Mosquito Species Composition Research Articles

Spatio-temporal distribution of mosquitoes and risk of malaria infection in Rwanda

To date, the Republic of Rwanda has not systematically reported on distribution, diversity and malaria infectivity rate of mosquito species throughout the country. Therefore, we assessed the spatial and temporal variation of mosquitoes in the domestic environment, as well as the nocturnal biting behavior and infection patterns of the main malaria vectors in Rwanda. For this purpose, mosquitoes were collected monthly from 2010 to 2013 by human landing catches (HLC) and pyrethrum spray collections (PSC) in seven sentinel sites. Mosquitoes were identified using morphological characteristics and PCR. Plasmodium falciparum sporozoite infection rates were determined using ELISA. A total of 340,684 mosquitoes was collected by HLC and 73.8% were morphologically identified as culicines and 26.2% as anophelines. Of the latter, 94.3% were Anopheles gambiae s.l., 0.4% Anopheles funestus and 5.3% other Anopheles species. Of An. gambiae s.l., An. arabiensis and An. gambiae s.s. represented 84.4% and 15.6%, respectively. Of all An. gambiae s.l. collected indoor and outdoor, the proportion collected indoors was 51.3% in 2010 and 44.9% in 2013. A total of 17,022 mosquitoes was collected by PSC of which 20.5% were An. gambiae s.l. and 79.5% were culicines. For the seven sentinel sites, the mean indoor density for An. gambiae s.l. varied from 0.0 to 1.0 mosquitoes/house/night. P. falciparum infection rates in mosquitoes varied from 0.87 to 4.06%. The entomological inoculation rate (EIR) ranged from 1.0 to 329.8 with an annual average of 99.5 infective bites/person/year. This longitudinal study shows, for the first time, the abundance, species composition, and entomological inoculation rate of malaria mosquitoes collected throughout Rwanda.

Converging Human and Malaria Vector Diagnostics with Data Management towards an Integrated Holistic One Health Approach.

Monitoring malaria prevalence in humans, as well as vector populations, for the presence of Plasmodium, is an integral component of effective malaria control, and eventually, elimination. In the field of human diagnostics, a major challenge is the ability to define, precisely, the causative agent of fever, thereby differentiating among several candidate (also non-malaria) febrile diseases. This requires genetic-based pathogen identification and multiplexed analysis, which, in combination, are hardly provided by the current gold standard diagnostic tools. In the field of vectors, an essential component of control programs is the detection of Plasmodium species within its mosquito vectors, particularly in the salivary glands, where the infective sporozoites reside. In addition, the identification of species composition and insecticide resistance alleles within vector populations is a primary task in routine monitoring activities, aiming to support control efforts. In this context, the use of converging diagnostics is highly desirable for providing comprehensive information, including differential fever diagnosis in humans, and mosquito species composition, infection status, and resistance to insecticides of vectors. Nevertheless, the two fields of human diagnostics and vector control are rarely combined, both at the diagnostic and at the data management end, resulting in fragmented data and mis- or non-communication between various stakeholders. To this direction, molecular technologies, their integration in automated platforms, and the co-assessment of data from multiple diagnostic sources through information and communication technologies are possible pathways towards a unified human vector approach.

Species composition and insecticide resistance status of mosquitoes collected by using light traps at kampung dusun nanding, Hulu Langat, Selangor, Malaysia

Species composition and insecticide resistance status of mosquitoes collected by using light traps at kampung dusun nanding, Hulu Langat, Selangor, Malaysia

How often do mosquitoes bite humans in southern England? A standardised summer trial at four sites reveals spatial, temporal and site-related variation in biting rates

BackgroundThis field-based study examined the abundance and species complement of mosquitoes (Diptera: Culicidae) attracted to humans at four sites in the United Kingdom (UK). The study used a systematic approach to directly measure feeding by mosquitoes on humans at multiple sites and using multiple volunteers. Quantifying how frequently humans are bitten in the field by mosquitoes is a fundamental parameter in assessing arthropod-borne virus transmission.MethodsHuman landing catches were conducted using a standardised protocol by multiple volunteers at four rural sites between July and August 2013. Collections commenced two hours prior to sunset and lasted for a total of four hours. To reduce bias occurring due to collection point or to the individual attractiveness of the volunteer to mosquitoes, each collection was divided into eight collection periods, with volunteers rotated by randomised Latin square design between four sampling points per site. While the aim was to collect mosquitoes prior to feeding, the source of blood meals from any engorged specimens was also identified by DNA barcoding.ResultsThree of the four sites yielded human-biting mosquito populations for a total of 915 mosquitoes of fifteen species/species groups. Mosquito species composition and biting rates differed significantly between sites, with individual volunteers collecting between 0 and 89 mosquitoes (over 200 per hour) of up to six species per collection period. Coquillettidia richiardii (Ficalbi, 1889) was responsible for the highest recorded biting rates at any one site, reaching 161 bites per hour, whilst maximum biting rates of 55 bites per hour were recorded for Culex modestus (Ficalbi, 1889). Human-biting by Culex pipiens (L., 1758) form pipiens was also observed at two sites, but at much lower rates when compared to other species.ConclusionsSeveral mosquito species are responsible for human nuisance biting pressure in southern England, although human exposure to biting may be largely limited to evening outdoor activities. This study indicates Cx. modestus can be a major human-biting species in the UK whilst Cx. pipiens f. pipiens may show greater opportunistic human-biting than indicated by earlier studies.

Species composition and fauna distribution of mosquitoes (Diptera: Culicidae) and its importance for vector-borne diseases in a rural area of Central Western - Mato Grosso, Brazil

Abstract. This study describes ecological data obtained in a rural area in the State of Mato Grosso, including the insects belonging to the family Culicidae, especially those framed as potential vectors of tropical diseases. In 2015, we collected adult mosquitoes in fragments of forest in a rural area located in Mato Grosso Central West of Brazil. We captured 18,256 mosquitoes of the sub-families Culicinae and Anophelinae and have identified 34 species belonging to 12 genera: Aedes (1 species), Anopheles (8 species), Coquillettidia (1 species), Haemagogus (1 species), Culex (5 species), Psorophora (5 species), Ochlerotatus (4 species), Deinocerites (1 species), Mansonia (4 species), Sabethes (2 species), Limatus (1 species), Wyeomyia (1 species). The family Culicidae presented high richness and abundance, established by diversity indexes (Margalef α =3.26; Shannon H' = 2.09; Simpson D = 0.19) with dominance of the species Anopheles (Nyssorhyncus) darlingi Root (89.8%). This species has considerable epidemiological value, considered the main vector of malaria in Mato Grosso. Many species of mosquitoes are vectors of pathogens that cause disease in humans and domestic animals, transmitting pathogens including viruses (arboviruses), filaria worms (helminths) and protozoa.Composição de espécies e distribuição da fauna de mosquitos (Diptera: Culicidae) e sua importância para doenças transmitidas por vetores em uma área rural do centro-ocidental - Mato Grosso, BrasilResumo. Este estudo descreve dados ecológicos de uma área rural do Estado de Mato Grosso e dos insetos da família Culicidae especialmente aqueles enquadrados como vetores potenciais de doenças tropicais. Em 2015, coletamos mosquitos adultos em fragmentos de floresta em localidades de áreas rurais no Mato Grosso região Centro Oeste do Brasil. Foram capturados 18.256 exemplares alados de mosquitos das subfamílias Culicinae e Anophelinae e identificadas 34 espécies pertencentes a 12 gêneros: Aedes (1 espécie), Anopheles (8 espécies), Coquillettidia (1 espécie), Haemagogus (1 espécie), Culex (5 espécies), Psorophora (5 espécies), Ochlerotatus (4 espécies), Deinocerites (1 espécie), Mansonia (4 espécies), Sabethes (2 espécies), Limatus (1 espécie), Wyeomyia (1 espécie). A família Culicidae apresentou alta riqueza e abundância, estabelecida por índices de diversidade (Margalef α = 3.26, Shannon H' = 2.09, Simpson D = 0.19) com predominância da espécie Anopheles (Nyssorhyncus)darlingi Root (89.8%). Esta espécie tem considerável valor epidemiológico, sendo considerada o principal vetor de malária em Mato Grosso. Muitas espécies de mosquitos são vetores de patógenos que causam doenças em humanos e animais domésticos, transmitindo patógenos incluindo vírus (arboviroses), filárias (helmintos) e protozoários.

Tree hole mosquito species composition and relative abundances differ between urban and adjacent forest habitats in northwestern Argentina.

Water-holding tree holes are main larval habitats for many pathogen vectors, especially mosquitoes (Diptera: Culicidae). Along 3 years, the diversity and composition of mosquito species in tree holes of two neighbouring but completely different environments, a city and its adjacent forest, were compared using generalized linear mixed models, PERMANOVA, SIMPER and species association indexes. The city area (Northwest Argentina) is highly relevant epidemiologically due to the presence of Aedes aegypti L. (main dengue vector) and occurrence of dengue outbreaks; the Yungas rainforests are highly biologically diverse. In total seven mosquito species were recorded, in descending order of abundance: Ae. aegypti, Haemagogus spegazzinii Brèthes, Sabethes purpureus (Theobald), Toxorhynchites guadeloupensis Dyar and Knab, Aedes terrens Walker, Haemagogus leucocelaenus Dyar & Shannon and Sabethes petrocchiae (Shannon and Del Ponte). The seven mosquito species were recorded in both city sites and forested areas; however, their mosquito communities significantly diverged because of marked differences in the frequency and relative abundance of some species: Tx. guadeloupensis and Ae. aegypti were significantly more abundant in forest and urban areas, respectively. Positive significant associations were detected between Ae. aegypti, Hg. spegazzinii and Hg. leucocelaenus. The combined presence of Ae. aegypti, Haemagogus and Sabethes in the area also highlight a potential risk of yellow fever epidemics. Overall results show an impoverished tree hole mosquito fauna in urban environments, reflecting negative effects of urbanization on mosquito diversity.

Analysis of population structure and insecticide resistance in mosquitoes of the genus Culex, Anopheles and Aedes from different environments of Greece with a history of mosquito borne disease transmission

Greece has been recently affected by several mosquito borne diseases with the West Nile Virus (WNV) outbreak in 2010 being one of the largest reported in Europe. Currently at the epicenter of an economic and refugee crisis and visited by over 16 million tourists a year the integrated management of diseases transmitted by mosquitoes is a public health and economic priority. Vector control programs rely mainly on insecticides, however data on insecticide resistance and the mosquito fauna is essential for successful applications.We determined the mosquito species composition and population dynamics in areas of increased vulnerability to vector borne disease transmission, as well as investigated the resistance status of major nuisance and disease vectors to insecticides. High mosquito densities were recorded in Thessaloniki and Evros, with Aedes caspius, a nuisance species, Culex pipiens, a known vector of WNV and Anopheles hyrcanus a potential vector of malaria being among the most prevalent species. Both vector species populations reached their peak in late summer. Aedes albopictus was recorded at high densities in Thessaloniki, but not in Evros. Notably, Cx. pipiens hybrids, which show an opportunistic biting behavior and are suspected to be involved in the transmission of the WNV, were recorded in considerable numbers in Thessaloniki and Attica. Culex pipiens and An. hyrcanus, but not Ae. caspius mosquitoes, showed moderate levels of resistance to deltamethrin. The presence of resistance in areas not exposed to vector control indicates that other factors could be selecting for resistance, i.e. pesticide applications for agriculture. Both L1014F and L101C kdr mutations were detected in Cx. pipiens populations. Anopheles hyrcanus resistance was not associated with mutations at the L1014 site. The Ace-1 mutations conferring insensitivity to organophosphates and carbamates were detected at low frequencies in all Cx. pipiens populations. Increased activity of P450s and esterases was found in Cx. pipiens individuals from Thessaloniki. Our study contributes evidence for sustainable and efficient vector control strategies and the prevention of disease outbreaks.

Pond dyes are Culex mosquito oviposition attractants.

BackgroundBritish mosquito population distribution, abundance, species composition and potential for mosquito disease transmission are intimately linked to the physical environment. The presence of ponds and water storage can significantly increase the density of particular mosquito species in the garden. Culex pipiens is the mosquito most commonly found in UK gardens and a potential vector of West Nile Virus WNV, although the current risk of transmission is low. However any factors that significantly change the distribution and population of C. pipiens are likely to impact subsequent risk of disease transmission. Pond dyes are used to control algal growth and improve aesthetics of still water reflecting surrounding planting. However, it is well documented that females of some species of mosquito prefer to lay eggs in dark water and/or containers of different colours and we predict that dyed ponds will be attractive to Culex mosquitoes.MethodsBlack pond dye was used in oviposition choice tests using wild-caught gravid C. pipiens. Larvae from wild-caught C. pipiens were also reared in the pond dye to determine whether it had any impact on survival. An emergence trap caught any adults that emerged from the water. Water butts (80 L) were positioned around university glasshouses and woodland and treated with black pond dye or left undyed. Weekly sampling over a six month period through summer and autumn was performed to quantified numbers of larvae and pupae in each treatment and habitat.ResultsGravid female Culex mosquitoes preferred to lay eggs in dyed water. This was highly significant in tests conducted under laboratory conditions and in a semi-field choice test. Despite this, survivorship in black dyed water was significantly reduced compared to undyed water. Seasonal analysis of wild larval and pupal numbers in two habitats with and without dye showed no impact of dye but a significant impact of season and habitat. Mosquitoes were more successful, with significantly higher numbers of pupae, in the habitat where they had vegetation cover and shade.DiscussionOur study has raised some interesting possibilities; one is that where used, pond dyes may be encouraging mosquitoes to breed in gardens in close proximity to people. Considering the concerns over potential future spread of disease in urban environments, this as well as shading of ponds and water butts, should inform future advice over reducing mosquito breeding and spread.

Mosquito (Diptera: Culicidae) communities of metropolitan Perth, Western Australia, and implications for managing pest and public health risks

AbstractMosquito population data in the Perth Metropolitan area are limited. This research aimed to determine mosquito species abundance and composition within three local government areas of inner metropolitan Perth. A secondary aim was to determine whether mosquito species abundance and composition in the study area were related to proximity of known saltmarsh mosquito breeding sites along two major tidal estuary systems. Eleven mosquito species were collected, of which four were found in high abundance: Aedes vigilax, Culex quinquefasciatus, Culex annulirostris and Aedes notoscriptus. The majority of mosquitoes were collected within 1 km of the tidal estuary systems, suggesting that productive mosquito breeding habitat is likely to be located along the fringe of the estuaries. The implication for mosquito management is that saltmarsh mosquitoes are not the only type of mosquito species in the study area. Broadening surveillance and management methods to include freshwater and container breeding species will reduce nuisance concerns for the public and is also likely to reduce incidence of disease in the area.

Seasonal prevalence and species composition of mosquitoes and chigger mites collected from Daegu, Gunwi and Sangju in South Korea, 2014

BackgroundAs the habitat changes in Korea due to climate change, the emergence of disease-mediated vectors is increasing rapidly. Thus for the surveillance of mosquito- and chigger mite-borne disease, their seasonal prevalence and species composition were investigated at seven locations in Daegu, Gunwi and Sangju.MethodsMosquitoes were collected twice every month from five collection sites using a black light and BG sentinel traps in Daegu and Gunwi from April through November. Chigger mites were investigated twice per month from wild rodents caught with Sherman live traps in Gunwi and Sangju from April through May and September through November.ResultsA total of 2,361 female mosquitoes were collected. Cowshed (626 individuals, Trap index (TI) 44.7) and Kyungpook National University campus (846 individuals, TI 60.4) in Daegu had the highest number of mosquitoes in the black light and BG sentinel trap, respectively. The mosquitoes were collected more by BG sentinel trap than the black light trap. Nine mosquito species were trapped, and the Culex pipiens complex was the most commonly mosquito (1,397 individuals, 59.2%), followed by Anopheles sinensis (554 individuals, 23.5%). Anopheles sinensis (531 individuals, 51.9%) and Culex pipiens complex (1,142 individuals, 85.4%) were the most mosquitoes from black light and BG sentinel trap, respectively. In terms of seasonal prevalence, the highest abundance was in July, with 824 individuals collected. In chigger mites, eighty-one wild rodents of five species that are hosts of chigger mites were collected; among them, 53 and 25 individuals of Apodemus agrarius and Crocidura suaveolens, respectively were trapped. Leptotrombidium pallidum was a dominant species, with 2,467 individuals collected (67.8%).ConclusionsThe mosquito was the dominant species in Culex pipiens complex and the highest in July and August. Apodemus agrarius was most abundant in wild rats and Leptotrombidium pallidum was dominant in the collected chigger mites.

"Looking over the Backyard Fence": Householders and Mosquito Control.

(1) Background: Vector-borne diseases are a significant public health problem in Western Australia. Mosquitoes are responsible for the transmission of a number of pathogens and may pose a serious nuisance problem. Prevention efforts in the State are multi-faceted and include physical, chemical, and cultural control methods for restricting mosquito breeding. This is less complex where breeding areas are located within public open spaces. In Australia’s developed urban areas, breeding sites are, however, frequently located within private residential landholdings, where the scope of public health officials to act is constrained by law and practicality. Consequently, mosquito prevention in these locations is predominantly the responsibility of the residents. This research addressed a gap, both in understanding the degree to which “backyard” mosquito breeding has the potential to contribute to local mosquito problems, and in assessing what residents “think and do” about mosquito control within their home environment. (2) Methods: The study was conducted in the Town of Bassendean, a metropolitan Local Government Area of Perth, Western Australia, in close proximity to two natural, productive mosquito breeding sites, namely Ashfield Flats and Bindaring Park. A total of 150 householders were randomly surveyed during the summer of 2015–2016, to gauge residents’ knowledge, attitudes, and practices (KAP (knowledge, attitudes, and practices) Survey) in regards to mosquitoes, their breeding and ecology, and avoidance or minimization strategies. The survey comprised nine questions covering residents’ knowledge (3 questions), attitudes (3 questions), and practices (3 questions), as well as additional questions regarding the basic demographics of the resident. Larvae were collected from backyard containers and reared to adults for species identification. A series of Encephalitis Vector Surveillance carbon dioxide (EVS CO2) traps were also deployed, to assess adult mosquito density and species composition. (3) Results: Aedes notoscriptus (Skuse), a known container-inhabiting species, accounted for just over 50% of all mosquitoes identified. Most residents were aware of mosquito-borne disease and its risk in their local area. While the majority (79%) of the sample correctly identified Ross River virus as the most common infection in WA, a significant gap in the general knowledge of residents in regards to mosquito biology and breeding habits, was noted. Furthermore, only 50% of residents reported using personal protective measures to reduce mosquito bites and only one in six residents undertook physical or chemical mosquito control around their home. Additionally, 60% of respondents believed that mosquito control was “a job for the council and the state government”, rather than for individual householders. (4) Conclusions: A significant gap in the knowledge of residents in the study area existed in regards to the general knowledge of mosquitoes and their breeding habits; types of treatments that could be employed within the home; and the residents’ responsibility for the management of mosquito breeding on their private property. A public education campaign has been deployed to educate the residents.

Kelimpahan Aedes spp. di kota semarang, purwokerto dan yogyakarta

Abundance of Aedes spp. in Semarang, Purwokerto and Yogyakarta. In Indonesia, Dengue Fever has a high morbidity rate. Incidence Rate (IR) during 39 years (1968-2007) showed a tendency to increase 00-30 per 100,000 populations, but the Case Fatality Rate (CFR) shows a decrease trend from 40% to 1.6%. Method of mosquito control that is mostly done today is chemical control methods. Unfortunately, this method is not always. A survey to find out the composition of the Aedes mosquito species in the field needs to as the first step to improve the method of vector control. This study employed a descriptive survey method, be done, taking eggs and adult mosquitoes from the three cities. From each city. Eggs and adult mosquitoes of Aedes spp from 90 ovitraps and 18 field locations were taken. Eggs obtained from Semarang, Purwokerto and Yogyakarta are 1835, 833, 1345, from 27 (30%), 22 (24,44%) and 25 (27,7%) ovitraps respectively, consisting of species A. aegypti and A. albopictus. A. aegypti and A. albopictus adults obtained in Semarang 17 (5%) and 323 (95%), in Purwokerto 6 (7%) and 81 (93%), while in Yogyakarta, 36 (25%) and 105 (75%) respectively. Research results show that in three cities A albopictus was more abundant than the A. aegypti.

Faunistic Study on Species Composition of Mosquitoes and Sand Flies around Mrima Hill a High Radiation Area in Kwale County, Kenya

Faunistic Study on Species Composition of Mosquitoes and Sand Flies around Mrima Hill a High Radiation Area in Kwale County, Kenya

КРОВОСИСНІ КОМАРІ (DIPTERA; CULICIDAE) ПИРЯТИНСЬКОГО РАЙОНУ

The research of the species diversity and ecological features of mosquitoes is an important stage in the development of insects' quantity control methods. The areas with low anthropogenic influence, among which a particular place is given to the special nature reserve areas, may serve as a model for this kind of studies. Until now, neither the species composition of mosquitoes from Pyryatin district nor the special features of their development and dispersal were not investigated, that establishes an academic and practical relevance of the current work. The aim of this investigation was to determine the species composition of mosquitoes, to make an analysis of the groups structure and to determine ecological features of adults that belong to common bloodsucking species. Research material of the years 2014-2015 was collected from Pyryatin district, which includes the National Park (NNP) "Pyryatinskyi." Gathering and collection of material were performed by conventional methods. The 20 species and subspecies of 5 mosquito generas – Anopheles, Coguillettidia, Aëdes, Ochlerotatus, and Culex were registered in the Pyryatyn district. Aëdes cinereus (dominance index: Di – 34%), Culex modestus (Di – 18%) and Aëdes vexans (Di – 16%) appeared to be mass species. According to given environmental characteristics, these mosquitoes are anthropophilous, eurygamous, eurytopic and mostly exophilic bloodsuckers. Aë. vexans in residential areas has shown itself to be an exophilic and endophilic bloodsucker. These types under certain circumstances may pose a potential epidemic danger.

The Species Composition of Malaria Mosquitoes in the Kharkov Region (Ukraine): Natural Factors of Malaria Spread

Objective: Article describes the species composition of malaria mosquitoes dominating in the Kharkov region, Ukraine, season of their possible effective infection, as well as antimalarial precautions taken. Methods: When collecting the material, the conventional methods of evaluation of abundance of mosquitoes were used. Collection of larvae and pupae was carried out with standard butterfly net or photo tray with subsequent recalculation per m 2 . Results: On the territory of the region were studied 30 species of bloodsucking mosquitoes of such three genera as Anopheles, Culex, Aedes were found. Conclusion: Facts demonstrate the favorable environmental conditions for malaria spread such as; increase in the number of vectors, increase in precipitation, long temperature period of transmission of infection.

Population dynamics of mosquito species in a West Nile virus endemic area in Madagascar.

Human and animal serological surveys suggest that West Nile virus (WNV) circulation is widely distributed in Madagascar. However, there are no reported West Nile fever outbreaks or epizootics in the country and only one fatal human case has been reported to date. Currently there is very limited information on the maintenance and the transmission of WNV in Madagascar and particularly on the mosquito species involved in transmission cycles. In 2014, we initiated a study to investigate mosquito species composition, relative abundance, and trophic behavior in Mitsinjo District close to Lake Kinkony, a WNV endemic area in north-western Madagascar. We collected a total of 2519 adult mosquitoes belonging to 21 different species. The most abundant species was Aedeomyia (Aedeomyia) madagascarica Brunhes, Boussès & da Cunha Ramos, which made up 83% of all the mosquitoes collected. Mosquito abundance was associated with proximity to the lake (Morafeno and Ankelimitondrotra). Additionally, a correlation was observed between the lake-side biotope and the abundance of mosquito vectors in Morafeno. WNV RNA was detected in one pool of Ae. madagascarica and one pool of Anopheles (Cellia) pauliani Grjebine, suggesting that these two species may be involved in the maintenance and/or transmission of WNV in Madagascar.

Species composition of mosquitoes (Diptera: Culicidae) in Farashband district, southwest of Iran

Mosquitoes are potential vectors of some important diseases for humans and animals. Apart from mosquito borne diseases, mosquitoes cause nuisances for both humans and animals when they are abundant. The objective of this study was to determine the fauna of mosquitoes (Diptera: Culicidae) in Farashband County, southwest of Iran. The study was carried out from April to September 2012. Four collection sites, were selected randomly with regard to existing facilities in Farashband County. Sampling was carried out by dipping technique for collecting larvae and pyrethrum space spray collection (PSSC) for adult mosquitoes. Mean temperature was recorded for every month. A total of 1152 adults and 1505 larvae of Culicidae mosquitoes were collected, of which 3 genera and 7 species of Culicidae were recognized, namely, <em>Anopheles superpictus</em>, <em>An. dthali,</em> <em>Culex sitaiticus, Cx. theileri, Cx. pipiens, Cx. tritaeniorhynchus</em> and <em>Culiseta longiareolata</em>. <em>Cs. longiareolata</em> was the most frequent Culicidae mosquito collected at Farashband, with a total of 513, and 249 specimens, by larval and PSSC collection, respectively. The highest numbers of mosquitoes were collected in July (34.9%) and the lowest in April (3.8%), respectively. Regarding this research, there are some potential vectors in medical and veterinary importance in Farashband County and they are more active in July and June.

Chromosomal polymorphism in the populations of malaria mosquito Anopheles messeae (Diptera, Culicidae) in the Volga region

We studied the species composition and chromosomal variability of malaria mosquitoes in the Volga Basin (Upper, Middle, and Lower Volga regions). We investigated larvae karyotypes of sibling species of the Anopheles maculipennis group. We calculated the frequencies of chromosomal inversions in the local populations of the dominant species An. messeae. We discovered that karyotypic structure of An. messeae populations depends on landscape-climatic zones. Populations of the Upper, Middle and Lower Volga differ in frequency of chromosome inversions XL, 2R, 3R, and 3L.

Diffusion, population dynamics and potential distribution of Armigeres subalbatus

To investigate the diffusion trend of Armigeres subalbatus and analyze its potential geographic distribution in China. The trend analysis of diffusion and population dynamics were carried out based on three aspects including literature reports, information of museum specimens and new collection records from our field survey. To compare the potential geographic distribution, two ecological niche models were constructed by Maxent software based on the geographic presence occurrence data and 20 environmental variables. The final models were evaluated with the receiver operating characteristics curve (ROC). The analyses of variable contributions were confirmed by using the Jackknife method. The populations in Weifang and Weihai, Shandong Province were reported for the first time. The results showed that this species was spread to the Palaearctic Northern Region and reached 42° north latitude regions. In some areas, it gradually developed into a dominant species. A total of 294 georeferenced occurrence points of A. subalbatus were found out. Two predictions of Maxent models were established based on the presence occurrence data in 2000 and 2016, respectively. The results showed that the current distribution range of A. subalbatus had been significantly northward expanded compared with 2000. It means that the potential suitable area gradually spread northward. The ROC analysis results showed the AUC values were 0.980 and 0.982, and it indicated that the models had a high reliability. The Jackknife method displayed that the precipitation of warmest quarter, precipitation of wettest month and precipitation of wettest quarter were the dominant environmental variables that mainly contributed to the distribution of A. subalbatus. A. subalbatus distribution gradually spreads northward, and climate warming is probably the main reason for the diffusion. It could affect the local mosquito species composition and increase the risk of mosquito-borne disease transmission.

Increasing outdoor host-seeking in Anopheles gambiae over 6years of vector control on Bioko Island.

BackgroundVector control through indoor residual spraying (IRS) has been employed on Bioko Island, Equatorial Guinea, under the Bioko Island Malaria Control Project (BIMCP) since 2004. This study analyses the change in mosquito abundance, species composition and outdoor host-seeking proportions from 2009 to 2014, after 11 years of vector control on Bioko Island.MethodsAll-night indoor and outdoor human landing catches were performed monthly in the Bioko Island villages of Mongola, Arena Blanca, Biabia and Balboa from 2009 to 2014. Collected mosquitoes were morphologically identified and a subset of Anopheles gambiae sensu lato (s.l.) were later identified molecularly to their sibling species. Mosquito collection rates, species composition and indoor/outdoor host-seeking sites were analysed using generalized linear mixed models to assess changes in mosquito abundance and behaviour.ResultsThe overall mosquito collection rate declined in each of the four Bioko Island villages. Anopheles coluzzii and Anopheles melas comprised the An. gambiae s.l. mosquito vector population, with a range of species proportions across the four villages. The proportion of outdoor host-seeking An. gambiae s.l. mosquitoes increased significantly in all four villages with an average increase of 58.8 % [57.9, 59.64 %] in 2009 to 70.0 % [67.8, 72.0 %] in 2014. Outdoor host-seeking rates did not increase in the month after an IRS spray round compared to the month before, suggesting that insecticide repellency has little impact on host-seeking behaviour.ConclusionWhile vector control on Bioko Island has succeeded in substantial reduction in overall vector biting rates, populations of An. coluzzii and An. melas persist. Host-seeking behaviour has changed in these An. gambiae s.l. populations, with a shift towards outdoor host-seeking. During this study period, the proportion of host-seeking An. gambiae s.l. caught outdoors observed on Bioko Island increased to high levels, exceeding 80 % in some locations. It is possible that there may be a genetic basis underlying this large shift in host-seeking behaviour, in which case outdoor feeding could pose a serious threat to current vector control programmes. Currently, the BIMCP is preparing for this potential challenge by testing source reduction as a complementary control effort that also targets outdoor transmission.Electronic supplementary materialThe online version of this article (doi:10.1186/s12936-016-1286-6) contains supplementary material, which is available to authorized users.