Objective:To predict the distribution of dengue vector Aedes(Ae.)albopictus and identify high-risk areas for dengue fever transmission.Methods:Data on Ae.albopictus occurrences were collected from electronic databases...Objective:To predict the distribution of dengue vector Aedes(Ae.)albopictus and identify high-risk areas for dengue fever transmission.Methods:Data on Ae.albopictus occurrences were collected from electronic databases.Ensemble models were developed to assess the impacts of climate,vegetation,and human activity on Ae.albopictus.The optimal ensemble model was then used to identify the distribution of suitable areas for Ae.albopictus.Results:After removing duplicate sites and retaining only one location per 100 m×100 m grid,189 Ae.albopictus breeding sites were identified.The optimal ensemble model revealed that Ae.albopictus exhibited higher breeding suitability in Shanghai under specific conditions:a normalized difference vegetation index of 0.1 to 0.6,maximum precipitation in the warmest month ranging from 400 mm to 470 mm,maximum temperature in the warmest month between 30.0℃and 31.0℃,and proximity to waterways within 0.5 km.The most suitable habitats for Ae.albopictus were primarily concentrated in Shanghai’s central urban areas and scattered across the inner suburban districts.Conclusions:The high-risk areas of Ae.albopictus are widely distributed throughout the central urban area and scattered across the inner suburban district of Shanghai,creating conditions conducive to the outbreak of dengue fever.It is essential to enhance targeted control measures for Ae.albopictus in the identified risk areas.展开更多
Objective:To evaluate the phenotypic resistance profile of Aedes(Ae.)albopictus against multiple insecticides and to delineate the frequency and pyrethroid-resistance association of knockdown resistance(kdr)mutations ...Objective:To evaluate the phenotypic resistance profile of Aedes(Ae.)albopictus against multiple insecticides and to delineate the frequency and pyrethroid-resistance association of knockdown resistance(kdr)mutations V1016G,I1532T and F1534S in Ae.albopictus in Pudong New Area,Shanghai,China.Methods:From June to July 2024,a total of 1249 Ae.albopictus eggs and 4732 adults were collected from five towns in the Pudong New Area.These collected specimens were then reared to obtain the F1 generation including 10235 larvae at the late 3rd to early 4th instar stages,as well as 5800 non-blood-fed adults aged 3 to 5 days.Larval resistance was assessed via the immersion method,and adult resistance via the contact tube method.For the larval,0≤resistance ratio(RR)<3 indicates sensitivity;3≤RR<10 denotes low resistance;10≤RR<40 signifies moderate resistance;RR≥40 represents high resistance.While for adults,a mortality rate of≥98%stands for sensitivity,80%≤mortality rate<98%indicates suspected resistance,and mortality rate<80%denotes a resistant population.A pooled sequencing strategy(8 sample pools)was used to detect genotype kdr mutations including V1016G,I1532T,F1534S in the voltage-gated sodium channel(VGSC)gene.Results:Ae.albopictus larvae displayed low resistance to fenthion(RR=5.85),temephos(RR=4.63)and β-cypermethrin(RR=3.20),but remained fully susceptible to propoxur(RR=0.33).Adults showed incipient resistance to β-cypermethrin(mortality:92.7%),lambda-cyhalothrin(mortality:96.8%)and permethrin(mortality:86.6%),while remained sensitive to propoxur(mortality:100%).For Ae.albopictus population in the Pudong New Area,pyrethroid tolerance was primarily driven by F1534S mutation,which was amplified when the mutation was paired with V1016G or I1532T.Conclusions:These findings highlight the need for integrated resistance monitoring and targeted insecticide rotation-such as prioritizing propoxur for Ae.albopictus larval and adult control-to mitigate resistance spread and preserve vector management efficacy.展开更多
Objective: To investigate the efficacies of 12 essential oil(EO) formulations from three Zingiberaceae plants(Alpinia galanga, Curcuma zedoaria, and Zingiber cassumunar) individually and in combination with an augment...Objective: To investigate the efficacies of 12 essential oil(EO) formulations from three Zingiberaceae plants(Alpinia galanga, Curcuma zedoaria, and Zingiber cassumunar) individually and in combination with an augmenting Eucalyptus globulus(E. globulus) EO against females of Aedes albopictus(Ae. albopictus) and Anopheles minimus(An. minimus). Methods: These formulations were evaluated for their ovicidal, oviposition deterrent and adulticidal activities against Ae. albopictus and An. minimus by a topical method, a double-choice method and a WHO susceptibility test, respectively. Results: It was found that all formulations of Zingiberaceae plants EOs augmented with E. globulus EO were more effective in oviposition deterrent, ovicidal, and adulticidal activities against the two mosquito species than all of the formulations used without E. globulus EO. Their oviposition deterrent, ovicidal and adulticidal activities were equivalent to those of 10% w/v cypermethrin. In contrast, 70% v/v ethyl alcohol as a control alone was not effective at all. The highest synergistic effect in effective repellency against Ae. albopictus was achieved by 5% Alpinia galanga EO + 5% E. globulus EO and against An. minimus was 5% Zingiber cassumunar EO + 5% E. globulus EO. Moreover, the highest synergistic effects in ovicidal activities against Ae. albopictus and An. minimus were achieved by 10% Zingiber cassumunar EO + 10% E. globulus EO and 5% Curcuma zedoaria EO + 5% E. globulus EO, respectively. For the adulticidal activities, the highest synergistic effect against two mosquitoes was achieved by 5% Curcuma zedoaria EO + 5% E. globulus EO. Conclusions: These results suggest that Zingiberaceae plant EOs augmented with E. globulus EO have a high potential to be developed into oviposition deterrent, ovicidal, and adulticidal agents for controlling populations of Ae. albopictus and An. minimus.展开更多
Objective:To generate life table characteristics for the dengue vector Aedes albopictus(A. albopictus) under uncontrolled conditions,incorporating both the aquatic and the adult stages. Methods:Ten females derived fro...Objective:To generate life table characteristics for the dengue vector Aedes albopictus(A. albopictus) under uncontrolled conditions,incorporating both the aquatic and the adult stages. Methods:Ten females derived from wild pupae were allowed to fully blood-feed on restrained mice.774 eggs were hatched in seasoned water.F1 larvae were followed for development until their F2 counterparts emerged as adults.Some population parameters were monitored(Fl) or estimated(F2).Results:A.albopictus exhibited increased fecundity and egg hatch success. Immature development was quick.Immature survival was high,with lowest rate in the pupal stage.Adult emergence was about 81%and sex ratio was close to 1:1.Generational mortality(K) was about 28%.A high proportion of females completed a reproductive cycle and the obtained parity rate was predicted to lead to higher fecundity in the next generation.Conclusios:It can be concluded that natural A.albopictus populations in Penang seem largely determined by quick development in combination with low immature loss and increased oviposition.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 record the human cases of dengue fever(DF) and investigate the Aedes mosquito species circulating during the Hanoi 2011 DF epidemics. Methods: 24 different outbreak points were recorded in 8 districts be...Objective: To record the human cases of dengue fever(DF) and investigate the Aedes mosquito species circulating during the Hanoi 2011 DF epidemics. Methods: 24 different outbreak points were recorded in 8 districts between August and December 2011. Results: 140 patients were hospitalized following dengue diagnostic with a predominance of males(59.3%) and the 15-34 age class. Only DENV-1(11.27%) and DENV-2(88.73%) serotypes were detected in human samples. Mosquito sampling performed in and around patients households revealed the predominance of Aedes aegypti(95.15%) versus Aedes albopictus(4.85%). There is a positive correlation between the population density of Aedes aegypti and the number of human cases and duration of outbreaks. Conclusions: This was not observed for Aedes albopictus. 3 pools of Aedes aegypti were positive with dengue virus, two with DENV-1 and one with DENV-2.展开更多
Objective: To investigate the larvicidal activity of Syzygium guineense(Myrtaceae)(S. guineense), Monodora myristica and Zanthoxylum heitzii(Rutaceae)(Z. heitzii) extracts against Aedes albopictus(Ae. albopictus).Meth...Objective: To investigate the larvicidal activity of Syzygium guineense(Myrtaceae)(S. guineense), Monodora myristica and Zanthoxylum heitzii(Rutaceae)(Z. heitzii) extracts against Aedes albopictus(Ae. albopictus).Methods: The larvicidal activity of the hydro-ethanolic extracts from these plant species was assessed at three different concentrations(50, 100 and 200 mg/L) on first-instar of Ae. albopictus larvae in comparison with untreated controls. Mortality rate was recorded daily for a period of 12 days. The values of LC_(50) and lethal time killing 50% of the tested individuals(LT_(50)) were calculated using the log-probit analysis.Results: The root extract of S. guineense exhibited the best activity with 100% mortality after 8 days of treatment at 200 mg/L, followed by the fruit extract of Z. heitzii with83.33% mortality at the same concentration. Nonetheless, larvae were most susceptible to the fruit extract of Z. heitzii both in terms of LC_(50)(39.89 mg/L) and LT_(50)(145.68 h). A statistically significant difference between the control and the group treated at 200 mg/L was noticed in all the extracts.Conclusions: The present study shows that the hydro-ethanolic extracts of S. guineense,Monodora myristica and Z. heitzii tested have significant larvicidal activity. These preliminary results are of great interest and some of these plant species can be proposed for the formulation of new bioinsecticides to control Ae. albopictus populations.展开更多
The Pearl River Delta,where Aedes albopictus(Ae.albopictus)is the only vector for dengue transmission,has exhibited one of the highest dengue burdens in southern China in recent decades.However,whether dengue virus(DE...The Pearl River Delta,where Aedes albopictus(Ae.albopictus)is the only vector for dengue transmission,has exhibited one of the highest dengue burdens in southern China in recent decades.However,whether dengue virus(DENV)can overwinter in Ae.albopictus in the Pearl River Delta has not been determined to date.In this study,300 field-derived Ae.albopictus mosquitoes from Guangzhou that were infected with the predominant endemic DENV-1 strain were investigated under simulated urban balcony environment from October 16,2016,to June 16,2017.The vertical transmission of DENV in the infected overwintering Ae.albopictus was analyzed.The DENV infected overwintering mosquitoes were evaluated for viral load at nine-time points using reverse transcription-quantitative PCR.The vector competence of the infected overwintering Ae.albopictus was also investigated by using suckling mice.Adult mosquitoes and larvae were found during the observation period.The vertical transmission of DENV-1 was documented.The DENV-1-positive rates between overwintering males and females had no difference.The proportion of DENV-1-positive overwintering mosquitoes decreased over time and had no difference beyond three months after the experiment.Overwintering mosquitoes can spread DENV-1 to hosts.No engorged mosquitoes at an ambient temperature below 15℃were observed.The ratio of engorged mosquitoes was positively correlated with the ambient temperature ranging from 15 to 30℃.Our results demonstrated that DENV can overwinter in Ae.albopictus in the Pearl River Delta,Ae.albopictus is the competent vector for DENV,and maintain autochthonous dengue outbreaks in the Pearl River Delta through vertical transmission.展开更多
Objective:To monitor the current duration of the application rates in vector programme and the level of Aedes albopictus larvae susceptibility from three selected areas in northeast district of Penang on two selected ...Objective:To monitor the current duration of the application rates in vector programme and the level of Aedes albopictus larvae susceptibility from three selected areas in northeast district of Penang on two selected larvicides,temephos and Bacillus thuringiensis subsp.israelensis(Bti) which are commonly used by Penang Health Department for vector control.Methods:The mosquito larvae were tested against two types of larvicides:(1) temephos(Abate®) with diagnostic dosage(0.012 mg/L) and operational dosage(1 mg/L) and(2)Bacillus thuringiensis subsp.israelensis(Vecto Bac®WG) with operational dosage ranging from 6 000 international toxic units per L to 24 000 international toxic unit per L.A total of 20 late third and early forth instar larvae were selected and transferred into paper cup sized 300 m L using wide-mouthed pipette.The larvae were distributed into each 300 m L paper cup containing 50 m L of aged tap water.The experiment was replicated five times for each concentration tested.Each test was repeated three times.The mortality was recorded after 24 h of exposure and recorded lethal time was based on 2 h for temephos and 6 h for Bti.The control consisted of ethanol for temephos and only seasoned water for Bti.Results:The result showed that Aedes albopictus from Flat Hamna,Kampung Sungai Gelugor and Kampung Tanjung Tokong were still susceptible to Bti and temephos.However,higher lethal time and resistance ratio were detected in strain from Flat Hamna which was a known dengue hot spot area in northeast of Penang.Conclusions:The application of temephos and Bti in vector control activity in these selected localities is still relevant in the control of Aedes larvae populations.展开更多
Objective： To obtain the complete β-actin gene from Aedes albopictus. Methods： Total RNA was extracted from C6/36 cells. Degenerate primers were designed based on the β-actin sequences of An. gambiae, Ae. aegypti,...Objective： To obtain the complete β-actin gene from Aedes albopictus. Methods： Total RNA was extracted from C6/36 cells. Degenerate primers were designed based on the β-actin sequences of An. gambiae, Ae. aegypti, Cx. pipiens pallens and D. melanogaster. By RT-PCR, the product was amplified, purified, cloned into the pGT vector and sequenced. The β-actin sequence was aligned and phylogenetically analyzed by the BLAST program and the CLUSTAL W program. Results： A sequence of 1132 bp including an open reading frame of 1131 bp was obtained （GenBank DQ657949）. The deduced protein had 376 amino acids. Aligned to SWISS-PROT, it exhibited a high level of identity with β-actins from Anopheles, Drosophila and Culex at the amino acid sequence level. Phylogenetic analysis indicated that Ae. albopictus β-acfin was much more homologous with invertebrate β- actin than with vertebrate β-actin. Conclusion： The gene may be used as the internal control in the experiments of Ae. albopictus.展开更多
Objective:To evaluate the growth inhibition activity of the crude extract of Cyperus aromaticus(C.aromaticus)cultured cells against the 3rd instar larvae of Aedes aegypti(Linn.)and Aedes albopictus Skuse(Ae.albopictus...Objective:To evaluate the growth inhibition activity of the crude extract of Cyperus aromaticus(C.aromaticus)cultured cells against the 3rd instar larvae of Aedes aegypti(Linn.)and Aedes albopictus Skuse(Ae.albopictus)under laboratory conditions,and determine the sublethal effects(EI_(50))of the crude extract of C.aromaticus cultured cells on some biological and morphological parameters of both Aedes mosquito species during two generations as well.Methods:The cell suspension cultures of C.aromaticus were activated from five callus lines(P4,Pa,Z1,Z6 and Ml)derived from the root explants of in vitro plantlets.The cultured cells were extracted in chloroform and used as plant material for the present study.For detection of juvenile hormone III.the crude extracts were analyzed by HPLC.Then the crude extracts of the three C.aromaticus cultured cell lines which contained varied amounts of juvenile hormone III[high level(P4 cell line),medium level(Z1 cell line)and low level(Ml cell line)]were tested against Aedes mosquito species.Laboratory evaluation was performed against late third instar larvae of the Vector Control Research Unit strains of Ae.aegypti and Ae.albopictus using the standard WHO method.The effects of EI_(50)of the C.aromaticus cultured P4 cells on fecundity,fertility,growth period,sex ratio,adult size and longevity of Aedes mosquitoes were assessed.Results:Bioassay tests presented the remarkable growth inhibition activity of the crude extracts of C.aromaticus cultured cells against the two Aedes mosquitoes.Between the two mosquito species,Ae.albopictus was more susceptible to the crude extracts with lower EI_(50)values.EI_(50)of the crude extract of C.aromaticus cultured cells(P4)increased the sterility indices in the parental generation females in both Aedes mosquito species.A significant delay in the pupal formation and adult emergence were observed in the parental generation of the both mosquito species.The sex ratio of the adult population either parental or F1 generation of the Aedes mosquito species was not significantly affected by the EI_(50)dosage of the crude extract of C.aromaticus cultured P4 cells.A significant decrease in the wing length of the treated adult(female and male)of Aedes aegypti as well as the treated female of Ae.albopictus were observed.Longevity of the adult female of the parental generation of both Aedes mosquitoes as well as females of F1 generation of Ae.albopictus were significantly decreased.Conclusions:The present study revealed the potential of the crude extract of C.aromaticus cultured cells in controlling vector mosquito populations in the effort to reduce the transmission of vector borne diseases.展开更多
Objective: To evaluate the efficacy of symbiotic bacteria, Xenorhabdus indica, Xenorhabdus stockiae, Photorhabdus luminescens subsp. akhurstii and Photorhabdus luminescens subsp. hainanensis as a larvicide against Aed...Objective: To evaluate the efficacy of symbiotic bacteria, Xenorhabdus indica, Xenorhabdus stockiae, Photorhabdus luminescens subsp. akhurstii and Photorhabdus luminescens subsp. hainanensis as a larvicide against Aedes aegypti and Aedes albopictus. Methods: Larvae(L3-L4) of Aedes aegypti and Aedes albopictus were given 2 m L of a suspension 107-108 CFU/m L of each symbiotic bacterium. Distilled water and Escherichia coli ATCC襅25922 were used as the control. The mortality rate of the larval mosquitoes was observed at 24, 48, 72 and 96 h. The experiment was performed in triplicates. Results: The larvae of both Aedes species started to die at 24 h exposure. Aedes aegypti showed the highest mortality rate(87%-99%), 96 h after exposure to Xenorhabdus stockiae(b NBP22.2_TH). The mortality rate of Aedes albopictus was between 82% and 96% at 96 h after exposure to Xenorhabdus indica(b KK26.2_TH). Low effectiveness of distilled water and Escherichia coli ATCC襅25922 were observed in both Aedes larvae, with a mortality rate of 2% to 12%. Conclusions: The study confirms the oral toxicity of Xenorhabdus and Photorhabdus bacteria against Aedes spp. Xenorhabdus stockiae and Xenorhabdus indica may be an alternative agent for control Aedes spp. This is basic information for further study on the mechanism of action on Aedes larvae or application to control mosquito larvae in the community.展开更多
Objective:To develop an artificial and modified Wolbaehia removal technique using tetracycline from naturally Wolbachia infected Aedes albopictus(Ae.albopictus)so as to be able to produce generations of Wolbaehia free...Objective:To develop an artificial and modified Wolbaehia removal technique using tetracycline from naturally Wolbachia infected Aedes albopictus(Ae.albopictus)so as to be able to produce generations of Wolbaehia free offsprings.Methods:In this study,seven different tetracycline treatment methods were conducted to obtain the best removal method.Four methods focused on larvae tetracycline treatment,one method on both larvae and adult tetracycline treatment and the last two methods on adult mosquito sucrose treatment.Results:All larval tetracycline treatments resulted in either high larvae mortality,sterile F_o adult mosquitoes or unsuccessful Wolbaehia removal.Treatment of both larvae and adults resulted in reduced larvae mortality,successful Wolbachia removal but slow mosquito fecundity.As for the adult treatment,1.0 mg/mL as previously published was not aisle to completely remove Wolbaehia in F,generation whereas 1.25 mg/mL successfully removed Wolbachia from F,and F,mosquitoes in 2 weeks.Conclusions:This method is different from the previously published methods as it provides an improved Watbachia removal technique from Ae.albopictus with high egg hatchability.low larvae mortality,increased fecundity and better Wolbaehia removal rate.展开更多
Objective:To determine the suitable ecological habitats of Aedes(Ae.)aegypti and Ae.albopictus in Iran due to climate change by the 2070s.Methods:All data relating to the spatial distribution of Ae.aegypti and Ae.albo...Objective:To determine the suitable ecological habitats of Aedes(Ae.)aegypti and Ae.albopictus in Iran due to climate change by the 2070s.Methods:All data relating to the spatial distribution of Ae.aegypti and Ae.albopictus worldwide,which indicated the geographical coordinates of the collection sites of these mosquitoes,were extracted from online scientific websites and entered into an Excel file.The effect of climatic and environmental variables on these mosquitoes was evaluated using the MaxEnt model in the current and future climatic conditions in the 2030s,2050s,and 2070s.Results:The most suitable areas for the establishment of Ae.aegypti are located in the southern and northern coastal areas of Iran,based on the model outputs.The modelling result for suitable ecological niches of Ae.albopictus shows that in the current climatic conditions,the southern half of Iran from east to west,and parts of the northern coasts are prone to the presence of this species.In the future,some regions,such as Gilan and Golestan provinces,will have more potential to exist/establish Ae.albopictus.Also,according to the different climate change scenarios,suitable habitats for this species will gradually change to the northwest and west of the country.The temperature of the wettest season of the year(Bio8)and average annual temperature(Bio1)were the most effective factors in predicting the model for Ae.aegypti and Ae.albopictus,respectively.Conclusions:It is required to focus on entomological studies using different collection methods in the vulnerable areas of Iran.The future modelling results can also be used for long-term planning to prevent the entry and establishment of these invasive Aedes vectors in the country.展开更多
The frequent cases of dengue incidences are leading cause of illness and death in urban areas and Aedes albopictus (Skuse) is a primary vector for Dengue transmission in India. Synthesis of leaf mediated silver nanopa...The frequent cases of dengue incidences are leading cause of illness and death in urban areas and Aedes albopictus (Skuse) is a primary vector for Dengue transmission in India. Synthesis of leaf mediated silver nanoparticles especially with Pongamia pinnata is a potential substitute for the existing organophosphorus insecticides like Tenophos, malathion and fenthion etc., for mosquito control programme. The nanoparticles were characterized by UV-visible absorption spectrum, X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) and Transmission Electron Microscopy (TEM). Analysis of TEM showed that the synthesized silver nanoparticles are in spherical shape with average size of 20 nm. Further the XRD analysis confirms the nano-crystalline phase of silver with face centred cubic (FCC) crystal structure. GC-MS analysis elucidated the presence of two active ingredients, such as 9-Octadecenoic acid (Z) and n-hexadecanoic acid, which are the prominent substances considered as larvicide. Larvae were exposed to varying concentrations of plant extracts and synthesized silver nanoparticles for 24 hours. From the results, it is found that plant extracts showed moderate larvicidal effects but, the synthesized silver nanoparticles had found to be toxic to larvae at LC50 (0.25 ppm) and LC90 (1 ppm).展开更多
TheRhabdoviridae family comprises a diverse range of negative-sense single-stranded ribonucleic acid(RNA)viruses,including significant human and mammalian viruses transmitted by various arthropod species.Herein,usingA...TheRhabdoviridae family comprises a diverse range of negative-sense single-stranded ribonucleic acid(RNA)viruses,including significant human and mammalian viruses transmitted by various arthropod species.Herein,usingAedes albopictus(Ae.albopictus)samples collected in two urban parks during 2023 and 2024,through metagenomics sequencing,16 sequences were identified as putative novel viruses,showing closest homology to insect-specific viruses,mycoviruses,or plant-associated viruses.Notably,two novel viruses,Aedes albopictus almendravirus GCCDC15(Aealb-AlmV GCCDC15)and Aedes albopictus almendravirus GCCDC16(Aealb-AlmV GCCDC16)were identified and successfully isolated.Both of these viruses belong to the genusAlmendravirus within theRhabdoviridae family.Phylogenetic analysis revealed that Aealb-AlmV GCCDC15 and GCCDC16 are distantly related to Coot Bay virus(the United States of America,2013)and Menghai rhabdovirus(Yunnan Province,China,2017).The genetic distances between these two viruses and their most similar viruses are marked by 59.85%and 87.20%of amino acid identity in the L protein,respectively,supporting their classification as two new species in theRhabdoviridae family.Cytopathic effects and rod-like virions were observed in mosquito cells(C6/36)after inoculating with supernatants from theAe.albopictus samples.To investigate the natural distribution and persistence of the novel almendraviruses,we conducted a specific reverse transcription-polymerase chain reaction(RT-PCR)screening ofAe.albopictus mosquitoes collected from two urban parks across different time points.The assays confirmed the presence of both Aealb-AlmV GCCDC15 and GCCDC16 in mosquito populations.Critically,these viruses were detected repeatedly over successive sampling periods and in mosquitoes from geographically distinct sites within the urban environment.In summary,our study delineates the virome characteristics ofAedes mosquitoes in the urban ecosystem and successfully isolated two novel rhabdoviruses.The recurrent detection provides clear evidence for the sustained circulation ofAe.albopictus-derived almendraviruses in urban parks,highlighting their ongoing transmission and establishment in these habitats.展开更多
Background The incompatible insect technique(IIT),based on Wolbachia-induced conditional sterility,has proven highly effective in suppressing mosquito populations for dengue control.However,concerns that accidental re...Background The incompatible insect technique(IIT),based on Wolbachia-induced conditional sterility,has proven highly effective in suppressing mosquito populations for dengue control.However,concerns that accidental release of infected females could drive population replacement have prompted integration of IIT with irradiation or advanced sex-separation technologies.Moreover,the broader ecological consequences of IIT-based suppression remain insufficiently understood.Here,we investigated whether standalone IIT,leveraging Wolbachia-associated fitness costs under real-world conditions,can effectively suppress Aedes albopictus populations without causing replacement,while also addressing key ecological concerns related to IIT-based mosquito population suppression.Methods We conducted field trials on Shazai Island,Nansha District,Guangzhou,China,releasing approximately 16,000 Wolbachia wPip-transinfected A.albopictus HC males per hectare per week from 2018 to 2019,following three years of combined IIT and sterile insect technique(SIT)application.Population suppression was monitored,with wPip infection frequency assessed to evaluate population replacement risks.Two-dimensional system of ordinary differential equations incorporating Wolbachia-induced fitness costs was established to predict population dynamics.Additionally,we assessed female mating preferences after three years of suppression and the impact on non-target Culex quinquefasciatus populations.Results We offer both empirical evidence and a mathematical model,demonstrating that the fitness costs associated with a Wolbachia triple-strain infection in A.albopictus,especially in adverse field conditions,empower a standalone IIT to effectively suppress mosquito populations without causing population replacement.Remarkably,reducing the previous release numbers to just 20% sustained a similar suppression level.We found no evidence of changes in female mating preferences after a three-year field suppression.The suppression of A.albopictus does not impact the population of the coexisting nontarget species C.quinquefasciatus.After stopping releases,the population rebounded partially in Year 1 and appeared to fully recover in Year 2,with the rate of this recovery likely influenced by mosquito immigration associated with population flow.Conclusions Our study demonstrates the robustness,cost-effectiveness,scalability,and ecological safety of IIT as a tool for controlling mosquito-borne diseases.These findings support the implementation of field-applicable,lowdose IIT for sustainable dengue control.展开更多
The vast majority of all global species have circadian rhythm cycles that allow them to adapt to natural environments.These regular rhythms are regulated by core clock genes and recent studies have also implicated rol...The vast majority of all global species have circadian rhythm cycles that allow them to adapt to natural environments.These regular rhythms are regulated by core clock genes and recent studies have also implicated roles for microRNAs in this regulation.Oviposition is an important circadian behavior in the reproductive cycle of insect vectors of diseases,and little is known about the rhythm or its regulation in mosquitoes.Aedes albopictus is a diurnal mosquito that transmits arboviruses and is the major cause of outbreaks of dengue fever in China.We analyzed the oviposition rhythm patterns of A.albopictus under different light/dark conditions and show that the mosquitoes have an oviposition peak between zeitgeber time 9(ZT 9)and ZT 12.Furthermore,the antagomir-mediated knockdown of expression of the microRNA miR-2940-1 affected the oviposition rhythm of A.albopictus.These data support the conclusion that miR-2940-1 is involved in the regulation of oviposition rhythm in A.albopictus and provide a foundation for using oviposition rhythms as a new target for vector mosquito control.展开更多
Background: This study aimed to investigate changes in the resistance of Aedes albopictus mosquitoes in Futian District, Shenzhen, to commonly used insecticides, providing a scientific basis for rational insecticide a...Background: This study aimed to investigate changes in the resistance of Aedes albopictus mosquitoes in Futian District, Shenzhen, to commonly used insecticides, providing a scientific basis for rational insecticide application and resistance management. Methods: Larval resistance to four commonly used insecticides was assessed using the World Health Organization (WHO)-recommended larval immersion method. Adult resistance was evaluated using the WHOrecommended adult contact tube method. Results: In 2025, Aedes albopictus larvae in Futian District, Shenzhen, exhibited high resistance to permethrin and beta-cypermethrin, with resistance ratios ranging from 224.6-239.5-fold and 88.3-118.8-fold, respectively. Low-level resistance was observed to propoxur and parathion, with resistance ratios of 3.3-3.4-fold and 4.0-4.9-fold, respectively. Adult Aedes albopictus mosquitoes showed resistance to permethrin and alpha-cypermethrin,with mortality rates of 8.9%-11.1% and 64.4%-72.2%, respectively. Possible resistance was detected to malathion and propoxur, with mortality rates of 87.8%-91.1% and 92.2%-94.4%, respectively. Conclusion: Aedes albopictus populations in Futian District, Shenzhen, have developed varying degrees of resistance to commonly used insecticides. Resistance to pyrethroid insecticides was markedly higher than that to carbamate and organophosphate insecticides. Insecticides should therefore be applied scientificaly and rationally based on resistance surveillance results to improve control efi cacy and delay the development of resistance.展开更多
基金supported by Three-Year Initiative Plan for Strengthening Public Health System Construction in Shanghai(2023-2025)Key Discipline Project(No.GWVI-11.1-12).
文摘Objective:To predict the distribution of dengue vector Aedes(Ae.)albopictus and identify high-risk areas for dengue fever transmission.Methods:Data on Ae.albopictus occurrences were collected from electronic databases.Ensemble models were developed to assess the impacts of climate,vegetation,and human activity on Ae.albopictus.The optimal ensemble model was then used to identify the distribution of suitable areas for Ae.albopictus.Results:After removing duplicate sites and retaining only one location per 100 m×100 m grid,189 Ae.albopictus breeding sites were identified.The optimal ensemble model revealed that Ae.albopictus exhibited higher breeding suitability in Shanghai under specific conditions:a normalized difference vegetation index of 0.1 to 0.6,maximum precipitation in the warmest month ranging from 400 mm to 470 mm,maximum temperature in the warmest month between 30.0℃and 31.0℃,and proximity to waterways within 0.5 km.The most suitable habitats for Ae.albopictus were primarily concentrated in Shanghai’s central urban areas and scattered across the inner suburban districts.Conclusions:The high-risk areas of Ae.albopictus are widely distributed throughout the central urban area and scattered across the inner suburban district of Shanghai,creating conditions conducive to the outbreak of dengue fever.It is essential to enhance targeted control measures for Ae.albopictus in the identified risk areas.
基金supported by The Young Medical Talents Training Program of Shanghai Pudong New Area Health Commission(Grant No.PWRq2022-25)Funded by Research Grant for Health Science and Technology of Shanghai Pudong New Area Center for Disease Control and Prevention Fudan University Pudong Institute of Preventive Medicine(Grant No.YJY-2024-06)+2 种基金The Academic Leaders Training Program of Shanghai Pudong New Area Health Commission(Grant No.PWRd2023-12)Shanghai's Three-year Ac tion Plan to Strengthen the Construction of Public Health System(2023-2025)Key Disciplines(Grant No.GW Ⅵ-11.1-02)The sixth Round of Three-Year Public Health Action Plan of Shanghai(Grant No.GW Ⅵ-11.1-13).
文摘Objective:To evaluate the phenotypic resistance profile of Aedes(Ae.)albopictus against multiple insecticides and to delineate the frequency and pyrethroid-resistance association of knockdown resistance(kdr)mutations V1016G,I1532T and F1534S in Ae.albopictus in Pudong New Area,Shanghai,China.Methods:From June to July 2024,a total of 1249 Ae.albopictus eggs and 4732 adults were collected from five towns in the Pudong New Area.These collected specimens were then reared to obtain the F1 generation including 10235 larvae at the late 3rd to early 4th instar stages,as well as 5800 non-blood-fed adults aged 3 to 5 days.Larval resistance was assessed via the immersion method,and adult resistance via the contact tube method.For the larval,0≤resistance ratio(RR)<3 indicates sensitivity;3≤RR<10 denotes low resistance;10≤RR<40 signifies moderate resistance;RR≥40 represents high resistance.While for adults,a mortality rate of≥98%stands for sensitivity,80%≤mortality rate<98%indicates suspected resistance,and mortality rate<80%denotes a resistant population.A pooled sequencing strategy(8 sample pools)was used to detect genotype kdr mutations including V1016G,I1532T,F1534S in the voltage-gated sodium channel(VGSC)gene.Results:Ae.albopictus larvae displayed low resistance to fenthion(RR=5.85),temephos(RR=4.63)and β-cypermethrin(RR=3.20),but remained fully susceptible to propoxur(RR=0.33).Adults showed incipient resistance to β-cypermethrin(mortality:92.7%),lambda-cyhalothrin(mortality:96.8%)and permethrin(mortality:86.6%),while remained sensitive to propoxur(mortality:100%).For Ae.albopictus population in the Pudong New Area,pyrethroid tolerance was primarily driven by F1534S mutation,which was amplified when the mutation was paired with V1016G or I1532T.Conclusions:These findings highlight the need for integrated resistance monitoring and targeted insecticide rotation-such as prioritizing propoxur for Ae.albopictus larval and adult control-to mitigate resistance spread and preserve vector management efficacy.
基金supported by Faculty of Agricultural Technology,KMITL,Bangkok,Thailand(Grant no 01-04-002)the National Research Council of Thailand(GRAD 6007KMITL)
文摘Objective: To investigate the efficacies of 12 essential oil(EO) formulations from three Zingiberaceae plants(Alpinia galanga, Curcuma zedoaria, and Zingiber cassumunar) individually and in combination with an augmenting Eucalyptus globulus(E. globulus) EO against females of Aedes albopictus(Ae. albopictus) and Anopheles minimus(An. minimus). Methods: These formulations were evaluated for their ovicidal, oviposition deterrent and adulticidal activities against Ae. albopictus and An. minimus by a topical method, a double-choice method and a WHO susceptibility test, respectively. Results: It was found that all formulations of Zingiberaceae plants EOs augmented with E. globulus EO were more effective in oviposition deterrent, ovicidal, and adulticidal activities against the two mosquito species than all of the formulations used without E. globulus EO. Their oviposition deterrent, ovicidal and adulticidal activities were equivalent to those of 10% w/v cypermethrin. In contrast, 70% v/v ethyl alcohol as a control alone was not effective at all. The highest synergistic effect in effective repellency against Ae. albopictus was achieved by 5% Alpinia galanga EO + 5% E. globulus EO and against An. minimus was 5% Zingiber cassumunar EO + 5% E. globulus EO. Moreover, the highest synergistic effects in ovicidal activities against Ae. albopictus and An. minimus were achieved by 10% Zingiber cassumunar EO + 10% E. globulus EO and 5% Curcuma zedoaria EO + 5% E. globulus EO, respectively. For the adulticidal activities, the highest synergistic effect against two mosquitoes was achieved by 5% Curcuma zedoaria EO + 5% E. globulus EO. Conclusions: These results suggest that Zingiberaceae plant EOs augmented with E. globulus EO have a high potential to be developed into oviposition deterrent, ovicidal, and adulticidal agents for controlling populations of Ae. albopictus and An. minimus.
基金Supported by grants from Universiti Sains Malaysi(No:#07-05-16-MG1-GM15,#1001/PBIOLOGI/842004)
文摘Objective:To generate life table characteristics for the dengue vector Aedes albopictus(A. albopictus) under uncontrolled conditions,incorporating both the aquatic and the adult stages. Methods:Ten females derived from wild pupae were allowed to fully blood-feed on restrained mice.774 eggs were hatched in seasoned water.F1 larvae were followed for development until their F2 counterparts emerged as adults.Some population parameters were monitored(Fl) or estimated(F2).Results:A.albopictus exhibited increased fecundity and egg hatch success. Immature development was quick.Immature survival was high,with lowest rate in the pupal stage.Adult emergence was about 81%and sex ratio was close to 1:1.Generational mortality(K) was about 28%.A high proportion of females completed a reproductive cycle and the obtained parity rate was predicted to lead to higher fecundity in the next generation.Conclusios:It can be concluded that natural A.albopictus populations in Penang seem largely determined by quick development in combination with low immature loss and increased oviposition.
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.
基金supported in part by the Erasmus Mundus project MAHEVAthe CNRS-UM1-UM2 PEPS project MoD yCAsupported by the Entomology department, National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
文摘Objective: To record the human cases of dengue fever(DF) and investigate the Aedes mosquito species circulating during the Hanoi 2011 DF epidemics. Methods: 24 different outbreak points were recorded in 8 districts between August and December 2011. Results: 140 patients were hospitalized following dengue diagnostic with a predominance of males(59.3%) and the 15-34 age class. Only DENV-1(11.27%) and DENV-2(88.73%) serotypes were detected in human samples. Mosquito sampling performed in and around patients households revealed the predominance of Aedes aegypti(95.15%) versus Aedes albopictus(4.85%). There is a positive correlation between the population density of Aedes aegypti and the number of human cases and duration of outbreaks. Conclusions: This was not observed for Aedes albopictus. 3 pools of Aedes aegypti were positive with dengue virus, two with DENV-1 and one with DENV-2.
文摘Objective: To investigate the larvicidal activity of Syzygium guineense(Myrtaceae)(S. guineense), Monodora myristica and Zanthoxylum heitzii(Rutaceae)(Z. heitzii) extracts against Aedes albopictus(Ae. albopictus).Methods: The larvicidal activity of the hydro-ethanolic extracts from these plant species was assessed at three different concentrations(50, 100 and 200 mg/L) on first-instar of Ae. albopictus larvae in comparison with untreated controls. Mortality rate was recorded daily for a period of 12 days. The values of LC_(50) and lethal time killing 50% of the tested individuals(LT_(50)) were calculated using the log-probit analysis.Results: The root extract of S. guineense exhibited the best activity with 100% mortality after 8 days of treatment at 200 mg/L, followed by the fruit extract of Z. heitzii with83.33% mortality at the same concentration. Nonetheless, larvae were most susceptible to the fruit extract of Z. heitzii both in terms of LC_(50)(39.89 mg/L) and LT_(50)(145.68 h). A statistically significant difference between the control and the group treated at 200 mg/L was noticed in all the extracts.Conclusions: The present study shows that the hydro-ethanolic extracts of S. guineense,Monodora myristica and Z. heitzii tested have significant larvicidal activity. These preliminary results are of great interest and some of these plant species can be proposed for the formulation of new bioinsecticides to control Ae. albopictus populations.
基金This project was supported by the Provincial Science and Technology Projects of Guangdong Province,China(Grant numbers:2014A020219007,2015A020218003,2016A020219006 and 2017A020215101)the Medical Scientific Research Foundation of Guangdong Province,China(Grant numbers:A2018167).
文摘The Pearl River Delta,where Aedes albopictus(Ae.albopictus)is the only vector for dengue transmission,has exhibited one of the highest dengue burdens in southern China in recent decades.However,whether dengue virus(DENV)can overwinter in Ae.albopictus in the Pearl River Delta has not been determined to date.In this study,300 field-derived Ae.albopictus mosquitoes from Guangzhou that were infected with the predominant endemic DENV-1 strain were investigated under simulated urban balcony environment from October 16,2016,to June 16,2017.The vertical transmission of DENV in the infected overwintering Ae.albopictus was analyzed.The DENV infected overwintering mosquitoes were evaluated for viral load at nine-time points using reverse transcription-quantitative PCR.The vector competence of the infected overwintering Ae.albopictus was also investigated by using suckling mice.Adult mosquitoes and larvae were found during the observation period.The vertical transmission of DENV-1 was documented.The DENV-1-positive rates between overwintering males and females had no difference.The proportion of DENV-1-positive overwintering mosquitoes decreased over time and had no difference beyond three months after the experiment.Overwintering mosquitoes can spread DENV-1 to hosts.No engorged mosquitoes at an ambient temperature below 15℃were observed.The ratio of engorged mosquitoes was positively correlated with the ambient temperature ranging from 15 to 30℃.Our results demonstrated that DENV can overwinter in Ae.albopictus in the Pearl River Delta,Ae.albopictus is the competent vector for DENV,and maintain autochthonous dengue outbreaks in the Pearl River Delta through vertical transmission.
基金Funded by FGRS Grant by Ministry of Education and Universiti Sains Malaysia(203/PBIOLOGI/6711359)
文摘Objective:To monitor the current duration of the application rates in vector programme and the level of Aedes albopictus larvae susceptibility from three selected areas in northeast district of Penang on two selected larvicides,temephos and Bacillus thuringiensis subsp.israelensis(Bti) which are commonly used by Penang Health Department for vector control.Methods:The mosquito larvae were tested against two types of larvicides:(1) temephos(Abate®) with diagnostic dosage(0.012 mg/L) and operational dosage(1 mg/L) and(2)Bacillus thuringiensis subsp.israelensis(Vecto Bac®WG) with operational dosage ranging from 6 000 international toxic units per L to 24 000 international toxic unit per L.A total of 20 late third and early forth instar larvae were selected and transferred into paper cup sized 300 m L using wide-mouthed pipette.The larvae were distributed into each 300 m L paper cup containing 50 m L of aged tap water.The experiment was replicated five times for each concentration tested.Each test was repeated three times.The mortality was recorded after 24 h of exposure and recorded lethal time was based on 2 h for temephos and 6 h for Bti.The control consisted of ethanol for temephos and only seasoned water for Bti.Results:The result showed that Aedes albopictus from Flat Hamna,Kampung Sungai Gelugor and Kampung Tanjung Tokong were still susceptible to Bti and temephos.However,higher lethal time and resistance ratio were detected in strain from Flat Hamna which was a known dengue hot spot area in northeast of Penang.Conclusions:The application of temephos and Bti in vector control activity in these selected localities is still relevant in the control of Aedes larvae populations.
基金This work was supported by the National Natural Science Foundationof China(No.30628022 and No.30671827)
文摘Objective： To obtain the complete β-actin gene from Aedes albopictus. Methods： Total RNA was extracted from C6/36 cells. Degenerate primers were designed based on the β-actin sequences of An. gambiae, Ae. aegypti, Cx. pipiens pallens and D. melanogaster. By RT-PCR, the product was amplified, purified, cloned into the pGT vector and sequenced. The β-actin sequence was aligned and phylogenetically analyzed by the BLAST program and the CLUSTAL W program. Results： A sequence of 1132 bp including an open reading frame of 1131 bp was obtained （GenBank DQ657949）. The deduced protein had 376 amino acids. Aligned to SWISS-PROT, it exhibited a high level of identity with β-actins from Anopheles, Drosophila and Culex at the amino acid sequence level. Phylogenetic analysis indicated that Ae. albopictus β-acfin was much more homologous with invertebrate β- actin than with vertebrate β-actin. Conclusion： The gene may be used as the internal control in the experiments of Ae. albopictus.
基金supported by University Sains Malaysia(USM)with the grant No 304.PBIOLOGI.650272.C112
文摘Objective:To evaluate the growth inhibition activity of the crude extract of Cyperus aromaticus(C.aromaticus)cultured cells against the 3rd instar larvae of Aedes aegypti(Linn.)and Aedes albopictus Skuse(Ae.albopictus)under laboratory conditions,and determine the sublethal effects(EI_(50))of the crude extract of C.aromaticus cultured cells on some biological and morphological parameters of both Aedes mosquito species during two generations as well.Methods:The cell suspension cultures of C.aromaticus were activated from five callus lines(P4,Pa,Z1,Z6 and Ml)derived from the root explants of in vitro plantlets.The cultured cells were extracted in chloroform and used as plant material for the present study.For detection of juvenile hormone III.the crude extracts were analyzed by HPLC.Then the crude extracts of the three C.aromaticus cultured cell lines which contained varied amounts of juvenile hormone III[high level(P4 cell line),medium level(Z1 cell line)and low level(Ml cell line)]were tested against Aedes mosquito species.Laboratory evaluation was performed against late third instar larvae of the Vector Control Research Unit strains of Ae.aegypti and Ae.albopictus using the standard WHO method.The effects of EI_(50)of the C.aromaticus cultured P4 cells on fecundity,fertility,growth period,sex ratio,adult size and longevity of Aedes mosquitoes were assessed.Results:Bioassay tests presented the remarkable growth inhibition activity of the crude extracts of C.aromaticus cultured cells against the two Aedes mosquitoes.Between the two mosquito species,Ae.albopictus was more susceptible to the crude extracts with lower EI_(50)values.EI_(50)of the crude extract of C.aromaticus cultured cells(P4)increased the sterility indices in the parental generation females in both Aedes mosquito species.A significant delay in the pupal formation and adult emergence were observed in the parental generation of the both mosquito species.The sex ratio of the adult population either parental or F1 generation of the Aedes mosquito species was not significantly affected by the EI_(50)dosage of the crude extract of C.aromaticus cultured P4 cells.A significant decrease in the wing length of the treated adult(female and male)of Aedes aegypti as well as the treated female of Ae.albopictus were observed.Longevity of the adult female of the parental generation of both Aedes mosquitoes as well as females of F1 generation of Ae.albopictus were significantly decreased.Conclusions:The present study revealed the potential of the crude extract of C.aromaticus cultured cells in controlling vector mosquito populations in the effort to reduce the transmission of vector borne diseases.
基金supported by Higher Education Research Promotion,The Commission on Higher Education,Thailand(Grant No.R2558A008)Naresuan University(Grant No.R2557B013)
文摘Objective: To evaluate the efficacy of symbiotic bacteria, Xenorhabdus indica, Xenorhabdus stockiae, Photorhabdus luminescens subsp. akhurstii and Photorhabdus luminescens subsp. hainanensis as a larvicide against Aedes aegypti and Aedes albopictus. Methods: Larvae(L3-L4) of Aedes aegypti and Aedes albopictus were given 2 m L of a suspension 107-108 CFU/m L of each symbiotic bacterium. Distilled water and Escherichia coli ATCC襅25922 were used as the control. The mortality rate of the larval mosquitoes was observed at 24, 48, 72 and 96 h. The experiment was performed in triplicates. Results: The larvae of both Aedes species started to die at 24 h exposure. Aedes aegypti showed the highest mortality rate(87%-99%), 96 h after exposure to Xenorhabdus stockiae(b NBP22.2_TH). The mortality rate of Aedes albopictus was between 82% and 96% at 96 h after exposure to Xenorhabdus indica(b KK26.2_TH). Low effectiveness of distilled water and Escherichia coli ATCC襅25922 were observed in both Aedes larvae, with a mortality rate of 2% to 12%. Conclusions: The study confirms the oral toxicity of Xenorhabdus and Photorhabdus bacteria against Aedes spp. Xenorhabdus stockiae and Xenorhabdus indica may be an alternative agent for control Aedes spp. This is basic information for further study on the mechanism of action on Aedes larvae or application to control mosquito larvae in the community.
基金Supported by University Malaya liesearch Grant of (MRG) with grant NO:RG372/11HTM
文摘Objective:To develop an artificial and modified Wolbaehia removal technique using tetracycline from naturally Wolbachia infected Aedes albopictus(Ae.albopictus)so as to be able to produce generations of Wolbaehia free offsprings.Methods:In this study,seven different tetracycline treatment methods were conducted to obtain the best removal method.Four methods focused on larvae tetracycline treatment,one method on both larvae and adult tetracycline treatment and the last two methods on adult mosquito sucrose treatment.Results:All larval tetracycline treatments resulted in either high larvae mortality,sterile F_o adult mosquitoes or unsuccessful Wolbaehia removal.Treatment of both larvae and adults resulted in reduced larvae mortality,successful Wolbachia removal but slow mosquito fecundity.As for the adult treatment,1.0 mg/mL as previously published was not aisle to completely remove Wolbaehia in F,generation whereas 1.25 mg/mL successfully removed Wolbachia from F,and F,mosquitoes in 2 weeks.Conclusions:This method is different from the previously published methods as it provides an improved Watbachia removal technique from Ae.albopictus with high egg hatchability.low larvae mortality,increased fecundity and better Wolbaehia removal rate.
基金Research Deputy,Tehran University of Medical Sciences,grant No.46857。
文摘Objective:To determine the suitable ecological habitats of Aedes(Ae.)aegypti and Ae.albopictus in Iran due to climate change by the 2070s.Methods:All data relating to the spatial distribution of Ae.aegypti and Ae.albopictus worldwide,which indicated the geographical coordinates of the collection sites of these mosquitoes,were extracted from online scientific websites and entered into an Excel file.The effect of climatic and environmental variables on these mosquitoes was evaluated using the MaxEnt model in the current and future climatic conditions in the 2030s,2050s,and 2070s.Results:The most suitable areas for the establishment of Ae.aegypti are located in the southern and northern coastal areas of Iran,based on the model outputs.The modelling result for suitable ecological niches of Ae.albopictus shows that in the current climatic conditions,the southern half of Iran from east to west,and parts of the northern coasts are prone to the presence of this species.In the future,some regions,such as Gilan and Golestan provinces,will have more potential to exist/establish Ae.albopictus.Also,according to the different climate change scenarios,suitable habitats for this species will gradually change to the northwest and west of the country.The temperature of the wettest season of the year(Bio8)and average annual temperature(Bio1)were the most effective factors in predicting the model for Ae.aegypti and Ae.albopictus,respectively.Conclusions:It is required to focus on entomological studies using different collection methods in the vulnerable areas of Iran.The future modelling results can also be used for long-term planning to prevent the entry and establishment of these invasive Aedes vectors in the country.
文摘The frequent cases of dengue incidences are leading cause of illness and death in urban areas and Aedes albopictus (Skuse) is a primary vector for Dengue transmission in India. Synthesis of leaf mediated silver nanoparticles especially with Pongamia pinnata is a potential substitute for the existing organophosphorus insecticides like Tenophos, malathion and fenthion etc., for mosquito control programme. The nanoparticles were characterized by UV-visible absorption spectrum, X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) and Transmission Electron Microscopy (TEM). Analysis of TEM showed that the synthesized silver nanoparticles are in spherical shape with average size of 20 nm. Further the XRD analysis confirms the nano-crystalline phase of silver with face centred cubic (FCC) crystal structure. GC-MS analysis elucidated the presence of two active ingredients, such as 9-Octadecenoic acid (Z) and n-hexadecanoic acid, which are the prominent substances considered as larvicide. Larvae were exposed to varying concentrations of plant extracts and synthesized silver nanoparticles for 24 hours. From the results, it is found that plant extracts showed moderate larvicidal effects but, the synthesized silver nanoparticles had found to be toxic to larvae at LC50 (0.25 ppm) and LC90 (1 ppm).
文摘TheRhabdoviridae family comprises a diverse range of negative-sense single-stranded ribonucleic acid(RNA)viruses,including significant human and mammalian viruses transmitted by various arthropod species.Herein,usingAedes albopictus(Ae.albopictus)samples collected in two urban parks during 2023 and 2024,through metagenomics sequencing,16 sequences were identified as putative novel viruses,showing closest homology to insect-specific viruses,mycoviruses,or plant-associated viruses.Notably,two novel viruses,Aedes albopictus almendravirus GCCDC15(Aealb-AlmV GCCDC15)and Aedes albopictus almendravirus GCCDC16(Aealb-AlmV GCCDC16)were identified and successfully isolated.Both of these viruses belong to the genusAlmendravirus within theRhabdoviridae family.Phylogenetic analysis revealed that Aealb-AlmV GCCDC15 and GCCDC16 are distantly related to Coot Bay virus(the United States of America,2013)and Menghai rhabdovirus(Yunnan Province,China,2017).The genetic distances between these two viruses and their most similar viruses are marked by 59.85%and 87.20%of amino acid identity in the L protein,respectively,supporting their classification as two new species in theRhabdoviridae family.Cytopathic effects and rod-like virions were observed in mosquito cells(C6/36)after inoculating with supernatants from theAe.albopictus samples.To investigate the natural distribution and persistence of the novel almendraviruses,we conducted a specific reverse transcription-polymerase chain reaction(RT-PCR)screening ofAe.albopictus mosquitoes collected from two urban parks across different time points.The assays confirmed the presence of both Aealb-AlmV GCCDC15 and GCCDC16 in mosquito populations.Critically,these viruses were detected repeatedly over successive sampling periods and in mosquitoes from geographically distinct sites within the urban environment.In summary,our study delineates the virome characteristics ofAedes mosquitoes in the urban ecosystem and successfully isolated two novel rhabdoviruses.The recurrent detection provides clear evidence for the sustained circulation ofAe.albopictus-derived almendraviruses in urban parks,highlighting their ongoing transmission and establishment in these habitats.
基金supported by Guangdong Innovative Research Team Program(2011S009)Scientific and Technological Leading Talents of Guangzhou Development District(2013L-P116)+1 种基金National Natural Science Foundation of China(82102430 to Y.Li,12371484 to B.Z.,and 12331017 to J.Y.)China Postdoctoral Science Foundation(2020M672573 to Y.Li).
文摘Background The incompatible insect technique(IIT),based on Wolbachia-induced conditional sterility,has proven highly effective in suppressing mosquito populations for dengue control.However,concerns that accidental release of infected females could drive population replacement have prompted integration of IIT with irradiation or advanced sex-separation technologies.Moreover,the broader ecological consequences of IIT-based suppression remain insufficiently understood.Here,we investigated whether standalone IIT,leveraging Wolbachia-associated fitness costs under real-world conditions,can effectively suppress Aedes albopictus populations without causing replacement,while also addressing key ecological concerns related to IIT-based mosquito population suppression.Methods We conducted field trials on Shazai Island,Nansha District,Guangzhou,China,releasing approximately 16,000 Wolbachia wPip-transinfected A.albopictus HC males per hectare per week from 2018 to 2019,following three years of combined IIT and sterile insect technique(SIT)application.Population suppression was monitored,with wPip infection frequency assessed to evaluate population replacement risks.Two-dimensional system of ordinary differential equations incorporating Wolbachia-induced fitness costs was established to predict population dynamics.Additionally,we assessed female mating preferences after three years of suppression and the impact on non-target Culex quinquefasciatus populations.Results We offer both empirical evidence and a mathematical model,demonstrating that the fitness costs associated with a Wolbachia triple-strain infection in A.albopictus,especially in adverse field conditions,empower a standalone IIT to effectively suppress mosquito populations without causing population replacement.Remarkably,reducing the previous release numbers to just 20% sustained a similar suppression level.We found no evidence of changes in female mating preferences after a three-year field suppression.The suppression of A.albopictus does not impact the population of the coexisting nontarget species C.quinquefasciatus.After stopping releases,the population rebounded partially in Year 1 and appeared to fully recover in Year 2,with the rate of this recovery likely influenced by mosquito immigration associated with population flow.Conclusions Our study demonstrates the robustness,cost-effectiveness,scalability,and ecological safety of IIT as a tool for controlling mosquito-borne diseases.These findings support the implementation of field-applicable,lowdose IIT for sustainable dengue control.
基金supported by grants from the Key R&D Program of Guangdong Province(2022B1111030002)the National Natural Science Foundation of China(31830087 and 82261128003/2022YFML1001)the National Institutes of Health,USA(AI136850)to X.-G.C.A.A.J.is a Donald Bren Professor at the University of California,Irvine.
文摘The vast majority of all global species have circadian rhythm cycles that allow them to adapt to natural environments.These regular rhythms are regulated by core clock genes and recent studies have also implicated roles for microRNAs in this regulation.Oviposition is an important circadian behavior in the reproductive cycle of insect vectors of diseases,and little is known about the rhythm or its regulation in mosquitoes.Aedes albopictus is a diurnal mosquito that transmits arboviruses and is the major cause of outbreaks of dengue fever in China.We analyzed the oviposition rhythm patterns of A.albopictus under different light/dark conditions and show that the mosquitoes have an oviposition peak between zeitgeber time 9(ZT 9)and ZT 12.Furthermore,the antagomir-mediated knockdown of expression of the microRNA miR-2940-1 affected the oviposition rhythm of A.albopictus.These data support the conclusion that miR-2940-1 is involved in the regulation of oviposition rhythm in A.albopictus and provide a foundation for using oviposition rhythms as a new target for vector mosquito control.
基金funded by the Shenzhen Futian District Health System Research Project(No.FTWS2025079).
文摘Background: This study aimed to investigate changes in the resistance of Aedes albopictus mosquitoes in Futian District, Shenzhen, to commonly used insecticides, providing a scientific basis for rational insecticide application and resistance management. Methods: Larval resistance to four commonly used insecticides was assessed using the World Health Organization (WHO)-recommended larval immersion method. Adult resistance was evaluated using the WHOrecommended adult contact tube method. Results: In 2025, Aedes albopictus larvae in Futian District, Shenzhen, exhibited high resistance to permethrin and beta-cypermethrin, with resistance ratios ranging from 224.6-239.5-fold and 88.3-118.8-fold, respectively. Low-level resistance was observed to propoxur and parathion, with resistance ratios of 3.3-3.4-fold and 4.0-4.9-fold, respectively. Adult Aedes albopictus mosquitoes showed resistance to permethrin and alpha-cypermethrin,with mortality rates of 8.9%-11.1% and 64.4%-72.2%, respectively. Possible resistance was detected to malathion and propoxur, with mortality rates of 87.8%-91.1% and 92.2%-94.4%, respectively. Conclusion: Aedes albopictus populations in Futian District, Shenzhen, have developed varying degrees of resistance to commonly used insecticides. Resistance to pyrethroid insecticides was markedly higher than that to carbamate and organophosphate insecticides. Insecticides should therefore be applied scientificaly and rationally based on resistance surveillance results to improve control efi cacy and delay the development of resistance.
