Mansonia Uniformis Research Articles

Detection of Wuchereria bancrofti infection in mosquitoes in areas co-endemic with Brugia malayi in Balasore district, Odisha, India

Lymphatic filariasis (LF) is a crippling and disfiguring parasitic condition. India accounts for 55% of the world’s LF burden. The filarial parasite Wuchereria bancrofti is known to cause 99.4% of the cases while, Brugia malayi accounts for 0.6% of the issue occurring mainly in some pockets of Odisha and Kerala states. The Balasore (Baleswar) district of Odisha has been a known focus of B. malayi transmission. We employed molecular xenomonitoring to detect filarial parasite DNA in vectors. In six selected villages, Gravid traps were used to collect Culex mosquitoes and hand catch method using aspirators was followed for collection of mansonioides. A total of 2903 mosquitoes comprising of Cx. quinquefasciatus (n = 2611; 89.94%), Cx. tritaeniorhynchus (n = 100; 3.44%), Mansonia annuliferea (n = 139; 4.78%) and Mansonia uniformis (n = 53; 1.82%) were collected from six endemic villages. The species wise mosquitoes were made into 118 pools, each with a maximum of 25 mosquitoes, dried and transported to the laboratory at VCRC, Puducherry. The mosquito pools were subjected to parasite DNA extraction, followed by Real-time PCR using LDR and HhaI probes to detect W. bancrofti and B. malayi infections, respectively. Seven pools (6.66%) of Cx. quinquefasciatus, showed infection with only W. bancrofti while none of the pools of other mosquito species showed infection with either W. bancrofti or B. malayi. Although the study area is endemic to B. malayi, none of the vectors of B. malayi was found with parasite infection. This study highlights the ongoing transmission of bancroftian filariasis in the study villages of Balasore district of Odisha and its implications for evaluating LF elimination programme.

Integrating wing morphometrics and mitochondrial DNA analysis to assess the filaria vector Mansonia uniformis (Diptera: Culicidae) populations in Thailand.

Mansonia uniformis (Diptera: Culicidae) is recognized as a vector of Brugia malayi and has been reported to transmit Wuchereria bancrofti, both causing lymphatic filariasis in humans. This study employed geometric morphometrics (GM) to investigate wing shape variation and analyzed genetic diversity through cytochrome c oxidase subunit 1 (COI) gene analyses in Ma. uniformis populations across Thailand. Wing GM analyses indicated significant differences in wing shape based on Mahalanobis distances among nearly all population pairs (p < 0.05), with no significant correlation between wing shape and geographic distance (r = 0.210, p > 0.05). Genetic analyses identified 63 haplotypes and 49 polymorphic sites, with the overall population exhibiting a nucleotide diversity of 0.006 (± 0.001) and a haplotype diversity of 0.912 (± 0.017). Deviations from neutrality, as indicated by Tajima's D and Fu's FS tests for the overall Ma. uniformis populations in Thailand, were statistically significant and negative, suggesting population expansion (both p < 0.05). Analysis of molecular variance revealed no significant genetic structure when all populations were categorized based on collection sites and geographic regions. However, significant differences in FST values were observed between some populations. These findings enhance our understanding of the geographical and genetic factors influencing Ma. uniformis populations, which are crucial for developing effective control strategies in Thailand.

Geometric morphometrics to differentiate species and explore seasonal variation in three Mansonia species (Diptera: Culicidae) in central Thailand and their association with meteorological factors.

Mansonia mosquito species are recognised as a significant vector of human pathogens, primarily transmitting the filarial nematode, Brugia malayi. In central Thailand, the three most prevalent Mansonia species are Mansonia annulifera, Mansonia indiana and Mansonia uniformis. This study explored the influence of seasonal changes on the phenotypic variation of these Mansonia species in central Thailand using the geometric morphometrics (GM). To ensure accurate species identification, we integrated GM techniques with DNA barcoding, examining distinctions in both phenotype and genotype among the species. The intraspecific genetic divergence ranged from 0.00% to 1.69%, whereas the interspecific genetic divergence ranged from 10.52% to 16.36%. The clear distinction between intra- and interspecific distances demonstrated the presence of a barcoding gap, confirming the successful differentiation of the three Mansonia mosquito species through DNA barcoding. Similarly, the interspecies GM assessment for classifying Mansonia species demonstrated a high degree of accuracy, with an overall performance of 98.12%. Exploring seasonal variation in the three Mansonia species revealed wing variations across different seasons, and pronounced variations appearing in the cool season. Regarding their association with meteorological factors, Ma. annulifera and Ma. uniformis showed significant positive correlations with temperature (p < 0.05), and Ma. uniformis also displayed a significant negative correlation with atmospheric pressure (p < 0.05). The insights from this study will deepen our understanding of the adaptive patterns of Mansonia mosquitoes in Thailand's central region, paving the way for enhanced disease surveillance related to these vectors.

Effect of expanding farmlands with domestication of animals in the vicinity of disturbed swamps and built-up farmland ponds on population dispersion and decline of locally adapted Mansonia vectors (Diptera: Culicidae).

The adaptive processes and resilience of Mansonia vectors responsible for bioindicators can change in response to climate, land use, and environmental changes. This study evaluated the effects of expanding farmlands with the domestication of animals in the vicinity of either disturbed swamps or built-up farmland ponds on the population dispersion and decline of locally adapted Mansonia faunas as a result of expanding farmlands in Thailand. Based on environmental surveys, four different geographically defined study sites were selected: I - the expanding farmlands with domestication of livestock and pet animals in the vicinity of low-lying swamp with habitat fragmentation and aquatic vegetation; II - the expanding farmlands with domestication of pet animals in the vicinity of elevated swamp with habitat destruction and aquatic vegetation; III - the expanding farmlands with domestication of livestock and pet animals in the vicinity of low-lying farmland ponds with restoration and aquatic vegetation; and IV - the expanding farmlands with domestication of pet animals in the vicinity of elevated farmland ponds with restoration and aquatic vegetation. Human landing catch collection method was used to periodically assess the species composition and abundance of Mansonia vectors. Aggregated distributions and seasonal abundances of Mansonia faunas (Mansonia uniformis, Mansonia indiana, Mansonia annulifera, Mansonia annulata, Mansonia bonneae, and Mansonia dives) with variable proportions were observed at all the study sites. A decline in the population of Mansonia faunas, except for Ma. uniformis, was observed at study sites I and II. The anticipated effects of expanding farmlands affected the population dispersion and decline of locally adapted Mansonia faunas, thus representing a diverse assemblage of Mansonia species with different adaptations, ecological tolerances, and host exploitation strategies in life. These effects depended either on the function of disturbed swamps or on the development of farmland ponds, whether they provided a wide range of freshwater habitats, or on the domestication of animals, whether they provided animal blood meal sources.

Brief report: Diversity of mosquito in East Surabaya

Mosquitoes are insects that are detrimental to human health because they act as disease vectors, such as dengue fever. Surabaya was known for its high risk of dengue fever. This study aims to describe the diversity of mosquitoes and breeding site distribution in Eastern Surabaya. The study was conducted in 2021 during the end of the wet season in different habitat types in the eastern Surabaya (residential, city park, bamboo forest, and mangrove forest). Eggs, larval, and adult-stage mosquitoes were collected and stored in the Entomology Laboratory for morphological identification. Adult mosquito was collected by using a sweep net and light trap method, while the larva and egg were collected incidentally from breeding sites. The diversity of mosquitoes in the Eastern Surabaya was determined by using the Shannon-Wiener diversity index (H’), dominance, species richness (R), and breeding site distribution. Eleven species were obtained in this study, namely Aedes aegypti, Aedes albopictus, Aedes annandalei, Anopheles subpictus, Anopheles vagus, Anopheles barbirostris, Culex bitaeniorhynchus, Culex pseudovishnui, Culex quinquefasciatus, Mansonia uniformis, and Malaya genurostris. The H’ index of 1.63 indicates the mosquito community was at a moderate level. The R-value of 1.56 indicates a low level of mosquito species richness. The most abundant species was Cx. quinquefasciatus (37.2%). Most of the breeding sites with mosquito larval infested were found in open areas (79.3%). These numbers mean the total of individuals of each species tends to be low and its dominance shows no effect on other species. The data on mosquito species and their distribution in Surabaya could be used as base information for vector control strategies.

Outline-based geometric morphometrics: Wing cell differences for mosquito vector classification in the Tanaosri mountain range, Thailand

Recent studies have revealed taxonomic signals within the wing cells of certain mosquito species. In our study, wing cell differentiation among mosquito vectors from the Tanaosri mountain range in Thailand was evaluated using the outline-based geometric morphometric (GM) approach. Our focus was on four specific wing cells for GM analysis: the wing contour (external cell), the second submarginal cell (internal cell 1), the first posterior cell (internal cell 2), and the third posterior cell (internal cell 3). Before proceeding with the GM approach, the identity of seven mosquito genera and 21 species was confirmed using molecular techniques. Our validated classification tests demonstrated that the performance of mosquito species classification varies according to genus. Notably, three Aedes species exhibited the highest accuracy for both internal cell 2 and internal cell 3, each registering a score of 93.20 %. In the case of two Mansonia species, the wing contour displayed a remarkable accuracy of 98.57 %. Consequently, we suggest the use of the outline-based GM approach, particularly focusing on the wing contour, for differentiating Mansonia annulifera and Mansonia uniformis. In contrast, the highest accuracy for classifying Culex species was found in internal cell 1, at 75.51 %, highlighting the challenges due to similarities in wing cells within this genus. These findings provide a guideline for future applications of the outline-based GM approach, focusing on wing cells, as an alternative method to classify mosquito vector species.

Novel strains of Culex flavivirus and Hubei chryso-like virus 1 from the Anopheles mosquito in western Kenya

Surveillance of mosquito vectors is critical for early detection, prevention and control of vector borne diseases. In this study we used advanced molecular tools, such as DNA barcoding in combination with novel sequencing technologies to discover new and already known viruses in genetically identified mosquito species. Mosquitoes were captured using BG sentinel traps in Western Kenya during May and July 2019, and homogenized individually before pooled into groups of ten mosquitoes. The pools and individual samples were then used for molecular analysis and to infect cell cultures. Of a total of fifty-four (54) 10-pools, thirteen (13) showed cytopathic effect (CPE) on VeroB4 cells, eighteen (18) showed CPE on C6/36 cells. Eight (8) 10-pools out of the 31 CPE positive pools showed CPE on both VeroB4 and C6/36 cells. When using reverse transcriptase polymerase chain reaction (RT-PCR), Sanger sequencing and Twist Comprehensive Viral Research Panel (CVRP) (Twist Biosciences), all pools were found negative by RT-PCR when using genus specific primers targeting alphaviruses, orthobunyaviruses and virus specific primers towards o'nyong-nyong virus, chikungunya virus and Sindbis virus (previously reported to circulate in the region). Interestingly, five pools were RT-PCR positive for flavivirus. Two of the RT-PCR positive pools showed CPE on both VeroB4 and C6/36 cells, two pools showed CPE on C6/36 cells alone and one pool on VeroB4 cells only. Fifty individual mosquito homogenates from the five RT-PCR positive 10-pools were analyzed further for flavivirus RNA. Of these, 19 out of the 50 individual mosquito homogenates indicated the presence of flavivirus RNA. Barcoding of the flavivirus positive mosquitoes revealed the mosquito species as Aedes aegypti (1), Mansonia uniformis (6), Anopheles spp (3), Culex pipiens (5), Culex spp (1), Coquilletidia metallica (2) and Culex quinquefasciatus (1). Of the 19 flavivirus positive individual mosquitoes, five (5) virus positive homogenates were sequenced. Genome sequences of two viruses were completed. One was identified as the single-stranded RNA Culex flavivirus and the other as the double-stranded RNA Hubei chryso-like virus 1. Both viruses were found in the same Anopheles spp. homogenate extracted from a sample that showed CPE on both VeroB4 and C6/36 cells. The detection of both viruses in a single mosquito homogenate indicated coinfection. Phylogenetic analyses suggested that the Culex flavivirus sequence detected was closely related to a Culex flavivirus isolated from Uganda in 2008. All four Hubei chryso-like virus 1 segments clusters closely to Hubei chryso-like virus 1 strains isolated in Australia, China and USA. Two novel strains of insect-specific viruses in Anopheles mosquitoes were detected and characterized.

Diverse novel Wolbachia bacteria strains and genera-specific co-infections with Asaiabacteria in Culicine mosquitoes from ecologically diverse regions of Cameroon.

Background: The endosymbiotic bacterium Wolbachia infects numerous species of insects and Wolbachia transinfection of Aedes mosquito species is now being used for biocontrol programs as Wolbachia strains can both inhibit arboviruses and invade wild mosquito populations. The discovery of novel, resident Wolbachia strains in mosquito species warrants further investigation as potential candidate strains for biocontrol strategies. Methods: We obtained mosquito specimens from diverse Culicine mosquitoes from Cameroon including ecologically diverse locations in the Central and West Regions. Wolbachia prevalence rates were assessed in addition to the environmentally acquired bacterial species Asaia in major Culicine genera. PCR-based methods were also used with phylogenetic analysis to confirm identities of host mosquito species and Wolbachia strains were classified using multi-locus sequence typing (MLST). Results: We report high Wolbachia prevalence rates for Culicine species, including in a large cohort of Aedes africanus collected from west Cameroon in which 100% of mono-specific pools were infected. Furthermore, co-infections with Asaia bacteria were observed across multiple genera, demonstrating that these two bacteria can co-exist in wild mosquito populations. Wolbachia strain MLST and phylogenetic analysis provided evidence for diverse Wolbachia strains in 13 different mosquito species across seven different genera. Full or partial MLST profiles were generated from resident Wolbachia strains in six Culex species ( quinquefasciatus, watti, cinerus, nigripalpus, perexiguus and rima), two Aedes species (africanus and denderensis) and in Mansonia uniformis, Catageiomyia argenteopunctata, Lutzia tigripes, Eretmapodites chrysogaster and Uranotaenia bilineata. Conclusions: Our study provides further evidence that Wolbachia is widespread within wild mosquito populations of diverse Culicine species and provides further candidate strains that could be investigated as future options for Wolbachia-based biocontrol to inhibit arbovirus transmission.

Diverse novel Wolbachia bacteria strains and widespread co-infections with Asaia bacteria in Culicine mosquitoes from ecologically diverse regions of Cameroon

Background: The endosymbiotic bacterium Wolbachia infects numerous species of insects and Wolbachia transinfection of Aedes mosquito species is now being used for biocontrol programs as Wolbachia strains can both inhibit arboviruses and invade wild mosquito populations. The discovery of novel, resident Wolbachia strains in mosquito species warrants further investigation as potential candidate strains for biocontrol strategies. Methods: We obtained mosquito specimens from diverse Culicine mosquitoes from Cameroon including ecologically diverse locations in the Central and West Regions. Wolbachia prevalence rates were assessed in addition to the environmentally acquired bacterial species Asaia in major Culicine genera. PCR-based methods were also used with phylogenetic analysis to confirm identities of host mosquito species and Wolbachia strains were classified using multi-locus sequence typing (MLST). Results: We report high Wolbachia prevalence rates for Culicine species, including in a large cohort of Aedes africanus collected from west Cameroon in which 100% of mono-specific pools were infected. Furthermore, co-infections with Asaia bacteria were observed across multiple genera, demonstrating that these two bacteria can co-exist in wild mosquito populations. Wolbachia strain MLST and phylogenetic analysis provided evidence for diverse Wolbachia strains in 13 different mosquito species across seven different genera. Full or partial MLST profiles were generated from resident Wolbachia strains in six Culex species (quinquefasciatus, watti, cinerus, nigripalpus, perexiguus and rima), two Aedes species (africanus and denderensis) and in Mansonia uniformis, Catageiomyia argenteopunctata, Lutzia tigripes, Eretmapodites chrysogaster and Uranotaenia bilineata. Conclusions: Our study provides further evidence that Wolbachia is widespread within wild mosquito populations of diverse Culicine species and provides further candidate strains that could be investigated as future options for Wolbachia-based biocontrol to inhibit arbovirus transmission.

Morphological and Molecular Characterization Using Genitalia and CoxI Barcode Sequence Analysis of Afrotropical Mosquitoes with Arbovirus Vector Potential

Potential arboviral Afrotropical mosquito vectors are underrepresented in public databases of CoxI barcode sequences. Furthermore, available CoxI sequences for many species are often not associated with voucher specimens to match the corresponding fine morphological characterization of specimens. Hence, this study focused on the characterization of Culicine mosquitoes from South Africa, Mozambique, and Angola and their classification using a complementary approach including a morphological analysis of specimens’ genitalia and phylogenetic study based on the analysis of CoxI barcode sequences using maximum likelihood and Bayesian phylogenetic inference methods, alongside Median-Joining Network and PCOORD analyses. Overall, 800 mosquitoes (652 males and 148 females) from 67 species, were analyzed. Genitalia from 663 specimens allowed the identification of 55 species of 10 genera. A total of 247 CoxI partial gene sequences corresponding to 65 species were obtained, 11 of which (Aedes capensis, Ae. mucidus, Culex andersoni, Cx. telesilla, Cx. inconspicuosus, Eretmapodites subsimplicipes, Er. quinquevittatus, Ficalbia uniformis, Mimomyia hispida, Uranotaenia alboabdominalis, and Ur. mashonaensis) are, to the best of our knowledge, provided here for the first time. The presence of Cx. pipiens ecotypes molestus and pipiens and their hybrids, as well as Cx. infula, is newly reported in the Afrotropical region. The rates of correct sequence identification using BOLD and BLASTn (≥95% identity) were 64% and 53%, respectively. Phylogenetic analysis revealed that, except for subgenus Eumelanomyia of Culex, there was support for tribes Aedini, Culicini, Ficalbiini, and Mansoniini. A divergence &gt;2% was observed in conspecific sequences, e.g., Aedeomyia africana, Ae. cumminsii, Ae. unilineatus, Ae. metallicus, Ae. furcifer, Ae. caballus, and Mansonia uniformis. Conversely, sequences from groups and species complexes, namely, Ae. simpsoni, Ae. mcintoshi, Cx. bitaeniorhynchus, Cx. simpsoni, and Cx. pipiens were insufficiently separated. A contribution has been made to the barcode library of Afrotropical mosquitoes with associated genitalia morphological identifications.

Bionomics study of Mansonia (Diptera: Culicidae) in a filariasis-endemic area of Sedang Village, Banyuasin Regency, South Sumatra, Indonesia

An investigation of bionomic study of Mansonia species was successfully conducted in Sedang village which is one of the filariasis-endemic areas in Indonesia. The study was carried out for 14 months from April 2017 to May 2018. In order to trap the local mosquitoes in the study area, indoor and outdoor human landing collection method was adopted. During the study, 7,908 mosquitoes were collected which consisted of 13 genera and 40 species of mosquitoes. Moreover, Mansonia uniformis, M. annulifera, and M. indiana were found to be the most abundant, dominant, and high frequency mosquitoes. The filariasis vector analysis through polymerase chain reaction test confirmed that only Mansonia annulifera positively detected as the filariasis vector. Furthermore, the longevity calculation showed that 81% of all the collected Mansonia spp. had already oviposited their eggs which indicates that the studied area possesses high possibilities of filariasis transmission.

Detection of Zika virus in Anopheles stephensi Liston, 1901 (Diptera: Culicidae) in India - First report

Zika virus (ZIKV) a mosquito-borne, causing acute febrile illness associated with rash, arthralgia and conjunctivitis in the patient, was reported from Thiruvananthapuram, Kerala, as an outbreak with 83 cases. Entomological surveillance revealed the presence of aedine mosquitoes viz., Aedes aegypti (Linnaeus, 1762), Ae. albopictus (Skuse, 1894) and Ae. vittatus (Bigot, 1861) and nonaedine mosquitoes viz., Anopheles stephensi Liston,1901, Mansonia uniformis (Theobald, 1901), Culex tritaeniorhynchus Giles, 1901 and Cx. gelidus Theobald,1901. Aedes (Ae. aegypti, Ae. vittatus and Ae. Albopictus) mosquito larvae were high in the Zika affected areas. Moreover ZIKV was detected in An. stephensi mosquitoes collected from Parassala, Thiruvananthapuram (the native place of the first ZIKV confirmed case in the present outbreak in Kerala). Molecular diagnostics of Ae. Aegypti, Ae. vittatu and An. stephensi mosquitoes revealed that the species were loaded with ZIKV. Significantly this is the first ever report of ZIKV detecting in An. stephensi in the world. Aedes adults (male and female) and An. stephensi emerged from fourth instar larvae and pupae were found to have ZIKV, indicating transovarial transmission of the virus.

Australian mosquito assemblages vary between ground and sub-canopy habitats

BackgroundThe surveillance and control of mosquito-borne diseases is dependent upon understanding the bionomics and distribution of the vectors. Most studies of mosquito assemblages describe species abundance, richness and composition close to the ground defined often by only one sampling method. In this study, we assessed Australian mosquito species near the ground and in the sub-canopy using two traps baited with a variety of lures.MethodsMosquitoes were sampled using a 4 × 4 Latin square design at the Cattana Wetlands, Australia from February to April 2020, using passive box traps with octenol and carbon dioxide and three variations of a sticky net trap (unbaited, and baited with octenol or octenol and carbon dioxide). The traps were deployed at two different heights: ground level (≤ 1 m above the ground) and sub-canopy level (6 m above the ground).ResultsIn total, 27 mosquito species were identified across the ground and sub-canopy levels from the different traps. The abundance of mosquitoes at the ground level was twofold greater than at the sub-canopy level. While the species richness at ground and sub-canopy levels was not significantly different, species abundance varied by the collection height.ConclusionsThe composition of mosquito population assemblages was correlated with the trap types and heights at which they were deployed. Coquillettidia species, which prefer feeding on birds, were mainly found in the sub-canopy whereas Anopheles farauti, Aedes vigilax and Mansonia uniformis, which have a preference for feeding on large mammals, were predominantly found near the ground. In addition to trap height, environmental factors and mosquito bionomic characteristics (e.g. larval habitat, resting behaviour and host blood preferences) may explain the vertical distribution of mosquitoes. This information is useful to better understand how vectors may acquire and transmit pathogens to hosts living at different heights.Graphical abstract

Fauna associated with Malayan filariasis transmission in Banyuasin, South Sumatra, Indonesia.

Background and Aim:Brugia malayi is known to be zoonotically important because it can be transmitted from animals (mammals and primates) to humans or from humans to humans through mosquito vectors. This study was conducted to explore the fauna associated with Malayan filariasis transmission in Sedang village, Suak Tapeh District, Banyuasin Regency, South Sumatra Province, Indonesia.Materials and Methods:A cross-sectional research design with an observational and analytical approach was applied in this study, and it was conducted in May 2018. Mosquitoes were collected twice using human bait both inside and outside the house from 6:00 p.m. to 6:00 a.m. The presence of competitors, predators, and reservoir hosts in the areas of five breeding habitats of Mansonia spp. was observed. The presence of microfilaria was confirmed under a microscope in night blood samples of inhabitants and cats. The presence of infective larvae (L3) of B. malayi was identified microscopically and based on the polymerase chain reaction method in female Mansonia mosquitoes.Results:A total of 12 mosquito species were found, among which Mansonia uniformis was the dominant mosquito, and the predominant competitor was Mansonia annulifera. Dragonflies, as predators were found in two breeding habitats and fish were found in one breeding habitat. The L3 of B. malayi were not identified in the mosquitoes, and the microfilariae of B. malayi were not found in the blood samples of inhabitants and cats.Conclusion:Although Mansonia mosquito population was abundant in Banyuasin Regency, the mosquito was not confirmed as an intermediate host of B. malayi, and the cat was not confirmed as a reservoir of B. malayi in the location.

Biting Pattern and Seasonality of Filariasis Vector of Mansonia spp. in Endemic Area of Banyuasin Regency, South Sumatera, Indonesia

The diversity and biting activity of Mansonia is important to be determined as to predict the incriminated vector and pattern the mosquito behaviour in establishing the vector control programme. The present study has been successfully conducted to investigate the prolonged biting behaviour of Mansonia spp. in two villages in Banyuasin Regency, South Sumatera Province-Indonesia, using Human Landing Collection method (HLC) in indoor and outdoor for 14 months. The result shows that there are 4956 Mansonia spp. mosquitoes collected during the study comprising 6 species: Mansonia uniformis (40.37%), Mansonia annulifera (32.04%), Mansonia indiana (19.97%), Mansonia bonneae (5.28), Mansonia dives (2.14%); and Mansonia annulata (0.18%). The further investigation confirms that Mansonia uniformis (41.254%) and Mansonia bonneae (45.490%) become the most dominant species caught in Sedang village and Muara Sugih village, respectively and find higher biting activities in outdoor than indoor with biting peaked time at approximately 18.00-19.00. However, the biting activities is also observed in daytime, indicating the behaviour change of Mansonia spp. as the nocturnal mosquitoes. Furthermore, the periods of the highest biting rates are found in April 2017 and May 2017 in Sedang village and May 2018 in Muara Sugih Village. The high period of biting activities and behaviours become the valuable information to arrange the further controlling action of filariasis transmission in Sedang and Muara Sugih Villages as the endemic area of filariasis in South Sumatera, Indonesia.

Assessing the Filariasis Causing Parasites in Adult Mosquitoes and the Vector Mosquito Larval Breeding in Selected Medical Officer of Health Areas in Gampaha District, Sri Lanka.

The present study was conducted to determine the prevalence of filariasis causing parasites in adult mosquitoes and vector mosquito larval breeding in four Medical Officer of Health (MOH) areas in Gampaha district, Sri Lanka. Adult female mosquitoes at their resting places were collected using a prokopack aspirator operated twice a day from 7.00 am to 8.00 am and 8.00 pm to 9 pm in predetermined dates. Microfilarial worms in dissected mosquitoes were morphologically identified. Nine species of mosquitoes, namely, Culex quinquefasciatus, Cx. pipiens, Cx. fuscocephala, Cx. gelidus, Armigeres subalbatus, Mansonia uniformis, Ma. annulifera, Aedes aegypti, and Ae. Albopictus, were captured. A total of 1194 mosquito larvae were collected that belonged into three genera, namely, Culex (62.73%), Armigeres (25.62%), and Mansonia (11.64%), from blocked drains, polluted drains, blocked canals, large polluted water bodies, stagnant water bodies, marsh lands, rice field mudflats, and concrete pits. Large polluted water bodies (Shannon-Wiener diversity index/H' = 1.5591) were the most diversed habitat type. In breeding water, average pH mainly lied in between 6 and 8 and average dissolved oxygen ranged from 3 to 7 mg/L. Cx. quinquefasciatus and Armigeres subalbatus adult female mosquitoes captured from Kelaniya MOH area were positive for microfilariae and were identified as Wuchereria bancrofti and Dirofilaria repens, respectively. This study concludes possible lymphatic filariasis situation is in extremely very low level persistent (0.06%) where transmission cannot be sustained and is restricted only to isolated pockets in the study area. The zoonotic strains of filariasis causing subcutaneous dirofilariasis in humans by Dirofilaria repens is continuing to survive due to the presence of stray dogs that serve as reservoir hosts.

The Larval Density of Mosquitos (Diptera: Culicidae) in Jiaxiang County, Shandong Province, China: Influence of Bacterial Diversity, Richness, and Physicochemical Factors

As Jiaxiang County of Shandong province is an area with complex mosquito vector composition, it is necessary to investigate the relationship between bacterial diversity, physicochemical factors, and larval density. Therefore, the physicochemical properties of 46 breeding sites for six kinds of habitat types (small puddles, small water containers, paddy fields, large water containers, irrigation channels, and drainage ditches) were investigated by a multiparameter analyzer; the water’s bacterial diversity was analyzed by the 16S rRNA full-length sequencing method. Spearman correlation and multiple linear regression were used to analyze the correlation between larval density and variables. The variables analyzed were dissolved oxygen, pH, hardness, turbidity, conductivity, temperature, ammonia nitrogen, water depth, and distance from the nearest house. One-Way ANOVA was used to understand whether there are differences in bacterial diversity in different habitats. Pearson linear correlation model was used to analyze the effects of bacterial diversity and richness on mosquito densities in breeding sites. A total of 3291 larvae were captured, and a total of 6 species of 4 genera were identified. The identified species were Culex pipiens pallens, Aedes albopictus, Anopheles sinensis, Culex tritaeniorhynchus, Culex bitaeniorhynchus, and Mansonia uniformis. The density and species can be jointly affected by physicochemical properties and bacterial diversity, especially Shannon index and distance from the nearest house. In general, the physicochemical parameters and bacterial diversity of different habitats were significantly different. Even for the same habitat type, the physicochemical parameters varied greatly due to different environments.

Identification and seasonal distribution of mosquito species in Telangana state, India

An entomological study was conducted to determine species composition, relative abundance, and seasonal population fluctuation of mosquitoes. Thirty localities were randomly selected and sampled once in summer, monsoon and winter seasons for a period of three years. Adult mosquitoes were collected from in and around human dwellings and animal sheds using aspirator and flash light between 6 PM and 7:30 PM hrs and 06:00 AM and 7:00 AM hrs. Larvae were collected from ditches, rock pool and other domestic habitats, reared to formation of adults in the lab. A total of 18425 mosquitoes were collected. Five genera (Culex, Anopheles, Aedes, Mansonia and Armigeres) were found to be circulating. Further, with respect to habitat, more number of mosquitoes were observed around cattle sheds and houses. Culex quinquefasciatus occupies top place, followed by Aedes albopictus and Culex gelidus, Culex tritaeniorhynchus with respect to density, whereas Mansonia uniformis occupies last place. Culex quinquifasciatus is top again followed by Culex gelidus and Aedes albopictus, Mansonia uniformis is last again with respect to distribution. The vector species studied were Aedes aegypti, Aedes albopictus for chikungunya and dengue, Anopheles stephensi, Anopheles culicifacies for malaria, Culex tritaeniorhynchus for Japanese encephalitis and Culex quiquefasciatus for lymphatic filaria.

DNA barcoding of mosquitoes collected through a nationwide survey in 2011 and 2012 in Malawi, Southeast Africa

We conducted a nationwide survey of mosquito distribution in Malawi from November 2011 to April 2012, and from July to September 2012. Using dried specimens of mosquito adults collected during the survey, we analyzed their cytochrome c oxidase subunit I (COI) gene sequences, prepared specimens, and registered the genetic information (658 bp) of 144 individuals belonging to 51 species of 10 genera in GenBank. Using the obtained genetic information, we analyzed the degree of intraspecific variation and investigated the various species from morphological and genetic perspectives. Moreover, we conducted phylogenetic analysis of the medically important species distributed from Africa to Asia and explored their geographical differentiation. Results showed that individuals morphologically classified as Culex univittatus complex included a individual of Cx. perexiguus which, to date, have not been reported in southern Africa. Furthermore, Mansonia uniformis, distributed in Africa and Asia, was revealed to belong to genetically distinct populations, with observed morphological differences of the samples suggesting that they are separate species. The results of genetic analysis further suggested that Cx. ethiopicus is not a synonym of Cx. bitaeniorhynchus, but that it is an independent species; although, in this study, the only definite morphological difference observed was in the shape of the wing scales. Further morphological and genetic investigation of individuals of these species, including larvae, is highly recommended.

Observations of an unexpected abundance of estuarine mosquitoes associated with an urban freshwater wetland

ABSTRACT Urban freshwater wetlands have been identified as a potential source of mosquitoes of pest and public health concern in Australia. Mosquitoes most commonly associated with these habitats include Anopheles annulipes, Culex annulirostris, Culex quinquefasciatus, Coquillettidia linealis and Mansonia uniformis. However, adaptive management of freshwater wetlands for wildlife conservation or vegetation management can alter the local environmental conditions and may provide opportunities for other mosquito species to exploit these habitats. A series of small wetlands at Sydney Olympic Park, NSW, were drained in spring 2016 and allowed to refill via rainfall to improve conditions for the endangered green and golden bell frog Litoria aurea. Below-average rainfall was experienced that summer and the wetlands did not fully refill until early autumn. Surprisingly, immature stages of the estuarine mosquito, Aedes vigilax, were observed in the freshwater wetlands in exceptional abundances during this period. Adjacent to these freshwater wetlands there are extensive saltmarsh and mangrove habitats where highly abundant populations of Ae. vigilax are common. Observations of use of freshwater habitats by this estuarine mosquito have implications for urban freshwater wetland management and rehabilitation strategies, which currently do not consider the potential pest and public health issues associated with estuarine mosquitoes.