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One of the strategies of integrated vector management is to lure gravid mosquitoes for surveillance purposes or to entice them to lay eggs in water containing toxins that kill the offspring (attract-and-kill or trap-and-kill). Typically, the major challenge of this approach is the development of a lure that stimulates oviposition plus a toxin with no deterrent effect. Bacillus thuringiensis var. israelensis (Bti) satisfies the latter criterion, but lures for these autocidal gravid traps are sorely needed. We observed that gravid Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus laid significantly more eggs in cups with extracts from 4th-stage larvae (4 L) of the same or different species. No activity was found when 4 L were extracted with hexane, diethyl ether, methanol, or butanol, but activity was observed with dimethyl sulfoxide extracts. Larval extracts contained both oviposition stimulant(s)/attractant(s) and deterrent(s), which partitioned in the water and hexane phases, respectively. Lyophilized larval extracts were active after a month, but activity was reduced by keeping the sample at 4 °C. In the tested range of 0.1 to 1 larvae-equivalent per milliliter, oviposition activity increased in a dose-dependent manner. In field experiments, Ae. aegpti laid significantly more eggs in traps loaded with larval extracts plus Bti than in control traps with water plus Bti.

Advancements in next-generation sequencing and bioinformatics have expanded our knowledge of the diversity of viruses (pathogens and non-pathogens) harbored by mosquitoes. Hubei reo-like virus 7 (HRLV 7) was recently detected by the virome analysis of fecal samples from migratory birds in Australia. We now report the detection of RNA-dependent RNA polymerase sequences of HRLV 7 in pools of Aedes aegypti and Culex quinquefasciatus mosquitoes species from the Brazilian Amazon forest. Phylogenetic inferences indicated that all HRLV 7 strains fall within the same independent clade. In addition, HRLV 7 shared a close ancestral lineage with the Dinovernavirus genus of the Reoviridae family. Our findings indicate that HRLV 7 is present in two species of mosquitoes.

Abstract Background Culex mosquitoes are involved in the transmission of arboviral diseases worldwide. Bio-ecology and identification of mosquitoes are of paramount importance to develop species-specific vector control strategies. Genetic-based species-specific approaches that reduce the burden of vector-borne diseases are made possible by molecular techniques. Results In the present study, the mitochondrial COI gene of Culex mosquitoes was used for molecular identification in addition to morpho-taxonomy. Our findings suggested the presence of important Culex mosquito vectors viz, Culex vishnui, Culex tritaeniorhynchus, Culex bitaeniorhynchus, Culex quinquefasciatus, Culex gelidus, Culex fuscocephala, and Culex fuscanus in the southern part of Odisha state, India. We examined the phylogeny and genetic diversity of the above seven different Culex populations from different geographical locations. An average intra-specific K2P distance of the COI gene was found to be 0.9%. Further, to measure the diversity of the Culex population among different geographical strains, haplotype diversity and nucleotide diversity were compared. Culex fuscanus showed high polymorphisms and mutations with high nucleotide diversity (0.013) and the Culex quinquefasciatus showed the lowest variation in P(i), 0.0013 in the intra-population polymorphism analysis of COI sequences. Similarly, the Haplotype diversity (Hd) found in Culex gelidus and Culex fuscocephala with the value of 0.972 and Culex quinquefasciatus (0.583) showed the lowest value of haplotype diversity. A haplotype network was constructed to establish the genealogical relationship between haplotypes. The phylogenetic tree was constructed that produces distinctive conspecific clusters in different Culex species. Population genetic study has illustrated the occurrence of genetic differentiation within the population. Conclusions The findings of this study contribute to greater evidence that DNA barcode sequences can be used to monitor mosquito species diversity. This study also adds valuable information about the systematics and molecular biology of seven public health important mosquito species acting as a significant vector for Japanese encephalitis in various Asian continents. This information is further used for the effective implementation of region-specific vector control strategies.

The Spissipes section of the subgenus Melanoconion Theobald, 1903 of Culex Linnaeus, 1758 (Diptera, Culicidae) consists of 23 species, many of which transmit various subtypes of Venezuelan equine encephalitis virus. Members of the Spissipes section are distributed throughout the American tropics, and most species are associated with mesic sylvatic environments. Here are reported two first records of Spissipes section females from Guainía Department, Colombia. Females of Culex gnomatos Sallum et al., 1997 and Culex portesi Senevet & Abonnenc, 1941, were observed biting the author and photographed in situ.

Abstract Background Choosing an appropriate strategy for mosquito vector control in an eco-climatic facies requires knowledge on vector ecology including population dynamics of species and productivity of the breeding sites. The aim of this study was to characterize Culex mosquitoes breeding places and to determine their population dynamics in two localities (Dschang and Santchou) separated by a forest cliff in the West Region of Cameroon. Field surveys were conducted from November 2019 to June 2020 in Dschang and Santchou. Mosquito breeding sites were georeferenced, and for each breeding site, physical parameters were measured and immature stages were collected. The collected immatures were reared in the laboratory until adult stage. Adult mosquitoes were identified using a stereomicroscope and morphological identification keys. Results A total of 44 breeding sites were identified: 24 in Dschang and 20 in Santchou. They were grouped into seven types and were mostly shallow, close to human dwellings, sunny, with organic matters and of anthropogenic nature. A total of 2706 mosquitoes belonging to four genera were identified. Culex genus was the most represented (90.4%) and was made up of Culex pipiens s.l. (61.79%), Culex duttoni (23.17%) and Culex (Culiciomyia) sp. (05.46%). High abundance of Culex species was observed in Santchou (52.71%) compared to Dschang (47.28%), while Dschang (S = 3; H = 0.87; D = 0.54) recorded the greatest diversity compared to Santchou (S = 2; H = 0.23; D = 0.11). Conclusions The proliferation and persistence of Culex mosquitoes independently of the breeding sites and localities might be attributable to the poor environmental management which favor the creation mosquito breeding sites. This study highlights the fact that prompt sanitation measures could be undertaken in these two localities to reduce mosquito abundance and the risk of vector-borne diseases.

BackgroundThe Culex pipiens complex consists of several morphologically similar, closely related species. In the United States, Cx. pipiens L. is distributed North of 39° latitude, while Cx. quinquefasciatus Say occurs South of 36° latitude; a hybrid zone occurs between these two latitudes including in the Central Valley of California. Members of the Cx. pipiens complex and their hybrids are vectors for West Nile virus (WNv). Hybrid offspring of Cx. pipiens and Cx. quinquefasciatus have been found to have enhanced transmission rates of WNv over those of pure populations of each species. We investigated whether hybrids of Cx. pipiens and Cx. quinquefasciatus occurred more frequently in any of five habitats which were dairies, rural, suburban, and urban areas, and wetlands. In addition, the proportion of alleles unique to Cx. quinquefasciatus and Cx. pipiens found in each habitat-associated population were determined.MethodsAmplified fragment length polymorphism (AFLP) markers were used to compare the population structure of the Cx. pipiens complex from each habitat to geographically distant populations considered pure Cx. pipiens and Cx. quinquefasciatus. Structure analyses were used to assign individuals to either Cx. pipiens, Cx. quinquefasciatus, or hybrids of the Cx. pipiens complex. The ancestry of hybrids (F1, F2, or backcrossed) in relation to the two parent populations was estimated for each Central Valley population. Loci unique to the pure Cx. pipiens population and the pure Cx. quinquefasciatus population were determined. The proportion of loci unique to Cx. pipiens and Cx. quinquefasciatus populations were subsequently determined for each population from the five Merced habitats and from the Oroville California population. The unique loci found in Merced populations and not in Cx. pipiens or Cx. quinquefasciatus were also determined. A principal components analysis was run, as was an analysis to determine loci under putative selection.ResultsThe Structure Harvester analysis found K = 3, and the Culex pipiens complex mosquitoes formed a genetic cluster distinct from Cx. quinquefasciatus and Cx. pipiens. Individuals collected from each habitat were nearly all hybrids. However, Cx. pipiens complex collected near dairies had more individuals categorized as Cx. pipiens than collections from the other habitats. None of the mosquitoes collected in Merced or Oroville were considered pure Cx. quinquefasciatus. Significant genetic divergence was detected among the Cx. pipiens complex from the five habitats in Merced; Cx. pipiens complex mosquitoes from dairies were divergent from the urban and suburban populations. New Hybrids analysis found that individuals from all five Merced habitat-associated populations and the population from Oroville were primarily categorized as hybrids backcrossed to the Cx. pipiens population. Finally, all five habitat-associated populations shared more alleles with Cx. pipiens than with Cx. quinquefasciatus, even though the pure Cx. quinquefasciatus population was more geographically proximate to Merced. Results from the principal component analysis, and the occurrence of several unique loci in Merced populations, suggest that Cx. pipiens molestus may also occur in the habitats sampled.ConclusionsNearly all mosquitoes in the five habitats in Merced in the Central Valley of California area were hybrids of Cx. pipiens and Cx. quinquefasciatus, consisting of hybrids backcrossed to Cx. pipiens. Habitat-associated mosquitoes collected near dairies had more individuals consisting of pure Cx. pipiens, and no mosquitoes from Merced or Oroville CA classified as pure Cx. quinquefasciatus. The genetic distances among Cx. pipiens and Cx. quinquefasciatus, and hybrid populations agree with previous studies using other molecular markers. Cx. pipiens hybrids in Merced shared more alleles with Cx. pipiens than Cx. quinquefasciatus which was unexpected, since Merced is geographically closer to the northern limit of Cx. quinquefasciatus distribution. Culex pipiens molestus may occur in more habitats in the Central Valley than previously suspected, which warrants further investigation. Future studies could investigate the vector competence of hybrids backcrossed to either Cx. pipiens or Cx. quinquefasciatus parent for their ability to transmit West Nile virus.

Abstract To determine the species composition, relative abundance and seasonal variation of different mosquitoes Genera (Aedes, Anopheles, Armigeres, Culex, and Culiseta) in different habitats the present research work was carried out in Entomology Research Laboratory of The University of Peshawar. Sampling performed from variety of permanent and temporary breeding habitats was carried out on monthly basis from targeted breeding sites for two consecutive years through dipping method. Species diversity in the survey sites was noted. Collection from these seventeen various types of potential larval habitats, yielded a total of 42,430 immature constituting 41,556 larvae and 874 pupae. Among these only 19,651 adult mosquitoes emerged comprising 11,512 female and 8,139 male mosquitoes. 78% (n= 15333) of mosquito larvae were from permanent and 22% (n=4318) were from temporary breeding sites. This study showed that Peshawar valley harbours 15 species from the genera Aedes, Anopheles, Armigeres, Culex and Culiseta. When the density of each species was examined, Culex quinquifasciatus was found to be dominant (79%) and constant in distribution. Among the temporary habitats Aedes albopictus was found as the most prevalent species particularly from tree holes and water cisterns. The highest intensity of mosquitoes was in June (2243 emerged adults) and November (2667 emerged adults) while the lowest was in January (203 emerged adults). A perfect positive correlation (r = +0.8) was found between temperature and population of mosquitoes (df 10 and α 0.05). The species diversity index for mosquitoes remained between 0.12 and 1.76. The Margalef’s richness components was noticeably low for bamboo traps (0.2) and fairly high for rice fields, Percolating water and Animal tracks (1.3) which shows the abundance of mosquito species in these habitats. Similarly Pielou’s Evenness was highest for bamboo traps (E=1) showing species uniform distribution. Animal tracks were presumed not only the diverse habitat rather also possessed high value for species richness and species evenness. Temperature, rainfall, humidity and other related attributes responsible for species variation and abundance need to be analysed further to pave way for controlling vector species in their oviposition targeted sites.

Background and Objectives: Although the study on the bacteria residing in the mid-gut, salivary gland, and reproductive organs of insect vectors have drawn appeal to the host-pathogen interactions, we know comparatively less about microbiota that naturally exist in different mosquito organs within Iran. Materials and Methods: In the current investigation, PCR assay by using 16S rRNA gene amplification and DNA sequencing, in addition to the traditional culture-based approach utilized for the detection of cultivable bacterial assemblages in mid-gut and reproductive tracts of Culex quinquefasciatus. Results: The identified bacteria isolated from different tissues of 45 individuals were consisted of Achromobacter, Aeromonas, Arthrobacter, Asaia, Enterobacter, Gluconobacter, Klebsiella, Lysinibacillus, Micrococcus, Psuedomonas and Serratia. The results showed that Proteobacteria was the most prevalent phylum in both genders' mid-gut and reproductive tracts, and Asaia was the most common bacteria that originated in adult females and males’ tissues. Conclusion: These outcomes recommend that the discovered microbiome may span through Cx. quinquefasciatus populations. This data can be utilized to interfere with the transmission of pathogens and design new strategies for the control of mosquito-borne diseases.

Culex coronator Dyar and Knab is a highly invasive Neotropical species, first described at the beginning of the 20th century in Trinidad and Tobago (Dyar and Knab 1906). This is an important invasive species in Florida, which needs to be carefully surveilled by mosquito control experts. This article is structured similar to those from Walter Reed Biosystematics Unit (WRBU) so that readers would obtain the similar level of details offered through WRBU species pages, which is widely used by anyone interested in mosquito biology, research, and education.

Background: Blood-feeding insects are important vectors for an array of zoonotic pathogens. While previous efforts toward generating molecular resources have largely focused on major vectors of global medical and veterinary importance, molecular data across a large number of hematophagous insect taxa remain limited. Advancements in long-read sequencing technologies and associated bioinformatic pipelines provide new opportunities for targeted sequencing of insect mitochondrial (mt) genomes. For engorged hematophagous insects, such technologies can be leveraged for both insect mitogenome genome assembly and identification of vertebrate blood-meal sources. Methods: We used nanopore adaptive sampling (NAS) to sequence genomic DNA from four species of field-collected, blood-engorged mosquitoes (Aedes and Culex spp.) and one deer fly (Chrysops sp.). NAS was used for bioinformatical enrichment of mtDNA reads of hematophagous insects and potential vertebrate blood-meal hosts using publically available mt genomes as references. We also performed an experimental control to compare results of traditional non-NAS nanopore sequencing to the mt genome enrichment by the NAS method. Results: Complete mitogenomes were assembled and annotated for all five species sequenced with NAS: Aedes trivittatus, Aedes vexans, Culex restuans, Culex territans and the deer fly, Chrysops niger. In comparison to data generated during our non-NAS control experiment, NAS yielded a substantially higher proportion of reference-mapped mtDNA reads, greatly streamlining downstream mitogenome assembly and annotation. The NAS-assembled mitogenomes ranged in length from 15,582 to 16,045 bp, contained between 78.1% and 79.0% A + T content and shared the anticipated arrangement of 13 protein-coding genes, two ribosomal RNAs, and 22 transfer RNAs. Maximum likelihood phylogenies were generated to further characterize each insect species. Additionally, vertebrate blood-meal analysis was successful in three samples sequenced, with mtDNA-based phylogenetic analyses revealing that blood-meal sources for Chrysops niger, Culex restuans and Aedes trivittatus were human, house sparrow (Passer domesticus) and eastern cottontail rabbit (Sylvilagus floridanus), respectively. Conclusions: Our findings show that NAS has dual utility to simultaneously molecularly identify hematophagous insects and their blood-meal hosts. Moreover, our data indicate NAS can facilitate a wide array of mitogenomic systematic studies through novel 'phylogenetic capture' methods. We conclude that the NAS approach has great potential for broadly improving genomic resources used to identify blood-feeding insects, answer phylogenetic questions and elucidate complex pathways for the transmission of vector-borne pathogens. [ABSTRACT FROM AUTHOR]

Mosquitoes and EDTA-treated blood samples from febrile racehorses were investigated for Getah virus infection from 2016 to 2019 at the Miho Training Center, where several outbreaks of Getah virus have occurred. We collected 5557 mosquitoes and 331 blood samples from febrile horses in this study. The most frequently captured mosquito species was Culex tritaeniorhynchus (51.9%), followed by Aedes vexans nipponii (14.2%) and Anopheles sinensis (11.2%). Getah virus was detected in mosquitoes (Aedes vexans nipponii) in 2016 (strain 16-0810-26) but not in 2017-2019. Six of 74 febrile horses in 2016 and one of 69 in 2019 tested positive for Getah virus; none of the horses tested positive in 2017 or 2018. Phylogenetic and sequence analysis showed that strain 16-0810-26 was closely related to strains that had been isolated from horses and a pig around the training center in 2014-2016 but have not been detected in samples collected at the training center since 2017. In contrast, the strain isolated from the infected horse in 2019 (19-I-703) was genetically distinct from the strains isolated from horses and a pig in 2014-2016 and was more closely related to a strain isolated in 1978 at the training center. The source of strain 19-I-703 is unclear, but the virus was not detected in other horses sampled in 2019. In summary, we found that the distribution of mosquito species present at the training center had not changed significantly since 1979, and although a small outbreak of Getah virus infection occurred among horses at the training center in 2016, limited Getah virus activity was detected in mosquitoes and horses at the training center from 2017 to 2019. [ABSTRACT FROM AUTHOR]

Risk assessment and vector control programs rely on a comprehensive knowledge of mosquito diversity in different areas. The present study aims to evaluate mosquito biodiversity in different areas of Sirjan County, Kerman Province, as one of the most important economic zones of Iran. Totally 4538 mosquitoes representing 19 species and four genera were collected and identified. Results showed that Culiseta longiareolata and Culex quinquefacsiatus were constant, Culex destricola, Culex pusillus, Culex pipiens and Culex laticinctus were common and the other captured species were accidental species in Sirjan County. In this study, Aedes vittatus was recorded for the first time in Kerman Province. The highest rate of richness was in Balvard (2034 meters above sea level) and the highest rate of evenness and Shannon-Wiener indices belong to Zeid Abad (1718 m.a.s.l.) districts. The lowest similarity rate was between Balvard (2034 m.a.s.l.) and Pariz (2322 m.a.s.l.), and the highest was between Homashahr (1984 m.a.s.l.) and Khajo- Shahr districts (1723 m.a.s.l.). In this study, an agricultural area showed the highest; conversely, the area neighboring a copper mine showed the lowest rate of biodiversity. Biotic and abiotic factors and human activities can affect mosquito biodiversity; therefore, mosquito surveillance and control programs should consider these factors. [ABSTRACT FROM AUTHOR]

The prevalence and distribution of African alphaviruses such as chikungunya have increased in recent years. Therefore, a better understanding of the local distribution of alphaviruses in vectors across the African continent is important. Here, entomological surveillance was performed from 2014 to 2018 at selected sites in north-eastern parts of South Africa where alphaviruses have been identified during outbreaks in humans and animals in the past. Mosquitoes were collected using a net, CDC-light, and BG-traps. An alphavirus genus-specific nested RT-PCR was used for screening, and positive pools were confirmed by sequencing and phylogenetic analysis. We collected 64,603 mosquitoes from 11 genera, of which 39,035 females were tested. Overall, 1462 mosquito pools were tested, of which 21 were positive for alphaviruses. Sindbis (61.9%, N = 13) and Middelburg (28.6%, N = 6) viruses were the most prevalent. Ndumu virus was detected in two pools (9.5%, N = 2). No chikungunya positive pools were identified. Arboviral activity was concentrated in peri-urban, rural, and conservation areas. A range of Culicidae species, including Culex univittatus, Cx. pipiens s.l., Aedes durbanensis, and the Ae. dentatus group, were identified as potential vectors. These findings confirm the active circulation and distribution of alphaviruses in regions where human or animal infections were identified in South Africa. [ABSTRACT FROM AUTHOR]

Emerging infectious diseases are one of the most important global health challenges because of their impact on human and animal health. The vector-borne West Nile virus (WNV) is transmitted between birds by mosquitos, but it can also infect humans and horses causing disease. The local circulation of WNV in Spain has been known for decades, and since 2010, there have been regular outbreaks in horses, although only six cases were reported in humans until 2019. In 2020, Spain experienced a major outbreak with 77 human cases, which was followed by 6 additional cases in 2021, most of them in the Andalusian region (southern Spain). This study aimed to characterize the genomes of the WNV circulating in wild-trapped mosquitoes during 2020 and 2021 in Andalusia. We sequenced the WNV consensus genome from two mosquito pools and carried out the phylogenetic analyses. We also compared the obtained genomes with those sequenced from human samples obtained during the outbreak and the genomes obtained previously in Spain from birds (2007 and 2017), mosquitoes (2008) and horses (2010) to better understand the eco-epidemiology of WNV in Spain. As expected, the WNV genomes recovered from mosquito pools in 2020 were closely related to those recovered from humans of the same outbreak. In addition, the strain of WNV circulating in 2021 was highly related to the WNV strain that caused the 2020 outbreak, suggesting that WNV is overwintering in the area. Consequently, future outbreaks of the same strain may occur in in the future. [ABSTRACT FROM AUTHOR]

Simple Summary: Culex pseudovishnui, Cx. tritaeniorhynchus, and Cx. vishnui are members of the Cx. vishnui subgroup and are vectors of Japanese encephalitis (JE) in Thailand. However, their extremely similar morphologies make identification difficult. Thus, geometric morphometrics (GM) and DNA barcoding were applied to identify Cx. pseudovishnui, Cx. tritaeniorhynchus, and Cx. vishnui in Thailand. Our results of cross-validation reclassification demonstrated that GM based on wing shape was relatively high potential for distinguishing three Culex species. Meanwhile, DNA barcoding was highly effective at identifying all three species based on the DNA barcode gap. Japanese encephalitis (JE) is a viral infection of the brain caused by the Japanese encephalitis virus, which spreads globally, particularly in 24 countries of Southeast Asia and the Western Pacific region. In Thailand, the primary vectors of JE are Cx. pseudovishnui, Cx. tritaeniorhynchus, and Cx. vishnui of the Cx. vishnui subgroup. The morphologies of three mosquito species are extremely similar, making identification challenging. Thus, geometric morphometrics (GM) and DNA barcoding were applied for species identification. The results of cross-validation reclassification revealed that the GM technique based on wing shape analysis had relatively high potential for distinguishing Cx. pseudovishnui, Cx. tritaeniorhynchus, and Cx. vishnui (total performance = 88.34% of correctly assigned individuals). While the DNA barcoding yielded excellent results in identifying these Culex species based on the DNA barcode gap (average intraspecific genetic distance = 0.78% ± 0.39% and average interspecific genetic distance = 6.14% ± 0.79%). However, in the absence of the required facilities for DNA barcoding, GM techniques can be employed in conjunction with morphological methods to enhance the reliability of species identification. Based on the results of this study, our approach can help guide efforts to identify members of the Cx. vishnui subgroup, which will be useful for the effective vector control of JE in Thailand. [ABSTRACT FROM AUTHOR]

Background: Space spraying of insecticides is still an important means of controlling Aedes and Culex mosquitoes and arboviral diseases. This study evaluated the space spray efficacy of Fludora Co-Max EW, (water-based insecticide space spray combining flupyradifurone and transfluthrin with film forming aqueous spray technology (FFAST)), against wild insecticide-resistant Aedes aegypti and Culex quinquefasciatus mosquitoes from Abidjan, Côte d'Ivoire, compared with K-Othrine EC (deltamethrin-only product), in small-scale field trials. Methods: Wild Ae. aegypti and Cx. quinquefasciatus mosquito larvae were collected in Abidjan, Côte d'Ivoire from August to December 2020. Mosquito larvae were reared in the laboratory until the adult stage. Fludora Co-Max EW and K-Othrine EC were tested against emerged adult females (F0 generation) using ultra-low volume cold fogging (ULV) and thermal fogging (TF) delivery technology, both outdoors and indoors in Agboville, Côte d'Ivoire. Specifically, cages containing 20 mosquitoes each were placed at distances of 10, 25, 50, 75 and 100 m from the spraying line for outdoor spraying, and at ceiling, mid-height and floor levels for indoor house spraying. Knockdown and mortality were recorded at each checkpoint and compared by treatments. Results: Overall, Fludora Co-Max EW induced significantly higher knockdown and mortality effects in the wild insecticide-resistant Ae. aegypti and Cx. quinquefasciatus compared with K-Othrine EC. In both species, mortality rates with Fludora Co-Max EW were > 80% (up to 100%) with the ULV spray outdoors at each distance checkpoint (i.e. 10–100 m), and 100% with the ULV and TF sprays indoors at all checkpoints (i.e. ceiling, mid-height and floor). K-Othrine EC induced high mortality indoors (97.9–100%), whereas mortality outdoors rapidly declined in Ae. aegypti from 96.7% (10 m) to 36.7% (100 m) with the ULV spray, and from 85.0% (10 m) to 38.3% (100 m) with the TF spray. Fludora Co-Max EW spray applied as ULV spray outdoors had higher knockdown and higher killing effects on Ae. aegypti and Cx. quinquefasciatus than when applied as TF spray. Fludora Co-Max EW performed better against Cx. quinquefasciatus than against Ae. aegypti. Conclusions: Fludora Co-Max EW induced high mortality and knockdown effects against wild insecticide-resistant Ae. aegypti and Cx. quinquefasciatus Abidjan strains and performed better than K-Othrine EC. The presence of flupyradifurone and transfluthrin (with new and independent modes of action) and FFAST technology in the current Fludora Co-Max EW formulation appears to have broadened its killing capacity. Fludora Co-Max EW is thus an effective adulticide and may be a useful tool for Aedes and Culex mosquito and arbovirus control in endemic areas. [ABSTRACT FROM AUTHOR]

Rice fields in Sri Lanka create suitable breeding places for vector mosquitoes. Such sites provide habitats for diversified naturally occurring microbiota. Ciliated protists, Zoothamnium sp., Chilodonella sp., and Vorticella microstoma are among such microbiota found in vector mosquito habitats especially in rice field habitats in Sri Lanka. The present study was carried out to determine the comparative larvicidal effect of these ciliated protists collected from naturally infested mosquito larvae in some rice-field habitats in Kurunegala, Sri Lanka, against vector mosquito larvae. Vector mosquito larvae, Culex tritaeniorhynchus, and Culex gelidus were reared in the laboratory from field-collected water samples while Aedes aegypti mosquito larvae were reared using egg sheets, for the laboratory bioassays. V. microstoma showed the potential for infection and mortality of Cx. tritaeniorhynchus larvae (71.33% ± 5.23). Results revealed a minimum of 1000 V. microstoma is required to kill a single third instar larva of Cx. tritaeniorhynchus at 69.60 ± 2.40 h of exposure. Cx. gelidus larvae showed 41.33% ± 3.43 mortality due to V. microstoma infestation. However, none of the ciliates were effective against Ae. aegypti larvae. Chilodonella sp. was very occasionally reported during this study hence was not possible to the mass rear for experimentations. This study concludes that V. microstoma is an effective ciliated parasite of Cx. tritaeniorhynchus larvae. Due to their effectiveness and eco-friendly nature, this species can be developed as an effective bio-controlling agent against Cx. tritaeniorhynchus mosquito species. [ABSTRACT FROM AUTHOR]

Culex pipiens molestus and Culex pipiens pallens are two distinct bioforms in the Culex pipiens complex that are important vectors of several pathogens and are widely distributed around the world. In the current study, we present a high‐quality chromosome‐level genome of Cx. pipiens f. molestus and describe the genetic characteristics of this genome. The assembly genome was 559.749 Mb with contig and scaffold N50 values of 200.952 Mb and 0.370 Mb, and more than 94.78% of the assembled bases were located on 3 chromosomes. A total of 19,399 protein‐coding genes were predicted. Many gene families were expanded in the genome of Cx. pipiens f. molestus, particularly those of the chemosensory protein (CSP) and gustatory receptor (GR) gene families. In addition, utilizing Hi‐C data, we improved the previously assembled draft genome of Cx. pipiens f. pallens, with scaffold N50 of 186.195 Mb and contig N50 of 0.749 Mb, and more than 97.02% of the assembled bases were located on three chromosomes. This reference genome provides a foundation for genome‐based investigations of the unique ecological and evolutionary characteristics of Cx. pipiens f. molestus, and the findings in this study will help to elucidate the mechanisms involved in species divergence in the Culex pipiens complex. [ABSTRACT FROM AUTHOR]

Background: Mosquitoes are blood sucking insects dreaded for their biting nuisance and annoyance; they are also incriminated in the transmission of public health diseases among humans and among animals. The study was conducted to determine the abundance of mosquitos and their biting patterns at the Awka Campus of Nnamdi Azikiwe University (NAU), Awka Anambra State between April and June 2021. Methods: Eggs of mosquito species were collected using ovitraps and larvae were sampled across five (5). Indoor-biting and resting mosquitoes were collected using pyrethroid knockdown (PKD) method. Outdoor-biting mosquitoes were collected using Human Landing Catch (HLC) method. Results: A total of twenty-one (21) mosquitoes comprising three species, Aedes aegypti 3(14.3%), Aedes africanus 13(61.9%) and Aedes albopictus 5(23.8%) were collected using ovitraps. Mosquito larvae collected from breeding sites were a total of sixty-eight (68). The highest number of mosquito larvae were collected from discarded tyres 54(79.4%). Indoors, a total of one hundred and ten (110) adult mosquitoes were collected, and outdoor adult mosquitoes collected were a total of one hundred and forty-eight (148). The abundance of mosquito species collected was significantly different (p<0.05) across the different sampling methods Human Bait> Insecticide Knockdown> Larvae Collection>Ovitrap. The relative abundance of Aedes aegypti 60(40.5%) was significantly higher (p<0.05) than other species. Conclusion: In general, outdoor mosquito biting peak was recorded between 6:45pm and 7:45pm. This study is of public health concern because the student and staff population may be exposed to mosquito bites and possible disease transmission. [ABSTRACT FROM AUTHOR]

There have been repeated episodes of the outbreak of Japanese encephalitis (JE) in Malkangiri district of Odisha State in the recent past. In the current study, we aimed to assess the entomological parameters of JE vectors in the district. Prevalence of JE vector species, their per man hour density (PMHD), dusk index (DI), human blood index (HBI), infection status and other factors responsible for transmission of JE were assessed over 5 years (2015–2019). Culex vishnui was the predominant JE vector species (32.0%) collected, followed by Cx. whitmorei (27.1%) and Cx. tritaeniorhynchus (18.0%). The PMHD was higher in cattle shed (CS) than human dwelling (HD) and outdoor resting collection (ODRC) sites for all the JE vector species, except An. barbirostris. In particular, the PMHD of Cx. vishnui (8.02), Cx. whitmorei (5.71) and Cx. tritaeniorhynchus (5.01) were significantly higher in CS than HD and ODRC. The DI of Cx. vishnui (2.47), Cx. whitmorei (1.66) and Cx. tritaeniorhynchus (1.59) was significantly higher in CS compared to HD and ODRC. The HBI of Cx. vishnui was 0.015, whereas the HBI of Cx. tritaeniorhynchus was 0.009 in the study area. Among the 829 pools of JE vector species subjected to PCR, JE virus was isolated from one pool of Cx. vishnui. Based on the abundance of JE vectors and JE virus isolation from Cx. vishnui, it is requisite to implement systematic and long-term control measures for effective control of JE vector species in Malkangiri district, Odisha State. [ABSTRACT FROM AUTHOR]

Background: The objective of this study was to estimate malaria transmission and insecticide resistance status in malaria vectors in Adjrako village from Zè District in Southern Benin. The present study was carried out prior to investigations on infectivity of blood from asymptomatic carriers of Plasmodium falciparum to malaria vector mosquitoes. Methods: Human landing collections (HLCs) were performed in Adjrako village during the rainy season (September—November 2021). In this village, host-seeking mosquitoes were collected during three nights per survey from 22:00 to 06:00 in six randomly selected houses. Malaria vectors were dissected in orders to determinate their parity. Plasmodium falciparum infection in malaria vectors was determined by qPCR and the entomological inoculation rate (EIR) was calculated. The World Health Organization (WHO) insecticide susceptibility test-kits were used to evaluate the susceptibility of Anopheles gambiae sensu lato (s.l.) to deltamethrin at 0.05% and bendiocarb at 0.1%. Results: A total of 3260 females of mosquitoes belonging to 4 genera (Anopheles, Culex, Aedes and Mansonia) were collected. Most of the mosquitoes collected were An. gambiae sensu lato (s.l.). The entomological inoculation rate (EIR) for the three collection months was 8.7 infective bites per person and the parity rate was 84%. Mortality rates of An. gambiae s.l. exposed to 0.05% deltamethrin and 0.1% bendiocarb were 18% and 96%, respectively, indicating that this vector population was resistant to deltamethrin and possibly resistant to bendiocarb in the study area. Conclusion: This study showed that malaria transmission is effective in the study area and that An. gambiae s.l. is the main malaria vector. The entomological parameters indicate this study area is potentially favourable for investigations on P. falciparum asymptomatic carriers. [ABSTRACT FROM AUTHOR]

Background: West Nile virus (WNV), primarily vectored by mosquitoes of the genus Culex, is the most important mosquito-borne pathogen in North America, having infected thousands of humans and countless wildlife since its arrival in the USA in 1999. In locations with dedicated mosquito control programs, surveillance methods often rely on frequent testing of mosquitoes collected in a network of gravid traps (GTs) and CO2-baited light traps (LTs). Traps specifically targeting oviposition-seeking (e.g. GTs) and host-seeking (e.g. LTs) mosquitoes are vulnerable to trap bias, and captured specimens are often damaged, making morphological identification difficult. Methods: This study leverages an alternative mosquito collection method, the human landing catch (HLC), as a means to compare sampling of potential WNV vectors to traditional trapping methods. Human collectors exposed one limb for 15 min at crepuscular periods (5:00–8:30 am and 6:00–9:30 pm daily, the time when Culex species are most actively host-seeking) at each of 55 study sites in suburban Chicago, Illinois, for two summers (2018 and 2019). Results: A total of 223 human-seeking mosquitoes were caught by HLC, of which 46 (20.6%) were mosquitoes of genus Culex. Of these 46 collected Culex specimens, 34 (73.9%) were Cx. salinarius, a potential WNV vector species not thought to be highly abundant in upper Midwest USA. Per trapping effort, GTs and LTs collected > 7.5-fold the number of individual Culex specimens than HLC efforts. Conclusions: The less commonly used HLC method provides important insight into the complement of human-biting mosquitoes in a region with consistent WNV epidemics. This study underscores the value of the HLC collection method as a complementary tool for surveillance to aid in WNV vector species characterization. However, given the added risk to the collector, novel mitigation methods or alternative approaches must be explored to incorporate HLC collections safely and strategically into control programs. [ABSTRACT FROM AUTHOR]

In 2022, Greece was the second most seriously affected European country in terms of the West Nile virus (WNV), after Italy. Specifically, Central Macedonia was the region with the most reported human cases (81.5%). In the present study, 30,816 female Culex pipiens sensu lato mosquitoes were collected from May to September 2022 in the seven regional units of Central Macedonia; they were then grouped into 690 pools and tested for WNV, while next-generation sequencing was applied to the samples, which showed a cycle threshold of Ct < 30 in a real-time RT-PCR test. WNV was detected in 5.9% of pools, with significant differences in the detection rate among regional units and months. It is of interest that in the Thessaloniki regional unit, where most of the human cases were observed, the virus circulation started earlier, peaked earlier, and lasted longer than in the other regional units. All sequences clustered into the Central European subclade of WNV lineage 2, and the virus strain differed from the initial Greek strain of 2010 by 0.52% and 0.27% at the nucleotide and amino acid levels, respectively. Signature substitutions were present, such as S73P and T157A in the prM and E structural proteins, respectively. The screening of mosquitoes provides useful information for virus circulation in a region with a potential for early warning, while the availability of whole-genome sequences is essential for further studies, including virus evolution. [ABSTRACT FROM AUTHOR]

Mosquitoes are vectors of various pathogens that cause diseases in humans and animals. To prevent the outbreak of mosquito-borne diseases, it is essential to control vector populations, as treatment or vaccination for mosquito-borne diseases are often unavailable. Insect-specific viruses (ISVs) have previously been described as being potentially helpful against arboviral disease outbreaks. In this study, we present the first in vivo characterization of the ISV Culex Y virus (CYV). CYV was first isolated from free-living Culex pipiens mosquitoes in 2010; then, it was found in several mosquito cell lines in a further study in 2018. For mammalian cells, we were able to confirm that CYV does not replicate as it was previously described. Additionally, we found that CYV does not replicate in honey bees or locusts. However, we detected replication in the Culex pipiens biotype molestus, Aedes albopictus, and Drosophila melanogaster, thus indicating dipteran specificity. We detected significantly higher mortality in Culex pipiens biotype molestus males and Drosophila melanogaster, but not in Aedes albopictus and female Culex pipiens biotype molestus. CYV could not be transmitted transovarially to offspring, but we detected venereal transmission as well as CYV in mosquitos' saliva, indicating that an oral route of infection would also be possible. CYV's dipteran specificity, transmission routes, and killing effect with respect to Culex males may be used as powerful tools with which to destabilize arbovirus vector populations in the future. [ABSTRACT FROM AUTHOR]

Ilheus virus (ILHV) is a mosquito-borne flavivirus circulating throughout Central and South America and the Caribbean. It has been detected in several mosquito genera including Aedes and Culex, and birds are thought to be its primary amplifying and reservoir host. Here, we describe the genomic and morphologic characterization of ten ILHV strains. Our analyses revealed a high conservation of both the 5′- and 3′-untranslated regions but considerable divergence within the open reading frame. We also showed that ILHV displays a typical flavivirus structural and genomic organization. Our work lays the foundation for subsequent ILHV studies to better understand its transmission cycles, pathogenicity, and emergence potential. [ABSTRACT FROM AUTHOR]

The knowledge about the geographical distribution of Aedes patersoni Shanon and Del Ponte, Ae. scapularis (Rondani), Culex dolosus (Lynch Arribálzaga), Mansonia indubitans Dyar and Shannon, Psorophora cingulata (Fabricius), Toxorhynchites haemorrhoidalis separatus (Lynch Arribálzaga), Tx. purpureus (Theobald), Tx. theobaldi s. l. Dyar & Knab and Uranotaenia lowii Theobald in the Northwest of Argentina is extended. Likewise, they provided the first known localities for Ma. indubitans in the province of Salta and for Ae. serratus (Theobald), Ma. titillans (Walker) and Ps. ciliata (Fabricius) in the province of Jujuy. The presence of Ae. fulvithorax (Lutz), Ps. pallescens Edwards in Jujuy, Ur. pulcherrima Lynch Arribálzaga in Santiago del Estero and Anopheles pictipennis (Philippi) in Argentina, is discussed. This contribution updates the list of mosquitoes for the northwestern provinces of Argentina, increasing their numbers of species in Jujuy, La Rioja, Salta, Santiago del Estero and Tucumán to 68, 26, 102, 29 and 70 species, respectively. Additionally, information on the habitat of immature stages and the sanitary importance of the species mentioned is provided, as well as a complete list of the species present in the northwestern provinces of Argentina. [ABSTRACT FROM AUTHOR]

Introduction: Vector-borne diseases are prevalent in the Amazon and Coastal regions of Ecuador. However, there is a scarcity of mosquito ecology studies in these areas. The most recent list of species reported for the country comprises 8 tribes, 22 genera, and 200 species. Objectives: To document the Culicidae species found in La Isla Amazon Park, Napo, Ecuador, including those with epidemiological significance; and to analyze their composition, abundance, and diversity, focusing on larval habitats during the dry and rainy periods. Methods: We evaluated different larval habitats, considering collection duration as the primary criterion. We used CDC and Shannon traps to collect adult mosquitoes during both rainy and dry periods. To assess sampling effort, we used accumulation curves and non-parametric estimators of species richness, while we employed Hill numbers to determine diversity. Additionally, we used the Berger-Parker and Pielou indices to evaluate species dominance and evenness. We conducted cluster analysis and ANOSIM tests to assess the similarity between habitats and the differences in taxonomic composition between periods. Results: We collected a total of 802 individuals from 15 species and 4 taxonomic units, 5 genera, and 4 tribes. Notably, this may be the first records of Wyeomyia felicia Dyar & Núñez Tovar and Culex derivator Dyar & Knab from Ecuador. Additionally, the presence of Culex dunni Dyar and Psorophora ferox von Humboldt (both recognized as vectors) was correlated with increased rainfall. Conclusions: The abundance of mosquitoes, including potential vector species, increased during the rainy season, indicating a higher risk of pathogen transmission. However, the relationship between rainfall amount and diversity patterns is not well-defined. [ABSTRACT FROM AUTHOR]

Background: In August 2013, a virus strain (DH13M98) was isolated from Culex tritaeniorhynchus Giles collected in Mangshi, the southwestern border area of Yunnan Province, China. The virus replicated and caused cytopathic effects (CPE) in Aedes albopictus (C6/36) cells, but not in baby hamster Syrian kidney (BHK-21) cells. Materials and Methods: Agarose gel electrophoresis (AGE) analysis revealed that the DH13M98 virus was a 10-segment double-stranded RNA (dsRNA) virus, with a "1-1-1-2-1-1-2-1" pattern. The full genome of the DH13M98 virus was sequenced by full-length amplification of complementary DNAs (FLAC). Results: Phylogenetic analysis of the viral RNA-dependent RNA polymerase (Pol), major subcore-shell (T2), and major core-surface (T13) protein showed that DH13M98 clustered with Umatilla virus (UMAV), and the amino acid (aa) sequences of DH13M98 shared more than 89.5% (Pol), 95% (T2), and 91.1% (T13) identity with UMAV. However, the aa identity of outer capsid protein one (OC1) of DH13M98 with other UMAV was 57.1–79.2%, suggesting that DH13M98 was UMAV, but distinct from other strains of UMAV from the United States, Japan, and Germany at OC1, and it may be a high variant strain of UMAV, even a new serotype. Conclusion: This is the first isolation of UMAV in China, which enriches the resources of virus species in China and provides new insights into the genetic diversity and geographical distribution of the virus. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This document examines the interpretation of a specific line in the Latin poem Culex. The line in question contains the phrase "densas pastor pecudes cogebat in umbras," and there is debate over whether the adjective "densas" should modify "pecudes" or "umbras." The author argues that it should be understood as "when the goatherd was gathering his flock into the thick shade," based on the context and the author's usage. The article suggests that the current reading may be a result of a scribal error and proposes a correction to the text. The document also provides a bibliography for further research. [Extracted from the article]

Copyright of Myrtia is the property of Servicio de Publicaciones de la Universidad de Murcia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Mosquitoes are important vectors for human and animal diseases. Genetic markers, like the mitochondrial COI gene, can facilitate the taxonomic classification of disease vectors, vector-borne disease surveillance, and prevention. Within the control region (CR) of the mitochondrial genome, there exists a highly variable and poorly studied non-coding AT-rich area that contains the origin of replication. Although the CR hypervariable region has been used for species differentiation of some animals, few studies have investigated the mosquito CR. In this study, we analyze the mosquito mitogenome CR sequences from 125 species and 17 genera. We discovered four conserved motifs located 80 to 230 bp upstream of the 12S rRNA gene. Two of these motifs were found within all 392 Anopheles (An.) CR sequences while the other two motifs were identified in all 37 Culex (Cx.) CR sequences. However, only 3 of the 304 non-Culicidae Dipteran mitogenome CR sequences contained these motifs. Interestingly, the short motif found in all 37 Culex sequences had poly-A and poly-T stretch of similar length that is predicted to form a stable hairpin. We show that supervised learning using the frequency chaos game representation of the CR can be used to differentiate mosquito genera from their dipteran relatives. [ABSTRACT FROM AUTHOR]

To increase our understanding of the diversity of the mosquito virome, 6956 mosquitoes of five species (Culex erraticus, Culex pipiens, Culex restuans, Culex tarsalis, and Culex territans) collected in Iowa in the United States in 2017 and 2020 were assayed for novel viruses by performing polyethylene glycol precipitation, virus isolation in cell culture, and unbiased high-throughput sequencing. A novel virus, provisionally named "Walnut Creek virus", was isolated from Cx. tarsalis, and its genomic sequence and organization are characteristic of viruses in the genus Hapavirus (family Rhabdoviridae). Replication of Walnut Creek virus occurred in avian, mammalian, and mosquito, but not tick, cell lines. A novel virus was also isolated from Cx. restuans, and partial genome sequencing revealed that it is distantly related to an unclassified virus of the genus Phytoreovirus (family Sedoreoviridae). Two recognized viruses were also isolated: Culex Y virus (family Birnaviridae) and Houston virus (family Mesoniviridae). We also identified sequences of eight novel viruses from six families (Amalgaviridae, Birnaviridae, Partitiviridae, Sedoreoviridae, Tombusviridae, and Totiviridae), two viruses that do not belong to any established families, and many previously recognized viruses. In summary, we provide evidence of multiple novel and recognized viruses in Culex spp. mosquitoes in the United States. [ABSTRACT FROM AUTHOR]

Culex spp. mosquitoes transmit several pathogens concerning public health, including West Nile virus and Saint Louis encephalitis virus. Understanding the antiviral immune system of Culex spp. mosquitoes is important for reducing the transmission of these viruses. Mosquitoes rely on RNA interference (RNAi) to control viral replication. While the siRNA pathway in mosquitoes is heavily studied, less is known about the piRNA pathway. The piRNA pathway in mosquitoes has recently been connected to mosquito antiviral immunity. In Aedes aegypti, Piwi4 has been implicated in antiviral responses. The antiviral role of the piRNA pathway in Culex spp. mosquitoes is understudied compared to Ae. aegypti. Here, we aimed to identify the role of PIWI genes and piRNAs in Culex quinquefasciatus and Culex tarsalis cells during virus infection. We examined the effect of PIWI gene silencing on virus replication of two arboviruses and three insect-specific viruses in Cx. quinquefasciatus derived cells (Hsu) and Cx. tarsalis derived (CT) cells. We show that Piwi4 is antiviral against the La Crosse orthobunyavirus (LACV) in Hsu and CT cells, and the insect-specific rhabdovirus Merida virus (MERDV) in Hsu cells. None of the silenced PIWI genes impacted replication of the two flaviviruses Usutu virus (USUV) and Calbertado virus, or the phasivirus Phasi-Charoen-like virus. We further used small RNA sequencing to determine that LACV-derived piRNAs, but not USUV-derived piRNAs were generated in Hsu cells and that PIWI gene silencing resulted in a small reduction in vpiRNAs. Finally, we determined that LACV-derived DNA was produced in Hsu cells during infection, but whether this viral DNA is required for vpiRNA production remains unclear. Overall, we expanded our knowledge on the piRNA pathway and how it relates to the antiviral response in Culex spp mosquitoes. [ABSTRACT FROM AUTHOR]

Japanese encephalitis virus (JEV) is an important arbovirus in Asia that can cause serious neurological disease. JEV is transmitted by mosquitoes in an enzootic cycle involving porcine and avian reservoirs, in which humans are accidental, dead-end hosts. JEV is currently not endemic in Singapore, after pig farming was abolished in 1992; the last known human case was reported in 2005. However, due to its location along the East-Asian Australasian Flyway (EAAF), Singapore is vulnerable to JEV re-introduction from the endemic regions. Serological and genetic evidence in the last decade suggests JEV's presence in the local fauna. In the present study, we report the genetic characterization and the first isolation of JEV from 3214 mosquito pools consisting of 41,843 Culex mosquitoes, which were trapped from April 2014 to May 2021. The findings demonstrated the presence of genotype I of JEV (n = 10), in contrast to the previous reports of the presence of genotype II of JEV in Singapore. The genetic analyses also suggested that JEV has entered Singapore on several occasions and has potentially established an enzootic cycle in the local fauna. These observations have important implications in the risk assessment and the control of Japanese encephalitis in non-endemic countries, such as Singapore, that are at risk for JEV transmission. [ABSTRACT FROM AUTHOR]

Transmission of arthropod-borne viruses (arboviruses) are an emerging global health threat in the last few decades. One important arbovirus family is the Togaviridae, including the species Sindbis virus within the genus Alphavirus. Sindbis virus (SINV) is transmitted by mosquitoes, but available data about the role of different mosquito species as potent vectors for SINV are scarce. Therefore, we investigated seven mosquito species, collected from the field in Germany (Ae. koreicus, Ae. geniculatus, Ae. sticticus, Cx. torrentium, Cx. pipiens biotype pipiens) as well as lab strains (Ae. albopictus, Cx. pipiens biotype molestus, Cx. quinquefasciatus), for their vector competence for SINV. Analysis was performed via salivation assay and saliva was titrated to calculate the amount of infectious virus particles per saliva sample. All Culex and Aedes species were able to transmit SINV. Transmission could be detected at all four investigated temperature profiles (of 18 ± 5 °C, 21 ± 5 °C, 24 ± 5 °C or 27 ± 5 °C), and no temperature dependency could be observed. The concentration of infectious virus particles per saliva sample was in the same range for all species, which may suggest that all investigated mosquito species are able to transmit SINV in Germany. [ABSTRACT FROM AUTHOR]

Simple Summary: Vietnam is one of the tropical countries of Asia where individuals are at high risk of attaining mosquito-borne diseases. Due to rapid urbanization in Vietnam, most of the major cities have immense population growth, along with inadequate control measures over mosquitoes. These factors contributed to a sudden increase in the population of disease vectors that lead to cyclical epidemics of mosquito-borne diseases. This review paper aims to (i) provide a complete checklist of Vietnamese mosquitoes, (ii) provide an overview of mosquito-borne diseases in Vietnam, and (iii) preventive measures for mosquitoes in Vietnam. We list 281 mosquito species, belonging to 42 subgenera of 22 genera. We found that three genera, namely, Anopheles, Aedes, and Culex are found to be potential vectors for mosquito-borne diseases in Vietnam. We found dengue and malaria are the most common mosquito-borne diseases in Vietnam with about 320,702 cases and 54 deaths in the 2019 outbreak and 4548 clinical cases and six deaths, respectively. We suggest that mosquito-borne diseases could be effectively controlled and prevented through mechanical, chemical, biological, and genetic methods. Mosquito-borne diseases pose a significant threat to humans in almost every part of the world. Key factors such as global warming, climatic conditions, rapid urbanisation, frequent human relocation, and widespread deforestation significantly increase the number of mosquitoes and mosquito-borne diseases in Vietnam, and elsewhere around the world. In southeast Asia, and notably in Vietnam, national mosquito control programmes contribute to reducing the risk of mosquito-borne disease transmission, however, malaria and dengue remain a threat to public health. The aim of our review is to provide a complete checklist of all Vietnamese mosquitoes that have been recognised, as well as an overview of mosquito-borne diseases in Vietnam. A total of 281 mosquito species of 42 subgenera and 22 genera exist in Vietnam. Of those, Anopheles, Aedes, and Culex are found to be potential vectors for mosquito-borne diseases. Major mosquito-borne diseases in high-incidence areas of Vietnam include malaria, dengue, and Japanese encephalitis. This review may be useful to entomological researchers for future surveys of Vietnamese mosquitoes and to decision-makers responsible for vector control tactics. [ABSTRACT FROM AUTHOR]

Tpp80Aa1 from Bacillus thuringiensis is a Toxin_10 family protein (Tpp) with reported action against Culex mosquitoes. Here, we demonstrate an expanded target range, showing Tpp80Aa1 is also active against the larvae of Anopheles gambiae and Aedes aegypti mosquitoes. We report the first crystal structure of Tpp80Aa1 at a resolution of 1.8 Å, which shows Tpp80Aa1 consists of two domains: an N-terminal β-trefoil domain resembling a ricin B lectin and a C-terminal putative pore-forming domain sharing structural similarity with the aerolysin family. Similar to other Tpp family members, we observe Tpp80Aa1 binds to the mosquito midgut, specifically the posterior midgut and the gastric caecum. We also identify that Tpp80Aa1 can interact with galactose-containing glycolipids and galactose, and this interaction is critical for exerting full insecticidal action against mosquito target cell lines. [ABSTRACT FROM AUTHOR]

Background: Mosquitoes (Diptera: Culicidae) have always been considered as the vector/s of viral and parasitic diseases. This study aimed to conduct a comprehensive survey on the species composition, spatial distribution, and biodiversity indices of mosquitoes in Kurdistan Province, western Iran. Methods: This study was carried out in 10 counties of Kurdistan Province. The immature stages of mosquitoes were collected monthly from June to September. ArcGIS software was used to spatial analysis and create maps. Alpha diversity indices were calculated using the related formula. Results: Totally, 5831 larvae belonging to the family Culicidae were collected. Twelve species were identified including: Anopheles claviger, An. maculipennis s.l, An. superpictus s.l, Culiseta. longiareolata, Cs. subochrea, Culex hortensis, Cx. mimeticus, Cx. perexiguus, Cx. pipiens, Cx. theileri, Cx. modestus and Cx. territans. Based on this analysis, the high-risk areas of the province are determined as Anopheles in the west, Culex in the north, and the Culiseta in the south of the province. Analyzing the Alpha biodiversity indices showed Baneh and Sarabad had the maximum and Bijar had the minimum mosquito biodiversity. Conclusion: The western counties of the province are regarded as the hotspots for anopheline mosquitos. Moreover, reporting of malaria cases in the past, bordering with Iraq and the high traffic of travelers have made these areas as potential foci for malaria transmission. So that, routine entomological inspections are proposed to detect any suspicious vector or case entrance. [ABSTRACT FROM AUTHOR]

In 2017, a mortality event affected Humboldt penguins at Chester Zoo (UK), which coincided with the diagnosis of avian malaria (AM) in some birds. AM is found worldwide wherever a competent mosquito vector is present, but the disease is particularly severe in penguins and other species that originate from non-endemic regions. To better understand the role of AM and manage its threat to penguin collections, Plasmodium was surveyed through PCR at Chester Zoo in mosquitoes, penguins, and dead free-living wild birds during and around the mortality event. Additional sequences were obtained from penguin fatalities from four other UK zoological collections. All sequences were integrated into phylogenetic analyses to determine parasite species and lineages. In total, 753/6459 positive mosquitoes were recorded (11.7% prevalence), reaching a weekly peak of 30% prevalence in mid-summer. Among penguin fatalities at Chester Zoo, several penguins presented signs and lesions compatible with AM; nevertheless, exoerythrocytic meronts were identified in only one case and Plasmodium spp. was identified in 5/22 birds. Phylogenetic analysis revealed at least five parasite cytb lineages of three Plasmodium species (P. matutinum, P. relictum and P. vaughani) circulating in mosquitoes at Chester Zoo; however, infections in free-living wild birds and penguins were only from P. matutinum. Plasmodium matutinum was confirmed as the cause of death of one penguin and was highly suspected to be the cause of death of another three. The lineage LINN1 was associated with 4/5 penguin infections. AM had a key role in the penguin multicausal mortality event. Understanding the risk of AM to penguin collections at Chester Zoo and elsewhere requires long-term surveillance to examine the association between Plasmodium infection and penguin mortality and the variability in parasite virulence. Surveillance of Plasmodium spp. in mosquitoes and local birds provides information about the parasite's transmission cycle locally, and could warn about infection risks to species of interest, which is essential for efficient disease control and prevention. [Display omitted] • Plasmodium infection in penguins, mosquito and wild birds is described. • Humboldt penguin mortality due to P. matutinum was recorded for the first time. • One of three Plasmodium spp. found in mosquitoes infected penguins and wild birds. • Detecting Plasmodium infections is challenging despite pathological evidence. [ABSTRACT FROM AUTHOR]

Background. Discarded vehicle tires are an important artificial habitat for the larvae of many container-breeding mosquito species worldwide, including in the United States. Unmanaged discarded vehicle tires create health, environmental and social costs, and with budget and staffing constraints, effective management of discarded used vehicle tires a mosquito larval habitat depends in part on the knowledge, attitude, and practices (KAP) of community residents. Objectives. This study aims to examine the knowledge, attitude and practices of New Orleans, Louisiana residents toward illegally discarded vehicle tires, and larval mosquito control. Methods. A descriptive cross-sectional design study was used where 422 households were selected using a two-stage cluster random sampling procedure in New Orleans, Louisiana. Heads of households or a person aged 18 years or older self-administered the survey. The questionnaire comprised five parts: screening, tire sightings, preferred communication method, knowledge, attitude and precautionary measures against mosquito control, disease risk and illegal discarding. We then statistically compared above and below median income household responses to identify likely causes of detected differences. The data were analyzed using ordinal regression models via IBM SPSS statistics V.26.0. Statistical significance was set at p<0:05. Results. Out of 290 responding households, 95.5% strongly agree or agree that mosquitoes can spread serious diseases like West Nile, Zika or Dengue. Only 2.3% of the sample had high knowledge of illegally discarded tires dumping and mosquito larval control. Those employed were 1.0 times more likely to possess good knowledge than the unemployed (p<0:001). Despite low knowledge levels regarding mosquito breeding and polluted water in discarded tires, 29.9% of respondents had positive attitude and 20.5% reported sufficient practices. Among the socio-demographic variables, only home ownership and being employed were predictors of knowledge and attitude towards mosquito breeding in illegally discarded tires (p<0:05). Conclusions. Despite the observed increasing number of illegally discarded vehicle tires in New Orleans, the knowledge of people about illegal tire dumping and their associated risk factors as suitable larval habitants was low. Therefore, there is a need for developing community-based and place-based tailored sensitization campaigns to prevent illegal used tire dumping, and larval control. [ABSTRACT FROM AUTHOR]

Epicuticular wax extract bearing n-alkane compounds were isolated from leaves of Holoptelea integrifolia and its chemical characterization was done by GC-MS analysis. Seven n-alkane compounds were isolated from epicuticular wax of H. integrifolia, which are Undecane [C11H24], Decane 5-methyl- [C11H24], Dodecane [C12H26], Undecane, 3,6-dimethyl- [C12H26], Hexadecane, 2,6,10,14-tetramethyl- [C20H42], Tridecane [C13H28], and Tetradecane [C14H30]. Different concentrations of crude extract as well as epicuticular wax extract bearing n-alkane each @ 2, 4 and 5 ppm cm-2 applied on human hand surface for repellence against Culex vishnui (vectors of JE) and at different time of exposure, gave a maximum protection of 73.33 per cent in the case of crude extract, and 94.33 per cent with epicuticular wax extract, both at 5 ppm cm-2, up to five hours of exposure. [ABSTRACT FROM AUTHOR]

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Abstract Background The Middle East Respiratory Syndrome coronavirus (MERS‐CoV) is still listed on the WHO Research and Development Blueprint of emerging pathogens. Dromedary camels remain the only known animal reservoir of the virus. The animal‐to‐animal as well as the animal‐to‐human transmission in the MERS‐CoV cycles were reported. However, many aspects of these transmission chains are not well studied. One of these directions is the potential roles of various species of arthropods in the transmission of the virus. Objectives The main goal of the current work was to study the roles of several species of arthropods in the transmission of MERS‐CoV. Methodology To achieve this goal, we identified some MERS‐CoV naturally infected dromedary camel populations. We conducted a longitudinal study among these animals for more than 2 months. This was done by repeated testing of nasal swabs biweekly from some selected animals in this population for the presence of MERS‐CoV‐RNAs by real‐time PCR. During the duration of this study, we collected several species of arthropods (Culicoides, Stomoxys, Musca domestica and some Culex species) that shared the habitat and were circulating in this farm during this longitudinal study. Results Our results showing, despite the detection of the viral RNAs in some animals throughout this study, none of the examined species of arthropods tested positive for the viral RNA. Conclusions These results are suggesting that at least the tested species of arthropods may not play roles in the transmission of MERS‐CoV. However, more large‐scale studies are required to explore any potential roles of arthropods in the transmission cycle of MERS‐CoV.

Rice is a crucial food source and an important economic activity globally. Rice fields provide habitats for birds and other organisms but also serve as ideal breeding grounds for mosquitoes, including potential vectors such as Culex , Aedes, and Anopheles. There is an urgent need to manage mosquitoes associated with rice crops, as they are important pests and vectors of diverse pathogens. Effective management should rely on cost-effective, legislative, and environmentally sustainable approaches. We gathered information from various sources on surveillance, phenology, mosquito nuisance, vector-borne diseases and control measures in the main rice paddies of the five major rice-producing regions in Europe: Italy, Spain, Greece, Portugal, and France. Mosquito problems in rice paddies are prevalent across most analyzed regions, with entomological and virological surveillance efforts varying in intensity and timing. Aedes caspius mosquitoes significantly contribute to nuisance levels, while recent West Nile virus (WNV) circulation poses the most serious threat, as these habitats support high densities of mosquito vectors such as Culex pipiens , Culex modestus, and Culex perexiguus. Different mosquito control strategies are applied, ranging from centralized programs to localized interventions funded by public entities and implemented by public or private companies. Biological larviciding with Bacillus thuringiensis serovar. israelensis is the primary method used, supplemented by adulticiding during epidemic outbreaks in nearby urban areas. These management approaches reflect diverse regional contexts and highlight the importance of adaptive strategies in addressing mosquito-related challenges across rice paddies in Europe. [Display omitted] • We compiled information from the five major rice-producing regions in Europe. • Mosquito problems in rice paddies are prevalent across most analyzed regions. • Rice fields support high density of mosquito vectors such as Cx. pipiens , Cx. modestus and Cx. perexiguus. • Biological larviciding is by far the primary adopted method to control mosquitoes. • We identified several operational challenges in managing mosquitoes in rice paddies. [ABSTRACT FROM AUTHOR]

· Microculex is a subgenus of Culex associated mostly to bromeliads in wild environments. · The presence of some Microculex species in impacted areas can appoint to adapted process. · The compilation of all information about this subgenus in single volume is an important contribution to Culicidae research field. · It is evident the necessity of more studies about ecology and taxonomy of Microculex species. Microculex is a subgenus of Culex that is mainly associated with natural breeding sites in wild environments such as cut bamboos, tree holes and bromeliads. However, recent findings of Culex (Microculex) species in bromeliads in urban areas and in artificial breeding sites close to human habitations suggest that they are becoming more tolerant of urbanization. Whilst dispersion studies of this subgenus have shown the ecological valency of some species in relation to human-impacted areas, there is a scarcity of studies on the blood-feeding habits, vector capacity and taxonomy of Microculex. As all the information about this subgenus is fragmented and restricted in most cases to physical libraries, this review seeks to compile all the information on Microculex published over the last century and a half so that this can be more easily consulted by specialists interested in the subject. The ability of some species of this subgenus to adapt to human-impacted environments by colonizing artificial breeding sites and thus become a potential vector of animal and human diseases is also discussed. [ABSTRACT FROM AUTHOR]

Using Illumina NextSeq sequencing and bioinformatics, we identified and characterized thirty-three viral sequences of unsegmented and multipartite viral families in Aedes spp. , Culex sp. and Anopheles darlingi female mosquito pools from Porto São Luiz and Pirizal, Alto Pantanal. Seventeen sequences belong to unsegmented viral families, twelve represent putative novel insect-specific viruses (ISVs) within families Chuviridae (3/33; partial genomes) and coding-complete sequences of Xinmoviridae (1/33) , Rhabdoviridae (2/33) and Metaviridae (6/33); and five coding-complete sequences of already-known ISVs. Notably, two putative novel rhabdoviruses, Corixo rhabdovirus 1 and 2, were phylogenetically related to Coxipo dielmovirus, but separated from other Alpharhabdovirinae genera, sharing Anopheles spp. as host. Regarding multipartite families, sixteen segments of different putative novel viruses were identified (13 coding-complete segments) within Durnavirales (4/33), Elliovirales (1/33), Hareavirales (3/33) and Reovirales (8/33) orders. Overall, this study describes twenty-eight (28/33) putative novel ISVs and five (5/33) already described viruses using metagenomics approach. • Thirty-three viral sequences were identified by Illumina NextSeq sequencing. • ISVs were identified in Aedes spp., Culex sp., and Anopheles darlingi mosquitoes. • Twenty-eight sequences represent putative novel viruses. • Seventeen coding-complete genomes belong to unsegmented viral families. • Two novel alpharhabdoviruses identified in Anopheles darlingi female mosquitoes. [ABSTRACT FROM AUTHOR]

Usutu virus (USUV) is a mosquito-borne flavivirus originating from Africa, that belongs to the Japanese encephalitis virus (JEV) complex. In nature, USUV involves Culex spp. mosquitoes acting as vectors and birds as amplifying hosts. The virus has recently spread in Europe and is considered an emerging human pathogen. This is the first research study performed in Greece revealing the presence and circulation of USUV in Culex spp. mosquito populations. Out of the 1,500 mosquito pools tested with real-time RT-PCR, four (Roesch et al., 2019) were positive for USUV. All four pools were collected from the region of Central Macedonia, Northern Greece. [ABSTRACT FROM AUTHOR]

Mosquitoes are medically important insects, and accurate species identification is crucial to understanding vector biology, forming the cornerstone of successful vector control programs. Identification is difficult owing to morphologically similar species. Wing morphometrics can provide a simple, fast, and accurate way to classify species, and using it as a method to differentiate vector species among its cryptic congeners has been underexplored. Using a total of 227 mosquitoes and 20 landmarks per specimen, we demonstrated the utility of wing morphometrics in differentiating species two groups occurring in sympatry – Culex (Culex) vishnui group and Culex (Lophoceraomyia) subgenus, as well as explored population-level variation in the wing shape of Aedes albopictus across habitats. Cytochrome oxidase subunit I (COI) gene region was sequenced to validate the morphological and morphometric identification. Procrustes ANOVA regression and CVA based on wing shape reflected that the wing landmarks across all species differed significantly, and leave-one-out cross validation revealed an overall high accuracy of >97% for the two Culex groups. Wing morphometrics uncovered population-level variation within Aedes albopictus , but cross validation accuracy was low. Overall, we show that wing geomorphometric analysis is able to resolve cryptic Culex species (including vectors) occurring sympatrically, and is a robust tool for identifying mosquitoes reliably. • Accurate species identification is crucial to understanding vector biology. • Relevant in mosquito groups which are speciose and taxonomically challenging. • Wing morphometrics is a simple, fast and accurate way to classify species. • Able to differentiate morphologically similar species occurring in sympatry. • Culex wing shapes are positively correlated with genetic distances in our study. [ABSTRACT FROM AUTHOR]