensive conclusions.展开更多
Objective:To investigate the prevalence,mechanisms,and trends of knockdown resistance(kdr)in Anopheles(An.)culicifacies and its impact on the efficacy of organochlorine and other insecticides.Methods:A systematic revi...Objective:To investigate the prevalence,mechanisms,and trends of knockdown resistance(kdr)in Anopheles(An.)culicifacies and its impact on the efficacy of organochlorine and other insecticides.Methods:A systematic review was conducted based on PRISMA guidelines,extracting data from biooan.org,Embase,ProQuest,PubMed,Scopus,and Web of Science without a time limit until the end of 2022.Articles meeting the inclusion criteria were assessed using the STROBE checklist.Data on kdr mutations,insecticide resistance,and effectiveness were analyzed across eight selected studies from various regions.Results:The review revealed widespread kdr-mediated resistance in An.culicifacies,primarily against dichloro-diphenyl-trichloroethane(DDT),persisting even decades after discontinued use.Key kdr mutations,including L1014F and L1014S,were identified.Resistance to deltamethrin was less stable,with increased sensitivity observed after short-term discontinuation.The findings underscore the vector's sustained resistance to organochlorine insecticides and relative sensitivity to pyrethroids.Conclusions:Stable kdr resistance in An.culicifacies to organochlorine insecticides highlights the need for periodic susceptibility assessments and strategic rotation or combination of insecticides to combat malaria effectively and prevent the development of resistance.展开更多
Anopheles(An.)stephensi is one of the dominant malaria vectors in India,Bangladesh,Pakistan,Iran,Iraq and some other Asian countries[1].It plays a crucial role in transmitting Plasmodium falciparum and Plasmodium viva...Anopheles(An.)stephensi is one of the dominant malaria vectors in India,Bangladesh,Pakistan,Iran,Iraq and some other Asian countries[1].It plays a crucial role in transmitting Plasmodium falciparum and Plasmodium vivax in India along with its rural counterpart,An.culicifacies.This mosquito species has adapted well to urban and peri-urban environments,making it a significant public health concern in the country.The presence of An.stephensi in urban areas contrasts with other malaria vectors that predominantly inhabit rural regions,thus complicating traditional malaria control strategies.It is well-adapted to human-made environments,breeding in various containers including tanks,cisterns,and barrels used for water storage.展开更多
Objective:To evaluate the larvicidal and pupicidal potential of the methanolic extracts from Moringa oleifera(M.oleifera) plant seeds against malarial vector Anopheles stephensi(A.stephensi) mosquitoes at different co...Objective:To evaluate the larvicidal and pupicidal potential of the methanolic extracts from Moringa oleifera(M.oleifera) plant seeds against malarial vector Anopheles stephensi(A.stephensi) mosquitoes at different concentrations(20,40,60,80 and 100 ppm).Methods:M.oleifera was collected from the area of around Bharathiar University,Coimbatore.The dried plant materials were powdered by an electrical blender.From each sample,100 g of the plant material were extracted with 300 mL of methanol for 8 h in a Soxhlet apparatus.The extracts were evaporated to dryness in rotary vacuum evaporator to yield 122 mg and 110 mg of dark greenish material(residue) from Arcang amara and Ocimum basilicum,respectively.One gram of the each plant residue was dissolved separately in 100 mL of acetone(stock solution) from which different concentrations, i.e.,20,40,60,80 and 100 ppm were prepared.Results:Larvicidal activity of M.oleifera exhibited in the first to fourth instar larvae of the A.stephensi,and the LC_(50) and LC_(90) values were 57.79 ppm and 125.93 ppm for the first instar,63.90 ppm and 133.07 ppm for the second inslar,72.45 ppm and 139.82 ppm for the third instar,78.93 ppm and 143.20 ppm for the fourth instar,respectively. During the pupal stage the methanolic extract of M.oleifera showed that the LC_(50),and LC_(90) values were 67.77 ppm and 141.00 ppm,respectively.Conclusions:The present study indicates that the phytochemicals derived from M.oleifera seeds extracts are effective mosquito vector control agents and the plant extracts may be used for further integrated pest management programs.展开更多
Objective:To determine the ovicidal and repellent activities of methanol leaf extract of Ervatamia coronaria(E.coronaria) and Caeslpinia pulckerrima(C.pulcherrima) against Culex quinquefasciatus(Cx.quinquefasciatus),A...Objective:To determine the ovicidal and repellent activities of methanol leaf extract of Ervatamia coronaria(E.coronaria) and Caeslpinia pulckerrima(C.pulcherrima) against Culex quinquefasciatus(Cx.quinquefasciatus),Aedes aegypti(Ae.aegypti) and Anopheles stephensi(An. stephensi).Methods:The ovicidal activity was determined against three mosquito species at various concentrations ranging from 50-450 ppm under the laboratory conditions.The hatch rates were assessed 48 h after treatment.The repellent efficacy was determined against three mosquito species at three concentrations viz.,1.0,2.5 and 5.0 mg/cm under the laboratory conditions. Results:The crude extract of E.coronaria exerted zero hatchability(100%mortality) at 250.200 and 150 ppm for Cx.quinqitefasciatus,Ae.aegypti and An.stephensi,respectively.The crude extract of C.pulchenima exerted zero hatchability(100%mortality) at 375.300 and 225 ppm for Cx.quinquefasciatus,Ae.aegypti and An.Stephensi,respectively.The methanol extract of E. coronaria found to be more repellenct than C.pukherrima extract.A higher concentration of 5.0 mg/cm^2 provided 100%protection up to 150.180 and 210 min against Cx.quinquefasciatus,Ae. aegypti and An.stephensi,respectively.The results clearly showed that repellent activity was dose dependent.Conclusions:From the results it can be concluded the crude extracts of E.coronaria and C.pukherrima are an excellent potential for controlling Cx.quinquefasciatus,Ae.aegypti and An.stephensi mosquitoes.展开更多
Anopheles sinensis and An. anihropophagus are two morphologically indistinguishable yet genetically and behaviorally distinct mosquito species that vary dramatically in their importance as vectors of malaria inChina. ...Anopheles sinensis and An. anihropophagus are two morphologically indistinguishable yet genetically and behaviorally distinct mosquito species that vary dramatically in their importance as vectors of malaria inChina. The sequence of the ribosomal DNA internal transcribed spacer 2 (ITS2) was determined for bothspecies to assess the species differentiation. The lengths of ITS2 was 468 hp for An. sinensis and 452 hp forAn. anthropophagus. Interspecies difference in sequence was 28. 8%. Intraspecies sequence divergence wasnegligible. A PCR method was developed for distinguishing the two species based on the species-specific variations of the ITS2 sequences. The method would amplify a diagnostic fragment in length of 425 hp for An.sinensis and 253 hp for An. anthropophagus. Field collections from 12 localities in 10 provinces of China weretested. In 440 mosquitoes identified by adult morphological characteristics as An. sinensis, 291 (66. 2 % ) wereidentified later as An. sinensis and 56 (12. 7 % ) as An. anthropophagus, the remaining 93 (22. 1 % ) were notamplified by PCR. The results showed that the morphological characteritics of adult was not reliable for fieldidentification. The PCR assay was a simple, fast and reliable method for species identification.展开更多
Objective:To determine the susceptibility of main malaria vector in Astra County,borderline of Iran and Republic of Azerbaijan for better control.Methods:Susceptibility of Anopheles mactdipennis to diagnostic doses of...Objective:To determine the susceptibility of main malaria vector in Astra County,borderline of Iran and Republic of Azerbaijan for better control.Methods:Susceptibility of Anopheles mactdipennis to diagnostic doses of DDT 4% ,dieldrin 0.4% ,malathion 5% ,lambdacyhalothrin 0.1% ,and delamethrin 0.025% ,was tested according to method recommended by WHO.All the impregnated papers were provided by WHO.Results:It was shown that this species exhibited resistance to DDT,dieldrin,whereas susceptible to malathrion,lambdacyhalothrin and deltamethrin.Conclusions:Findings of susceptibility tests of this species provided a clue for control of malaria vector in the region.展开更多
ObjectiveTo determine the adulticidal and repellent activities of different solvent leaf extracts of Eclipta alba (E. alba) and Andrographis paniculata (A. paniculata) against malarial vector, Anopheles stephensi (An....ObjectiveTo determine the adulticidal and repellent activities of different solvent leaf extracts of Eclipta alba (E. alba) and Andrographis paniculata (A. paniculata) against malarial vector, Anopheles stephensi (An. stephensi).MethodsAdulticidal efficacy of the crude leaf extracts of E. alba and A. paniculata with five different solvents like benzene, hexane, ethyl acetate, methanol and chloroform was tested against the five to six day old adult female mosquitoes of An. stephensi. The adult mortality was observed after 24 h under the laboratory conditions. The repellent efficacy was determined against An. stephensi mosquito species at three concentrations viz., 1.0, 2.5 and 5.0 mg/cm2 under laboratory conditions.ResultsAmong the tested solvents the maximum efficacy was observed in the methanol extract. The LC50 and LC90 values of E. alba and A. paniculata against adults of An. stephensi were 150.36, 130.19 ppm and 285.22, 244.16 ppm, respectively. No mortality was observed in controls. The chi-square values were significant at P<0.05 level. Methanol extract of E. alba and A. paniculata was produce maximum repellency against An. stephensi.ConclusionsFrom the results it can be concluded the crude extract of E. alba and A. paniculata was an excellent potential for controlling An. stephensi mosquitoes.展开更多
Zika virus(ZIKV)has been isolated from mosquitoes such as Aedes,Mansonia uniformis,and Culex perfuscus;However,the isolation of ZIKV from Anopheles sinensis and Culex tritaeniorhynchus has not yet been reported.In Jun...Zika virus(ZIKV)has been isolated from mosquitoes such as Aedes,Mansonia uniformis,and Culex perfuscus;However,the isolation of ZIKV from Anopheles sinensis and Culex tritaeniorhynchus has not yet been reported.In June and July2018,22,985 mosquitoes and 57,500 midges were collected in Jiangxi Province in southeastern China.Among them,six strains of ZIKV were isolated from mosquitoes:four from An.sinensis and two from Cx.tritaeniorhynchus.Molecular genetic analysis showed that the ZIKV isolated from An.sinensis and Cx.tritaeniorhynchus belonged to genotype 2 in the Asian evolutionary branch of ZIKV.In addition,the ZIKV strains isolated from An.sinensis and Cx.tritaeniorhynchus had amino acid substitutions identical to ZIKV strains prevalent in South America since 2015.This study is the first to isolate ZIKV from mosquito specimens collected in the wild of Jiangxi Province,China;This is also the first time that ZIKV has been isolated from An.sinensis and Cx.tritaeniorhynchus.Given that An.sinensis and Cx.tritaeniorhynchus have a very wide geographical distribution in China and even in eastern and southern Asia,the isolation of several strains of ZIKV from these two mosquitoes poses new challenges for the prevention and control of ZIKV infection in the mainland of China and countries and regions with the same distribution of mosquitoes.展开更多
Objective:To identify the biological forms,sporozoite rate and molecular characterization of the Anopheles stephensi(An.stephensi)in Hormozgan and Sistan-Baluchistan provinces,the most important malarious areas in Ira...Objective:To identify the biological forms,sporozoite rate and molecular characterization of the Anopheles stephensi(An.stephensi)in Hormozgan and Sistan-Baluchistan provinces,the most important malarious areas in Iran.Methods:Wild live An.stephensi samples were collected from different malarious areas in southern Iran.The biological forms were identified based on number of egg-ridges.Molecular characterization of biological forms was verified by analysis of the mitochondrial cytochrome oxidase subunit I and II(mtDNA-COI/COII).The Plasmodium infection was examined in the wild female specimens by species-specific nested-PCR method.Results:Results showed that all three biological forms including mysorensis,intermediate and type are present in the study areas.Molecular investigations revealed no genetic variation between mtDNA COI/COII sequences of the biological forms and no Plasmodium parasites was detected in the collected mosquito samples.Conclusions:Presence of three biological forms with identical sequences showed that the known biological forms belong to a single taxon and the various vectorial capacities reported for these forms are more likely corresponded to other epidemiological factors than to the morphotype of the populations.Lack of malaria parasite infection in An,stephensi,the most important vector of malaria,may be partly due to the success and achievement of ongoing active malaria control program in the region.展开更多
Objective:To explore the larvicidal and pupicidal activity of Euphorbia hirta（E.hirta） leaf extract and Bacillus sphaericus（B.sphaericus） against the malarial vector.Anopheles siephensi（An. stephensi）.Methods:Th...Objective:To explore the larvicidal and pupicidal activity of Euphorbia hirta（E.hirta） leaf extract and Bacillus sphaericus（B.sphaericus） against the malarial vector.Anopheles siephensi（An. stephensi）.Methods:The larvicidal and pupicidal activity was assayed against An.stephensi at various concentrations ranging from（75-375 ppm） under the laboratory as well as field conditions. The LC<sub>50</sub> and LC<sub>90</sub> value of the E.hirta leaf extract was determined by probit analysis.Results: The plant extract showed larvicidal effects after 24 h of exposure;however,the highest larval mortality was found in the methanol extract of E.hirta against the first to fourth instars larvae and pupae of values LC<sub>50</sub>=137.40,172.65,217.81,269.37 and 332.39 ppm;B.sphaericus against the first to fourth instars larvae and pupae of values LC<sub>50</sub>= 44.29,55.83,68.51,82.19 and 95.55 ppm, respectively.Moreover,combined treatment of values of LC<sub>50</sub>= 79.13,80.42,86.01,93.00 and 98.12 ppm,respectively.No mortality was observed in the control.Conclusions:These results suggest methanol leaf extracts of E.hirta and B.sphaericus have potential to be used as an ideal ecofriendly approach for the control of the malarial vector.An.stephensi as target species of vector control programs.This study provides the first report on the combined mosquito larvicidal and pupicidal activity of this plant crude extract and bacterial toxin against An.stephensi mosquitoes.展开更多
Objective: To investigate the larvicidal and pupicidal activities of aqueous, ethyl acetate and methanol extracts of Catharanthus roseus ( C. roseus ) against malaria and filariasis vectors. Methods: The larvicidal an...Objective: To investigate the larvicidal and pupicidal activities of aqueous, ethyl acetate and methanol extracts of Catharanthus roseus ( C. roseus ) against malaria and filariasis vectors. Methods: The larvicidal and pupicidal activities of C. roseus leaf extracts were tested against the fourth instar larvae and pupae of Anopheles stephensi ( An. stephensi ) and Culex quinquefasciatus ( Cx. quinquefasciatus ). The mortality was observed after 24 and 48 h post the treatment. The data were subjected to probit analysis to determine the lethal concentrations (LC 50 and LC 90 ) at which 50% and 90% of the treated larvae or pupae of the tested species were killed. Results: The larval and pupal mortality were observed after 24 and 48 h of exposure of aqueous, ethyl acetate and methanol extracts of C. roseus ; no mortality was observed in the control group. The LC 50 values against the fourth-instar larvae of An. stephensi were 68.62 and 72.04 mg/mL for the aqueous extract, 82.47 mg/mL for the ethyl acetate extract, and 78.80 and 86.64 mg/mL for the methanol extract, while the aqueous, ethyl acetate and methanol extracts had LC 50 values of 85.21, 76.84 and 94.20 mg/mL against the fourth-instar larvae of Cx. quinquefasciatus . The aqueous, ethyl acetate and methanol extracts had LC 50 values of 118.08, 182.47 and 143.80 mg/mL against the pupae of An. stephensi and 146.20, 226.84 and 156.62 mg/mL against the pupae of Cx. quinquefasciatus , respectively. Conclusions: The aqueous and methanol extracts of C. roseus leaves had an excellent potential to control the malarial vector An. stephensi and filariasis vector Cx. quinquefasciatus .展开更多
Objective:To determine the larvicidal efficacy of different solvent leaf extract of Ficus benghalensis（F.benghalensis） against Culex tritaeniorhynchus（Cx.tritaeniorhynchus） and Anopheles subpictus（An.subpictus）....Objective:To determine the larvicidal efficacy of different solvent leaf extract of Ficus benghalensis（F.benghalensis） against Culex tritaeniorhynchus（Cx.tritaeniorhynchus） and Anopheles subpictus（An.subpictus）.Methods:Twenty five early third instar larvae of Cx. tritaeniorhynchus and An.subpictus were exposed to various concentrations and were assayed in the laboratory by using the protocol of WHO 2005.The larval mortality was observed after 24 h of treatment.Results:Among three solvent extracts tested the maximum efficacy was observed in the methanol extract.The LC<sub>50</sub> and LC<sub>90</sub> values of F.benghalensis against early third instar of Cx. tritaeniorhynchus and An.subpictus were 100.88.159.76 ppm and 56.66.85.84 ppm.respectively. No mortality was observed in controls.The chi-square values were significant at P【0.05 level. Conclusions:From the results it can be concluded the crude extract of F.benghalensis was an excellent potential for controlling Cx.tritaeniorhynchus and Art.subpictus mosquito larvae.展开更多
【Aim】The objective of this study is to characterize eight digestive carboxypeptidase genes in Anopheles sinensis,and to analyze their expression patterns before and post blood meal feeding.【Methods】The characteris...【Aim】The objective of this study is to characterize eight digestive carboxypeptidase genes in Anopheles sinensis,and to analyze their expression patterns before and post blood meal feeding.【Methods】The characteristics of eight digestive carboxypeptidase genes of An.sinensis were analyzed using bioinformatics methods,and their expression levels in different tissues at different developmental stages and in the midguts of female adults at different time points post blood meal feeding(PBM)were compared by semi-quantitative reverse transcription PCR and quantitative realtime PCR(qRT-PCR),respectively.【Results】Bioinformatics analysis indicated that of the eight carboxypeptidase genes,six genes encode carboxypeptidases A(AsCPA-I-AsCPA-VI)and two encode carboxypeptidases B(AsCPB-I and AsCPB-II).The expression of AsCPA-V was only detected in midguts and carcasses(whole mosquitoes minus midgut)of the 4th instar larvae,suggesting that it might have specific expression in larvae,while the other seven genes were simultaneously expressed in the 4th instar larvae and adults.After blood meal feeding,the expression levels of AsCPA-I,AsCPA-II,AsCPA-III,AsCPA-IV,AsCPA-VI,AsCPB-I and AsCPB-II in the midguts of female adults significantly changed,but their expression patterns were completely different,suggesting that the blood protein digestion is a complex process involving the coordinative expressions of multiple genes.The expression levels of AsCPA-I,AsCPA-III,AsCPA-IV,AsCPA-VI and AsCPB-II were all up-regulated and peaked at 24 h PBM.Especially,the expression level of AsCPA-VI rapidly increased at 3 h PBM,and peaked at 24 h PBM with^418fold induction,and that of AsCPB-II also increased by more than 40-fold at 24 h PBM,suggesting that they might be involved in blood protein digestion.However,the expression levels of AsCPA-II and AsCPB-I in midguts of female adults were significantly down-regulated after blood meal feeding.【Conclusion】Eight carboxypeptidase genes from An.sinensis were characterized.Among them,AsCPA-I,AsCPA-III,AsCPA-IV,AsCPA-VI and AsCPB-II are putatively involved in blood protein digestion;in particular,AsCPA-VI and AsCPB-II might play more important roles.Our results provide a basis for further study on the molecular mechanism of blood protein digestion in mosquitos as well as in An.sinensis.展开更多
Objective To study the relationship of remote sensing normalized differential vegetation index （NDVI） to Anopheles density and malaria incidence rate. Methods Data of monthly average climate, environment, Anopheles ...Objective To study the relationship of remote sensing normalized differential vegetation index （NDVI） to Anopheles density and malaria incidence rate. Methods Data of monthly average climate, environment, Anopheles density and malaria incidence rate, and remote sensing NDVI were collected from 27 townships of 10 counties in southeastern Yunnan Province from 1984 to 1993. The relationship of remote sensing ecological proxy index, NDVI, to Anopheles density and malaria incidence rate was studied by principal component analysis, factor analysis and grey correlation analysis. Results The correlation matrix showed that NDVI highly correlated with Anopheles density in 4 townships of Mengla, Jinghong, and Yuanjiang counties, but in other 23 townships the relationship was not clear. Principal component and factor analyses showed that remote sensing NDVI was the representative index of the first principal component and the first common factor of Anopheles density evaluation. Grey correlation analysis showed that in rainy season NDVI had a high grey correlation with Anopheles density and malaria incidence rate. The grey correlation analysis showed that in rainy season the grey degree of NDVI correlated with Anopheles. Minimus density was 0.730, and 0.713 with Anopheles sinensis density, and 0.800 with malarial incidence rate. Conclusion Remote sensing NDVI can serve as a sensitive evaluation index of Anopheles density and malaria incidence rate.展开更多
Objective: To investigate the efficacies of 12 essential oil(EO) formulations from three Zingiberaceae plants(Alpinia galanga, Curcuma zedoaria, and Zingiber cassumunar) individually and in combination with an augment...Objective: To investigate the efficacies of 12 essential oil(EO) formulations from three Zingiberaceae plants(Alpinia galanga, Curcuma zedoaria, and Zingiber cassumunar) individually and in combination with an augmenting Eucalyptus globulus(E. globulus) EO against females of Aedes albopictus(Ae. albopictus) and Anopheles minimus(An. minimus). Methods: These formulations were evaluated for their ovicidal, oviposition deterrent and adulticidal activities against Ae. albopictus and An. minimus by a topical method, a double-choice method and a WHO susceptibility test, respectively. Results: It was found that all formulations of Zingiberaceae plants EOs augmented with E. globulus EO were more effective in oviposition deterrent, ovicidal, and adulticidal activities against the two mosquito species than all of the formulations used without E. globulus EO. Their oviposition deterrent, ovicidal and adulticidal activities were equivalent to those of 10% w/v cypermethrin. In contrast, 70% v/v ethyl alcohol as a control alone was not effective at all. The highest synergistic effect in effective repellency against Ae. albopictus was achieved by 5% Alpinia galanga EO + 5% E. globulus EO and against An. minimus was 5% Zingiber cassumunar EO + 5% E. globulus EO. Moreover, the highest synergistic effects in ovicidal activities against Ae. albopictus and An. minimus were achieved by 10% Zingiber cassumunar EO + 10% E. globulus EO and 5% Curcuma zedoaria EO + 5% E. globulus EO, respectively. For the adulticidal activities, the highest synergistic effect against two mosquitoes was achieved by 5% Curcuma zedoaria EO + 5% E. globulus EO. Conclusions: These results suggest that Zingiberaceae plant EOs augmented with E. globulus EO have a high potential to be developed into oviposition deterrent, ovicidal, and adulticidal agents for controlling populations of Ae. albopictus and An. minimus.展开更多
Malaria is one of the most important parasitic diseases in the world which is transmitted by the Anopheles mosquitoes. There are several methods for malaria control.One of them is application of repellents on skin in ...Malaria is one of the most important parasitic diseases in the world which is transmitted by the Anopheles mosquitoes. There are several methods for malaria control.One of them is application of repellents on skin in malarious area as an intergrated vectro management measures.This study evaluated two repellents of DMP as a synthtic and locally product of neem oil as a botanical repellent against Anopheles stephensi.The modified method of K & D was used for the tests.Probing/biting rates on the shaved belly of white rabbits were counted. ED50 and ED95 values were calculated by probit statistic software.Calculation of effective dose(ED50, ED90 ) on human volunteer and white rabbit was performed using regression line.Protection and failure time of DMP and neem oil was also determined.ED50 value of DMP and neem oil was determined as 0.0076 and 0. 159 mg/cm respectively on white rabit.The figures of ED90 value of DMP and neem oil was determined as 0. 046 and 1.388 mg/cm^2.DMP and neem oil showed repellency effects against An.stephensi on human volunteers with ED50 value of 0.0037 and 0.127 mg/cm^2 respectively.ED90 value of DMP was determined as 0. 032 mg/cm^2.neem oil exhibited a ED90 value of 1.066 mg/cm^2 on human volunteer.The protection time of 6-7 hours for DMP and 31 minute for neem oil was determined.The failure times for DMP and Neem was 9 hours and 65 minutes rspectively on human bait.Our results exhibited that plant-based repellent is generally less effective than synthetic repellents.However,use of locally made botanical materials would be of great advantages for personal protection against mosquito biting.展开更多
Objective:To determine phytochemistry and larvicidal activity of Eucalyptus eamaldulensis against Anopheles stephensi.Methods:The chemical compositions of the leaf essential oils were analyzed using gas chromatography...Objective:To determine phytochemistry and larvicidal activity of Eucalyptus eamaldulensis against Anopheles stephensi.Methods:The chemical compositions of the leaf essential oils were analyzed using gas chromatography/mass spectrometry（GC/MS）.The larvicidal activity of essential oils and extract of leaf were tested against 4th instar larvae of laboratory-reared Anopheles stephensi.Results:GC/MS analyses identified the presence of 28 compounds corresponding to 99.60%of the total oil.The main constituents in the leaf essential oil were 1,8-cineole（69.46%）,γ-Terpinene（15.10%）,α-Pinene（5.47%） and Globulol（2%）.The leaf extract and volatile oil exerted significant larvicidal activity with LC<sub>50</sub> values of 89.85 and 397.75 ppm,respectively.Clear dose-response relationships were established with the highest dose of 320 ppm essential oil extract resulted almost 100%mortality in the population.Conclusions:The larvicidal properties suggest that the essential oil of plant is a potential source of valuable larvicidal compounds against malaria vector and can be used as an alternative to synthetic insecticides.展开更多
Objective:To determine the mosquito larvicidal activities of hexane,chloroform,ethyl acetate, acetone and methanol leaf extract of Orthosiphon thymiflorus（O.thymiflorus） against Anopheles stephensi（An.stephensi）,C...Objective:To determine the mosquito larvicidal activities of hexane,chloroform,ethyl acetate, acetone and methanol leaf extract of Orthosiphon thymiflorus（O.thymiflorus） against Anopheles stephensi（An.stephensi）,Culex quinquefasciatus（Cx.quinquefasciatus） and Aedes aegypti （Ae.aegypti）.Methods:The larvicidal activity was assayed against three mosquito species at various concentrations ranging from（50-450 ppm） under the laboratory conditions.The LC<sub>50</sub> and LC<sub>90</sub>value of the O.thymiflorus leaf extract was determined by Probit analysis.Results:The LC<sub>50</sub> values of hexane,chloroform,ethyl acetate,acetone and methanol extract of O.thymiflorus third instar larvae of An.stephensi were LC<sub>50</sub>= 201.39,178.76,158.06,139.22 and 118.74 ppm; Cx.quinquefasciatus were LC<sub>50</sub>=228.13,209.72.183.35,163.55 and 149.96 ppm and Ae.aegypti were LC<sub>50</sub>=215.65,197.91,175.05,154.80 and 137.26 ppm,respectively.Maximum larvicidal activity was observed in the methanolic extract followed by acetone,ethyl acetate chloroform and hexane extract.The larval mortality was observed after 24 h exposure.No mortality was observed in control.Conclusions:The present results suggest that the effective plant crude extracts have potential to be used as an ideal eco-friendly approach for the control of mosquito vectors.This study provides the first report on the larvicidal activity of this plant crude solvent extract of against An.stephensi,Cx.quinquefasciatus and Ae.aegypti mosquitoes.展开更多
文摘Introduction: A recent study in Kenya highlighted a promising advance in malaria control by demonstrating that infecting mosquitoes with the endosymbiont Microsporidia MB blocks Plasmodium transmission. However, the influence of biotic and abiotic factors such as diet, relative humidity (RH) and temperature on this infection remains poorly studied. This study, aimed to gain a better understanding of this relationship. Methods: To highlight the influence of diet quantity, we defined a range of 3 quantities: 0.00375 g, 0.015 g and 0.09 g. Each quantity was tested on two groups of larvae: a group of 150 larvae infected with Microsporidia MB (MB+), and a group of 150 larvae not infected with Microsporidia MB (MB−) (control group), each divided into three replicates of 50 larvae. Each replicate was fed each morning with the assigned quantity until the pupal stage. In addition to this factor, we investigated the influence of temperature and RH. We defined three temperature-RH combinations: 21˚C-80% RH, 39˚C-50% RH, and 27˚C-75% RH. Each combination was tested on two groups of larvae: a group of 150 MB+ larvae and a group of 150 MB− larvae, each divided into three replicates of 50 larvae. Each replicate was subjected to the assigned combination until pupation. Pupae that had reached the adult stage were tested by PCR to determine their Microsporidia MB infection status for each factor studied. Results: The results showed that only the lowest quantity (0.00375 g) significantly reduced the prevalence of Microsporidia MB compared with the medium quantity (chi-2 test, χ2 = 4.9088, df = 1, p = 0.02672) and the high quantity (chi-2 test, χ2 = 4.7958, df = 1, p = 0.02853). As for temperature and RH, the combination 39˚C-50% RH led to a significant reduction in the prevalence of Microsporidia MB compared with the combination 27˚C-75% RH (chi-2 test, χ2 = 6.3736, ddl = 1, p = 0.01158) and that 21˚C-80% RH (chi-2 test, χ2 = 9.983, ddl = 1, p = 0.00158). Conclusion: This work contributes to a better understanding of some key factors linked to Microsporidia MB infection in mosquitoes. However, further research on several generations is necessary to draw more comprehensive conclusions.
文摘Objective:To investigate the prevalence,mechanisms,and trends of knockdown resistance(kdr)in Anopheles(An.)culicifacies and its impact on the efficacy of organochlorine and other insecticides.Methods:A systematic review was conducted based on PRISMA guidelines,extracting data from biooan.org,Embase,ProQuest,PubMed,Scopus,and Web of Science without a time limit until the end of 2022.Articles meeting the inclusion criteria were assessed using the STROBE checklist.Data on kdr mutations,insecticide resistance,and effectiveness were analyzed across eight selected studies from various regions.Results:The review revealed widespread kdr-mediated resistance in An.culicifacies,primarily against dichloro-diphenyl-trichloroethane(DDT),persisting even decades after discontinued use.Key kdr mutations,including L1014F and L1014S,were identified.Resistance to deltamethrin was less stable,with increased sensitivity observed after short-term discontinuation.The findings underscore the vector's sustained resistance to organochlorine insecticides and relative sensitivity to pyrethroids.Conclusions:Stable kdr resistance in An.culicifacies to organochlorine insecticides highlights the need for periodic susceptibility assessments and strategic rotation or combination of insecticides to combat malaria effectively and prevent the development of resistance.
文摘Anopheles(An.)stephensi is one of the dominant malaria vectors in India,Bangladesh,Pakistan,Iran,Iraq and some other Asian countries[1].It plays a crucial role in transmitting Plasmodium falciparum and Plasmodium vivax in India along with its rural counterpart,An.culicifacies.This mosquito species has adapted well to urban and peri-urban environments,making it a significant public health concern in the country.The presence of An.stephensi in urban areas contrasts with other malaria vectors that predominantly inhabit rural regions,thus complicating traditional malaria control strategies.It is well-adapted to human-made environments,breeding in various containers including tanks,cisterns,and barrels used for water storage.
文摘Objective:To evaluate the larvicidal and pupicidal potential of the methanolic extracts from Moringa oleifera(M.oleifera) plant seeds against malarial vector Anopheles stephensi(A.stephensi) mosquitoes at different concentrations(20,40,60,80 and 100 ppm).Methods:M.oleifera was collected from the area of around Bharathiar University,Coimbatore.The dried plant materials were powdered by an electrical blender.From each sample,100 g of the plant material were extracted with 300 mL of methanol for 8 h in a Soxhlet apparatus.The extracts were evaporated to dryness in rotary vacuum evaporator to yield 122 mg and 110 mg of dark greenish material(residue) from Arcang amara and Ocimum basilicum,respectively.One gram of the each plant residue was dissolved separately in 100 mL of acetone(stock solution) from which different concentrations, i.e.,20,40,60,80 and 100 ppm were prepared.Results:Larvicidal activity of M.oleifera exhibited in the first to fourth instar larvae of the A.stephensi,and the LC_(50) and LC_(90) values were 57.79 ppm and 125.93 ppm for the first instar,63.90 ppm and 133.07 ppm for the second inslar,72.45 ppm and 139.82 ppm for the third instar,78.93 ppm and 143.20 ppm for the fourth instar,respectively. During the pupal stage the methanolic extract of M.oleifera showed that the LC_(50),and LC_(90) values were 67.77 ppm and 141.00 ppm,respectively.Conclusions:The present study indicates that the phytochemicals derived from M.oleifera seeds extracts are effective mosquito vector control agents and the plant extracts may be used for further integrated pest management programs.
文摘Objective:To determine the ovicidal and repellent activities of methanol leaf extract of Ervatamia coronaria(E.coronaria) and Caeslpinia pulckerrima(C.pulcherrima) against Culex quinquefasciatus(Cx.quinquefasciatus),Aedes aegypti(Ae.aegypti) and Anopheles stephensi(An. stephensi).Methods:The ovicidal activity was determined against three mosquito species at various concentrations ranging from 50-450 ppm under the laboratory conditions.The hatch rates were assessed 48 h after treatment.The repellent efficacy was determined against three mosquito species at three concentrations viz.,1.0,2.5 and 5.0 mg/cm under the laboratory conditions. Results:The crude extract of E.coronaria exerted zero hatchability(100%mortality) at 250.200 and 150 ppm for Cx.quinqitefasciatus,Ae.aegypti and An.stephensi,respectively.The crude extract of C.pulchenima exerted zero hatchability(100%mortality) at 375.300 and 225 ppm for Cx.quinquefasciatus,Ae.aegypti and An.Stephensi,respectively.The methanol extract of E. coronaria found to be more repellenct than C.pukherrima extract.A higher concentration of 5.0 mg/cm^2 provided 100%protection up to 150.180 and 210 min against Cx.quinquefasciatus,Ae. aegypti and An.stephensi,respectively.The results clearly showed that repellent activity was dose dependent.Conclusions:From the results it can be concluded the crude extracts of E.coronaria and C.pukherrima are an excellent potential for controlling Cx.quinquefasciatus,Ae.aegypti and An.stephensi mosquitoes.
文摘Anopheles sinensis and An. anihropophagus are two morphologically indistinguishable yet genetically and behaviorally distinct mosquito species that vary dramatically in their importance as vectors of malaria inChina. The sequence of the ribosomal DNA internal transcribed spacer 2 (ITS2) was determined for bothspecies to assess the species differentiation. The lengths of ITS2 was 468 hp for An. sinensis and 452 hp forAn. anthropophagus. Interspecies difference in sequence was 28. 8%. Intraspecies sequence divergence wasnegligible. A PCR method was developed for distinguishing the two species based on the species-specific variations of the ITS2 sequences. The method would amplify a diagnostic fragment in length of 425 hp for An.sinensis and 253 hp for An. anthropophagus. Field collections from 12 localities in 10 provinces of China weretested. In 440 mosquitoes identified by adult morphological characteristics as An. sinensis, 291 (66. 2 % ) wereidentified later as An. sinensis and 56 (12. 7 % ) as An. anthropophagus, the remaining 93 (22. 1 % ) were notamplified by PCR. The results showed that the morphological characteritics of adult was not reliable for fieldidentification. The PCR assay was a simple, fast and reliable method for species identification.
基金support of Malaria Department,Ministry of Health & Medical Education of Iran
文摘Objective:To determine the susceptibility of main malaria vector in Astra County,borderline of Iran and Republic of Azerbaijan for better control.Methods:Susceptibility of Anopheles mactdipennis to diagnostic doses of DDT 4% ,dieldrin 0.4% ,malathion 5% ,lambdacyhalothrin 0.1% ,and delamethrin 0.025% ,was tested according to method recommended by WHO.All the impregnated papers were provided by WHO.Results:It was shown that this species exhibited resistance to DDT,dieldrin,whereas susceptible to malathrion,lambdacyhalothrin and deltamethrin.Conclusions:Findings of susceptibility tests of this species provided a clue for control of malaria vector in the region.
基金the Department of Science and Technology(DST,SERC-Fast Track Young Scientist Project), New Delhi,India for providing financial assistance for the present investigation
文摘ObjectiveTo determine the adulticidal and repellent activities of different solvent leaf extracts of Eclipta alba (E. alba) and Andrographis paniculata (A. paniculata) against malarial vector, Anopheles stephensi (An. stephensi).MethodsAdulticidal efficacy of the crude leaf extracts of E. alba and A. paniculata with five different solvents like benzene, hexane, ethyl acetate, methanol and chloroform was tested against the five to six day old adult female mosquitoes of An. stephensi. The adult mortality was observed after 24 h under the laboratory conditions. The repellent efficacy was determined against An. stephensi mosquito species at three concentrations viz., 1.0, 2.5 and 5.0 mg/cm2 under laboratory conditions.ResultsAmong the tested solvents the maximum efficacy was observed in the methanol extract. The LC50 and LC90 values of E. alba and A. paniculata against adults of An. stephensi were 150.36, 130.19 ppm and 285.22, 244.16 ppm, respectively. No mortality was observed in controls. The chi-square values were significant at P<0.05 level. Methanol extract of E. alba and A. paniculata was produce maximum repellency against An. stephensi.ConclusionsFrom the results it can be concluded the crude extract of E. alba and A. paniculata was an excellent potential for controlling An. stephensi mosquitoes.
基金supported by grants from the National Science and Technology Major Project(2018ZX10711001,2018ZX10102001)The National Key Research and Development Program of China(2017YFC1200202)+1 种基金Science and Technology Project of Jiangxi(2014BBG70097)Development Grant of State Key Laboratory of Infectious Disease Prevention and Control(2014SKLID103,2015SKLID505)
文摘Zika virus(ZIKV)has been isolated from mosquitoes such as Aedes,Mansonia uniformis,and Culex perfuscus;However,the isolation of ZIKV from Anopheles sinensis and Culex tritaeniorhynchus has not yet been reported.In June and July2018,22,985 mosquitoes and 57,500 midges were collected in Jiangxi Province in southeastern China.Among them,six strains of ZIKV were isolated from mosquitoes:four from An.sinensis and two from Cx.tritaeniorhynchus.Molecular genetic analysis showed that the ZIKV isolated from An.sinensis and Cx.tritaeniorhynchus belonged to genotype 2 in the Asian evolutionary branch of ZIKV.In addition,the ZIKV strains isolated from An.sinensis and Cx.tritaeniorhynchus had amino acid substitutions identical to ZIKV strains prevalent in South America since 2015.This study is the first to isolate ZIKV from mosquito specimens collected in the wild of Jiangxi Province,China;This is also the first time that ZIKV has been isolated from An.sinensis and Cx.tritaeniorhynchus.Given that An.sinensis and Cx.tritaeniorhynchus have a very wide geographical distribution in China and even in eastern and southern Asia,the isolation of several strains of ZIKV from these two mosquitoes poses new challenges for the prevention and control of ZIKV infection in the mainland of China and countries and regions with the same distribution of mosquitoes.
基金financially supported by Tehran University of Medical Sciences(TUMS)(Grant No.89-01-27-10448)
文摘Objective:To identify the biological forms,sporozoite rate and molecular characterization of the Anopheles stephensi(An.stephensi)in Hormozgan and Sistan-Baluchistan provinces,the most important malarious areas in Iran.Methods:Wild live An.stephensi samples were collected from different malarious areas in southern Iran.The biological forms were identified based on number of egg-ridges.Molecular characterization of biological forms was verified by analysis of the mitochondrial cytochrome oxidase subunit I and II(mtDNA-COI/COII).The Plasmodium infection was examined in the wild female specimens by species-specific nested-PCR method.Results:Results showed that all three biological forms including mysorensis,intermediate and type are present in the study areas.Molecular investigations revealed no genetic variation between mtDNA COI/COII sequences of the biological forms and no Plasmodium parasites was detected in the collected mosquito samples.Conclusions:Presence of three biological forms with identical sequences showed that the known biological forms belong to a single taxon and the various vectorial capacities reported for these forms are more likely corresponded to other epidemiological factors than to the morphotype of the populations.Lack of malaria parasite infection in An,stephensi,the most important vector of malaria,may be partly due to the success and achievement of ongoing active malaria control program in the region.
基金Defence Research & Development Organisation-Life Sciences Research Board, Ministry of Defence,Govt.of India,New Delhi,for providing financial support for the present work
文摘Objective:To explore the larvicidal and pupicidal activity of Euphorbia hirta（E.hirta） leaf extract and Bacillus sphaericus（B.sphaericus） against the malarial vector.Anopheles siephensi（An. stephensi）.Methods:The larvicidal and pupicidal activity was assayed against An.stephensi at various concentrations ranging from（75-375 ppm） under the laboratory as well as field conditions. The LC<sub>50</sub> and LC<sub>90</sub> value of the E.hirta leaf extract was determined by probit analysis.Results: The plant extract showed larvicidal effects after 24 h of exposure;however,the highest larval mortality was found in the methanol extract of E.hirta against the first to fourth instars larvae and pupae of values LC<sub>50</sub>=137.40,172.65,217.81,269.37 and 332.39 ppm;B.sphaericus against the first to fourth instars larvae and pupae of values LC<sub>50</sub>= 44.29,55.83,68.51,82.19 and 95.55 ppm, respectively.Moreover,combined treatment of values of LC<sub>50</sub>= 79.13,80.42,86.01,93.00 and 98.12 ppm,respectively.No mortality was observed in the control.Conclusions:These results suggest methanol leaf extracts of E.hirta and B.sphaericus have potential to be used as an ideal ecofriendly approach for the control of the malarial vector.An.stephensi as target species of vector control programs.This study provides the first report on the combined mosquito larvicidal and pupicidal activity of this plant crude extract and bacterial toxin against An.stephensi mosquitoes.
文摘Objective: To investigate the larvicidal and pupicidal activities of aqueous, ethyl acetate and methanol extracts of Catharanthus roseus ( C. roseus ) against malaria and filariasis vectors. Methods: The larvicidal and pupicidal activities of C. roseus leaf extracts were tested against the fourth instar larvae and pupae of Anopheles stephensi ( An. stephensi ) and Culex quinquefasciatus ( Cx. quinquefasciatus ). The mortality was observed after 24 and 48 h post the treatment. The data were subjected to probit analysis to determine the lethal concentrations (LC 50 and LC 90 ) at which 50% and 90% of the treated larvae or pupae of the tested species were killed. Results: The larval and pupal mortality were observed after 24 and 48 h of exposure of aqueous, ethyl acetate and methanol extracts of C. roseus ; no mortality was observed in the control group. The LC 50 values against the fourth-instar larvae of An. stephensi were 68.62 and 72.04 mg/mL for the aqueous extract, 82.47 mg/mL for the ethyl acetate extract, and 78.80 and 86.64 mg/mL for the methanol extract, while the aqueous, ethyl acetate and methanol extracts had LC 50 values of 85.21, 76.84 and 94.20 mg/mL against the fourth-instar larvae of Cx. quinquefasciatus . The aqueous, ethyl acetate and methanol extracts had LC 50 values of 118.08, 182.47 and 143.80 mg/mL against the pupae of An. stephensi and 146.20, 226.84 and 156.62 mg/mL against the pupae of Cx. quinquefasciatus , respectively. Conclusions: The aqueous and methanol extracts of C. roseus leaves had an excellent potential to control the malarial vector An. stephensi and filariasis vector Cx. quinquefasciatus .
文摘Objective:To determine the larvicidal efficacy of different solvent leaf extract of Ficus benghalensis（F.benghalensis） against Culex tritaeniorhynchus（Cx.tritaeniorhynchus） and Anopheles subpictus（An.subpictus）.Methods:Twenty five early third instar larvae of Cx. tritaeniorhynchus and An.subpictus were exposed to various concentrations and were assayed in the laboratory by using the protocol of WHO 2005.The larval mortality was observed after 24 h of treatment.Results:Among three solvent extracts tested the maximum efficacy was observed in the methanol extract.The LC<sub>50</sub> and LC<sub>90</sub> values of F.benghalensis against early third instar of Cx. tritaeniorhynchus and An.subpictus were 100.88.159.76 ppm and 56.66.85.84 ppm.respectively. No mortality was observed in controls.The chi-square values were significant at P【0.05 level. Conclusions:From the results it can be concluded the crude extract of F.benghalensis was an excellent potential for controlling Cx.tritaeniorhynchus and Art.subpictus mosquito larvae.
文摘【Aim】The objective of this study is to characterize eight digestive carboxypeptidase genes in Anopheles sinensis,and to analyze their expression patterns before and post blood meal feeding.【Methods】The characteristics of eight digestive carboxypeptidase genes of An.sinensis were analyzed using bioinformatics methods,and their expression levels in different tissues at different developmental stages and in the midguts of female adults at different time points post blood meal feeding(PBM)were compared by semi-quantitative reverse transcription PCR and quantitative realtime PCR(qRT-PCR),respectively.【Results】Bioinformatics analysis indicated that of the eight carboxypeptidase genes,six genes encode carboxypeptidases A(AsCPA-I-AsCPA-VI)and two encode carboxypeptidases B(AsCPB-I and AsCPB-II).The expression of AsCPA-V was only detected in midguts and carcasses(whole mosquitoes minus midgut)of the 4th instar larvae,suggesting that it might have specific expression in larvae,while the other seven genes were simultaneously expressed in the 4th instar larvae and adults.After blood meal feeding,the expression levels of AsCPA-I,AsCPA-II,AsCPA-III,AsCPA-IV,AsCPA-VI,AsCPB-I and AsCPB-II in the midguts of female adults significantly changed,but their expression patterns were completely different,suggesting that the blood protein digestion is a complex process involving the coordinative expressions of multiple genes.The expression levels of AsCPA-I,AsCPA-III,AsCPA-IV,AsCPA-VI and AsCPB-II were all up-regulated and peaked at 24 h PBM.Especially,the expression level of AsCPA-VI rapidly increased at 3 h PBM,and peaked at 24 h PBM with^418fold induction,and that of AsCPB-II also increased by more than 40-fold at 24 h PBM,suggesting that they might be involved in blood protein digestion.However,the expression levels of AsCPA-II and AsCPB-I in midguts of female adults were significantly down-regulated after blood meal feeding.【Conclusion】Eight carboxypeptidase genes from An.sinensis were characterized.Among them,AsCPA-I,AsCPA-III,AsCPA-IV,AsCPA-VI and AsCPB-II are putatively involved in blood protein digestion;in particular,AsCPA-VI and AsCPB-II might play more important roles.Our results provide a basis for further study on the molecular mechanism of blood protein digestion in mosquitos as well as in An.sinensis.
文摘Objective To study the relationship of remote sensing normalized differential vegetation index （NDVI） to Anopheles density and malaria incidence rate. Methods Data of monthly average climate, environment, Anopheles density and malaria incidence rate, and remote sensing NDVI were collected from 27 townships of 10 counties in southeastern Yunnan Province from 1984 to 1993. The relationship of remote sensing ecological proxy index, NDVI, to Anopheles density and malaria incidence rate was studied by principal component analysis, factor analysis and grey correlation analysis. Results The correlation matrix showed that NDVI highly correlated with Anopheles density in 4 townships of Mengla, Jinghong, and Yuanjiang counties, but in other 23 townships the relationship was not clear. Principal component and factor analyses showed that remote sensing NDVI was the representative index of the first principal component and the first common factor of Anopheles density evaluation. Grey correlation analysis showed that in rainy season NDVI had a high grey correlation with Anopheles density and malaria incidence rate. The grey correlation analysis showed that in rainy season the grey degree of NDVI correlated with Anopheles. Minimus density was 0.730, and 0.713 with Anopheles sinensis density, and 0.800 with malarial incidence rate. Conclusion Remote sensing NDVI can serve as a sensitive evaluation index of Anopheles density and malaria incidence rate.
基金supported by Faculty of Agricultural Technology,KMITL,Bangkok,Thailand(Grant no 01-04-002)the National Research Council of Thailand(GRAD 6007KMITL)
文摘Objective: To investigate the efficacies of 12 essential oil(EO) formulations from three Zingiberaceae plants(Alpinia galanga, Curcuma zedoaria, and Zingiber cassumunar) individually and in combination with an augmenting Eucalyptus globulus(E. globulus) EO against females of Aedes albopictus(Ae. albopictus) and Anopheles minimus(An. minimus). Methods: These formulations were evaluated for their ovicidal, oviposition deterrent and adulticidal activities against Ae. albopictus and An. minimus by a topical method, a double-choice method and a WHO susceptibility test, respectively. Results: It was found that all formulations of Zingiberaceae plants EOs augmented with E. globulus EO were more effective in oviposition deterrent, ovicidal, and adulticidal activities against the two mosquito species than all of the formulations used without E. globulus EO. Their oviposition deterrent, ovicidal and adulticidal activities were equivalent to those of 10% w/v cypermethrin. In contrast, 70% v/v ethyl alcohol as a control alone was not effective at all. The highest synergistic effect in effective repellency against Ae. albopictus was achieved by 5% Alpinia galanga EO + 5% E. globulus EO and against An. minimus was 5% Zingiber cassumunar EO + 5% E. globulus EO. Moreover, the highest synergistic effects in ovicidal activities against Ae. albopictus and An. minimus were achieved by 10% Zingiber cassumunar EO + 10% E. globulus EO and 5% Curcuma zedoaria EO + 5% E. globulus EO, respectively. For the adulticidal activities, the highest synergistic effect against two mosquitoes was achieved by 5% Curcuma zedoaria EO + 5% E. globulus EO. Conclusions: These results suggest that Zingiberaceae plant EOs augmented with E. globulus EO have a high potential to be developed into oviposition deterrent, ovicidal, and adulticidal agents for controlling populations of Ae. albopictus and An. minimus.
文摘Malaria is one of the most important parasitic diseases in the world which is transmitted by the Anopheles mosquitoes. There are several methods for malaria control.One of them is application of repellents on skin in malarious area as an intergrated vectro management measures.This study evaluated two repellents of DMP as a synthtic and locally product of neem oil as a botanical repellent against Anopheles stephensi.The modified method of K & D was used for the tests.Probing/biting rates on the shaved belly of white rabbits were counted. ED50 and ED95 values were calculated by probit statistic software.Calculation of effective dose(ED50, ED90 ) on human volunteer and white rabbit was performed using regression line.Protection and failure time of DMP and neem oil was also determined.ED50 value of DMP and neem oil was determined as 0.0076 and 0. 159 mg/cm respectively on white rabit.The figures of ED90 value of DMP and neem oil was determined as 0. 046 and 1.388 mg/cm^2.DMP and neem oil showed repellency effects against An.stephensi on human volunteers with ED50 value of 0.0037 and 0.127 mg/cm^2 respectively.ED90 value of DMP was determined as 0. 032 mg/cm^2.neem oil exhibited a ED90 value of 1.066 mg/cm^2 on human volunteer.The protection time of 6-7 hours for DMP and 31 minute for neem oil was determined.The failure times for DMP and Neem was 9 hours and 65 minutes rspectively on human bait.Our results exhibited that plant-based repellent is generally less effective than synthetic repellents.However,use of locally made botanical materials would be of great advantages for personal protection against mosquito biting.
基金Supported by Centre of Ernriromental Research,TUMS,Iran. (grant No.88-01-46-661)
文摘Objective:To determine phytochemistry and larvicidal activity of Eucalyptus eamaldulensis against Anopheles stephensi.Methods:The chemical compositions of the leaf essential oils were analyzed using gas chromatography/mass spectrometry（GC/MS）.The larvicidal activity of essential oils and extract of leaf were tested against 4th instar larvae of laboratory-reared Anopheles stephensi.Results:GC/MS analyses identified the presence of 28 compounds corresponding to 99.60%of the total oil.The main constituents in the leaf essential oil were 1,8-cineole（69.46%）,γ-Terpinene（15.10%）,α-Pinene（5.47%） and Globulol（2%）.The leaf extract and volatile oil exerted significant larvicidal activity with LC<sub>50</sub> values of 89.85 and 397.75 ppm,respectively.Clear dose-response relationships were established with the highest dose of 320 ppm essential oil extract resulted almost 100%mortality in the population.Conclusions:The larvicidal properties suggest that the essential oil of plant is a potential source of valuable larvicidal compounds against malaria vector and can be used as an alternative to synthetic insecticides.
基金the Department of Science and Technology(DST),Govt.of India New Delhi,IndiaTamil Nadu State Council for Science and Technology(TNSCST), Chennai,Tamil Nadu for providing financial support for the present work
文摘Objective:To determine the mosquito larvicidal activities of hexane,chloroform,ethyl acetate, acetone and methanol leaf extract of Orthosiphon thymiflorus（O.thymiflorus） against Anopheles stephensi（An.stephensi）,Culex quinquefasciatus（Cx.quinquefasciatus） and Aedes aegypti （Ae.aegypti）.Methods:The larvicidal activity was assayed against three mosquito species at various concentrations ranging from（50-450 ppm） under the laboratory conditions.The LC<sub>50</sub> and LC<sub>90</sub>value of the O.thymiflorus leaf extract was determined by Probit analysis.Results:The LC<sub>50</sub> values of hexane,chloroform,ethyl acetate,acetone and methanol extract of O.thymiflorus third instar larvae of An.stephensi were LC<sub>50</sub>= 201.39,178.76,158.06,139.22 and 118.74 ppm; Cx.quinquefasciatus were LC<sub>50</sub>=228.13,209.72.183.35,163.55 and 149.96 ppm and Ae.aegypti were LC<sub>50</sub>=215.65,197.91,175.05,154.80 and 137.26 ppm,respectively.Maximum larvicidal activity was observed in the methanolic extract followed by acetone,ethyl acetate chloroform and hexane extract.The larval mortality was observed after 24 h exposure.No mortality was observed in control.Conclusions:The present results suggest that the effective plant crude extracts have potential to be used as an ideal eco-friendly approach for the control of mosquito vectors.This study provides the first report on the larvicidal activity of this plant crude solvent extract of against An.stephensi,Cx.quinquefasciatus and Ae.aegypti mosquitoes.
