In addition to causing discomfort, female mosquitoes introduce disease-carrying viruses and bacteria into the bloodstream of their victims. There are numerous publications describing the uses of sugary mosquito baits ...In addition to causing discomfort, female mosquitoes introduce disease-carrying viruses and bacteria into the bloodstream of their victims. There are numerous publications describing the uses of sugary mosquito baits with promising results. Without temperature control measures however, these methods are mainly useful for only nectar-feeding insects, including male mosquitoes, because the warmth of the blood is a condition for the females to locate their meals. The efforts required to keep the baits fresh against the natural spoiling process make them less attractive or impractical to implement. These experiments address these issues by using warm baits of water, sugar, boric acid, and antibiotics. Overnight, the general areas became clear of blood-sucking female mosquitoes while in numbers, the harmless males concentrated into the immediate vicinities. Control vs. experiment protocol established no other logical explanation for this phenomenon other than that females were attracted and killed by the bait. As expected, there was no female mosquito’s activity in these areas. There weren’t many left to do the work.展开更多
In the context of mosquito control, a plethora of devices have been put on the market. The effectiveness of these devices is not always proven, but some have interesting principles that have the potential to be a good...In the context of mosquito control, a plethora of devices have been put on the market. The effectiveness of these devices is not always proven, but some have interesting principles that have the potential to be a good means of mosquito control. Among these interesting devices are the photonic traps. We have carried out nightly captures of mosquitoes on human baits in the presence and absence of the device. These captures were made during the rainy season in the localities of Zogbadjè and Mènontin. The captures were made under the same atmospheric conditions at the same locations at 5-day intervals. These captures were made twice per house, indoors and outdoors, with one blank capture without the device and one capture with the device. The captured mosquitoes were identified and classified by genus and their aggressiveness determined by calculating the biting rate. A total of 845 mosquitoes were captured during these captures with 296 mosquitoes captured indoors without the device and 132 mosquitoes with the device present. This represents a decrease of 55.40% in culicidae density. Furthermore, a significant decrease was observed in aggressiveness, from 49 to 22 bites per man per night (b/m/n) with the use of the device. This decrease is even more important for nocturnal species such as Anopheles spp. whose aggressiveness decreased by 90%. The present study confirms the effectiveness of the “Electron go out mosquito small lamp” in reducing Culicidae density and mosquito aggression even in the presence of chemotactic interference. However, this study was limited in time and focused only on the ability of the device to reduce mosquito numbers and did not assess its epidemiological efficacy. It is therefore important to extend the work to examine the influence of the use of this device on population health and the occurrence of mosquito-borne diseases, particularly malaria.展开更多
The periodic outbreak of mosquito-borne diseases like dengue fever,zika fever,and yellow fever all over the world highlights the need for effective mosquito control methods targeting the biological system.Due to the l...The periodic outbreak of mosquito-borne diseases like dengue fever,zika fever,and yellow fever all over the world highlights the need for effective mosquito control methods targeting the biological system.Due to the lack of therapeutic measures,preventive treatments or vaccines against pathogens,insecticide resistance eventually lead the research focus towards novel technological applications in mosquito management.Nanomaterials with ovicidal,larvicidal,adulticidal,and repellent properties for controlling mosquito vectors are under research.A literature search was carried out for advancements in nanomaterials,insecticides,and mosquito control in PubMed/MEDLINE,Scopus,Google Scholar,ScienceDirect,and Web of Science.This paper aims to provide insights into various nanomaterials relevant to mosquito-borne diseases,in vivo and in vitro toxicity evaluation against mosquito species,mode of action,effect on non-target organisms,and ecological risks.Organic and inorganic materials that provide controlled release,target delivery,less dosage,prolonged efficacy,a reduction in the use of organic solvents and emulsifiers,and minimum pollution to the environment have already been explored.Indeed,further research on the ecological risk and economic feasibility of nanomaterials in mosquitocidal applications should be done prior to commercialization.展开更多
Mosquitoes are of great concern for occasionally carrying noxious diseases(dengue,malaria,zika,and yellow fever).To control mosquitoes,it is very crucial to effectively monitor their behavioral trends and presence.Tra...Mosquitoes are of great concern for occasionally carrying noxious diseases(dengue,malaria,zika,and yellow fever).To control mosquitoes,it is very crucial to effectively monitor their behavioral trends and presence.Traditional mosquito repellent works by heating small pads soaked in repellant,which then diffuses a protected area around you,a great alternative to spraying yourself with insecticide.But they have limitations,including the range,turning them on manually,and then waiting for the protection to kick in when the mosquitoes may find you.This research aims to design a fuzzy-based controller to solve the above issues by automatically determining a mosquito repellent’s speed and active time.The speed and active time depend on the repellent cartridge and the number of mosquitoes.The Mamdani model is used in the proposed fuzzy system(FS).The FS consists of identifying unambiguous inputs,a fuzzification process,rule evaluation,and a defuzzification process to produce unambiguous outputs.The input variables used are the repellent cartridge and the number of mosquitoes,and the speed of mosquito repellent is used as the output variable.The whole FS is designed and simulated using MATLAB Simulink R2016b.The proposed FS is executed and verified utilizing a microcontroller using its pulse width modulation capability.Different simulations of the proposed model are performed in many nonlinear processes.Then,a comparative analysis of the outcomes under similar conditions confirms the higher accuracy of the FS,yielding a maximum relative error of 10%.The experimental outcomes show that the root mean square error is reduced by 67.68%,and the mean absolute percentage error is reduced by 52.46%.Using a fuzzy-based mosquito repellent can help maintain the speed of mosquito repellent and control the energy used by the mosquito repellent.展开更多
Background: In lacustrine communities, whether in Benin or elsewhere, populations use impregnated mosquito nets (IMNs) as fishing nets. This depletes the lake of its fishery resources, which in turn are contaminated b...Background: In lacustrine communities, whether in Benin or elsewhere, populations use impregnated mosquito nets (IMNs) as fishing nets. This depletes the lake of its fishery resources, which in turn are contaminated by the pyrethroids impregnated in the nets. This study aims to determine the scale and factors associated with the use of pyrethroid-impregnated mosquito nets as fishing tools in the municipality of Sô-Ava in Benin. Methods: This is a cross-sectional and analytical study with two components. First, a quantitative component was made up of 280 volunteers who were interviewed in the seven districts of the city. Data collection was done in two phases: the first from September to October 2020, and the second in August 2022. Data were analyzed with Stata and logistic regression was used. Another qualitative component was made up of forty participants chosen by reasoned choice, of which 32 were split into four focus groups of eight members each, and the rest participated in semi-structured interviews. Triangulation of the different sources was used to analyze the data. Results: Around 67% of the population reported using impregnated mosquito nets as fishing tools and 33% exclusively for malaria. Seasonal fishermen (ORa = 2.03, CI = 1.35 - 4.97, P = 0.004) and years of professional experience (ORa = 1.53, CI = 1.00 - 2.05, P = 0.021) increase the risk of using these nets as fishing tools. The use of insecticide-treated mosquito nets against mosquitoes causes skin scratching and impairs breathing because of the impregnation products, as reported by respondents. Conclusion: A high prevalence of inappropriate use of impregnated mosquito nets in fishing practices is highlighted in this study. Interviews in the field revealed that nets are diverted for fishing purposes to increase the volume of catches. Consequently, it will be appropriate to assess the pyrethroid content in water and fishery products.展开更多
Objective:To determine resistance status of Culex species to different class of insecticides and assess the major anti-mosquito strategies employed by urban households and their possible effects on malaria acquisition...Objective:To determine resistance status of Culex species to different class of insecticides and assess the major anti-mosquito strategies employed by urban households and their possible effects on malaria acquisition.Methods:Structured questionnaires were randomly administered to obtain information on demographic characteristics,measures that people use to prevent mosquito bites and their perception of where mosquitoes breed in their communities.Adult susceptibility assays were also carried out using WHO discriminating dosages of four insecticides from different chemical classes against Culex species.Results:Majority of respondents(54.75%) preferred the use of domestic insecticides in the form of aerosols and coils.Among households that used domestic insecticides,the use of coil was most frequent(62.9%) with a mean(95%CI) of 9.18(8.99,9.37) coils per week.Strong level of pyrethroid-resistance and multiple insecticide resistance in Culex species were also detected in some of the study sites.Conclusions:The excessive use of domestic insecticides and high level of resistance in Culex species observed in the study area has implications for the ITN component of the nation's malaria control program in more subtle ways.People will lose interest in the use of ITN when it fails to protect users from bites of resistant Culex species.Excessive use of domestic insecticides may also select resistance in both malaria vectors and Culex species.On this account we recommend that nuisance mosquitoes must be controlled as part of malaria control programs to improve acceptance and utilization of ITN.展开更多
Objective:To investigate what kind of mosquito sample is necessary for the determination of insecticide susceptibility in malaria vectors.Methods:Larvae and pupae of Anopheles gambiae s.l.(An.gambiae)mosquitoes were c...Objective:To investigate what kind of mosquito sample is necessary for the determination of insecticide susceptibility in malaria vectors.Methods:Larvae and pupae of Anopheles gambiae s.l.(An.gambiae)mosquitoes were collected from the breeding sites in Littoral and Oueme departments.The Centers for Disease Control and Prevention(CDC)susceptibility tests were conducted on unfed male and female mosquitoes aged 2-5 days old.CDC susceptibility tests were also conducted on unfed,blood fed and gravid female mosquitoes aged2-5 days old.These susceptibility tests were also conducted on unfed and blood fed female mosquitoes aged 2-5 days old and 20 days old.CDC biochemical assay using synergist was also carried out to detect any increase in the activity of enzyme typically involved in insecticide metabolism.Results:Female An,gambiae Ladji and Sekandji populations were more susceptible than the males when they were unfed and aged 2-5 days old.The mortality rates of blood fed female An.gambiae Ladji and Sekandji populations aged 2-5 days old were lower than those obtained when females were unfed.In addition,the mortality rales of gravid female An.gambiae Ladji and Sekandji populations aged2-5 days old were lower than those obtained when they were unfed.The mortality rate obtained when female An.gambiae Sekandji populations were unfed and aged 20 days old was higher than the one obtained when these populations were unfed and aged 2-5 days old.The results obtained after effects of synergist penicillin in beeswax on F1 progeny of An.gambiae Ladji populations resistant to permethrin showed that mono-oxygenases were involved in permethrin resistant F1 progeny from Ladji.Conclusions:The resistance is a hereditary and dynamic phenomenon which can be due to metabolic mechanisms like overproduction of detoxifying enzymes activity.Many factors influence vector susceptibility to insecticide.Among these factors,there are mosquito sex,mosquito age,its physiological status.Therefore,it is useful to respect the World Health Organization criteria in the assessment of insecticide susceptibility tests in malaria vectors.Otherwise,susceptibility testing is conducted using unfed female mosquitoes aged 3-5 days old.Tests should also be carried out at(25±2)°C and(80±10)%relative humidity.展开更多
Objective:To establish an efficacious and efficient surveillance method of Armigeres(Ar.)subalbatus,a known filarial vector,surviving in forest habitats to estimate realistic population density and assess the impact o...Objective:To establish an efficacious and efficient surveillance method of Armigeres(Ar.)subalbatus,a known filarial vector,surviving in forest habitats to estimate realistic population density and assess the impact of altitudinal variations on the efficacy of the trap.Methods:In the study,12 locations in areas with an altitudinal range from 82 m to 920 m were selected in three reserve forests for night sampling of adult Ar.subalbatus mosquito using standard chemical lure based BG-Sentinel traps and CDC-light traps in pairs.Effects of locations and time were estimated on the efficacy of traps as mosquito density using multifactor analysis of variance for significant differences.Impact of altitudinal variations on the efficacy of traps was assessed using multiple regression with slope comparison.Results:BG-Sentinel trap collected significantly more adult Ar.subalbatus,4.43 folds in Gorumara NP,5.19 folds in Neora Valley NP and 12.10 folds in Mahananda WLS than the CDC-light trap irrespective to locations.BG-Sentinel traps were tolerant of altitudinal variations(80 m-170 m)and showed no significant relationship between density and altitudes in contrast to CDC-light traps which showed a significant negative impact on capturing efficacy with increase in altitudes(P<0.001).Conclusions:The study suggests that BG-Sentinel traps can be used effectively and efficiently to collect more Ar.subalbatus mosquitoes during night time in comparison to CDC-light trap under complex climatic conditions of forest and variable altitudes.展开更多
Mosquitoes are exceptional in their ability to pierce into human skin with a natural ultimate painless microneedle, namedfascicle. Here the structure of the Aedes albopictus mosquito fascicle is obtained using a Scann...Mosquitoes are exceptional in their ability to pierce into human skin with a natural ultimate painless microneedle, namedfascicle. Here the structure of the Aedes albopictus mosquito fascicle is obtained using a Scanning Electron Microscope (SEM),and the whole process of the fascicle inserting into human skin is observed using a high-speed video imaging technique. Directmeasurements of the insertion force for mosquito fascicle to penetrate into human skin are reported. Results show that themosquito uses a very low force (average 18 μN) to penetrate into the skin. This force is at least three orders of magnitude smallerthan the reported lowest insertion force for an artificial microneedle with an ultra sharp tip to insert into the human skin. In orderto understand the piercing mechanism of mosquito fascicle tip into human multilayer skin tissue, a numerical simulation isconducted to analyze the insertion process using a nonlinear finite element method. A good agreement occurs between thenumerical results and the experimental measurements.展开更多
Objective:To determine the larvicidal and adult emergence inhibition activities of castor （Ricinus communis） seed extract against three potential mosquito vectors Anopheles stephensi（An. slephensi）,Culex quinquefa...Objective:To determine the larvicidal and adult emergence inhibition activities of castor （Ricinus communis） seed extract against three potential mosquito vectors Anopheles stephensi（An. slephensi）,Culex quinquefasciatus（Cx.quinquefasciatus） and Aedes albopictus（Ae.albopictus） in India.Methods:The R.communis seed extract was tested,employing WHO procedure,against fourth larval instars of the three mosquito species for 24 h and larval mortalities were recorded at various concentrations（2-64μg/mL）:the 24 h LC<sub>50</sub> values of the R.communis seed extract were determined following Probit analysis.The larval killing,antipupation and adult emergence inhibition rates of the test extract,using a single concentration of 2μLC<sub>50</sub>,were studied at different time periods（24-72 h）:the extract toxicity was tested against a fish.Oreochromis niloticus（O.niloticus）.Results:The R.communis seed extract exhibited larvicidal effects with 100%killing activities at concentrations 32-64μg/mL,and with LC<sub>50</sub> values 7.10.11.64 and 16.84μg/mL for Cx.quinquefasciatus,An.stephensi and Ae.albopictus larvae,respectively. When the larvae were treated with the extract at a single concentration of 2×LC<sub>50</sub>,significant differences were observed,compared to control groups,in rate of pupation（P【0.001） as well as in adult formation（P【0.001）.Conclusions:The present findings suggest that the R.communis seed extract provided an excellent potential for controlling An.stephensi,Cx.quinquefasciatus and Ae. albopictus mosquito vectors.展开更多
Objective:To determine the mosquito larvicidal activity of leaf essential oil and their chemical constituents from Clausena anisata（C.anisata）（Willd.） Hook.f.ex Benth.against Culex quinquefasciatus,Aedes aegypti a...Objective:To determine the mosquito larvicidal activity of leaf essential oil and their chemical constituents from Clausena anisata（C.anisata）（Willd.） Hook.f.ex Benth.against Culex quinquefasciatus,Aedes aegypti and Anopheles Stephensi.Methods:Essential oil was obtained by hydro-distillation and the chemical composition of the leaf essential oil was analyzed using gas chromatography—mass spectrometry.The mosquitoes were reared in the vector control laboratory and twenty lateⅢinstar larvae of three mosquito species were exposed to based on the wide range and narrow range tests,essential oil was tested at 50.100.150,200 and 250 ppm and each compound was tested at various concentration（5-75 ppm） and were assayed in the laboratory by using the protocol of WHO 2005:the 24 h LC<sub>50</sub> values of the C.anisata leaf essential oil and their major compounds were determined following Probit analysis.Results:The oil contained were mainlyβ-pinene（32.8%）,sabinene（28.3%）,germacrene-D（12.7%）,estragole （6.4%） and linalool（5.9%）.The essential oil from the leaves of C.anisata exhibited significant larvicidal activity,with 24 h LC<sub>50</sub> values of 140.96,130.19 and 119.59 ppm.respectively.The five pure constituents extracted from the C.anisata leaf essential oil were also tested individually against three mosquito larvae.The LC<sub>50</sub> values ofβ-pinene,sabinene,germacrene-D,estragole and linalool appeared to be most effective against Anopheles stephensi(LC<sub>50</sub>-23.17,19.67,16.95. 11.01,35.17 ppm) followed by Aedes aegypti(LC<sub>50</sub>-27.69,21.20,18.76,12.70,38.64 ppm) and Culex quinquefasciatus(LC<sub>50</sub>-32.23,25.01.21.28,14.01,42.28).Conclusions:The essential oil of C. anisata contains five major compounds and has remarkable larvicidal properties,which may be considered as a potent source for the production of natural larvicides.展开更多
Objective:To determine the larvicidal and repellent activities of Sida acuta Burm.F.（Family: Malvaceae）extract against Culex quinquefasciatus,Aedes aegypti and Anopheles stephensi. Methods:Twenty five late III insta...Objective:To determine the larvicidal and repellent activities of Sida acuta Burm.F.（Family: Malvaceae）extract against Culex quinquefasciatus,Aedes aegypti and Anopheles stephensi. Methods:Twenty five late III instar larve of three mosquito species were exposed to various concentrations（15-90 mg/L） and were assayed in the laboratory by using the protocol of WHO 2005:the 24 h LC<sub>50</sub> values of the Sida acuta leaf extract was determined following Probit analysis. The repellent efficacy was determined against three mosquito species at three concentrations viz.,1.0,2.5 and 5.0 mg/cm<sup>2</sup> under the laboratory conditions.Results:Results showed varying degree of larvicidal activity of crude extract of Sida acuta against three important mosquitoes with LC<sub>50</sub> values ranging between 38 to 48 mg/L.The crude extract had strong repellent action against three species of mosquitoes as it provided 100%protection against Anopheles stephensi for 180 min followed by Aedes aegypti（150 min） and Culex quinquefasciatus（120 min）.Conclusions: From the results it can be concluded the crude extract of Sida acuta was an excellent potential for controlling Culex quinquefasciatus,Aedes aegypti and Anopleles stephensi mosquitoes.展开更多
Objective:To determine lead level primarily in Culex quinquefasciatus(Cx.quinquefasciatus), and Culex gelidus(Cx.gelidus) larvae inhabiting lead consuming factories,and to putatively estimate eco-toxicological impact ...Objective:To determine lead level primarily in Culex quinquefasciatus(Cx.quinquefasciatus), and Culex gelidus(Cx.gelidus) larvae inhabiting lead consuming factories,and to putatively estimate eco-toxicological impact of effluents from the firms.Methods:Third instars larvae were sampled by standard dipping method and lead concentrations in the larvae and their respective surrounding factory aquatic environments were determined through standard atomic absorption spectrophotometry(AAS).Results:Cx.quinquefasciatus was the most abundant species followed by Cx.gelidus.The levels of lead were higher in the Cx.quinquefasciatus(1.08-47.47μg/g),than in the wastewaters surface(0.01-0.78 μg/mL) from the factories or closer areas around factories. Other species were not reaching the.criteria for lead determination.Conclusions:The Cx. quinquefasciatus larvae can bio-accumulate the metal and can potentially serve as a biomarker of lead contamination,to complemente conventional techniques.展开更多
Objective:To assess the chemical composition and mosquito larvicidal potentials of essential oils of locally sourced Pinus sylvestris(P.sylvestris)and Syzygium aromatkum(S.aromaticum)against Aedes aegypti(A.aegypti)an...Objective:To assess the chemical composition and mosquito larvicidal potentials of essential oils of locally sourced Pinus sylvestris(P.sylvestris)and Syzygium aromatkum(S.aromaticum)against Aedes aegypti(A.aegypti)and Culex quinquefasciatus(C.quinquefasciatus).Method:The chemical composition of the essential oils of both plants was determined using GCMS while the larvicidal bioassay was carried out using different concentrations of the oils against the larvae of A.aegypti and C.quinquefasciatus in accordance with the standard protocol.Results:The results as determined by GC-MS showed that oil of S.aromaticum has eugenol(80.5%)as its principal constituent while P.sylvestris has 3-Cyclohexene-1-methanol,.alpha.,.alpha.4-trimethyl(27.1%)as its dominant constituent.Both oils achieved over 85%larval mortality within24 h.The larvae of A.aegypti were more susceptible to the oils[LC_(50)(S.aromaticum)=92.56 mg/L,LC_(50)(P.sylvestris)=100.39 mg/L]than C.quinquefasciatus[LC_(50)(S.aromaticum)=124.42 mg/L;LC_(50)(P.sylvestris)=128.00 mg/L].S.aromaticum oil was more toxic to the mosquito larvae than oil of P.sylvatris but the difference in lethal concentrations was insignificant(P>0.05).Condusioii:The results justify the larvicidal potentials of both essential oils and the need to incorporate them in vector management and control.展开更多
Objective:To investigate the abundance and seasonal dynamics of mosquitoes,and to detect Japanese encephalitis virus(JEV)in these mosquitoes at the nesting colony of ardeid birds.Methods:Mosquitoes were collected bimo...Objective:To investigate the abundance and seasonal dynamics of mosquitoes,and to detect Japanese encephalitis virus(JEV)in these mosquitoes at the nesting colony of ardeid birds.Methods:Mosquitoes were collected bimonthly from July 2009 to May 2010 by Centers for Disease Control.Light traps and dry ice,as a source of CO_2,were employed to attract mosquitoes.Mosquitoes were first identified,pooled into groups of upto 50 mosquitoes by species,and tested for JEV infection by viral isolation and reverse transcriptase polymerase chain reaction.Results:A total of 20370 mosquitoes comprising 14 species in five genera were collected.The five most abundant mosquito species collected were Culex tritaeniorhynchus(95.46%),Culex vishnui(2.68%),Culex gelidus(0.72%),Anopheles peditaeniatus(0.58%)and Culex quinquefasciatus(0.22%).Mosquito peak densities were observed in July.All of 416 mosquito pools were negative for JEV.Conclusions:This study provides new information about mosquito species and status of JEV infection in mosquitoes in Thailand.Further study should be done to continue a close survey for the presence of this virus in the ardeid birds.展开更多
Prevention and control of mosquito-borne diseases is a key challenge of huge public health importance.Plant-mediated synthesis of nanoparticles has recently gained attention as a cheap,rapid and eco-friendly method to...Prevention and control of mosquito-borne diseases is a key challenge of huge public health importance.Plant-mediated synthesis of nanoparticles has recently gained attention as a cheap,rapid and eco-friendly method to control mosquito vector populations,with special reference to young instars.Furthermore,plant-fabricated nanoparticles have been successfully employed as dengue virus growth inhibitors.In this Editorial,parasitologists,entomologists and researchers in drug nanosynthesis are encouraged to deal with a number of crucial challenges of public health importance.展开更多
Objective:To evaluate the larvicidal efficacy of crude and fractionated extracts of Dracaena loureiri endocarp against Aedes aegypti,Aedes albopictus,Culex quinquefasciatus,and Anopheles minimus mosquitos.Methods:Larv...Objective:To evaluate the larvicidal efficacy of crude and fractionated extracts of Dracaena loureiri endocarp against Aedes aegypti,Aedes albopictus,Culex quinquefasciatus,and Anopheles minimus mosquitos.Methods:Larvicidal activity was tested according to World Health Organization standard protocol.The third-stage larvae of each mosquito species were exposed to various concentrations of Dracaena loureiri crude extract and six groups of Dracaena loureiri fractionated extracts(RC-DT 009-014).Larval mortality rates were observed after 24 h and48 h of exposure.Then,a computerized probit analysis of the mortality data was performed to determine lethal concentration 50(LC_(50))and lethal concentration 90 values.Results:Anopheles minimus larvae(24-h LC_(50)77.88 mg/L)had the highest susceptibility to crude extract,whereas others(Aedes aegypti,24-h LC_(50)224.73 mg/L;Aedes albopictus,24-h LC_(50)261.75 mg/L;and Culex quinquefasciatus,24-h LC_(50)282.86 mg/L)were significantly less susceptible.The most effective groups of fractionated extracts were RC-DT 012 and RC-DT 013.The mosquito species most susceptible to fractionated extracts was Culex quinquefasciatus,with 24-h LC_(50)values of 0.66 and 0.94 mg/L for RC-DT 012 and RC-DT 013,respectively.Conclusions:The larvicidal activity of fractionated extracts is more effective than that of crude extract against all tested mosquito species.For the most effective alternative larvicide,purification and a phytochemical constituent analysis must be performed.展开更多
Objective:To investigate the studies on effects of Andrographis paniculata(A.paniculata) (Burm.f.) and Andrographis lineata(A.lineata) nees(Family:Acanthaeeae)extracts against two mosquitoes Culex quinquefasciatus(Cx....Objective:To investigate the studies on effects of Andrographis paniculata(A.paniculata) (Burm.f.) and Andrographis lineata(A.lineata) nees(Family:Acanthaeeae)extracts against two mosquitoes Culex quinquefasciatus(Cx.quinquefasciatus)(Say.) and Aedes aegypti(Ae.aegypti) (Linn.).Methods:The aqueous and petroleum ether extracts of two plant species.A.paniculata and A.lineate were examined against the larvae of,4.aegypti(L.) and Cx.quinquefasciatus with gradually increasing concenlration ie.from 50 to 200 ppm of solvent extracts and to test their activity in combination with each other.Results:In a 24 h bioassay experiment with plant extracts,highest mortalities were recorded at 200 ppm of concentrations for leaves of 4.lineta and A.paniculata individually.For combination effect,only 150 ppm of the mixture of solvent extracts of petroleum ether:aqueous(1:1) extracts showed 100%mortality after 24 h of exposure. Conclusions:The results show that,insecticides of plant combination is ecofriend and has better larvicidal activity compared to individual extracts.展开更多
Objective:To establish the larvicidal activities,if any of solvent extracts of Rauvolfia serpentina (R.serpentina) L.seeds against Culex quinquefasciatus(Cx.quinquefasciatus) Say.1823 as target species.Methods:Seeds o...Objective:To establish the larvicidal activities,if any of solvent extracts of Rauvolfia serpentina (R.serpentina) L.seeds against Culex quinquefasciatus(Cx.quinquefasciatus) Say.1823 as target species.Methods:Seeds of R.serpentina were extracted with five solvents graded according to the polarity[viz.petroleum ether.benzene,ethyl acetate,acetone and absolute alcohol] continuing one after another with the same seeds.Results:Mortality rate with petroleum ether extract was significantly higher than other extracts.The mortality rates of late 3rd instar larvae wore 50.33±5.51.10.00±1.00.0.00±0.00.21.33±1.53 and 0.00±0.00 in 100 ppm concentration of petroleum ether,benzene,ethyl acetate,acetone and absolute alcohol respectively,after 24 h of exposure period.Conclusions:Results of this study show that petroleum ether extract of R. serpentina seed may be considered as a potent source of mosquito larvicidal agent.展开更多
Objective:To evaluate some agricultural waste extracts as insecticide and their effects on enzyme activities in liver and kidney of male mice.Methods:The insecticidal activity of five tested compounds(one crude extrac...Objective:To evaluate some agricultural waste extracts as insecticide and their effects on enzyme activities in liver and kidney of male mice.Methods:The insecticidal activity of five tested compounds(one crude extract and 4 waste compounds) was bioassay against the 3rd instars of the Culex pipiens(Cx.pipiens) larvae in the laboratory.The LC_(50) values of eucalyptol,apricot kernel.Rice bran,corn,black liquor and white liquor are 91.45.1166.1,1203.3.21449.65.4025.78 and 6343.18 ppm,respectively.Selection of the compounds for the subsequent studies was not only dependent on LC_(50) values but also on the persistence of these wastes products on large scale.Results:White and black liquor did not produce any gross effect at 200 mg/Kg body weight.No apparent toxic symptoms were observed in tested animals during the whole period of the experimenl which run out for 14 days.No statistically significance was observed in the enzyme choliuesterase activity,the activities of liver enzymes and kidney function in treated mice with black and while liquors.While,no and slighl inhibition was observed after the 2weeks ol treatment period with deltamethrin and lenilrothion reached to about 24%in plasma cholinesterase enzyme activity.Significantly increase in the activities ol liver enzymes and kidney function in treated mice with deltamethrin and fenitrothion.Conclusions:Black liquor can be used efficiently In control Cx.pipiens larvae under laboratory condition.Environmental problem caused by rice straw can be solved by converting the waste material to beneficial natural selective insecticide.展开更多
文摘In addition to causing discomfort, female mosquitoes introduce disease-carrying viruses and bacteria into the bloodstream of their victims. There are numerous publications describing the uses of sugary mosquito baits with promising results. Without temperature control measures however, these methods are mainly useful for only nectar-feeding insects, including male mosquitoes, because the warmth of the blood is a condition for the females to locate their meals. The efforts required to keep the baits fresh against the natural spoiling process make them less attractive or impractical to implement. These experiments address these issues by using warm baits of water, sugar, boric acid, and antibiotics. Overnight, the general areas became clear of blood-sucking female mosquitoes while in numbers, the harmless males concentrated into the immediate vicinities. Control vs. experiment protocol established no other logical explanation for this phenomenon other than that females were attracted and killed by the bait. As expected, there was no female mosquito’s activity in these areas. There weren’t many left to do the work.
文摘In the context of mosquito control, a plethora of devices have been put on the market. The effectiveness of these devices is not always proven, but some have interesting principles that have the potential to be a good means of mosquito control. Among these interesting devices are the photonic traps. We have carried out nightly captures of mosquitoes on human baits in the presence and absence of the device. These captures were made during the rainy season in the localities of Zogbadjè and Mènontin. The captures were made under the same atmospheric conditions at the same locations at 5-day intervals. These captures were made twice per house, indoors and outdoors, with one blank capture without the device and one capture with the device. The captured mosquitoes were identified and classified by genus and their aggressiveness determined by calculating the biting rate. A total of 845 mosquitoes were captured during these captures with 296 mosquitoes captured indoors without the device and 132 mosquitoes with the device present. This represents a decrease of 55.40% in culicidae density. Furthermore, a significant decrease was observed in aggressiveness, from 49 to 22 bites per man per night (b/m/n) with the use of the device. This decrease is even more important for nocturnal species such as Anopheles spp. whose aggressiveness decreased by 90%. The present study confirms the effectiveness of the “Electron go out mosquito small lamp” in reducing Culicidae density and mosquito aggression even in the presence of chemotactic interference. However, this study was limited in time and focused only on the ability of the device to reduce mosquito numbers and did not assess its epidemiological efficacy. It is therefore important to extend the work to examine the influence of the use of this device on population health and the occurrence of mosquito-borne diseases, particularly malaria.
文摘The periodic outbreak of mosquito-borne diseases like dengue fever,zika fever,and yellow fever all over the world highlights the need for effective mosquito control methods targeting the biological system.Due to the lack of therapeutic measures,preventive treatments or vaccines against pathogens,insecticide resistance eventually lead the research focus towards novel technological applications in mosquito management.Nanomaterials with ovicidal,larvicidal,adulticidal,and repellent properties for controlling mosquito vectors are under research.A literature search was carried out for advancements in nanomaterials,insecticides,and mosquito control in PubMed/MEDLINE,Scopus,Google Scholar,ScienceDirect,and Web of Science.This paper aims to provide insights into various nanomaterials relevant to mosquito-borne diseases,in vivo and in vitro toxicity evaluation against mosquito species,mode of action,effect on non-target organisms,and ecological risks.Organic and inorganic materials that provide controlled release,target delivery,less dosage,prolonged efficacy,a reduction in the use of organic solvents and emulsifiers,and minimum pollution to the environment have already been explored.Indeed,further research on the ecological risk and economic feasibility of nanomaterials in mosquitocidal applications should be done prior to commercialization.
文摘Mosquitoes are of great concern for occasionally carrying noxious diseases(dengue,malaria,zika,and yellow fever).To control mosquitoes,it is very crucial to effectively monitor their behavioral trends and presence.Traditional mosquito repellent works by heating small pads soaked in repellant,which then diffuses a protected area around you,a great alternative to spraying yourself with insecticide.But they have limitations,including the range,turning them on manually,and then waiting for the protection to kick in when the mosquitoes may find you.This research aims to design a fuzzy-based controller to solve the above issues by automatically determining a mosquito repellent’s speed and active time.The speed and active time depend on the repellent cartridge and the number of mosquitoes.The Mamdani model is used in the proposed fuzzy system(FS).The FS consists of identifying unambiguous inputs,a fuzzification process,rule evaluation,and a defuzzification process to produce unambiguous outputs.The input variables used are the repellent cartridge and the number of mosquitoes,and the speed of mosquito repellent is used as the output variable.The whole FS is designed and simulated using MATLAB Simulink R2016b.The proposed FS is executed and verified utilizing a microcontroller using its pulse width modulation capability.Different simulations of the proposed model are performed in many nonlinear processes.Then,a comparative analysis of the outcomes under similar conditions confirms the higher accuracy of the FS,yielding a maximum relative error of 10%.The experimental outcomes show that the root mean square error is reduced by 67.68%,and the mean absolute percentage error is reduced by 52.46%.Using a fuzzy-based mosquito repellent can help maintain the speed of mosquito repellent and control the energy used by the mosquito repellent.
文摘Background: In lacustrine communities, whether in Benin or elsewhere, populations use impregnated mosquito nets (IMNs) as fishing nets. This depletes the lake of its fishery resources, which in turn are contaminated by the pyrethroids impregnated in the nets. This study aims to determine the scale and factors associated with the use of pyrethroid-impregnated mosquito nets as fishing tools in the municipality of Sô-Ava in Benin. Methods: This is a cross-sectional and analytical study with two components. First, a quantitative component was made up of 280 volunteers who were interviewed in the seven districts of the city. Data collection was done in two phases: the first from September to October 2020, and the second in August 2022. Data were analyzed with Stata and logistic regression was used. Another qualitative component was made up of forty participants chosen by reasoned choice, of which 32 were split into four focus groups of eight members each, and the rest participated in semi-structured interviews. Triangulation of the different sources was used to analyze the data. Results: Around 67% of the population reported using impregnated mosquito nets as fishing tools and 33% exclusively for malaria. Seasonal fishermen (ORa = 2.03, CI = 1.35 - 4.97, P = 0.004) and years of professional experience (ORa = 1.53, CI = 1.00 - 2.05, P = 0.021) increase the risk of using these nets as fishing tools. The use of insecticide-treated mosquito nets against mosquitoes causes skin scratching and impairs breathing because of the impregnation products, as reported by respondents. Conclusion: A high prevalence of inappropriate use of impregnated mosquito nets in fishing practices is highlighted in this study. Interviews in the field revealed that nets are diverted for fishing purposes to increase the volume of catches. Consequently, it will be appropriate to assess the pyrethroid content in water and fishery products.
文摘Objective:To determine resistance status of Culex species to different class of insecticides and assess the major anti-mosquito strategies employed by urban households and their possible effects on malaria acquisition.Methods:Structured questionnaires were randomly administered to obtain information on demographic characteristics,measures that people use to prevent mosquito bites and their perception of where mosquitoes breed in their communities.Adult susceptibility assays were also carried out using WHO discriminating dosages of four insecticides from different chemical classes against Culex species.Results:Majority of respondents(54.75%) preferred the use of domestic insecticides in the form of aerosols and coils.Among households that used domestic insecticides,the use of coil was most frequent(62.9%) with a mean(95%CI) of 9.18(8.99,9.37) coils per week.Strong level of pyrethroid-resistance and multiple insecticide resistance in Culex species were also detected in some of the study sites.Conclusions:The excessive use of domestic insecticides and high level of resistance in Culex species observed in the study area has implications for the ITN component of the nation's malaria control program in more subtle ways.People will lose interest in the use of ITN when it fails to protect users from bites of resistant Culex species.Excessive use of domestic insecticides may also select resistance in both malaria vectors and Culex species.On this account we recommend that nuisance mosquitoes must be controlled as part of malaria control programs to improve acceptance and utilization of ITN.
基金Funded by the Ministere de I'Enseignement Superieur et de la Recherche Scientifique(MESRS),Benin and the President's Malaria Initiative of the U.S.Government through USAID
文摘Objective:To investigate what kind of mosquito sample is necessary for the determination of insecticide susceptibility in malaria vectors.Methods:Larvae and pupae of Anopheles gambiae s.l.(An.gambiae)mosquitoes were collected from the breeding sites in Littoral and Oueme departments.The Centers for Disease Control and Prevention(CDC)susceptibility tests were conducted on unfed male and female mosquitoes aged 2-5 days old.CDC susceptibility tests were also conducted on unfed,blood fed and gravid female mosquitoes aged2-5 days old.These susceptibility tests were also conducted on unfed and blood fed female mosquitoes aged 2-5 days old and 20 days old.CDC biochemical assay using synergist was also carried out to detect any increase in the activity of enzyme typically involved in insecticide metabolism.Results:Female An,gambiae Ladji and Sekandji populations were more susceptible than the males when they were unfed and aged 2-5 days old.The mortality rates of blood fed female An.gambiae Ladji and Sekandji populations aged 2-5 days old were lower than those obtained when females were unfed.In addition,the mortality rales of gravid female An.gambiae Ladji and Sekandji populations aged2-5 days old were lower than those obtained when they were unfed.The mortality rate obtained when female An.gambiae Sekandji populations were unfed and aged 20 days old was higher than the one obtained when these populations were unfed and aged 2-5 days old.The results obtained after effects of synergist penicillin in beeswax on F1 progeny of An.gambiae Ladji populations resistant to permethrin showed that mono-oxygenases were involved in permethrin resistant F1 progeny from Ladji.Conclusions:The resistance is a hereditary and dynamic phenomenon which can be due to metabolic mechanisms like overproduction of detoxifying enzymes activity.Many factors influence vector susceptibility to insecticide.Among these factors,there are mosquito sex,mosquito age,its physiological status.Therefore,it is useful to respect the World Health Organization criteria in the assessment of insecticide susceptibility tests in malaria vectors.Otherwise,susceptibility testing is conducted using unfed female mosquitoes aged 3-5 days old.Tests should also be carried out at(25±2)°C and(80±10)%relative humidity.
基金Dr.Kailash Chandra,Director,Zoological Survey of India(ZSI),Ministry of Environment,Forest and Climate Change(MoEFCC),Govt.of India,for providing funding and logistic support.
文摘Objective:To establish an efficacious and efficient surveillance method of Armigeres(Ar.)subalbatus,a known filarial vector,surviving in forest habitats to estimate realistic population density and assess the impact of altitudinal variations on the efficacy of the trap.Methods:In the study,12 locations in areas with an altitudinal range from 82 m to 920 m were selected in three reserve forests for night sampling of adult Ar.subalbatus mosquito using standard chemical lure based BG-Sentinel traps and CDC-light traps in pairs.Effects of locations and time were estimated on the efficacy of traps as mosquito density using multifactor analysis of variance for significant differences.Impact of altitudinal variations on the efficacy of traps was assessed using multiple regression with slope comparison.Results:BG-Sentinel trap collected significantly more adult Ar.subalbatus,4.43 folds in Gorumara NP,5.19 folds in Neora Valley NP and 12.10 folds in Mahananda WLS than the CDC-light trap irrespective to locations.BG-Sentinel traps were tolerant of altitudinal variations(80 m-170 m)and showed no significant relationship between density and altitudes in contrast to CDC-light traps which showed a significant negative impact on capturing efficacy with increase in altitudes(P<0.001).Conclusions:The study suggests that BG-Sentinel traps can be used effectively and efficiently to collect more Ar.subalbatus mosquitoes during night time in comparison to CDC-light trap under complex climatic conditions of forest and variable altitudes.
基金supported by the National Natural Science Foundation of China (No.10672035,No.90816025,No.10721062)SRFDP (No.20060141007)
文摘Mosquitoes are exceptional in their ability to pierce into human skin with a natural ultimate painless microneedle, namedfascicle. Here the structure of the Aedes albopictus mosquito fascicle is obtained using a Scanning Electron Microscope (SEM),and the whole process of the fascicle inserting into human skin is observed using a high-speed video imaging technique. Directmeasurements of the insertion force for mosquito fascicle to penetrate into human skin are reported. Results show that themosquito uses a very low force (average 18 μN) to penetrate into the skin. This force is at least three orders of magnitude smallerthan the reported lowest insertion force for an artificial microneedle with an ultra sharp tip to insert into the human skin. In orderto understand the piercing mechanism of mosquito fascicle tip into human multilayer skin tissue, a numerical simulation isconducted to analyze the insertion process using a nonlinear finite element method. A good agreement occurs between thenumerical results and the experimental measurements.
文摘Objective:To determine the larvicidal and adult emergence inhibition activities of castor （Ricinus communis） seed extract against three potential mosquito vectors Anopheles stephensi（An. slephensi）,Culex quinquefasciatus（Cx.quinquefasciatus） and Aedes albopictus（Ae.albopictus） in India.Methods:The R.communis seed extract was tested,employing WHO procedure,against fourth larval instars of the three mosquito species for 24 h and larval mortalities were recorded at various concentrations（2-64μg/mL）:the 24 h LC<sub>50</sub> values of the R.communis seed extract were determined following Probit analysis.The larval killing,antipupation and adult emergence inhibition rates of the test extract,using a single concentration of 2μLC<sub>50</sub>,were studied at different time periods（24-72 h）:the extract toxicity was tested against a fish.Oreochromis niloticus（O.niloticus）.Results:The R.communis seed extract exhibited larvicidal effects with 100%killing activities at concentrations 32-64μg/mL,and with LC<sub>50</sub> values 7.10.11.64 and 16.84μg/mL for Cx.quinquefasciatus,An.stephensi and Ae.albopictus larvae,respectively. When the larvae were treated with the extract at a single concentration of 2×LC<sub>50</sub>,significant differences were observed,compared to control groups,in rate of pupation（P【0.001） as well as in adult formation（P【0.001）.Conclusions:The present findings suggest that the R.communis seed extract provided an excellent potential for controlling An.stephensi,Cx.quinquefasciatus and Ae. albopictus mosquito vectors.
文摘Objective:To determine the mosquito larvicidal activity of leaf essential oil and their chemical constituents from Clausena anisata（C.anisata）（Willd.） Hook.f.ex Benth.against Culex quinquefasciatus,Aedes aegypti and Anopheles Stephensi.Methods:Essential oil was obtained by hydro-distillation and the chemical composition of the leaf essential oil was analyzed using gas chromatography—mass spectrometry.The mosquitoes were reared in the vector control laboratory and twenty lateⅢinstar larvae of three mosquito species were exposed to based on the wide range and narrow range tests,essential oil was tested at 50.100.150,200 and 250 ppm and each compound was tested at various concentration（5-75 ppm） and were assayed in the laboratory by using the protocol of WHO 2005:the 24 h LC<sub>50</sub> values of the C.anisata leaf essential oil and their major compounds were determined following Probit analysis.Results:The oil contained were mainlyβ-pinene（32.8%）,sabinene（28.3%）,germacrene-D（12.7%）,estragole （6.4%） and linalool（5.9%）.The essential oil from the leaves of C.anisata exhibited significant larvicidal activity,with 24 h LC<sub>50</sub> values of 140.96,130.19 and 119.59 ppm.respectively.The five pure constituents extracted from the C.anisata leaf essential oil were also tested individually against three mosquito larvae.The LC<sub>50</sub> values ofβ-pinene,sabinene,germacrene-D,estragole and linalool appeared to be most effective against Anopheles stephensi(LC<sub>50</sub>-23.17,19.67,16.95. 11.01,35.17 ppm) followed by Aedes aegypti(LC<sub>50</sub>-27.69,21.20,18.76,12.70,38.64 ppm) and Culex quinquefasciatus(LC<sub>50</sub>-32.23,25.01.21.28,14.01,42.28).Conclusions:The essential oil of C. anisata contains five major compounds and has remarkable larvicidal properties,which may be considered as a potent source for the production of natural larvicides.
文摘Objective:To determine the larvicidal and repellent activities of Sida acuta Burm.F.（Family: Malvaceae）extract against Culex quinquefasciatus,Aedes aegypti and Anopheles stephensi. Methods:Twenty five late III instar larve of three mosquito species were exposed to various concentrations（15-90 mg/L） and were assayed in the laboratory by using the protocol of WHO 2005:the 24 h LC<sub>50</sub> values of the Sida acuta leaf extract was determined following Probit analysis. The repellent efficacy was determined against three mosquito species at three concentrations viz.,1.0,2.5 and 5.0 mg/cm<sup>2</sup> under the laboratory conditions.Results:Results showed varying degree of larvicidal activity of crude extract of Sida acuta against three important mosquitoes with LC<sub>50</sub> values ranging between 38 to 48 mg/L.The crude extract had strong repellent action against three species of mosquitoes as it provided 100%protection against Anopheles stephensi for 180 min followed by Aedes aegypti（150 min） and Culex quinquefasciatus（120 min）.Conclusions: From the results it can be concluded the crude extract of Sida acuta was an excellent potential for controlling Culex quinquefasciatus,Aedes aegypti and Anopleles stephensi mosquitoes.
文摘Objective:To determine lead level primarily in Culex quinquefasciatus(Cx.quinquefasciatus), and Culex gelidus(Cx.gelidus) larvae inhabiting lead consuming factories,and to putatively estimate eco-toxicological impact of effluents from the firms.Methods:Third instars larvae were sampled by standard dipping method and lead concentrations in the larvae and their respective surrounding factory aquatic environments were determined through standard atomic absorption spectrophotometry(AAS).Results:Cx.quinquefasciatus was the most abundant species followed by Cx.gelidus.The levels of lead were higher in the Cx.quinquefasciatus(1.08-47.47μg/g),than in the wastewaters surface(0.01-0.78 μg/mL) from the factories or closer areas around factories. Other species were not reaching the.criteria for lead determination.Conclusions:The Cx. quinquefasciatus larvae can bio-accumulate the metal and can potentially serve as a biomarker of lead contamination,to complemente conventional techniques.
基金Logistic support from the Management of Osun State University Osogbo through grant support number UNIOSUN/SET/010
文摘Objective:To assess the chemical composition and mosquito larvicidal potentials of essential oils of locally sourced Pinus sylvestris(P.sylvestris)and Syzygium aromatkum(S.aromaticum)against Aedes aegypti(A.aegypti)and Culex quinquefasciatus(C.quinquefasciatus).Method:The chemical composition of the essential oils of both plants was determined using GCMS while the larvicidal bioassay was carried out using different concentrations of the oils against the larvae of A.aegypti and C.quinquefasciatus in accordance with the standard protocol.Results:The results as determined by GC-MS showed that oil of S.aromaticum has eugenol(80.5%)as its principal constituent while P.sylvestris has 3-Cyclohexene-1-methanol,.alpha.,.alpha.4-trimethyl(27.1%)as its dominant constituent.Both oils achieved over 85%larval mortality within24 h.The larvae of A.aegypti were more susceptible to the oils[LC_(50)(S.aromaticum)=92.56 mg/L,LC_(50)(P.sylvestris)=100.39 mg/L]than C.quinquefasciatus[LC_(50)(S.aromaticum)=124.42 mg/L;LC_(50)(P.sylvestris)=128.00 mg/L].S.aromaticum oil was more toxic to the mosquito larvae than oil of P.sylvatris but the difference in lethal concentrations was insignificant(P>0.05).Condusioii:The results justify the larvicidal potentials of both essential oils and the need to incorporate them in vector management and control.
基金supported by the Monitoring and Surveillance Center for Zoonotic Diseases in Wildlife and Exotic Animals (MOZWE).Faculty of Veterinary Science,Mahidol University(Grant No.0517.131/5944)
文摘Objective:To investigate the abundance and seasonal dynamics of mosquitoes,and to detect Japanese encephalitis virus(JEV)in these mosquitoes at the nesting colony of ardeid birds.Methods:Mosquitoes were collected bimonthly from July 2009 to May 2010 by Centers for Disease Control.Light traps and dry ice,as a source of CO_2,were employed to attract mosquitoes.Mosquitoes were first identified,pooled into groups of upto 50 mosquitoes by species,and tested for JEV infection by viral isolation and reverse transcriptase polymerase chain reaction.Results:A total of 20370 mosquitoes comprising 14 species in five genera were collected.The five most abundant mosquito species collected were Culex tritaeniorhynchus(95.46%),Culex vishnui(2.68%),Culex gelidus(0.72%),Anopheles peditaeniatus(0.58%)and Culex quinquefasciatus(0.22%).Mosquito peak densities were observed in July.All of 416 mosquito pools were negative for JEV.Conclusions:This study provides new information about mosquito species and status of JEV infection in mosquitoes in Thailand.Further study should be done to continue a close survey for the presence of this virus in the ardeid birds.
文摘Prevention and control of mosquito-borne diseases is a key challenge of huge public health importance.Plant-mediated synthesis of nanoparticles has recently gained attention as a cheap,rapid and eco-friendly method to control mosquito vector populations,with special reference to young instars.Furthermore,plant-fabricated nanoparticles have been successfully employed as dengue virus growth inhibitors.In this Editorial,parasitologists,entomologists and researchers in drug nanosynthesis are encouraged to deal with a number of crucial challenges of public health importance.
基金supported by the Naresuan University Research Fund(Reference Number:R2560B057)
文摘Objective:To evaluate the larvicidal efficacy of crude and fractionated extracts of Dracaena loureiri endocarp against Aedes aegypti,Aedes albopictus,Culex quinquefasciatus,and Anopheles minimus mosquitos.Methods:Larvicidal activity was tested according to World Health Organization standard protocol.The third-stage larvae of each mosquito species were exposed to various concentrations of Dracaena loureiri crude extract and six groups of Dracaena loureiri fractionated extracts(RC-DT 009-014).Larval mortality rates were observed after 24 h and48 h of exposure.Then,a computerized probit analysis of the mortality data was performed to determine lethal concentration 50(LC_(50))and lethal concentration 90 values.Results:Anopheles minimus larvae(24-h LC_(50)77.88 mg/L)had the highest susceptibility to crude extract,whereas others(Aedes aegypti,24-h LC_(50)224.73 mg/L;Aedes albopictus,24-h LC_(50)261.75 mg/L;and Culex quinquefasciatus,24-h LC_(50)282.86 mg/L)were significantly less susceptible.The most effective groups of fractionated extracts were RC-DT 012 and RC-DT 013.The mosquito species most susceptible to fractionated extracts was Culex quinquefasciatus,with 24-h LC_(50)values of 0.66 and 0.94 mg/L for RC-DT 012 and RC-DT 013,respectively.Conclusions:The larvicidal activity of fractionated extracts is more effective than that of crude extract against all tested mosquito species.For the most effective alternative larvicide,purification and a phytochemical constituent analysis must be performed.
文摘Objective:To investigate the studies on effects of Andrographis paniculata(A.paniculata) (Burm.f.) and Andrographis lineata(A.lineata) nees(Family:Acanthaeeae)extracts against two mosquitoes Culex quinquefasciatus(Cx.quinquefasciatus)(Say.) and Aedes aegypti(Ae.aegypti) (Linn.).Methods:The aqueous and petroleum ether extracts of two plant species.A.paniculata and A.lineate were examined against the larvae of,4.aegypti(L.) and Cx.quinquefasciatus with gradually increasing concenlration ie.from 50 to 200 ppm of solvent extracts and to test their activity in combination with each other.Results:In a 24 h bioassay experiment with plant extracts,highest mortalities were recorded at 200 ppm of concentrations for leaves of 4.lineta and A.paniculata individually.For combination effect,only 150 ppm of the mixture of solvent extracts of petroleum ether:aqueous(1:1) extracts showed 100%mortality after 24 h of exposure. Conclusions:The results show that,insecticides of plant combination is ecofriend and has better larvicidal activity compared to individual extracts.
基金the financial support provided by The University of Burdwan,India
文摘Objective:To establish the larvicidal activities,if any of solvent extracts of Rauvolfia serpentina (R.serpentina) L.seeds against Culex quinquefasciatus(Cx.quinquefasciatus) Say.1823 as target species.Methods:Seeds of R.serpentina were extracted with five solvents graded according to the polarity[viz.petroleum ether.benzene,ethyl acetate,acetone and absolute alcohol] continuing one after another with the same seeds.Results:Mortality rate with petroleum ether extract was significantly higher than other extracts.The mortality rates of late 3rd instar larvae wore 50.33±5.51.10.00±1.00.0.00±0.00.21.33±1.53 and 0.00±0.00 in 100 ppm concentration of petroleum ether,benzene,ethyl acetate,acetone and absolute alcohol respectively,after 24 h of exposure period.Conclusions:Results of this study show that petroleum ether extract of R. serpentina seed may be considered as a potent source of mosquito larvicidal agent.
文摘Objective:To evaluate some agricultural waste extracts as insecticide and their effects on enzyme activities in liver and kidney of male mice.Methods:The insecticidal activity of five tested compounds(one crude extract and 4 waste compounds) was bioassay against the 3rd instars of the Culex pipiens(Cx.pipiens) larvae in the laboratory.The LC_(50) values of eucalyptol,apricot kernel.Rice bran,corn,black liquor and white liquor are 91.45.1166.1,1203.3.21449.65.4025.78 and 6343.18 ppm,respectively.Selection of the compounds for the subsequent studies was not only dependent on LC_(50) values but also on the persistence of these wastes products on large scale.Results:White and black liquor did not produce any gross effect at 200 mg/Kg body weight.No apparent toxic symptoms were observed in tested animals during the whole period of the experimenl which run out for 14 days.No statistically significance was observed in the enzyme choliuesterase activity,the activities of liver enzymes and kidney function in treated mice with black and while liquors.While,no and slighl inhibition was observed after the 2weeks ol treatment period with deltamethrin and lenilrothion reached to about 24%in plasma cholinesterase enzyme activity.Significantly increase in the activities ol liver enzymes and kidney function in treated mice with deltamethrin and fenitrothion.Conclusions:Black liquor can be used efficiently In control Cx.pipiens larvae under laboratory condition.Environmental problem caused by rice straw can be solved by converting the waste material to beneficial natural selective insecticide.
