Current resistance status of Aedes aegypti and Aedes albopictus populations in Penang Island,Malaysia

Objective:To determine the current insecticide resistance status of Aedes(Ae.)aegypti and Ae.albopictus to four insecticides,namely 0.05%deltamethrin,0.75%permethrin,5%malathion and 0.25%pirimiphos-methyl using the World Health Organisation(WHO)susceptibility test kit.Methods:Adult bioassays were carried out using the standard protocol of the World Health Organisation.All F1 generation urban and suburban field strains of Ae.aegypti and Ae.albopictus were tested against pyrethroid and organophosphate insecticides,including the presence of piperonyl butoxide(PBO)in four replicates of 25 non-blood-fed female mosquitoes ranging from 3 to 5 days old.The Vector Control Research Unit(VCRU)laboratory strain served as a reference strain.Results:In this study,0.05%deltamethrin demonstrated a lower value of knockdown time when 50%of the mosquito population died(KT50)and knockdown time when 95%of the mosquito population died(KT95),which is significantly more effective compared to 0.75%permethrin against adult female Ae.aegypti(urban and suburban)and Ae.albopictus(urban and suburban)(ANOVA,P<0.01).Meanwhile,5%malathion was a more effective insecticide,amounting to the shorter KT50 and KT95 compared to 0.25%pirimiphos-methyl against Ae.aegypti(urban and suburban)and Ae.albopictus(urban and suburban).Ae.aegypti urban and Ae.aegypti suburban performed a higher resistance ratio(RR)towards both 0.05%deltamethrin and 0.75%permethrin due to the wide use of permethrin in dengue vector control programs in Malaysia.However,Ae.albopictus urban and suburban have lower resistance than Ae.aegypti urban and suburban towards 0.05%deltamethrin and 0.75%permethrin at 24 hours post-treatment.The addition of PBO with these insecticides successfully reduced knockdown time(KT50 and KT95)values of most of the Ae.aegypti and Ae.albopictus field strains except PBO+0.75%permethrin against Ae.aegypti suburban.Conclusions:The addition of PBO to insecticides has significantly reduced the knockdown time(KT50 and KT95)values on most of Ae.aegypti and Ae.albopictus urban strain except PBO+5%malathion against Ae.albopictus urban strain and PBO+0.75%permethrin against Ae.albopictus suburban strain in comparison to exposure to insecticides without PBO.Ae.aegypti showed a higher resistance ratio of 50(RR50)when compared with the VCRU laboratory reference strain(susceptible strain)at the exposure to the deltamethrin,including with pre-exposure to PBO.This study found that the addition of PBO with organophosphates(5%malathion and 0.25%pirimiphos-methyl)was significantly more effective than pyrethroids against Ae.aegypti and Ae.albopictus(urban and suburban)due to their high mortality rate at 24 hours.It can be concluded that the usage of PBO can help reduce resistance alteration in Aedes mosquitoes.

Target-site mediated insecticide resistance in major mosquito(Diptera:Culicidae)vectors:A systematic review

The use of insecticides remain the most effective vector control approach for mosquito borne diseases like malaria,dengue fever,chikungunya,and Zika virus disease;however,their increasing resistance has complicated the management.Mutations in kdr,ace-1/ace-2,rdl,and nAChR,are involved in target-site mediated resistance and prevent the binding of pyrethroids and dichlorodiph enyltrichloroethane,organophosphorus pesticide,carbamates and cyclodienes,respectively.Here,we review the current knowledge on target-site mediated insecticidal resistance mechanisms in major mosquito vectors and the techniques used to identify these mutations.The results showed that kdr mutations are frequently reported in mosquito species,indicating the overuse of pyrethroid in mosquito control.Report on ace mutations is very limited,primarily detected in Anopheles and Culex,with extremely low detection rate in Aedes,despite the wide application of organophosphates in their control.Notably,reports of rdl mutations and changes in nAChR are rare,which provides an opportunity to exploit these target sites,particularly in the event of disease outbreaks.Among various detection methods such as RFLP,TaqMan,Multiplex PCR and FRET,allele-specific PCR is mostly employed,especially in detecting kdr mutation.However,allele-specific PCR cannot detect novel mutation.As a result,there is an urgent need to develop a scalable,cost-effective tool that can be widely applied especially as these mutations are genetic markers for early detection of insecticide resistance.Robust monitoring methods remain critical to manage insecticide resistance and effective control of mosquito-borne diseases.

Mosquito Control, Killing off the Females

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.

On the Range of Action of Adult Culex pipiens s.l.

Mosquitoes are an interesting topic due to their medical importance, as they play an active role in the transmission of many pathogens and parasites, acting as vectors for various pathologies that are deadly to humans, such as dengue, yellow fever, chikungunya, West Nile virus, encephalitis and malaria, among many others that are less common. In terms of morbidity and mortality caused by vector-borne diseases, mosquitoes are the most dangerous animals for humanity and, although they also play a role in the ecosystem as a food source for other organisms, their importance for public health cannot be overlooked. As highly efficient vectors, they put more than three billion people at risk, mainly in tropical and subtropical regions as well as in Europe, since heat waves and flooding are becoming more frequent and severe, and summers are getting longer and warmer, accelerating mosquito development, biting rates, and the incubation of the pathogens within their bodies. Female mosquitoes bite to acquire proteins for the development of their ovaries and eggs and, in the process, acquire pathogens and/or parasites from one vertebrate host and transmit them to another, usually after a short period of replication. Three of their four life stages are lived in still freshwater, so it is crucial to understand their range of action when they reach adulthood and leave the water, in order to plan and implement local prevention measures. A set of georeferenced abundance data collected in mainland Portugal over seven years was linked to cartographed water bodies in a geographic information system to estimate the distances at which Culex pipiens s.l. had a significant presence, with criteria based on the size of the catches. The result allows for an estimate of the fly range of those mosquitoes, which can be used to focus countermeasures.

Breeding Site Characteristics of Mosquito in Ouagadougou, Burkina Faso

Urban areas deal with the emergence or resurgence of transmissible and non-transmissible diseases, linked in particular to urban lifestyle and sanitation issues. Human practices create or maintain conditions that favour mosquitoes’ breeding. This study investigates mosquito breeding sites characteristics in Ouagadougou, from September to November 2020. Mosquito larvae were sampled across three districts in the city, chosen based on socio-demographic and urbanization levels. The larval collection from natural breeding sites using the ladle technique and larvae transferred to can. For artificial sites, the larvae were transferred directly into can Larvae were collected from 83 breeding sites, predominantly artificial: 39% in plastic containers, 23% in clay containers, and 13% in metal, while natural sites like puddles accounted for only 25%. A total of 8352 mosquitoes were identified as six species: Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, Anopheles gambiae s.l., Anopheles funestus, and Mansonia africana. Ae. aegypti was the most prevalent, found across all breeding site types, whereas Culex quinquefasciatus and Anopheles gambiae were mainly in natural sites. Physico-chemical analysis of the breeding sites revealed that conductivity and turbidity were consistent across breeding sites. The highest median pH values were observed in ceramic and metal containers. Water temperature showed minimal variation. The presence of Anopheles gambiae and Culex quinquefasciatus correlated with higher water temperature, turbidity, and conductivity. Anopheles funestus preferred high pH environments. Conversely, Aedes aegypti, Aedes albopictus, and Mansonia africana were less influenced by these parameters. The findings underscore the need for community involvement in water and waste management to control mosquito populations, especially targeting the Aedes aegypti species. Raising awareness among locals about proper water storage and disposal practices is crucial for effective vector control.

不同方法提取驱蚊香草精油中化学成分的比较

[目的]比较不同方法提取的驱蚊香草精油的化学成分。[方法]应用GC/MS分别对2种方法提取的精油进行分离和检测。[结果]在水蒸气蒸馏法提取的精油中检测到23个成分,在有机溶剂法提取的精油中检测到49个成分;精油的主要成分为香茅醇、马兜铃烯、乙酸香茅酯、香叶醇、芳樟醇、异薄荷酮、β-波旁烯和香榧烯醇等。[结论]水蒸气蒸馏法使驱蚊香草精油化学成分大量损失,但对沸点高、相对难挥发的主要化学成分有很好地富集作用;有机溶剂提取法能很好地保留驱蚊香草精油的化学成分。

Monitoring Report on Mosquitoes at Ports of Four Regions in East China during 2011—2014

[Objective] The aim was to understand the species composition, distribution, density, seasonal fluctuation and pathogens of mosquitoes in four regions of East China to provide basic data for prevention and control of mosquitoes at ports. [Method] The mosquitoes at 21 ports of four regions in East China were investigated during 2011-2014 by CO2 lamp method, egg collection method, scoop method and visual method. The species of mosquitoes was identified, and pathogens in mosquitoes were detected. [Result] From 2011 to 2014, 102 583 mosquitoes were captured at the ports, belonging to 18 species, 6 genera and 1 family. Culex pipi- ens quinquefasciatus or Culex pipiens pallens was the dominant species at most ports. Mosquitoes could be captured from May to October, and the captured mosquitoes were the most in June. The positive rate of egg collectors was 9.41%, and the positive rate of breeding places was 7.23%. Rare entry mosquitoes were captured, and most of them were C. pipiens pallens. The detection results of dengue fever, malaria and other pathogens were negative. [Conclusion] C. pipiens quinquefasciatus or C. pipiens pallens was dominant at most ports, and the peak period was June. There were breeding environments of mosquitoes at some ports, so the prevention and control of mosquitoes at these ports should be paid more at- tention to in future.

Application of DNA Barcode Technology to the Identification of Exotic Mosquitoes at Ningbo Port

[Objective] The study aimed to solve the problem of morphological identi- fication difficulties and propose solutions for the identification of foreign mosquitoes that are difficult to identify. [Method] Based on the sequencing, alignment and anal- ysis of COl gene fragment, DNA barcode technology was used to identify 7 exotic mosquitoes, and the phylogenetic analysis was performed using MEGA6.0 and DNASTAR software. Then the morphological characteristics of the mosquitoes were reviewed. [Result[ These mosquitoes were Armigeres subalbatus, Culex gefidus, Anopheles gambiae, and Culiseta incidens. [Conclusion] DNA barcode technology is a useful supplement to the morphological classification method of mosquitoes.

Larvicidal and repellent potential of Moringa oleifera against malarial vector,Anopheles stephensi Liston(Insecta:Diptera:Culicidae)

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.

Measurement and Prediction of Insertion Force for the Mosquito Fascicle Penetrating into Human Skin

Mosquitoes are exceptional in their ability to pierce into human skin with a natural ultimate painless microneedle, named fascicle. 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. Direct measurements of the insertion force for mosquito fascicle to penetrate into human skin are reported. Results show that the mosquito uses a very low force (average 18 μN) to penetrate into the skin. This force is at least three orders of magnitude smaller than the reported lowest insertion force for an artificial microneedle with an ultra sharp tip to insert into the human skin. In order to understand the piercing mechanism of mosquito fascicle tip into human multilayer skin tissue, a numerical simulation is conducted to analyze the insertion process using a nonlinear finite element method. A good agreement occurs between the numerical results and the experimental measurements.

Ovicidal and repellent activities of botanical extracts against Culex quinquefasciatus,Aedes aegypti and Anopheles stephensi(Diptera:Culicidae)

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.

Chemical composition and larvicidal activity of leaf essential oil from Clausena anisata (Willd.) Hook.f.ex Benth (Rutaceae) against three mosquito species

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 LC50 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 LC50 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 LC50 values ofβ-pinene,sabinene,germacrene-D,estragole and linalool appeared to be most effective against Anopheles stephensi(LC50-23.17,19.67,16.95. 11.01,35.17 ppm) followed by Aedes aegypti(LC50-27.69,21.20,18.76,12.70,38.64 ppm) and Culex quinquefasciatus(LC50-32.23,25.01.21.28,14.01,42.28).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.

Exploration of larvicidal and adult emergence inhibition activities of Ricinus communis seed extract against three potential mosquito vectors in Kolkata,India

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 LC50 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 2μLC50,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 LC50 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×LC50,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.

Larvicidal and repellent activities of Sida acuta Burm.F.(Family:Malvaceae) against three important vector mosquitoes

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 LC50 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/cm2 under the laboratory conditions.Results:Results showed varying degree of larvicidal activity of crude extract of Sida acuta against three important mosquitoes with LC50 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.

Lead levels of Culex mosquito larvae inhabiting lead utilizing factory

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.

Chikungunya infection:A potential re-emerging global threat

Infectious diseases are indeed a lifelong threat to everyone irrespective of age, sex, lifestyle and socio-economic status. The infectious diseases have persisted among the prominent causes of death globally. Recently, re-emergence of Chikungunya viral infection harmed many in Asian and African countries. Chikungunya was considered as a major threat in developing and underdeveloped countries; the recent epidemiological outbreak of Chikungunya in La Reunion urges the global researchers to develop effective vaccine against this viral disease. In this review, Chikungunya, pathogenesis and epidemiology were briefly described.

Larvicidal and repellent properties of some essential oils against Culex tritaeniorhynchus Giles and Anopheles subpictus Grassi(Diptera:Culicidae)

Objective:To investigate the larvicidal and repellent properties of essential oils from various parts of four plant species Cymbopogan citrates,Cinnamomum zeylanicum,Rosmarinus of ficinalis and Zingiber of ficinale against Culex tritaeniorhynchus（Cx.tritaeniorhynchus） and Anopheles subpictus（An.subpktus）.Methods:Essential oils were obtained by hydro-distillation method.The mosquitoes were reared in the vector control laboratory and twenty five late third ins tar larvae of Cx.tritaeniorhynchus and An.subpictus were exposed to based on the wide range and narrow range test,essential oil tested at various concentrations ranging from 25 to 250 ppm.The larval mortality was observed after 24 h under the laboratory conditions.The repellent efficacy was determined against two mosquito species at three concentrations viz., 1.0,2.5 and 5.0 mg/cm2 under laboratory conditions.Results:Results showed all the four plant essential oil produced significant larval mortality against two mosquito species.However,the highest larvicidal activity was observed in the essential oil from Zingiber of ficinale against Cx. tritaeniorhynchus and An.subpktus with the LC50 and LC90 values as 98.83,57.98 ppm and 186.55, 104.23 ppm,respectively.All the four essential oil shows significant repellency against Cx. tritaeniorhynchus than An.subpktus.Among four essential oil tested the highest repellency was observed in Zingiber of ficinale,a higher concentration of 5.0 mg/cm2 provided 100%protection up to 150 and 180 min against Cx.tritaeniorhynchus and An.subpktus,respectively.Conclusions: In this work,it can be concluded that four essential oils which were distilled from Cymbopogan citrates,Cinnamomum zeylanicum,Rosmarinus of ficinalis and Zingiber of ficinale showed promising larvicidal and repellent agent against Cx.tritaeniorhynchus and An.subpktus.

Larvicidal efficacies and chemical composition of essential oils of Pinus sylvestris and Syzygium aromaticum against mosquitoes

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.

Seasonal abundance and potential of Japanese encephalitis virus infection in mosquitoes at the nesting colony of ardeid birds,Thailand

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.

Plant-mediated synthesis of nanoparticles:A newer and safer tool against mosquito-borne diseases?

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.