Anopheles Vagus Research Articles

The genetic composition of Anopheles mosquitoes and the diverse population of gut-microbiota within the Anopheles subpictus and Anopheles vagus mosquitoes in Tamil Nadu, India

In recent days, in tropical and subtropical regions, secondary vectors of Anopheles mosquitoes are becoming more important in transmitting diseases to humans as primary vectors. Various molecular techniques have separated closely related Anopheles subpictus and Anopheles vagus mosquitoes based on their diversity with other mosquito species. Despite their widespread distribution, the An. subpictus and An. vagus mosquitoes, which carry Plasmodium in their salivary glands, were not considered primary malaria vectors in India. An. vagus mosquitoes are zoophilic and physically similar to An. subpictus. We intend to identify An. subpictus and An. vagus mosquito's sister species based on their Interspaced Transcribed Region-2 (ITS2). We isolated the midgut gDNA from each mosquito and used ITS2-PCR and Sanger sequencing to characterize the mosquito species. BioEdit software aligned the sequences, and MEGA7 built a phylogenetic tree from them. According to this study, the information gathered from these mosquito samples fits the An. subpictus species A form and the An. vagus Indian form. Furthermore, gut microbiome plays an important role in providing nutrients, immunity, and food processing, whereas mosquitoes' midgut microbiota changes their hosts and spreads illnesses. So, we used the Illumina sequencer to look at the gut microbiome diversity of An. subpictus and An. vagus mosquitoes using 16S rRNA-based metagenomic sequencing. Both mosquito species had an abundant phylum of Pseudomonadota (Proteobacteria), Bacillota, Bacteroidota, and Actinomycetota in their gut microbiomes. Notably, both mosquito species had the genus Serratia in their gut. In the subpictus midgut, the genus of Haematosprillum bacteria was dominant, whereas in the vagus mosquito, the genus of Salmonella was dominant. Notably, current research has observed the Sodalis spp. Bacterial genus for the first time.

Molecular characterization of proteolytic bacteria associated with Malaria vectors: Anopheles sundaicus and Anopheles vagus

Molecular characterization of proteolytic bacteria associated with Malaria vectors: Anopheles sundaicus and Anopheles vagus

Rapid entomological assessment in eight high malaria endemic regencies in Papua Province revealed the presence of indoor and outdoor malaria transmissions

Malaria in eastern Indonesia remains high despite significant reduction and elimination in other parts of the country. A rapid entomological assessment was conducted in eight high malaria endemic regencies of Papua Province, Indonesia, to expedite malaria elimination efforts in this region. This study aims to characterize specific, actionable endpoints toward understanding where and when malaria transmission is happening, where interventions may function best, and identify gaps in protection that result in continued transmission. The entomological assessment included identifying potential vectors through human landing catch (HLC), indoor morning and night resting collections, identification of larval sites through surveillance of water bodies, and vector incrimination toward understanding exposure to malaria transmission. Human landing catches (HLCs) and larval collections identified 10 Anopheles species, namely Anopheles koliensis, Anopheles punctulatus, Anopheles farauti, Anopheles hinesorum, Anopheles longirostris, Anopheles peditaeniatus, Anopheles tesselatus, Anopheles vagus, Anopheles subpictus and Anopheles kochi. The most common and abundant species found overall were An. koliensis and An. punctulatus, while An. farauti was found in large numbers in the coastal areas of Mimika and Sarmi Regencies. Vector incrimination on Anopheles collected from HLCs and night indoor resting demonstrated that An. koliensis and An. punctulatus carried Plasmodium in Keerom, Jayapura, and Sarmi Regencies. Analysis of HLCs for the most common species revealed that the An. koliensis and An. punctulatus, bite indoors and outdoors at equal rates, while An. farauti predominantly bite outdoors. Larval surveillance demonstrated that most water bodies in and surrounding residential areas contained Anopheles larvae. This study demonstrated indoor and outdoor exposure to mosquito bites and gaps in protection, enabling exposure to infectious bites in all regencies. This explains why current malaria control efforts focusing on indoor protection have failed to substantially reduce malaria incidence in the region. Optimization of insecticide-treated bed nets (ITNs), as well as installment of mosquito screens in houses, may further reduce indoor transmission. For outdoor transmission, the use of community-centric approaches to reduce or eliminate larval sources within and surrounding the village through the guidance of locally stationed entomologists, along with Social and Behavior Change mediated health education towards the local adoption of mosquito protection tools during outdoor activities, may reduce malaria transmission.

Relative Frequency (Composition) of Anopheles sp. Mosquitoes as Malaria Vectors in Kulon Progo District Special Region of Yogyakarta

Malaria is caused by Plasmodium infection transmitted Anopheles sp. One of the obstacles in malaria control is the variation of Anopheles sp. Species which have various characteristics and behaviour, so it’s very important to understand the species of Anopheles sp. with aim to develop the disease control program. This study was conducted in Kulon Progo Regency, Yogyakarta, one of the malaria endemic areas in Indonesia. Data collection of Anopheles sp. species diversity was carried out through landing collection inside and outside people’s homes at 18.00 - 06.00 WIB. Observations of abiotics factors in the habitat of Anopheles sp. larvae was carried out around the landing collection location. The result of research conducted in the Samigaluh, Kalibawang, and Pengasih Sub-Districts showed that the most common species found was Anopeheles vagus. The dominance of Anopheles vagus occurred in the Kalibawang and Pengasih dictricts, while in the Samigaluh Sub-Districts it became the second most among other species. Measurement of abiotic factors in the habitat of Anopheles sp. larvae through the parameters of temperature, air humidity, pH DO of water shows that the location where the larvae were found can support larval breeding and growth. That can be a factor in the large population of Anopheles sp., especially Anopheles vagus, which is a known vector of malarias based on research and its vectorial capacity.

Impact of a spatial repellent intervention on Anopheles kdr insecticide resistance allele in Sumba, Indonesia

BackgroundThe emergence of insecticide resistance and outdoor transmission in malaria-endemic areas underlines the urgent need to develop innovative tools, such as spatial repellents (SR), that may circumvent this residual transmission. With limited options for effective insecticides, regular resistance monitoring is warranted for selecting and using appropriate tools. This study evaluates the pyrethroid knockdown resistance (kdr) allele before and after implementing a transfluthrin-based spatial repellent (SR) intervention in placebo-treated clusters.MethodsThis study looks at the frequency distribution of the kdr allele in Sumba Island from June 2015 to August 2018. Insecticide susceptibility tests were carried out on female Anopheles sp. aged 3–5 days against permethrin 21.5 μg/ml, deltamethrin 12.5 μg/ml, and transfluthrin 10 μg/ml using CDC bottle assay. PCR sequencing of representative samples from adult mosquito collections and insecticide tests revealed the presence of kdr mutations (L1014F and L1014S) in the VGSC gene.ResultsA total of 12 Anopheles species, Anopheles tesselatus, Anopheles. aconitus, Anopheles barbirostris, Anopheles kochi, Anopheles annularis, Anopheles maculatus, Anopheles sundaicus, Anopheles flavirostris, Anopheles balabacensis, Anopheles indefinitus, Anopheles subpictus, and Anopheles vagus were analysed. Anopheles vagus and An. sundaicus predominated in the larval populations. Susceptibility assays for all insecticides identified fully susceptible phenotypes in all species examined. Anopheles increasing frequency of kdr mutant alleles during the 3 year SR deployment was observed in both SR-treated and placebo areas, a statistically significant increase occurred in each arm. However, it is unclear how significant SR is in causing the increase in mutant alleles. The L1014S, knockdown resistance east type (kdr-e) allele was detected for the first time among the mosquito samples in this study. The L1014F, knockdown resistance west type (kdr-w) allele and heteroduplex form (wild-type—mutant) were found in almost all Anopheles species examined, including An. vagus, An. aconitus, An. subpictus, An. tesselatus, An. annularis, An. flavirostris and An. sundaicus.ConclusionThe presence of fully susceptible phenotypes over time, along with an increase in the frequency distribution of the L1014F/S mutations post-intervention, suggest drivers of resistance external to the study, including pyrethroid use in agriculture and long-lasting insecticidal nets (LLINs). However, this does not negate possible SR impacts that support resistance. More studies that enable the comprehension of possible SR-based drivers of resistance in mosquitoes need to be conducted.

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.

The Abundance of Mosquito Larval Species (Diptera: Culicidae) and the Physicocemical Characteristics of Their Habitat in Rice Field at Dramaga Sub-District, Bogor Regency

This study aims to identify the species diversity, density, and their distribution and analyze mosquito larvae' habitat's physicochemical characteristics in the Dramaga sub-district, Bogor Regency rice fields.. This research used purposive sampling method by taking samples from 92 breeding site in four villages of Dramaga district. The physicochemical characteristics of larval habitats, including pH, temperature, Total Dissolve Solid (TDS), and Electrical Conductivity (EC) were measured in the field. Breeding site are marked using a Garmin Montana 680 GPS for further processing. Larvae were collected and identified until species level. The result showed Anopheles vagus, An. barbirostris, An. indefinitus, Culex. vishnui, Cx. fuscocephala, Cx. tritaeniorhynchus, Cx. sitiens, Cx. hutchinsoni, and Armigeres sp. were found in the rice fields of Dramaga district. The highest diversity and density of larvae was found in Cikarawang Village. The highest relative abundance of mosquitoes larvae were An. vagus and Cx. vishnui. The physicochemical characteristics of larval habitats such as pH, TDS, and EC, had no correlation with the larval abundance, however the temperature of larval habitat had a negative correlation between temperature and larval density.

The Abundance of Mosquito Larval Species (Diptera: Culicidae) and the Physicocemical Characteristics of Their Habitat in Rice Field at Dramaga Sub-District, Bogor Regency

This study aims to identify the species diversity, density, and their distribution and analyze mosquito larvae' habitat's physicochemical characteristics in the Dramaga sub-district, Bogor Regency rice fields.. This research used purposive sampling method by taking samples from 92 breeding site in four villages of Dramaga district. The physicochemical characteristics of larval habitats, including pH, temperature, Total Dissolve Solid (TDS), and Electrical Conductivity (EC) were measured in the field. Breeding site are marked using a Garmin Montana 680 GPS for further processing. Larvae were collected and identified until species level. The result showed Anopheles vagus, An. barbirostris, An. indefinitus, Culex. vishnui, Cx. fuscocephala, Cx. tritaeniorhynchus, Cx. sitiens, Cx. hutchinsoni, and Armigeres sp. were found in the rice fields of Dramaga district. The highest diversity and density of larvae was found in Cikarawang Village. The highest relative abundance of mosquitoes larvae were An. vagus and Cx. vishnui. The physicochemical characteristics of larval habitats such as pH, TDS, and EC, had no correlation with the larval abundance, however the temperature of larval habitat had a negative correlation between temperature and larval density.

Bacterial community structure of Anopheles hyrcanus group, Anopheles nivipes, Anopheles philippinensis, and Anopheles vagus from a malaria-endemic area in Thailand.

Bacterial content of mosquitoes has given rise to the development of innovative tools that influence and seek to control malaria transmission. This study identified the bacterial microbiota in field-collected female adults of the Anopheles hyrcanus group and three Anopheles species, Anopheles nivipes, Anopheles philippinensis, and Anopheles vagus, from an endemic area in the southeastern part of Ubon Ratchathani Province, northeastern Thailand, near the Lao PDR-Cambodia-Thailand border. A total of 17 DNA libraries were generated from pooled female Anopheles abdomen samples (10 abdomens/ sample). The mosquito microbiota was characterized through the analysis of DNA sequences from the V3-V4 regions of the 16S rRNA gene, and data were analyzed in QIIME2. A total of 3,442 bacterial ASVs were obtained, revealing differences in the microbiota both within the same species/group and between different species/group. Statistical difference in alpha diversity was observed between An. hyrcanus group and An. vagus and between An. nivipes and An. vagus, and beta diversity analyses showed that the bacterial community of An. vagus was the most dissimilar from other species. The most abundant bacteria belonged to the Proteobacteria phylum (48%-75%) in which Pseudomonas, Serratia, and Pantoea were predominant genera among four Anopheles species/group. However, the most significantly abundant genus observed in each Anopheles species/group was as follows: Staphylococcus in the An. hyrcanus group, Pantoea in the An. nivipes, Rosenbergiella in An. philippinensis, and Pseudomonas in An. vagus. Particularly, Pseudomonas sp. was highly abundant in all Anopheles species except An. nivipes. The present study provides the first study on the microbiota of four potential malaria vectors as a starting step towards understanding the role of the microbiota on mosquito biology and ultimately the development of potential tools for malaria control.

Composition of Anopheles species and bionomic characteristics over the peak malaria transmission season in Bandarban, Bangladesh

BackgroundJoint efforts by government and non-government organizations have helped to reduce malaria in Bangladesh and set the country on a clear path to eventual malaria elimination. However, achieving that goal would be challenging without a comprehensive understanding of vector bionomics.MethodsTargeted capturing of Anopheles mosquitoes over a rainy season, utilizing specific sampling methods, including human landing catches (HLCs), CDC-light traps (CDC-LTs), and pyrethrum spray catches (PSCs) were aimed to characterize entomological drivers of transmission in four sites of Bandarban, Bangladesh.ResultsMolecular characterization of a subset of 4637 mosquitoes has demonstrated the presence of at least 17 species whose capture rates were representative of the rainy season. Species compositions and bionomic traits did not vary between sites with Anopheles maculatus having the highest landing rate by HLCs and Anopheles vagus having the highest capture rate with CDC-LTs. Interestingly, Anopheles species compositions and capture rates varied significantly (p < 0.05) for An. vagus, between HLCs and its often-used proxy—CDC-LTs- suggesting impacts on downstream analysis. CDC-LTs capture rates demonstrated differing compositions with indoor and outdoor biting rates. For example, Anopheles nigerrimus and Anopheles nivipes were more endophagic by HLCs and more exophagic by CDC-LTs. The use of a cow-baited CDC-LT also demonstrated significantly different results when compared to a human-baited CDC-LT considering the high degree of anthropophily in these species. The exception to both zoophily and indoor resting was An. vagus, which demonstrated both anthropophily and high resting rates indoors—pointing to this species being a possible primary vector at this site.ConclusionA diverse Anopheles fauna in Bandarban has been confirmed through molecular methods, highlighting the potential impact of sampling techniques. Given the complexity of the local ecosystem, a better understanding of mosquito behaviour and ecology is required to achieve the goal of malaria elimination in Bangladesh.

Molecular characterization of anopheline mosquitoes from the goat malaria-endemic areas of Thailand.

Despite the fact that over a 100 anopheline mosquito species have been identified as human malaria vectors, little is known about ungulate malaria vectors. Consequently, we focused on investigating the bionomics and genetic characterizations of anopheline mosquitoes in goat malaria-endemic regions. We also attempted to screen for ungulate malaria potential vectors. A total of 1019 female anopheline mosquitoes were collected from six goat farms in four provinces of Thailand from 2020 to 2021. Mosquitoes were morphologically identified and subsequently confirmed using the mitochondrial DNA barcoding region-cytochrome oxidase c subunit I (MtDNA-COI), mitochondrial DNA-cytochrome c oxidase subunit II (MtDNA-COII), and ribosomal DNA internal transcribed spacer 2 (rDNA-ITS2) sequences. The current study reveals the genetic characteristics and distribution of nine mosquito species within the Anopheles and Cellia subgenera. Four dominant species, including Anopheles peditaeniatus, Anopheles subpictus, Anopheles vagus, and Anopheles aconitus exhibited significant intraspecific gene flow within their corresponding species. Although malaria parasites were not found in 126 mosquito pools, meaning more investigation is necessary, the current study adds to the existing DNA barcoding data collection and improves the current understanding of the genetic structure and distribution of anopheline mosquito species, which could be useful for effective control of mosquito-borne diseases.

Survey of malaria vectors on the Cambodia, Thailand and China-Laos Borders

BackgroundAnopheles maculatus, Anopheles minimus and Anopheles dirus are the major vectors of malaria transmission in the Greater Mekong Subregion (GMS). The malaria burden in this region has decreased significantly in recent years as all GMS countries progress towards malaria elimination. It is necessary to investigate the Anopheles diversity and abundance status and assess the Plasmodium infection rates to understand the malaria transmission potential of these vector species in GMS countries to guide the development of up-to-date vector control strategies and interventions.MethodsA survey of mosquitoes was conducted in Stung Treng, Sainyabuli and Phongsaly Provinces on the Cambodia-Laos, Thailand-Laos and China-Laos borders, respectively. Mosquito collection was done by overnight trapping at sentinel sites in each province. After morphological identification, the 18S rRNA-based nested-PCR was performed to detect malaria parasites in the captured Anopheles mosquitoes.ResultsA total of 18 965 mosquitoes comprising of 35 species of 2 subgenera (Subgenus Anopheles and Subgenus Cellia) and 4 tribes (Tribes Culicini, Aedini, Armigerini and Mansoniini) were captured. Tribe Culicini accounted for 85.66% of captures, followed by Subgenus Anopheles (8.15%). Anopheles sinensis dominated the Subgenus Anopheles by 99.81%. Plasmodium-infection was found in 25 out of the 1 683 individual or pooled samples of Anopheles. Among the 25 positive samples, 19, 5 and 1 were collected from Loum, Pangkhom and Siem Pang village, respectively. Eight Anopheles species were found infected with Plasmodium, i.e., An. sinensis, Anopheles kochi, Anopheles vagus, An. minimus, Anopheles annularis, Anopheles philippinensis, Anopheles tessellatus and An. dirus. The infection rates of Plasmodium falciparum, Plasmodium vivax and mixture of Plasmodium parasite species were 0.12% (2/1 683), 1.31% (22/1 683) and 0.06% (1/1 683), respectively.ConclusionsOverall, this survey re-confirmed that multiple Anopheles species carry malaria parasites in the international border areas of the GMS countries. Anopheles sinensis dominated the Anopheles collections and as carriers of malaria parasites, therefore may play a significant role in malaria transmission. More extensive investigations of malaria vectors are required to reveal the detailed vector biology, ecology, behaviour, and genetics in GMS regions in order to assist with the planning and implementation of improved malaria control strategies.Graphical

The Absence of Sporozoites in Anopheles Mosquitoes in the Malaria Pre-elimination Area

Introduction: The existence of sporozoites in the salivary gland of Anopheles is a prominent factor in the transmission and spread of malaria. Malaria control programs must be comprehensive including the treatment of patients, management of the vector population, and efforts to prevent human-vector contact. The present study aimed to track the presence of sporozoite in the Anopheles mosquito population in a malaria pre-elimination area and evaluate the implementation of a malaria elimination program. Methods: This cross-sectional study was conducted in a malaria pre-elimination area over a period of one year. Mosquitos were caught using human bait and in resting sites close to cattle pens. Sporozoites were detected microscopically and circumsporozoite protein (CSP) was tested using polymerase chain reaction technique. Results: A total of 212 Anopheles mosquitoes were caught. Anopheles maculatus, Anopheles aconitus, Anopheles subpictus, Anopheles barbirostris, Anopheles vagus, and Anopheles kochi species were identified. Salivary gland of 111 mosquitoes were dissected and CSP was detected in 101 specimens. Neither type of test found any sporozoites in the captured Anopheles. Conclusion: The absence of sporozoites in Anopheles in the pre-elimination area is a good sign of the ongoing malaria control program. Breaking the life cycle of the parasite that causes it by minimizing contact with vectors is an effective method that should be continuously improved.

Prevalence of Plasmodium spp. in Anopheles mosquitoes in Thailand: a systematic review and meta-analysis

BackgroundThe entomological inoculation rate (EIR) is one of the key indices used to evaluate malaria transmission and vector control interventions. One of the components of the EIR is the sporozoite rate in Anopheles vectors. A systematic review and meta-analysis was performed to identify the prevalence of Plasmodium spp. in field-collected Anopheles species across Thailand.MethodsThis systematic review was registered under the PROSPERO number CRD42021297255. Studies that focused on the identification of Plasmodium spp. in Anopheles mosquitoes were identified from the electronic databases PubMed, Web of Science, and Scopus. The quality of the identified studies was determined using the Strengthening the Reporting of Observational Studies in Epidemiology approach. The proportion of Anopheles mosquitoes collected, Anopheles vectors for Plasmodium species, and specificity of Anopheles vectors for Plasmodium species were analyzed. The pooled prevalence of Plasmodium species among the primary vectors (Anopheles dirus, Anopheles minimus, and Anopheles maculatus) was estimated using the random-effects model.ResultsOf the 1113 studies identified, 31 were included in the syntheses. Of the 100,910 Anopheles mosquitoes identified for species and sibling species, An. minimus (40.16%), An. maculatus (16.59%), and Anopheles epiroticus (9.18%) were the most prevalent Anopheles species. Of the 123,286 Anopheles mosquitoes identified, 566 (0.46%) were positive for Plasmodium species. The highest proportions of Plasmodium species were identified in Anopheles hodgkini (2/6, 33.3%), Anopheles nigerrimus (2/24, 8.33%), Anopheles balabacensis (4/84, 4.76%), An. dirus (114/4956, 2.3%), Anopheles annularis (16/852, 1.88%), Anopheles kochi (8/519, 1.54%), Anopheles vagus (3/215, 1.4%), and Anopheles baimaii (1/86, 1.16%). The pooled prevalence of Plasmodium species identified in the main Anopheles vectors was 0.4% of that of Plasmodium species identified in An. dirus was 2.1%, that of Plasmodium species identified in An. minimus was 0.4%, and that of Plasmodium species identified in An. maculatus was 0.4%.ConclusionsWe found a low prevalence of Plasmodium infection in Anopheles mosquitoes across Thailand. Therefore, the use of EIR to determine the impact of vector control intervention on malaria parasite transmission and elimination in Thailand must be undertaken with caution, as a large number of Anopheles specimens may be required.Graphical

Diversity of mosquito species and potential arbovirus transmission in long-tailed macaque (Macaca fascicularis) breeding facilities

Background and Aim:Mosquito-borne viral infections are diseases that reduce human and animal health levels. Their transmission involves wildlife animals as reservoirs and amplifying hosts, including long-tailed macaques (Macaca fascicularis), and potentially transmits to humans and vice versa. This study aimed to determine the species diversity, richness, and biting activity of mosquitoes in a long-tailed macaque breeding area facility and discover the presence of Flavivirus and Alphavirus as the two main arboviruses reported to infect macaques.Materials and Methods:Human landing catch, light trap, and sweep net methods were used for mosquito collection around long-tailed macaques cages at parallel times for 12 h (18:00–06:00) for 12 nights. Mosquito species were identified to the species level based on the morphological identification key for Indonesian mosquitoes. Mosquito diversity was analyzed by several diversity indices. Mosquitoes caught using the human landing catch method were pooled based on mosquito species for viral ribonucleic acid extraction. Reverse transcription-polymerase chain reaction (RT-PCR) detected the non-structural protein 5 of the Flavivirus region and the non-structural protein 4 of the Alphavirus region. This study used the man-hour density and man-biting rate formulas for mosquito density.Results:Ten mosquito species were collected, namely, Aedes albopictus, Anopheles aconitus, Anopheles minimus, Anopheles vagus, Armigeres foliatus, Armigeres subalbatus, Culex gelidus, Culex hutchinsoni, Culex tritaeniorhynchus, and Culex quinquefasciatus. The number of mosquitoes caught using the light trap method had the highest abundance. In contrast, the number of mosquito species caught using the sweep net method had lower diversity than the other two methods. Seven mosquito species were obtained using the human landing catch method. The mosquito species with the highest density was Cx. quinquefasciatus within the observed densest period from 20:00 to 21:00. Negative results were obtained from RT-PCR testing on five species detected using universal Flavivirus and Alphavirus primers.Conclusion:The occurrence of mosquitoes in long-tailed macaque breeding facilities can be a source of transmission of zoonotic vector-borne diseases between animals and humans and vice versa.

UV Light-Emitting-Diode Traps for Collecting Nocturnal Biting Mosquitoes in Urban Bangkok

Simple SummaryThis study was conducted to evaluate the efficacy of six ultraviolet light-emitting diodes (UV-LED) traps and a fluorescent light trap for sampling urban nocturnal mosquitoes. Results demonstrated that the fluorescent light trap outperformed all the UV-LED traps throughout the 72 sampling nights and between wet and dry seasons. Among the UV-LED traps, the LED375 trapped the highest number of mosquitoes. Additional field trials are needed to validate these findings in different ecological settings.Well-designed surveillance systems are required to facilitate a control program for vector-borne diseases. Light traps have long been used to sample large numbers of insect species and are regarded as one of the standard choices for baseline insect surveys. The objective of this study was to evaluate the efficacy of six ultraviolet light-emitting diodes and one fluorescent light for trapping urban nocturnal mosquito species within the Kasetsart University (KU), Bangkok. Ultraviolet light-emitting diodes (UV-LEDs), (LED365, LED375, LED385, LED395, and LED405) and a fluorescent light were randomly assigned to six different locations around the campus in a Latin square design. The traps were operated continuously from 18:00 h to 06:00 h throughout the night. The traps were rotated between six locations for 72 collection-nights during the dry and wet seasons. In total, 6929 adult mosquitoes were caught, with the most predominant genus being Culex, followed by Aedes, Anopheles, Armigeres and Mansonia. Among the Culex species, Culex quinquefasciatus (n = 5121: 73.9%) was the most abundant followed by Culex gelidus (n = 1134: 16.4%) and Culex vishnui (n = 21: 0.3%). Small numbers of Aedes, Armigeres, and Anopheles mosquitoes were trapped [Aedes albopictus (n = 219: 3.2%), Aedes pocilius (n = 137: 2.0%), Armigeres subalbatus (n = 97: 1.4%), Anopheles vagus (n = 70: 1.0%), Aedes aegypti (n = 23: 0.3%)]. There were 2582 specimens (37.2%) captured in fluorescent light traps, whereas 942 (13.6%), 934 (13.5%), 854 (12.3%), 820 (11.8%), and 797 (11.5%) were captured in the LED375, LED405, LED395, LED365, and LED385 traps, respectively. None of the UV-LED light traps were as efficacious for sampling nocturnal mosquito species as the fluorescent light trap. Among the five UV-LED light sources, LED375 trapped the greatest number of mosquitoes. Additional field trials are needed to validate these findings in different settings in order to substantially assess the potential of the LEDs to trap outdoor nocturnal mosquitoes.

The Analysis Of Characteristics, Habitat Spatial Distribution, and The Impacts On Anopheles Sp. Larvae Dencities at Perimeter and Buffer Area in The Mota’ain Cross-Border Station Of Port Health Office Kupang 2021

East Nusa Tenggara (NTT) is still the third largest contributor to Malaria cases in Indonesia, with a prevalence of 12%, Papua (18.4%) and West Papua (26.1%). Directly border with The Democratic Republic of Timor Leste (RDTL) with Mota'ain as the main crossing point, increases the risk of infectious diseases transmission. Mota’ain is located in coastal areas, swamps, river basins, former fish ponds, and rice fields potentially to be Anopheles sp. habitats. The purpose of this research is to examine the characteristics and spatial distribution of potential breeding habitats for Anopheles sp. in Mota'ain. This is a descriptive analytic study with a cross-sectional design. The Anopheles sp mosquito bionomic area, which included swamps, rice fields, estuaries around the perimeter, and the buffer area of the Mota'ain border, served as the research sample. The spatial regression test was used to analyze the data, and the results revealed three points of Anopheles sp larvae habitats, namely fish ponds, swamps, and river basin. In the buffer area, 24 (80%) of the larvae habitats were found within a 200-meter radius, and 24 (80%) of the larvae habitats were found within a 400-meter radius 6 (20%). There was no habitat found around the perimeter. With a habitat index of 50%, the density of Anopheles sp larvae per catch ranged from 0.04 to 12.03. Anopheles sp larvae discovered included Anopheles Barbirostris, Anopheles Subpictus, and Anopheles Vagus. Swamps have the most habitat (3,004.7 m2), while river basins have the least (3,004.7 m2) (2.93 m2). The Spatial Regression Test revealed that habitat area (p = 0.014), water pH (p = 0.015), and salinity (p = 0.00012) were significant. This means that habitat area, water pH, and salinity all have an effect on Anopheles sp. density, whereas temperature has no effect (p = 0.778). Cleaning aquatic plants and employing larval predators to prevent larval breeding.

Composition of Mosquito Species in Three Selected Villages in Mahabubnagar District, Telangana

Mosquito prevalence was studied in three areas of Mahabubnagar district of Telangana viz. Mannanur,Janampeta, B Veerapur. Mosquito sampling was done in three selected villages in Mahabubnagar districtin all seasons from 2014-2016. Density, Distribution and habitat preferences are studied for three years2014- 2016. A total of 1787 mosquitoes were collected. Identification was done using identification keysof Christophers (1933) and Barraud (1934). Three genera Culex, Aedes and Anopheles were observed.Anopheles contributes 44%, Culex 39% and Aedes contributes 17%. Culex quinquefasciatus is predominantspecies (16%), while Aedes albopictus (15%) and Culex gelidus (15%) occupy the second place. Anophelesculicifacies contributes 12%, while Culex tritaeniorhynchus (8%) and Anopheles vagus (8%) contributeequally. Anopheles subpictus (7%), and Anopheles stephensi (7%) contributed equally, while Aedes aegyptiis with only 5%. Human dwellings inhabit 50% due to breeding sites; cattle shed have 25%, and rainwater ditch have very less, as these are available only in monsoons. Cx. quinquefasciatus, Cx. gelidus werefound in all habitats, while An. subpictus, An. stephensi, An. culicifacies, Ae. aegypti, Ae. albopictus werefound in some of the habitats.

Anopheline Diversity in Indonesia: An Evaluation of Animal-Baited Sampling Techniques.

Indonesia has rich Anopheline (Diptera: Culicidae) mosquito species living in various types of ecosystems. The study was conducted to profile and compare Anopheles diversity, equitability, and dominance in various ecosystems using different animal-based sampling techniques. The present study analyzed a subset of data collected from a nation-wide vector and animal reservoirs survey in 2016. Analyses were restricted to three ecosystem types (forest, nonforest, and coastal areas) in Java and Sumatera Islands. A total of 5,477 Anopheles were collected by using animal-baited (n = 1,909) and animal-baited trap nets (n = 1,978), consisting of 23 Anopheline species. Overall, Anopheles vagus was the most abundant species, followed by An. subpictus and An. barbirostris. Among the three ecosystems, the forest had a higher diversity index (H' = 1.98), but each ecosystem has its specific predominant species. Compared with the animal-baited method, the Anopheles abundance collected by animal-baited trap nets was two-fold higher. Ecosystem, elevation, and sampling methods were associated with the abundance of female Anopheles (P-value < 0.001). Our findings revealed that Anopheles were found in a different ecosystem, indicating the potential of malaria transmission. This suggests that improved malaria vector surveillance is essential in all types of ecosystem. Furthermore, the study suggested that animal-baited trap nets could be used as the standard method of outdoor resting sampling in Indonesia in addition to the traditional human landing collection approach.

Entomological survey in two communes with residual malaria transmission in Gia Lai Province in the central highlands of Vietnam

BackgroundIn 2018, the National Malaria Control Programme in Vietnam switched from prioritizing malaria control to elimination. However, with the ongoing elimination programme, there are still areas where residual malaria transmission persists, including the central highlands. This entomological survey was conducted to evaluate Anopheles diversity and host-seeking activity of Anopheles vectors in two communes with very low malaria transmission in Gia Lai Province.MethodsAnopheles species were collected in Ia DReh commune and Ia KDam commune, Gia Lai Province in the central highlands of Vietnam. Collections were conducted using human-baited double net trap, light trap and manual aspiration collections around cattle sheds, in the dry and rainy season. Mosquito specimens were identified morphologically, and members of species complexes were distinguished molecularly. Mosquito night-feeding patterns were investigated during the dry and rainy seasons.ResultsOverall, 18,835 specimens including 19 taxa were collected in Ia KDam and Ia DReh communes. These included the primary malaria vectors, Anopheles dirus and Anopheles minimus, and other secondary vector species. Anopheles dirus was observed to be an anthropophilic species, whereas An. minimus and a number of secondary vectors were observed to be zoophilic. Anopheles vagus was the dominant species, followed by Anopheles sinensis and Anopheles peditaeniatus. The majority of specimens were collected in the rainy season due to the relatively large number of An. vagus, while An. peditaeniatus, An. dirus, Anopheles kochi, Anopheles monstrosus and Anopheles tessellatus were collected in greater numbers during the dry season. The peak of host-seeking activity for An. dirus, An. sinensis, and An. vagus was between 18.00 and 19.00 h.ConclusionThis study provided information on the diversity, seasonal prevalence and behaviour of Anopheles at the study sites. Identifying the diverse mosquito fauna in the central highlands of Vietnam allows species-specific control measures to be implemented by the National Programme to reduce malaria in areas of very low malaria transmission. The peak Anopheles host-seeking activity observed in this study was between 18.00 and 23.00 h, which highlights the need to better characterize Anopheles behaviour in this region of Vietnam to inform on vector control strategies.