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
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
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 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
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 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
Objective:To assess the larvicidal and egg hatching inhibition property of the leaf essential oil of Cocrinia indica（C.indica） against Anopheles stephensi（An.stephensi）.Methods:The larvicidal potential of C.indica...Objective:To assess the larvicidal and egg hatching inhibition property of the leaf essential oil of Cocrinia indica（C.indica） against Anopheles stephensi（An.stephensi）.Methods:The larvicidal potential of C.indica leaf essential oil was evaluated against 1st.2nd.3rd and 4th instars larvae of An.stephensi using WHO protocol.The 24h LC<sub>50</sub>and LC<sub>90</sub> values of the essential oil were determined following probit analysis.The egg hatching inhibition activity was also tested at 10.20.40.and 60 mg/L The IC<sub>50</sub> value of essential oil was determined against eggs of An. stephensi.Results:The essential oil extracted from C.indica possessed excellent larvicidal and egg hatching inhibition activity against An.stephensi.The bioassays showed LC<sub>50</sub>—LC<sub>90</sub>of 54.3- 140.3.65.5-155.6,86.8-180.7 and 95.3-192.6 for 1 st.2nd.3rd.and 4th larval insiars.respectively. The 5095 egg hatching inhibition concentration(IC<sub>50</sub>) was noted at 16.5 mg/L.Conclusions:The present finding suggest that the C.indica leaf essential oil provided an excellent potential for controlling An.slephemi mosquito at earlier stage of their life cycle.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 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 investigate the potentiality of mosquitocidal activity of Gliricidia sepium（C.sepium） （Jacq.）（Leguminosae）.Methods:Twenty five early third instar larvae of Anopheles stephensi （An.stephensi） were ...Objective:To investigate the potentiality of mosquitocidal activity of Gliricidia sepium（C.sepium） （Jacq.）（Leguminosae）.Methods:Twenty five early third instar larvae of Anopheles stephensi （An.stephensi） were exposed to various concentrations（50-250 ppm） and the 24 h LC<sub>50</sub> values of the G.sepium extract was determined by probit analysis.The ovicidal activity was determined against An.stephensi to various concentrations ranging from 25-100 ppm under laboratory conditions.The eggs hatchabilily was assessed 48 h post treatment.The pupicidal activity was determined against An.stephensi to various concentrations ranging from 25-100 ppm.Mortality of each pupa was recorded after 24 h of exposure to the extract.Results:Results pertaining to the experiment clearly revealed that ethanol extract showed significant larvicidal,ovicidal and pupicidal activity against the An.stephensi.Larvicidal activity of ethanol extracts of G.sepium showed maximum mortality in 250 ppm concentration（96.0±2.4）%.Furthermore,the LC<sub>50</sub> was found to be 121.79 and the LC<sub>50</sub> value was recorded to be 231.98 ppm.Ovicidal activity of ethanol extract was assessed by assessing the egg hatchabilily.Highest concentration of both solvent extracts exhibited 100%ovicidal activity.Similarly,pupae exposed to different concentratioiLs of ethanol extract were found dead with 58.10%adult emergence when it was treated with 25 ppm concentration.Similarly,18.36（n=30;61.20%）;21.28（70.93） and 27.33（91.10） pupal mortality was recorded from the experimental pupae treated with 50,75 and 100 ppm concentration of extracts. Three fractions have been tested for their larvicidal activity of which the Fraction 3 showed the LC<sub>50</sub> and LC<sub>90</sub> values of 23.23 and 40.39 ppm.With regard to the ovicidal effect fraction 3 showed highest ovicidal activities than the other two fractions.Furthermore,there were no hatchabilily was recorded above 50 ppm（100%egg mortality） in the experimental group.Statistically significant pupicidal activity was recorded from 75 ppm concentration.Conclusions:From the results it can be concluded the crude extract of G.sepium is an excellent potential for controlling An.stephensi mosquito.It is apparent that,iraction 3 possess a novel and active principle which could be responsible for those biological activities.展开更多
Objective:To investigate in vitro larvicidal and antioxidant enzymes potential of the medicinal plants Ginkgo biloba（G.biloba）,Stevia rebaudiana（S.rebaudiana） and Parthenium hysterophorous（P.hysterophorous） agai...Objective:To investigate in vitro larvicidal and antioxidant enzymes potential of the medicinal plants Ginkgo biloba（G.biloba）,Stevia rebaudiana（S.rebaudiana） and Parthenium hysterophorous（P.hysterophorous） against Anopheles stephensi（An.stephensi） 4th instars larvae. Methods:For evaluation of larvicidal potential,the ethanolic,methanolic and dichloromethane leaves extracts of three different plants were used in dose-dependent experiments in two media, while the antioxidant enzymes activities were investigated using four different methods viz., superoxide dismutase,peroxidase,ascorbate and catalase.Results:An.stephensi has developed resistance to various synthetic insecticides,making its control increasingly difficult.The comparative performance of ethanolic extracts（65%-90%） was found better than the methanolic extract（70%-87%） and dichloromethane extract（60%-70%）.Among the three plants extracts tested in two media,S.rebaudiana exhibited higher larvicidal activity with LC<sub>50</sub>（24 h） in methanolic extract than P.hysterophorous and G.biloba.G.biloba and P.hysterophorous exhibited the strongest antioxidative enzymes activity and S.rebaudiana were less active and no significant difference was observed.Conclusions:These three plants exhibit larvicidal potential and can be further used for vector control alternative to synthetic insecticide due to eco-friendly and diseases control,furthermore these plant species have potent antioxidative enzyme activities, therefore,making them strong natural candidate particularly for diseases which are caused due to free radicals.展开更多
ObjectiveTo investiagte insecticide resistance in target species for better insecticide resistance managemnet in malaria control programs.MethodsThe status of insecticide resistance to different imagicides in Anophele...ObjectiveTo investiagte insecticide resistance in target species for better insecticide resistance managemnet in malaria control programs.MethodsThe status of insecticide resistance to different imagicides in Anopheles stephensi (An. stephensi) including DDT 4%, lambdacyhalothrin 0.50%, deltamethrin 0.05%, permethrin 0.75%, cyfluthrin 0.15% and etofenprox 0.50% was performed according to WHO standard method.ResultsThe mortality rate to lambdacyhalothrin, permethrin, cyfluthrin, deltamethrin, etofenprox and DDT was (88.0±3.2), (92.0±2.7), (52.0±5.0), (96.0±2.2), (90.0±3.0) and (41.0±5.7) percent, respectively at diagnostic dose for one hour exposure time followed by 24 h recovery period.ConclusionsThese results showed first indication of pyrethroid resistance in An. stephensi in a malarious area, from southern Iran. There is widespread, multiple resistances in the country in An. stephensi to organochlorine and some report of tolerance to organophosphate insecticides and recently to pyrethroids. However, results of this paper will provide a clue for monitoring and mapping of insecticide resistance in the main malaria vector for implementation of any vector control.展开更多
Objective:To determine the adult emergence inhibition（EI） and adulticidal activities of hexane,chloroform,ethyl acetate,and acetone leaves extracts of Anisomeles malabarica（A. malabarica）,Euphorbia hirta（E,hirta...Objective:To determine the adult emergence inhibition（EI） and adulticidal activities of hexane,chloroform,ethyl acetate,and acetone leaves extracts of Anisomeles malabarica（A. malabarica）,Euphorbia hirta（E,hirta）,Ocimum basilicum（0.basilicum）,Ricinus communis（R. communis）,Solanum trilobatum（S.trilobatum）,Tridax procumbens（T.procumbens） and seeds of Gloriosa superba（G.superba） against Anopheles stephensi（An,stephensi）.Methods:The EI and adulticidal trials were carried out according to World Health Organization（WHO） procedures with slight modifications.The extracts were diluted in dimethyl sulphoxide in order to prepare a serial dilution of test dosages（15.625,31.25,62.5,125,250,500 and 1 000μg/mL）.Five duplicate trials were carried out for every sample concentration,and for each trial a negative control was included and the mortality was determined after 24 h of exposure.Results:The highest EI activity was found in ethyl acetate extracts of A malabarica,chloroform extracts of O.basilicum, S.trilobatum,acetone of extract of R.communis,T.procumbens,and seed extract of G.superba with EI<sub>50</sub> values 143.12,119.82.157.87,139.39,111.19,and 134.85μg/mL,and the effective adulticidal activity was observed in chloroform,acetone extracts of G.superba,T.procumbens,R. communis,S.trilobatum and ethyl acetate extract of 0.basilicum with LD<sub>50</sub> values 120.17,108.77, 127.22,163.11,118.27,and 93.02μg/mL,respectively.Chi-square value was significant at P【0.05 level.Conclusions:These results should encourage further efforts to investigate the compounds that might possess good EI and adulticidal properties when isolated in pure form.展开更多
Objective:To investigate the larvicidal activities of crude and chlor of orm:methanol(1:1 v/ v) extracts of some common spices(Cuminum cyminum,Allium sativum,Zingiber offinale, Curcuma longa) and vegetable waste(Solan...Objective:To investigate the larvicidal activities of crude and chlor of orm:methanol(1:1 v/ v) extracts of some common spices(Cuminum cyminum,Allium sativum,Zingiber offinale, Curcuma longa) and vegetable waste(Solanum tuberosum germinated tuber) against Anopheles stephensi and Culex quinquefasciatus mosquito larvae.Methods:Larval mortality of above mosquito species were observed after 24,48 and 72 h of exposure to five concentrations of aqueous extract(0.1%,0.2%,0.3%,0.4%and 0.5%) and four concentrations(25,50,75 ppm) of chlor of orm:methanol(1:1 v/v) extract.The lethal concentration of individual spices or vegetable waste was determined by log-probit analysis(at 95%confidence level) and effect of crude and chlor of orm:methanol(1:1 v/v) extracts were recorded on non target organisms.Results: Relative mortality rate of both larval mosquito species were recorded in the following sequences: Cuminum cyminum】 Allium sativum】Zingiber offinale,Curcuma longa 】 Solanum tuberosum germinated tuber for crude extract,and efficacy of chlor of orm:methanol(1:1 v/v) extract were as follows:Curcuma longa 】 Zingiber offinale 】 Solanum tuberosum germinated tuber 】 Cuminum cyminum】 Allium sativum.Conclusions:Crude and chlor of orm:methanol(1:1 v/v) extract of Cuminum cyminum,Allium sativum,Zingiber offinale,Curcuma longa and Solanum tuberosum germinated tuber can be recommended effectively in mosquito control programmes at very low concentrations.No mortality and other abnormalities were noticed on non target organisms and further studies are needed to investigate the chemical structure of active principal which are responsible for larvicidal activity.展开更多
Efficacy of 25 essential oils was screened against filarial vector, Culex quinquefasciatus, for their larvicidal and knockdown effects in a preliminary study. Of these, 8 oils viz. calamus oil, cinnamon oil, citronell...Efficacy of 25 essential oils was screened against filarial vector, Culex quinquefasciatus, for their larvicidal and knockdown effects in a preliminary study. Of these, 8 oils viz. calamus oil, cinnamon oil, citronella oil, clove oil, eucalyptus oil, lemon oil, mentha oil and orange oil exhibited 100% larvicidal activity at 1000 ppm and 100% knockdown effect at 10% concentration. These 8 oils were screened further against Cx. Quinquefasciatus, Aedes aegypti and Anopheles stephensi for their larvicial and knockdown effects at different concentrations. Mentha oil was the most promising against An. Stephensi and Ae. Aegypti recording LC50 and LC90 values of 39.74 and 115.67 ppm and 46.23 and 165.36 ppm, respectively for larvicidal activity. Calamus oil was the most effective against Cx. Quinquefasciatus with LC50 and LC90 values of 40.40, and 140.07 ppm, respectively for larvicidal activity. Orange oil showed the most potent knockdown effect with the KT50 and KT95 values of 27.44, 26.22 and 29.91 and 70.81, 65.33 and 68.57 min, against An. stephensi, Cx. Quinquefasciatus and Ae. Aegypti, respectively. The results clearly indicated that mentha oil and calamus oil were the most promising larvicides and orange oil had potent knockdown effect against the tested mosquito species. These oils could be used to develop a new formulation to control mosquitoes.展开更多
Objective:To determine the significance of temperature,rainfall and humidity in the seasonal abundance of Anopheles stephensi in southern Iran.Methods:Data on the monthly abundance of Anopheles stephensi larvae and ad...Objective:To determine the significance of temperature,rainfall and humidity in the seasonal abundance of Anopheles stephensi in southern Iran.Methods:Data on the monthly abundance of Anopheles stephensi larvae and adults were gathered from earlier studies conducted between 2002 and 2019 in malaria prone areas of southeastern Iran.Climatic data for the studied counties were obtained from climatology stations.Generalized estimating equations method was used for cluster correlation of data for each study site in different years.Results:A significant relationship was found between monthly density of adult and larvae of Anopheles stephensi and precipitation,max temperature and mean temperature,both with simple and multiple generalized estimating equations analysis(P<0.05).But when analysis was done with one month lag,only relationship between monthly density of adults and larvae of Anopheles stephensi and max temperature was significant(P<0.05).Conclusions:This study provides a basis for developing multivariate time series models,which can be used to develop improved appropriate epidemic prediction systems for these areas.Long-term entomological study in the studied sites by expert teams is recommended to compare the abundance of malaria vectors in the different areas and their association with climatic variables.展开更多
Objective:To investigate the larvicidai activity of essential oil and methanol extract of the Nepeta menthoides（N.menthoides） against main malaria vector,Anopheles stephensi（An. stephensi）.Methods:The essential oi...Objective:To investigate the larvicidai activity of essential oil and methanol extract of the Nepeta menthoides（N.menthoides） against main malaria vector,Anopheles stephensi（An. stephensi）.Methods:The essential oil of planl was obtained by Clevenger type apparatus and the methanol extract was supplied with Percolation method,larvicidai activity was tested by WHO method.Twenty five fourth-instar larvae of An.stephensi were used in the larvicidai assay and four replicates were tested for each concentration.Five different concentrations of the oil and extract were tested for calculation of LC<sub>50</sub> and LC<sub>50</sub> values.Results:The LC<sub>50</sub> and LC<sub>90</sub> values were determined by probit analysis.IC<sub>50</sub> was 69.5 and 234.3 ppm and LC<sub>50</sub> was 175.5 and 419.9 ppm for the extract and essential oil respectively.Conclusions:According to the results of this study methanolic extract of plant exhibited more larvicidai activity than essential oil.This could be useful for investigation of new natural larvicidai compounds.展开更多
Objective:To explore the larvicidal activity of Catharanthus roseus(C.roseus) leaf extract and Raeillus thuringiensis(B.thuringiensis) against the malarial vector Anopheles stephensi(An. stephensi),when being used alo...Objective:To explore the larvicidal activity of Catharanthus roseus(C.roseus) leaf extract and Raeillus thuringiensis(B.thuringiensis) against the malarial vector Anopheles stephensi(An. stephensi),when being used alone or together.Methods:The larvicidal activity was assayed at various concentrations under the laboratory and field conditions.The LC_(50) and LC_(90) values of the C.roseus leaf extract were 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 petroleum ether extract of C.roseus against the first to fourth instars larvae with LC_(50)=3.34,4.48, 5.90 and 8.17 g/L,respectively;B.thuringiensis against the first to fourth instars larvae with LC_(50)=1.72.1.93.2.17 and 2.42 g/L.respectively:and the combined treatment with LC_(50)=2.18.2.41. 2.76 and 3.22 g/L,respectively.No mortality was observed in the control.Conclusions:The petroleum ether extract of C.roseus extract and B.thuringiensis have potential to be used as ideal eco-friendly agents for the control of An.stephensi in vector control programs.The combined treatment with this plant crude extract and bacterial toxin has better larvicidal efficacy against An.stephensi.展开更多
Objective: To assess the chemical composition and mosquito larvicidal potentials of essential oil of wild chive(Allium schoenoprasum L.) against Anopheles stephensi.Methods: In the search for an environmentally safer ...Objective: To assess the chemical composition and mosquito larvicidal potentials of essential oil of wild chive(Allium schoenoprasum L.) against Anopheles stephensi.Methods: In the search for an environmentally safer alternative mosquitoes control, the larvicidal efficacy of essential oil obtained from the leaves of Allium schoenoprasum L. against Anopheles stephensi was determined. The composition of chive essential oil was analyzed by gas chromatography–mass spectrometry. Results: In toxicity assays, the essential oil demonstrated substantial larvicidal activity against larvae of Anopheles stephensi with LC_(50) and LC_(90) values of 2.60, and 7.31 ppm after 24 h of exposure, respectively. Gas chromatography–mass spectrometry analysis of chive essential oil identified 35 components representing more than 97.31% of the total essential oil. The main constituents were sulfur compounds, including diallyl trisulfide(13.72%), 2-ethyl[1,3]dithiane(8.93%), allyl methyl trisulfide(8.77%), and trimethylene trisulfide(6.64%), respectively. Conclusions: This study demonstrated that wild chive essential oil has a rich source of eco-friendly bioactive compounds for use as a mosquito larvicide. The main reason for its extraordinary properties may be related to the high percentage of sulfur compounds.展开更多
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.
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.
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.
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.
文摘Objective:To assess the larvicidal and egg hatching inhibition property of the leaf essential oil of Cocrinia indica（C.indica） against Anopheles stephensi（An.stephensi）.Methods:The larvicidal potential of C.indica leaf essential oil was evaluated against 1st.2nd.3rd and 4th instars larvae of An.stephensi using WHO protocol.The 24h LC<sub>50</sub>and LC<sub>90</sub> values of the essential oil were determined following probit analysis.The egg hatching inhibition activity was also tested at 10.20.40.and 60 mg/L The IC<sub>50</sub> value of essential oil was determined against eggs of An. stephensi.Results:The essential oil extracted from C.indica possessed excellent larvicidal and egg hatching inhibition activity against An.stephensi.The bioassays showed LC<sub>50</sub>—LC<sub>90</sub>of 54.3- 140.3.65.5-155.6,86.8-180.7 and 95.3-192.6 for 1 st.2nd.3rd.and 4th larval insiars.respectively. The 5095 egg hatching inhibition concentration(IC<sub>50</sub>) was noted at 16.5 mg/L.Conclusions:The present finding suggest that the C.indica leaf essential oil provided an excellent potential for controlling An.slephemi mosquito at earlier stage of their life cycle.
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 .
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Higher Authorities for the grant of financial assistance with the Award of University Research Fellowship(Ref.No.No.H5/2009-2010/URF Order of the Vice chancellore,23011/2009)Professor and Head,Department of Zoology,Annamalai University for the laboratory facilities provided.
文摘Objective:To investigate the potentiality of mosquitocidal activity of Gliricidia sepium（C.sepium） （Jacq.）（Leguminosae）.Methods:Twenty five early third instar larvae of Anopheles stephensi （An.stephensi） were exposed to various concentrations（50-250 ppm） and the 24 h LC<sub>50</sub> values of the G.sepium extract was determined by probit analysis.The ovicidal activity was determined against An.stephensi to various concentrations ranging from 25-100 ppm under laboratory conditions.The eggs hatchabilily was assessed 48 h post treatment.The pupicidal activity was determined against An.stephensi to various concentrations ranging from 25-100 ppm.Mortality of each pupa was recorded after 24 h of exposure to the extract.Results:Results pertaining to the experiment clearly revealed that ethanol extract showed significant larvicidal,ovicidal and pupicidal activity against the An.stephensi.Larvicidal activity of ethanol extracts of G.sepium showed maximum mortality in 250 ppm concentration（96.0±2.4）%.Furthermore,the LC<sub>50</sub> was found to be 121.79 and the LC<sub>50</sub> value was recorded to be 231.98 ppm.Ovicidal activity of ethanol extract was assessed by assessing the egg hatchabilily.Highest concentration of both solvent extracts exhibited 100%ovicidal activity.Similarly,pupae exposed to different concentratioiLs of ethanol extract were found dead with 58.10%adult emergence when it was treated with 25 ppm concentration.Similarly,18.36（n=30;61.20%）;21.28（70.93） and 27.33（91.10） pupal mortality was recorded from the experimental pupae treated with 50,75 and 100 ppm concentration of extracts. Three fractions have been tested for their larvicidal activity of which the Fraction 3 showed the LC<sub>50</sub> and LC<sub>90</sub> values of 23.23 and 40.39 ppm.With regard to the ovicidal effect fraction 3 showed highest ovicidal activities than the other two fractions.Furthermore,there were no hatchabilily was recorded above 50 ppm（100%egg mortality） in the experimental group.Statistically significant pupicidal activity was recorded from 75 ppm concentration.Conclusions:From the results it can be concluded the crude extract of G.sepium is an excellent potential for controlling An.stephensi mosquito.It is apparent that,iraction 3 possess a novel and active principle which could be responsible for those biological activities.
文摘Objective:To investigate in vitro larvicidal and antioxidant enzymes potential of the medicinal plants Ginkgo biloba（G.biloba）,Stevia rebaudiana（S.rebaudiana） and Parthenium hysterophorous（P.hysterophorous） against Anopheles stephensi（An.stephensi） 4th instars larvae. Methods:For evaluation of larvicidal potential,the ethanolic,methanolic and dichloromethane leaves extracts of three different plants were used in dose-dependent experiments in two media, while the antioxidant enzymes activities were investigated using four different methods viz., superoxide dismutase,peroxidase,ascorbate and catalase.Results:An.stephensi has developed resistance to various synthetic insecticides,making its control increasingly difficult.The comparative performance of ethanolic extracts（65%-90%） was found better than the methanolic extract（70%-87%） and dichloromethane extract（60%-70%）.Among the three plants extracts tested in two media,S.rebaudiana exhibited higher larvicidal activity with LC<sub>50</sub>（24 h） in methanolic extract than P.hysterophorous and G.biloba.G.biloba and P.hysterophorous exhibited the strongest antioxidative enzymes activity and S.rebaudiana were less active and no significant difference was observed.Conclusions:These three plants exhibit larvicidal potential and can be further used for vector control alternative to synthetic insecticide due to eco-friendly and diseases control,furthermore these plant species have potent antioxidative enzyme activities, therefore,making them strong natural candidate particularly for diseases which are caused due to free radicals.
基金supports of School of Public Health & National Institute of Health research,Tehran University of Medical Sciences, World Health Organization and postgraduate students for helping for conduction of study
文摘ObjectiveTo investiagte insecticide resistance in target species for better insecticide resistance managemnet in malaria control programs.MethodsThe status of insecticide resistance to different imagicides in Anopheles stephensi (An. stephensi) including DDT 4%, lambdacyhalothrin 0.50%, deltamethrin 0.05%, permethrin 0.75%, cyfluthrin 0.15% and etofenprox 0.50% was performed according to WHO standard method.ResultsThe mortality rate to lambdacyhalothrin, permethrin, cyfluthrin, deltamethrin, etofenprox and DDT was (88.0±3.2), (92.0±2.7), (52.0±5.0), (96.0±2.2), (90.0±3.0) and (41.0±5.7) percent, respectively at diagnostic dose for one hour exposure time followed by 24 h recovery period.ConclusionsThese results showed first indication of pyrethroid resistance in An. stephensi in a malarious area, from southern Iran. There is widespread, multiple resistances in the country in An. stephensi to organochlorine and some report of tolerance to organophosphate insecticides and recently to pyrethroids. However, results of this paper will provide a clue for monitoring and mapping of insecticide resistance in the main malaria vector for implementation of any vector control.
文摘Objective:To determine the adult emergence inhibition（EI） and adulticidal activities of hexane,chloroform,ethyl acetate,and acetone leaves extracts of Anisomeles malabarica（A. malabarica）,Euphorbia hirta（E,hirta）,Ocimum basilicum（0.basilicum）,Ricinus communis（R. communis）,Solanum trilobatum（S.trilobatum）,Tridax procumbens（T.procumbens） and seeds of Gloriosa superba（G.superba） against Anopheles stephensi（An,stephensi）.Methods:The EI and adulticidal trials were carried out according to World Health Organization（WHO） procedures with slight modifications.The extracts were diluted in dimethyl sulphoxide in order to prepare a serial dilution of test dosages（15.625,31.25,62.5,125,250,500 and 1 000μg/mL）.Five duplicate trials were carried out for every sample concentration,and for each trial a negative control was included and the mortality was determined after 24 h of exposure.Results:The highest EI activity was found in ethyl acetate extracts of A malabarica,chloroform extracts of O.basilicum, S.trilobatum,acetone of extract of R.communis,T.procumbens,and seed extract of G.superba with EI<sub>50</sub> values 143.12,119.82.157.87,139.39,111.19,and 134.85μg/mL,and the effective adulticidal activity was observed in chloroform,acetone extracts of G.superba,T.procumbens,R. communis,S.trilobatum and ethyl acetate extract of 0.basilicum with LD<sub>50</sub> values 120.17,108.77, 127.22,163.11,118.27,and 93.02μg/mL,respectively.Chi-square value was significant at P【0.05 level.Conclusions:These results should encourage further efforts to investigate the compounds that might possess good EI and adulticidal properties when isolated in pure form.
基金The University of Burdwan for the facilities provided and acknowledges the financial support provided by The University of Burdwan,India
文摘Objective:To investigate the larvicidal activities of crude and chlor of orm:methanol(1:1 v/ v) extracts of some common spices(Cuminum cyminum,Allium sativum,Zingiber offinale, Curcuma longa) and vegetable waste(Solanum tuberosum germinated tuber) against Anopheles stephensi and Culex quinquefasciatus mosquito larvae.Methods:Larval mortality of above mosquito species were observed after 24,48 and 72 h of exposure to five concentrations of aqueous extract(0.1%,0.2%,0.3%,0.4%and 0.5%) and four concentrations(25,50,75 ppm) of chlor of orm:methanol(1:1 v/v) extract.The lethal concentration of individual spices or vegetable waste was determined by log-probit analysis(at 95%confidence level) and effect of crude and chlor of orm:methanol(1:1 v/v) extracts were recorded on non target organisms.Results: Relative mortality rate of both larval mosquito species were recorded in the following sequences: Cuminum cyminum】 Allium sativum】Zingiber offinale,Curcuma longa 】 Solanum tuberosum germinated tuber for crude extract,and efficacy of chlor of orm:methanol(1:1 v/v) extract were as follows:Curcuma longa 】 Zingiber offinale 】 Solanum tuberosum germinated tuber 】 Cuminum cyminum】 Allium sativum.Conclusions:Crude and chlor of orm:methanol(1:1 v/v) extract of Cuminum cyminum,Allium sativum,Zingiber offinale,Curcuma longa and Solanum tuberosum germinated tuber can be recommended effectively in mosquito control programmes at very low concentrations.No mortality and other abnormalities were noticed on non target organisms and further studies are needed to investigate the chemical structure of active principal which are responsible for larvicidal activity.
文摘Efficacy of 25 essential oils was screened against filarial vector, Culex quinquefasciatus, for their larvicidal and knockdown effects in a preliminary study. Of these, 8 oils viz. calamus oil, cinnamon oil, citronella oil, clove oil, eucalyptus oil, lemon oil, mentha oil and orange oil exhibited 100% larvicidal activity at 1000 ppm and 100% knockdown effect at 10% concentration. These 8 oils were screened further against Cx. Quinquefasciatus, Aedes aegypti and Anopheles stephensi for their larvicial and knockdown effects at different concentrations. Mentha oil was the most promising against An. Stephensi and Ae. Aegypti recording LC50 and LC90 values of 39.74 and 115.67 ppm and 46.23 and 165.36 ppm, respectively for larvicidal activity. Calamus oil was the most effective against Cx. Quinquefasciatus with LC50 and LC90 values of 40.40, and 140.07 ppm, respectively for larvicidal activity. Orange oil showed the most potent knockdown effect with the KT50 and KT95 values of 27.44, 26.22 and 29.91 and 70.81, 65.33 and 68.57 min, against An. stephensi, Cx. Quinquefasciatus and Ae. Aegypti, respectively. The results clearly indicated that mentha oil and calamus oil were the most promising larvicides and orange oil had potent knockdown effect against the tested mosquito species. These oils could be used to develop a new formulation to control mosquitoes.
基金financially supported by Research Deputy,Tehran University of Medical Sciences,Project No.29953
文摘Objective:To determine the significance of temperature,rainfall and humidity in the seasonal abundance of Anopheles stephensi in southern Iran.Methods:Data on the monthly abundance of Anopheles stephensi larvae and adults were gathered from earlier studies conducted between 2002 and 2019 in malaria prone areas of southeastern Iran.Climatic data for the studied counties were obtained from climatology stations.Generalized estimating equations method was used for cluster correlation of data for each study site in different years.Results:A significant relationship was found between monthly density of adult and larvae of Anopheles stephensi and precipitation,max temperature and mean temperature,both with simple and multiple generalized estimating equations analysis(P<0.05).But when analysis was done with one month lag,only relationship between monthly density of adults and larvae of Anopheles stephensi and max temperature was significant(P<0.05).Conclusions:This study provides a basis for developing multivariate time series models,which can be used to develop improved appropriate epidemic prediction systems for these areas.Long-term entomological study in the studied sites by expert teams is recommended to compare the abundance of malaria vectors in the different areas and their association with climatic variables.
基金financially supported by Tehran University of Medical Sciences
文摘Objective:To investigate the larvicidai activity of essential oil and methanol extract of the Nepeta menthoides（N.menthoides） against main malaria vector,Anopheles stephensi（An. stephensi）.Methods:The essential oil of planl was obtained by Clevenger type apparatus and the methanol extract was supplied with Percolation method,larvicidai activity was tested by WHO method.Twenty five fourth-instar larvae of An.stephensi were used in the larvicidai assay and four replicates were tested for each concentration.Five different concentrations of the oil and extract were tested for calculation of LC<sub>50</sub> and LC<sub>50</sub> values.Results:The LC<sub>50</sub> and LC<sub>90</sub> values were determined by probit analysis.IC<sub>50</sub> was 69.5 and 234.3 ppm and LC<sub>50</sub> was 175.5 and 419.9 ppm for the extract and essential oil respectively.Conclusions:According to the results of this study methanolic extract of plant exhibited more larvicidai activity than essential oil.This could be useful for investigation of new natural larvicidai compounds.
文摘Objective:To explore the larvicidal activity of Catharanthus roseus(C.roseus) leaf extract and Raeillus thuringiensis(B.thuringiensis) against the malarial vector Anopheles stephensi(An. stephensi),when being used alone or together.Methods:The larvicidal activity was assayed at various concentrations under the laboratory and field conditions.The LC_(50) and LC_(90) values of the C.roseus leaf extract were 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 petroleum ether extract of C.roseus against the first to fourth instars larvae with LC_(50)=3.34,4.48, 5.90 and 8.17 g/L,respectively;B.thuringiensis against the first to fourth instars larvae with LC_(50)=1.72.1.93.2.17 and 2.42 g/L.respectively:and the combined treatment with LC_(50)=2.18.2.41. 2.76 and 3.22 g/L,respectively.No mortality was observed in the control.Conclusions:The petroleum ether extract of C.roseus extract and B.thuringiensis have potential to be used as ideal eco-friendly agents for the control of An.stephensi in vector control programs.The combined treatment with this plant crude extract and bacterial toxin has better larvicidal efficacy against An.stephensi.
文摘Objective: To assess the chemical composition and mosquito larvicidal potentials of essential oil of wild chive(Allium schoenoprasum L.) against Anopheles stephensi.Methods: In the search for an environmentally safer alternative mosquitoes control, the larvicidal efficacy of essential oil obtained from the leaves of Allium schoenoprasum L. against Anopheles stephensi was determined. The composition of chive essential oil was analyzed by gas chromatography–mass spectrometry. Results: In toxicity assays, the essential oil demonstrated substantial larvicidal activity against larvae of Anopheles stephensi with LC_(50) and LC_(90) values of 2.60, and 7.31 ppm after 24 h of exposure, respectively. Gas chromatography–mass spectrometry analysis of chive essential oil identified 35 components representing more than 97.31% of the total essential oil. The main constituents were sulfur compounds, including diallyl trisulfide(13.72%), 2-ethyl[1,3]dithiane(8.93%), allyl methyl trisulfide(8.77%), and trimethylene trisulfide(6.64%), respectively. Conclusions: This study demonstrated that wild chive essential oil has a rich source of eco-friendly bioactive compounds for use as a mosquito larvicide. The main reason for its extraordinary properties may be related to the high percentage of sulfur compounds.
