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Background: Aedes albopictus is an important vector of chikungunya, dengue, yellow fever and Zika viruses. Insecticides are often the most effective tools for rapidly decreasing the density of vector populations, especially during arbovirus disease outbreaks. However, the intense use of insecticides, particularly pyrethroids, has led to the selection of resistant mosquito populations worldwide. Mutations in the voltage-gated sodium channel (VGSC) gene are one of the main drivers of insecticide resistance in Ae. albopictus and are also known as "knockdown resistance" (kdr) mutations. Knowledge about genetic mutations associated with insecticide resistance is a prerequisite for developing techniques for rapid resistance diagnosis. Here, we report studies on the origin and dispersion of kdr haplotypes in samples of Ae. albopictus from the Yangtze River Basin, China; METHODS: Here, we report the results of PCR genotyping of kdr mutations in 541 Ae. albopictus specimens from 22 sampling sites in 7 provinces and municipalities in the Yangtze River Basin. Partial DNA sequences of domain II and domain III of the VGSC gene were amplified. These DNA fragments were subsequently sequenced to discover the possible genetic mutations mediating knockdown resistance (kdr) to pyrethroids. The frequency and distribution of kdr mutations were assessed in 22 Ae. albopictus populations. Phylogenetic relationships among the haplotypes were used to infer whether the kdr mutations had a single or multiple origins; RESULTS: The kdr mutation at the 1016 locus had 2 alleles with 3 genotypes: V/V (73.38%), V/G (26.43%) and G/G (0.18%). The 1016G homozygous mutation was found in only one case in the CQSL strain in Chongqing, and no 1016G mutations were detected in the SHJD (Shanghai), NJDX (Jiangsu) or HBQN (Hubei) strains. A total of 1532 locus had two alleles and three genotypes, I/I (88.35%), I/T (8.50%) and T/T (3.14%). A total of 1534 locus had four alleles and six genotypes: F/F (49.35%), F/S (19.96%), F/C (1.48%) and F/L (0.18%); S/S (23.66%); and C/C (5.36%). Haplotypes with the F1534C mutation were found only in Ae. albopictus populations in Chongqing and Hubei, and C1534C was found only in three geographic strains in Chongqing. Haplotypes with the 1534S mutation were found only in Ae. albopictus populations in Sichuan and Shanghai. F1534L was found only in HBYC. The Ae. albopictus populations in Shanghai were more genetically differentiated from those in the other regions (except Sichuan), and the genetic differentiation between the populations in Chongqing and those in the middle-lower reaches of the Yangtze River (Huber, Jiangsu, Jiangxi, and Anhui) was lower. Shanghai and Sichuan displayed low haplotype diversity and low nucleotide diversity. Phylogenetic analysis and sequence comparison revealed that the 1016 locus was divided into three branches, with the Clade A and Clade B branches bearing the 1016 mutation occurring mostly in Jiangsu and the Clade C branch bearing the 1016 mutation occurring mostly in Chongqing, suggesting at least two origins for 1016G. IIIS6 phylogenetic analysis and sequence comparison revealed that F1534S, F1534C and I1532T can be divided into two branches, indicating that IIIS6 has two origins; CONCLUSIONS: Combined with the distribution of kdr mutations and the analysis of population genetics, we infer that besides the local selection of pyrethroid resistance mutations, dispersal and colonization of Ae. albopictus from other regions may explain why kdr mutations are present in some Ae. albopictus populations in the Yangtze River Basin., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Recently, the effect of artificial light at night (ALAN) on the physiology and behavior of insects has gradually attracted the attention of researchers and has become a new research topic. Aedes albopictus is an important vector that poses a great public health risk. Further studies on the diapause of Ae. albopictus can provide a basis for new vector control, and it is also worth exploring whether the effect of ALAN on the diapause of Ae. albopictus will provide a reference for the prevention and control of infectious diseases mediated by Ae. albopictus., Methods: In this study, we experimentally studied the diapause characteristics of different geographical strains of Ae. albopictus under the interference of ALAN, explored the effect of ALAN on the diapause of Ae. albopictus and explored the molecular mechanism of ALAN on the diapause process through RNA-seq., Results: As seen from the diapause incidence, Ae. albopictus of the same geographic strain showed a lower diapause incidence when exposed to ALAN. The differentially expressed genes (DEGs) were mainly enriched in signaling and metabolism-related pathways in the parental females and diapause eggs of the ALAN group., Conclusions: ALAN inhibits Ae. albopictus diapause. In the short photoperiod induced diapause of Ae. albopictus in temperate strain Beijing and subtropical strain Guangzhou, the disturbance of ALAN reduced the egg diapause rate and increased the egg hatching rate of Ae. albopictus, and the disturbance of ALAN also shortened the life cycle of Ae. albopictus eggs after hatching., Competing Interests: Declaration of competing interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Aedes albopictus (Skuse) (Diptera: Culicidae) is one of the 100 most invasive species in the world and represents a significant threat to public health. The distribution of Ae. albopictus has been expanding rapidly due to increased international trade, population movement, global warming and accelerated urbanization. Consequently, it is very important to know the potential distribution area of Ae. albopictus in advance for early warning and control of its spread and invasion. We randomly selected 282 distribution sites from 27 provincial-level administrative regions in China, and used the GARP and MaxEnt models to analyze and predict the current and future distribution areas of Ae. albopictus in China. The results showed that the current range of Ae. albopictus in China covers most provinces such as Yunnan and Guizhou Provinces, and the distribution of Ae. albopictus in border provinces such as Tibet, Gansu and Jilin Provinces tend to expand westwards. In addition, the potential distribution area of Ae. albopictus in China will continue to expand westwards due to future climate change under the SSP126 climate scenario. Furthermore, the results of environmental factor filtering showed that temperature and precipitation had a large effect on the distribution probability of Ae. albopictus., Competing Interests: Declaration of Competing Interest No conflict of interest exits in this manuscript., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Dengue virus type Ⅱ (DENV2) is a primary serotype responsible for the dengue fever epidemic, and Aedes aegypti is the main DENV2 vector. Understanding the Aedes aegypti immune mechanism against DENV2 is the basis for research on immune blockade in mosquitoes. Some preliminary studies lack validation in the literature, so this study was performed to further study and validate the potential target genes to provide a further basis for screening key target genes. We screened 51 genes possibly related to Aedes aegypti infection and immunity from the literature for further verification. First, bioinformatic methods such as GO, KEGG and PPI analysis were used, and then RT-qPCR was used to detect the changes in mRNA expression in the midguts and salivary glands of Aedes aegypti infected with DENV2.Bioinformatic analysis showed that mostly genes of the glucose metabolism pathway and myoprotein were influenced. In salivary glands, the Gst (x a ) and Toll (x b ) expression levels were significantly correlated with DENV2 load (y, lg[DENV2 RNA copies]), y = -3436x a +0.2287x b +3.8194 (adjusted R 2  = 0.5563, F = 9.148, P F  = 0.0045). In midguts, DENV2 load was significantly correlated with the relative Fba(R 2  = 0.4381, t = 2.497, p < 0.05, df = 8), UcCr(R 2  = 0.4072, t = 2.344, p < 0.05, df = 8) and Gbps1(R 2  = 0.4678, t = 2.652, p < 0.05, df = 8) expression levels, but multiple regression did not yield significant results. This study shows that genes related to glucose metabolism and muscle proteins contribute to the interaction between Aedes aegypti and dengue virus. It was confirmed that SAAG-4, histone H4, endoplasmin, catalase and other genes are involved in the regulation of DENV2 infection in Aedes aegypti. It was revealed that GST and Toll in salivary glands may have antagonistic effects on the regulation of DENV2 load. Fba, UcCr and Gbps1 in the midgut may increase DENV2 load. These study results further condensed the potential target gene range of the Aedes aegypti immune mechanism against DENV2 infection and provided basic information for research on the Aedes aegypti in vivo blockade strategy against DENV2., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier B.V.)

Aedes albopictus is an indigenous primary vector of dengue and Zika viruses in China. Understanding the population spatial genetic structure, migration, and gene flow of vector species is critical to effectively preventing and controlling vector-borne diseases. The genetic variation and population structure of Ae. albopictus populations collected from 22 cities along the Yangtze River Basin were investigated with nine microsatellite loci and the mitochondrial CoxI gene. The polymorphic information content (PIC) values ranged from 0.534 to 0.871. The observed number of alleles ( Na ) values ranged from 5.455 to 11.455, and the effective number of alleles ( Ne ) values ranged from 3.106 to 4.041. The Shannon Index (I) ranged from 1.209 to 1.639. The observed heterozygosity ( Ho ) values ranged from 0.487 to 0.545. The F IS value ranged from 0.047 to 0.212. All Ae. albopictus populations were adequately allocated to three clades with significant genetic differences. Haplotype 2 is the most primitive molecular type and forms 26 other haplotypes after one or more site mutations. The rapid expansion of high-speed rail, aircraft routes and highways along the Yangtze River Basin have accelerated the dispersal and communication of mosquitoes, which appears to have contributed to inhibited population differentiation and promoted genetic diversity among Ae. albopictus populations.

Background: Aedes aegypti is one of the most important vectors of zoonotic diseases worldwide, and its survival and reproductive processes depend heavily on its olfactory system. In this study, the expression levels of all odorant receptor (OR) genes of Ae. aegypti were explored during different physiological periods to identify olfactory genes that may be associated with mosquito blood-feeding and the search for oviposition sites., Methods: Four experimental groups, consisting of Ae. aegypti males, pre-blood-feeding females, post-blood-feeding females and post-oviposition females, were established. A total of 114 pairs of primers targeting all messenger RNA encoded by OR genes were designed based on the whole genome of Ae. aegypti. The expression of OR genes was evaluated by real-time fluorescence quantitative PCR for relative quantification and the comparison of differences between groups., Results: A total of 53 differentially expressed OR genes were identified between males and females in Ae. aegypti antennae. Also, eight, eight and 13 differentially expressed OR genes were identified in pre- versus post-blood-feeding females, in pre- versus post-oviposition females and in post-blood-feeding versus post-oviposition females, respectively. In addition, 16 OR genes were significantly differentially expressed in multiple physiological periods of the mosquitoes., Conclusions: A large number of ORs with significant intergroup differences and high expression levels were screened in this study. Some of these genes are reported for the first time, providing possible targets for the development of mosquito control pathways based on the olfactory system., (© 2022. The Author(s).)

Background: Aedes albopictus is an indigenous primary vector for dengue and Zika viruses in China. Compared with its insecticide resistance, biology and vector competence, little is known about its genetic variation, which corresponds to environmental variations. Thus, the present study examines how Ae. albopictus varies among different climatic regions in China and deciphers its potential dispersal patterns., Methods: The genetic variation and population structure of 17 Ae. albopictus populations collected from three climatic regions of China were investigated with 11 microsatellite loci and the mitochondrial coxI gene., Results: Of 44 isolated microsatellite markers, 11 pairs were chosen for genotyping analysis and had an average PIC value of 0.713, representing high polymorphism. The number of alleles was high in each population, with the n e value increasing from the temperate region (3.876) to the tropical region (4.144). Twenty-five coxI haplotypes were detected, and the highest diversity was observed in the tropical region. The mean Ho value (ca. 0.557) of all the regions was significantly lower than the mean He value (ca. 0.684), with nearly all populations significantly departing from HWE and displaying significant population expansion (p value < 0.05). Two genetically isolated groups and three haplotype clades were evaluated via STRUCTURE and haplotype phylogenetic analyses, and the tropical populations were significantly isolated from those in the other regions. Most genetic variation in Ae. albopictus was detected within populations and individuals at 31.40 and 63.04%, respectively, via the AMOVA test, and a relatively significant positive correlation was observed among only the temperate populations via IBD analysis (R 2  = 0.6614, p = 0.048). Recent dispersions were observed among different Ae. albopictus populations, and four major migration trends with high gene flow (Nm > 0.4) were reconstructed between the tropical region and the other two regions. Environmental factors, especially temperature and rainfall, may be the leading causes of genetic diversity in different climatic regions., Conclusions: Continuous dispersion contributes to the genetic communication of Ae. albopictus populations across different climatic regions, and environmental factors, especially temperature and rainfall, may be the leading causes of genetic variation.

Background: Dengue virus (DENV) is a flavivirus transmitted by mosquitoes that is prevalent in tropical and subtropical countries and has four serotypes (DENV1-4). Aedes aegypti, as the main transmission vector of DENV, exhibits strong infectivity and transmission. With the aim of obtaining a better understanding of the Ae. aegypti-DENV interaction, the transcriptome changes in DENV-2-infected Aag2 cells were studied to describe the immune responses of mosquitoes using the Ae. aegypti Aag2 cell line as a model., Methods: RNAseq technology was used to sequence the transcripts of the Ae. aegypti Aag2 cell line before and after infection with DENV-2. A bioinformatics analysis was then performed to assess the biological functions of the differentially expressed genes, and the sequencing data were verified by quantitative reverse transcription-polymerase chain reaction (qRT-PCR)., Results: The transcriptome analysis generated 8866 unigenes that were found in both groups, 225 unigenes that were only found in the infection group, and 683 unigenes that only existed in the control group. A total of 1199 differentially expressed genes, including 1014 upregulated and 185 downregulated genes, were identified. The bioinformatics analysis showed that the differentially expressed genes were mainly involved in the longevity regulating pathway, circadian rhythm, DNA replication, and peroxisome, purine, pyrimidine, and drug metabolism. The qRT-PCR verification results showed the same trend, which confirmed that the expression of the differentially expressed genes had changed, and that the transcriptome sequencing data were reliable., Conclusions: This study investigated the changes in the transcriptome levels in the DENV-2-infected Ae. aegypti Aag2 cell line, which provides a faster and effective method for discovering genes related to Ae. aegypti pathogen susceptibility. The findings provide basic data and directions for further research on the complex mechanism underlying host-pathogen interactions.

Background: There was no record of Aedes aegypti in Yunnan Province, China, until 2002, but this species is now continuously found in nine cities (or counties). Until now, little was known about the genetic diversity and population structure of this invasive species. Thus, a detailed understanding of the invasion strategies, colonisation and dispersal of this mosquito from a population genetics perspective is urgently needed for controlling and eliminating this disease vector., Methods: The genetic diversity and population structure of Ae. aegypti communities were analysed by screening nine microsatellite loci from 833 Ae. aegypti mosquitoes sampled from 28 locations in Yunnan Province., Results: In total, 114 alleles were obtained, and the average polymorphic information content (PIC) value was 0.672. The value of the alleles per locus ranged from 2.90 to 5.18, with an average of 4.04. The value of He ranged from 0.353 to 0.681, and the value of Ho within populations ranged from 0.401 to 0.689. Of the 28 locations, two showed significant departures from the Hardy-Weinberg equilibrium (HWE) with P-values less than 0.05, and a bottleneck effect was detected among locations from Ruili and the border areas with the degree of 60% and 50%, respectively. Combined with the F-statistics (F IT  = 0.222; F CT  = 0.145), the analysis of molecular variance (AMOVA) revealed that there was substantial molecular variation among individuals, accounting for 77.76% of the sample, with a significant P-value (<0.0001). The results suggest that genetic differences in Ae. aegypti originated primarily among individuals rather than among populations. Furthermore, the STRUCTURE and UPGMA cluster analyses showed that Ae. aegypti from the border areas were genetically isolated compared to those from the cities Ruili and Jinghong, consistent with the results of the Mantel test (R 2  = 0.245, P < 0.0001)., Conclusions: Continuous invasion contributes to the maintenance of Ae. aegypti populations' genetic diversity and different invasion accidents result in the genetic difference among Ae. aegypti populations of Yunnan Province.

Zika virus (ZIKV) has become a serious threat to global health since the outbreak in Brazil in 2015. Additional Chinese cases have continuously been reported since the first case of laboratory-confirmed ZIKV infection in China on 6 February 2016. Aedes aegypti is the most important vector for ZIKV. This study shows that two strains from China exhibit high levels of midgut infection and highly disseminated infection of salivary glands and ovaries. Both strains can transmit ZIKV to infant mice bitten by infectious mosquitoes. Moreover, the results provide the evidence of transovarial transmission of ZIKV in mosquitoes. The study indicates that the two Ae. aegypti strains are not only effective transmission vectors but also persistent survival hosts for ZIKV during unfavorable inter-epidemic periods. This function as a reservoir of infection has epidemiological implications that further enhance the risk of potential future outbreaks.

Dengue is an acute, emerging, infectious disease transmitted by Aedes mosquitoes that has become a serious global public health problem. The DEN2-FJ10 and DEN2-FJ11 strains of the dengue 2 virus were originally isolated from the serum of a patient with dengue fever in Fujian Province, China, in 1999. Our data provide the first assessment of the vector competence of Aedes mosquitoes with respect to the DEN2-FJ10 and DEN2-FJ11 strains of the dengue virus. There were significant differences in the replication rates of these two viral strains in Aedes albopictus and Aedes aegypti (P<0.05); replication of the DEN2-FJ10 strain was greater in Ae. aegypti than in Ae. albopictus 5 days post infection whereas replication of the DEN2-FJ11 was greater in Ae. albopictus than in Ae. aegypti 7 days post infection. The replicative ability of the DEN2-FJ11 strain was greater than that of the DEN2-FJ10 strain in infected Ae. albopictus. In infected Ae. aegypti, rapid proliferation of the DEN2-FJ10 strain occurred earlier than in the DEN2-FJ11 strain. There were no significant differences in the midgut and salivary gland infection rates of Ae. albopictus and Ae. aegypti with respect to either viral strain. Although the DEN2-FJ10 and DEN2-FJ11 strains differ in their virulence to neonatal rats, there was no significant difference in the ability of either Ae. albopictus or Ae. aegypti to transmit the DEN2-FJ10 and DEN2-FJ10 strains of the dengue 2 virus (P>0.05). In summary, our results indicate that Ae. albopictus and Ae. aegypti mosquitoes are moderately competent vectors of the DEN2-FJ10 and DEN2-FJ11 strains of the dengue virus and provide the first evidence of the effect of these two viral strains on the vector competence of mosquitoes in China., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Aedes albopictus is the primary vector of dengue fever and dengue hemorrhagic fever in China. Although there are previous studies on the application of adulticides to control this species, the application methods have either been back-pack or vehicle-mounted systems. However, many sites are too large to be effectively treated with back-pack sprayers, and the lack of roads restricts the use of vehicle-mounted sprayers. This paper provides the first study of using unmanned aerial vehicles to conduct cold mist sprays on Ae. albopictus habitats. A spray containing 4% permethrin and 1% tetramethylfluthrin was applied at an effective application rate of 9.0 mg/m(2). This method reduced Ae. albopictus populations by more than 90%. The results indicate this novel spray system is a powerful method to achieve a rapid decline of mosquito population in Ae. albopictus habitats in China.

Background: Aedes aegypti is an important vector for dengue virus and thus has been targeted with pyrethroid insecticides in many areas of the world. As such, resistance has been detected to several of these insecticides, including in China, but the mechanisms of the resistance are not well understood in this country., Methods: Using the World Health Organization larval mosquito bioassay, five field populations of Aedes aegypti from Southern China were characterized for their resistance to cypermethrin and cyhalothrin. RNA extraction with PCR amplification, cloning and sequencing of the sodium channel gene was followed by comparisons of susceptible and wild mosquito strains Additionally, genomic DNA was used for Allele-specific PCR (AS-PCR) genotyping of the sodium channel genes to detect S989P, V1016G and F1534C mutations and allow for correlation analysis of resistance expression for the different mutations., Results: All wild strains expressed resistance to cypermethrin and cyhalothrin and the resistance expression between the two insecticides was highly correlated suggesting cross-resistance between these two pyrethroids. The AS-PCR technique effectively distinguished individual genotypes for all three mutations. Among the five wild strains tested, two strains carried all three mutations. Although the S989P and V1016G mutations were positively correlated to resistance expression of both pyrethroids, the F1534C mutation was negatively correlated., Conclusions: Our methodology proved highly reliable and will aid future detection of kdr mutations. The three sodium channel mutations were common in the Ae. aegypti strains sampled from Southern China. The V1016G mutation appears to be the most important kdr mutation in Ae. aegypti strains in Southern China.

The mosquito Aedes vexans and black fly Simulium maculatum are important blood-sucking pests in northern China. Control of these pests using current methods is difficult because of complex larval developmental sites. In the present study, lambda-cyhalothrin was applied as a barrier spray to vegetation and various structures surrounding human dwellings for control against the adults of each species. The barrier spray resulted in an 88.2-99.4% reduction in Ae. vexans abundance and a 67.8-89.6% reduction in S. maculatum abundance for 2 wk postapplication. Our results indicated that lambda-cyhalothrin applied as a barrier spray to vegetation and other structures that serve as harborage for adults of both species could be adopted as part of an integrated pest management approach against these pests.

The vector competence of Aedes albopictus and Aedes aegypti with regard to DEN2-43 and New Guinea C (NGC) virus strains of Dengue 2 viruses was assessed and compared. The infection and dissemination rate and distribution of DEN2-43 antigens in orally infected Ae. albopictus was investigated using the reverse transcription polymerase chain reaction and an indirect immunofluorescence assay. To better understand the initial infection, dissemination and transmission of these viral strains in vector mosquitoes, Ae. albopoictus and Ae. aegypti were fed an artificial blood meal containing either the DEN2-43 or NGC strain. There was no significant difference in the infection and dissemination rates of DEN2-43 and NGC virus strains in Ae. albopictus, however, Ae. aegypti was more susceptible to infection by NGC than DEN2-43 vrius strain. Ae. albopictus mosquitoes infected with the NGC strain developed a higher percentage of midgut infections than those infected with the DEN2-43 strain (t=2.893, df=7, P=0.024). Approximately 26.7% of midgut samples were positive for the NGC antigen 5 days after infection, and 80% of mosquitoes had infected midgets after 15 days. The NGC antigen first became evident in mosquito salivary glands on Day 5, and 40% of mosquitoes had infected salivary by Day 9. In contrast, the DEN2-43 antigen first became evident in salivary glands on Day 7. The infection rate of NGC and DEN2-43 virus strains in salivary glands were similar. These results indicate that Ae. albopictus and Ae. aegypti are moderately competent vectors for the DEN2-43 virus, which could provide basic data for the epidemiology study of dengue fever in China., (Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.)

A Pioneer Eco-Backpack electric cold ultra-low volume (ULV) sprayer and a gas-powered Twister XL 3950 series 2 motorized knapsack ULV sprayer with Aqualuer (20.6% permethrin AI) were evaluated against caged adult Aedes albopictus and Culex quinquefasciatus in St. Augustine, FL. The Pioneer Eco-Backpack sprayer provided 100% knockdown of both species of mosquitoes at 15 min; the Twister XL backpack sprayer resulted in 17-23% knockdown at 15 min. Both backpack sprayers with Aqualuer resulted in 100% mortality of both species at 24 h. The new Pioneer Eco-Backpack sprayer powered by electricity could be a potential tool for mosquito control.

In order to better understand the role a barrier application plays in an integrated mosquito management program, we applied a bifenthrin barrier application to a large golf course community and evaluated the mosquito population, service requests, and money spent for control from our barrier site as well as a site that was only treated via ground ultra-low-volume (ULV) application or that was left as a control site. Both the barrier application (t = 2.63, df = 126, P = 0.0147) and the ground ULV application (t = 2.49, df = 126, P = 0.0054) significantly reduced mosquito populations compared to the control, but means within treatments did not differ from each other. Mosquito populations in Centers for Disease Control and Prevention traps were reduced by 84% by barrier application and by 52% by ground ULV application at 6 wk posttreatment compared with untreated control. The 2 major species collected during the evaluation period were Anopheles crucians (81%) and Aedes atlanticus (13%). Anopheles crucians was significantly reduced compared with controls for the barrier application (t = 1.55, df = 126, P = 0.003) and ground ULV application (t = 1.85, df = 126, P = 0.052). Aedes atlanticus was significantly reduced by the barrier application (t = 1.54, df = 128, P = 0.002) but not by ground ULV application (P = 0.083). Overall the barrier application resulted in a significant decrease (chi2 = 35.4, df = 1, P < 0.0001) in the number of service requests and ground ULV application (chi2 = 5.3, df = 1, P = 0.02) compared to the site that was only treated with ground ULV application. The barrier application saved an estimated $2,700. Thus, large-scale barrier applications are an appropriate tool for control of floodwater mosquito populations.

Aedes albopictus is a primary nuisance pest and disease vector in China. Control of Ae. albopictus using current methods is difficult because of diverse larval breeding sites. In the present study, lambda-cyhalothrin was applied as a barrier spray to vegetation surrounding human dwellings for control of adult mosquito populations. Compared to the landing rate counts in the untreated control site, the barrier spray resulted in an 83-98% reduction of Ae. albopictus within 9 wk posttreatment. The study results indicate that lambda-cyhalothrin applied as a barrier spray to vegetation can reduce Ae. albopictus landing rates collections for more than 2 months.

Objective: To construct the suppression subtracted cDNA library of deltamethrin-resistant Aedes albopictus., Methods: Total RNA was extracted from the deltamethrin-resistant (R-lab) and -sensitive (S-lab) isolates, mRNA was obtained after purification. Double stranded cDNAs were synthesized after reverse transcription. Two subtractions were performed by suppression subtractive hybridization with S-lab as tester and R-lab as driver or S-lab as driver and R-lab as tester. Enriched different expressed cDNA was cloned into pMD18-T vector to construct subtractive libraries., Results: The subtracted cDNA libraries contained 580 and 477 positive clones respectively. The PCR results of 150 clones picked randomly from each library showed that the positive ratio of constructed cDNA libraries was 93%, with a length of cDNA fragments ranged from 150bp to 750bp., Conclusion: The suppression subtracted cDNA library of deltamethrin-resistant Ae. albopictus is constructed.