Immature Stages Of Mosquitoes Research Articles

Assessment of Mayaro virus vector competence of the mosquito Aedes aegypti (Linnaeus, 1762) populations in Argentine using dose-response assays.

Mayaro virus (MAYV; Alphavirus: Togaviridae) is an emerging pathogen in Latin America, causing fever and polyarthritis. Sporadic outbreaks of MAYV have occurred in the region, with reported human cases being imported to Europe and North America. Although primarily a risk for those residing in the Amazon basin's tropical forests, recent reports highlight that urbanization would increase the risk of MAYV transmission in Latin America. Urban emergence depends on human susceptibility and the ability of mosquitos like Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae) to transmit MAYV. Despite the absence of active MAYV transmission in Argentine, the risk of introduction is substantial due to human movement and the presence of Ae. aegypti in the region. This study aimed to evaluate the susceptibility of different Argentine Ae. aegypti populations to MAYV genotype L (MAYV-L) using dose-response assays and determine barriers to virus infection, dissemination and transmission. Immature mosquito stages were collected in Buenos Aires, Córdoba and Rosario cities. Female Ae. aegypti (F2) were orally infected by feeding on five concentrations of MAYV-L, ranging from 1.0 to 6.0 log10 PFU/mL. Abdomens, legs and saliva were analysed using viral plaque assays. Results revealed that MAYV-L between infection and dissemination were associated with viral doses rather than the population origin. Infection rates varied between 3% and 65%, with a 50% infectious dose >5.5 log10 PFU/mL. Dissemination occurred at 39%, with a 50% dissemination dose of ~6.0 log10 PFU/mL. Dissemination among infected mosquitoes ranged from 60% to 86%, and transmission from disseminated mosquitoes ranged from 11% to 20%. Argentine Ae. aegypti populations exhibited a need for higher viral doses of MAYV-L than those typically found in humans to become infected. In addition, only a small proportion of infected mosquitoes were capable of transmitting the virus. Understanding MAYV transmission in urban areas is crucial for public health interventions.

Trait- and density-mediated effects of predation on fecundity and fertility of Aedes aegypti (Diptera: Culicidae) mosquitoes.

Prey populations that encounter predators experience density-mediated effects through lethality and associated numerical changes in the population. Prey also exhibit trait-mediated effects through nonlethal alterations in phenotypic traits associated with exposure to predators. Immature stages of mosquitoes commonly co-occur in habitats along with predators, a natural source of mortality and potential biocontrol agent. Toxorhynchites rutilus Coquillett 1896 is a natural source of mortality with potential as a biological control agent. Previous studies have shown that predation and the mere presence of Tx. rutilus (predator cues) can alter the life-history traits of Aedes aegypti (L. 1762). In addition to observed reductions in recruitment of adults (lethality), exposure to Tx. rutilus without consumption resulted in adult Ae. aegypti females with altered growth and reduced lifespan. To determine the influence of predation on the reproductive biology of Ae. aegypti, we tested the hypothesis that predation, or exposure to predator cues, will compromise the reproduction of adult survivors through reductions in fecundity (egg batch size) and fertility (hatch rate). We observed that for both female and male Ae. aegypti, survival to adulthood was the lowest and development time the shortest in treatments containing prey removal effects, attributable to predation and treatment manipulations of density reduction. There were effects of Ae. aegypti weight, but not predation treatments, on fecundity and fertility. Results suggest that predator-mediated effects on Ae. aegypti derive from lethal effects due to consumption and alterations in other phenotypic traits of survivors, including development, weight, lifespan of adults, and population growth, but not reproductive parameters measured here.

Interventions against Aedes/dengue at the household level: a systematic review and meta-analysis.

Because the evidence for the role of structural housing and combinations of interventions (domestic or peri-domestic) against Aedes mosquitoes or dengue is still lacking, this systematic review and meta-analysis aimed to analyse and synthesize research focusing on the household as the unit of allocation. We searched MEDLINE, LILACS, and Web of Science databases until February 2023 using three general keyword categories: (1) "Aedes" or "dengue"; (2) structural housing interventions including "house", "water", or "drainage"; and (3) vector control interventions of potential relevance and their combinations. We performed a qualitative content analysis and a meta-analysis for 13 entries on dengue seroconversion data. 14,272 articles were screened by titles, 615 by abstracts, 79 by full-text. 61 were selected. Satisfactory data quality allowed for detailed content analysis. Interventions at the household level against the immature mosquito stages (21 studies, 34%) showed positive or mixed results in entomological and epidemiological outcomes (86% and 75% respectively). Combined interventions against immature and adult stages (11 studies, 18%) performed similarly (91% and 67%) while those against the adult mosquitoes (29 studies, 48%) performed less well (79%, 22%). A meta-analysis on seroconversion outcomes showed a not-statistically significant reduction for interventions (log odds-ratio:-0.18 [-0.51, 0.14 95% CI]). No basic research on housing structure or modification was eligible for this systematic review but many interventions with clear impact on vector indices and, to a lesser extent, on dengue were described. The small and not-statistically significant effect size of the meta-analysis highlights the difficulty of proving effectiveness against this highly-clustered disease and of overcoming practical implementation obstacles (e.g. efficacy loss, compliance). The long-term success of interventions depends on suitability, community commitment and official support and promotion. The choice of a specific vector control package needs to take all these context-specific aspects into consideration. This work was funded by a grant from the World Health Organization (2021/1121668-0, PO 202678425, NTD/VVE).

A Community-Level Knowledge, Attitude, and Practice about Dengue Fever and the Identification of Mosquito Breeding Containers in Dire Dawa City of Ethiopia: A Cross-Sectional Study

Background. Lately, dengue fever (DF) is an emerging viral disease, one of the top 10 threats to global health, causing 24 million–130 million symptomatic cases and 10,000–50,000 deaths yearly. DF threat has expanded beyond traditional areas of endemicity, with over 50% of the world population now estimated to live in areas at risk of dengue virus (DV) transmission. Hence, the current study aimed to assess the community’s knowledge, attitude, and practice about DF transmission and its prevention and to identify mosquito breeding containers in Dire Dawa City, Ethiopia. Methods. A household-based cross-sectional study was conducted from February to September 2022. A semistructured questionnaire was used to collect data. Immature stages of mosquitoes were collected from human habitations to identify their breeding containers. Both descriptive and inferential statistics were used to analyze the data. A p value of <0.05 was used to declare a significant association between variables at a 95% level of confidence. Results. About 95.1% of respondents had information about DF, where the majority (58.0%) heard from relatives, friends, and families and 43.3% from health professionals. Only 17.9% knew DF was caused by viruses. Around 83%, 79%, and 50.8% of respondents knew that fever, headache, and back pain are the sign and symptoms of DF, respectively. Sadly, only 4.2% knew that DF vectors bite during day time and 10.5% of respondents did not know DF transmission season. The majority (80.5%) of respondents knew that DF is a preventable disease. Totally, 6,853 water-holding containers were identified, out of this 77% were jerrycans and 14.1% were barreled. Out of the identified water-holding containers, 7.73% were positive for mosquito larvae/pupae. House index (HI), container index (CI), and Breteau index (BI) were 19.5, 8.38, and 45.14, respectively. Conclusion. The majority of the community members has no awareness of the DF vectors, time of bites, pick transmission season, and their protection mechanisms. The habit to store water in and around habitation was prevalent. Hence, programmed and institutionalized awareness is mandatory for the control and prevention of DF and its vectors and for breaking the transmission cycle in Dire Dawa communities.

Species Composition and Biting Activities of Mosquitoes in a Selected Community in Anambra State, Southeast Nigeria

Mosquitoes are common biting and sucking arthropods whose females bite man and animals for their blood meal which leads to itching and causes diseases. The study investigated the species composition and biting activities of mosquitoes at Ifite-Awka, Awka South Local Government Area, Anambra State, south east Nigeria. The study was carried out between November and December, 2021 and the mosquitoes were collected using the Human Landing Catch (HLC) and Pyrethrum Spray Collection Method (PSC), whereas Larval Sampling (LS) method was used to collect the immature stages of mosquito. The HLC was carried out from 5:00pm to 8:00pm and the biting peak was observed from 5:45pm to 7:00pm. A total of 158 adult mosquitoes were collected which comprised of 3 species namely Culex quinquefasciatus, Anophles gambiae and Mansonia africana. Culex quinquefasciatus was the most abundant species irrespective of the method of collection which was attributed to their anthropohilic, endophagic and endophilic nature. Pyrethrum Spray Collection method (PKC) produced the highest species of 120 mosquitoes which constitute of 75.83% (91/158) Culex quinquefasciatus, 22.5% (27/158) Anopheles gambiae and 1.66% (2/158) Mansonia africana. The HLC method caught mosquitoes of two different species which was Culex quinquefasciatus 89.29% (25/28) and Mansonia africana 10.71% (3/28). The Larval Sampling method caught 10 Culex quinquefasciatus. Although there was no significant difference among the methods of collection (p>0.05), but in the distribution of the mosquitoes species, there was a significant difference (p<0.05) among the seven (7) lodges sampled. The study observed high exposure to mosquitoes and the possibility of epidemics of mosquito - borne diseases among Ifite-Awka residents. The need for proper health education, immediate and effective control measures of the mosquito vectors, which includes environmental sanitation is highly advised.

Biodiversity and Spatial Distribution of Mosquitoes (Diptera: Culicidae) in Kurdistan Province, Western Iran.

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

Mosquito (Diptera: Culicidae) Diversity and Community Structure in Doi Inthanon National Park, Northern Thailand.

Simple SummaryMosquitoes are small flies, some of which are known as principal vectors of the pathogens that cause dengue, malaria, filariasis, chikungunya, Japanese encephalitis, and Zika in many countries of the world. However, the majority of the species are important components of ecosystems. We evaluated the diversity and community structure of mosquitoes in Doi Inthanon National Park, named for the highest mountain in Thailand. The park mainly consists of natural forest, but it hosts a number of human activities. A total of 140 mosquito species were identified among 3,795 specimens. The most dominant genera were Culex (34.3%), Aedes (19.3%), Anopheles (13.6%), Uranotaenia (10.7%), and Armigeres (5.8%). The five most abundant species were Ae. albopictus, Ae. vittatus, Cx. bitaeniorhynchus, Cx. mimulus, and Tripteroides aranoides. Species richness was higher in the rainy season than in the cold and hot seasons. Natural phytotelm habitats for immature stages had a higher diversity than artificial container habitats. A greater number of species were found in forest areas than in agricultural areas and villages. Ground pools, stream pools, rock pools, bamboo stumps, bamboo internodes, and rice fields were the most preferred natural habitats. Ground pools, rock pools, and stream margins, which had a high diversity index, were the most important habitats for mosquitoes in the park.Urbanization and human activities create new suitable aquatic habitats for the immature stages of mosquitoes in many countries. This also applies to Doi Inthanon National Park in northern Thailand, which is named for the highest mountain in the country. Despite its popularity, there is no information regarding mosquito diversity and community structure in the different ecosystems of the park. Monthly collections of immature stages from various habitats were conducted from August 2004 to December 2005 using dipping and sucking methods. The specimens collected from each habitat were reared to adults and identified based on their morphology. Diversity parameters and community structure were statistically analyzed. A total of 140 species (3795 specimens) belonging to 15 genera were identified. Among these, four genera (Culex, Aedes, Anopheles, and Uranotaenia) had high species richness, each represented by 48, 27, 19, and 15 species, respectively. Aedes albopictus was the most relatively abundant species, representing 6.7% of the total number of captured specimens, followed by Tripteroides aranoides (5.6%) and Cx. mimulus (5%). Species richness in natural habitats was significantly higher than in artificial containers. Species richness and abundance were highest in the rainy season. In comparison to agricultural areas and villages, mosquito diversity was found to be higher in forest areas. Ground pools, stream pools, rock pools, bamboo stumps, bamboo internode, and rice fields were the most preferred natural habitats. The results indicate that Doi Inthanon National Park has a high mosquito diversity. Each species exhibits differences in abundance and distribution in different habitats, which is useful information for planning conservation measures and vector control in the park.

Sublethal exposure to pyriproxyfen does not impair the abilities of the backswimmer Buenoa amnigenus to prey upon Aedes aegypti larvae.

Pyriproxyfen is a juvenile hormone analogue that is commonly used to control the immature stages of mosquitoes in both artificial and natural water reservoirs. Recently, concerns have been raised regarding the community effectiveness of pyriproxyfen in preventing vector-transmitted diseases. Such concerns have been based on the unintended effects on non-target organisms and the selection of resistant mosquito populations. This investigation was, therefore, conducted to evaluate the toxicity of pyriproxyfen to Aedes aegypti (Diptera: Culicidae) larvae and the backswimmer Buenoa amnigenus (Hemiptera: Notonectidae), a naturally occurring mosquito larvae predator. We also assessed the abilities of backswimmers exposed to sublethal levels of pyriproxyfen to prey upon mosquito larvae (L2) under three larval densities (3, 6, or 9 larvae/100 mL of water) using artificial containers. Our results revealed that pyriproxyfen killed backswimmers only at concentrations higher than 100 μg active ingredient [a.i.]/L, which is 10 times higher than that recommended for larvicidal field application (i.e, 10 μg a.i./L). The abilities of backswimmers exposed to sublethal levels of pyriproxyfen (100 μg a.i./L) to prey upon mosquito larvae were not affected. Harmful effects on the backswimmer predatory abilities were detected only at concentrations of 150 μg a.i./L and when there was a higher prey availability (i.e., 9 larvae/100 mL of water). Together, our findings indicate that the reduced community effectiveness of this insecticide derives from factors other than its detrimental effects on non-target organisms such as backswimmers.

Super- or Single Infection: Wolbachia Supergrouping of Wild Mosquito Populations from Varied Location Types in Peninsular Malaysia

Wolbachia has the ability to cause reproductive abnormalities in infected hosts including cytoplasmic incompatibility (CI). CI is activated when there are multiple Wolbachia supergroups or strains infection present in insect populations. Wolbachia-transinfected mosquitoes have been used widely in some countries as a biological control agent. In order to ensure a successful Wolbachia establishment, it is important to determine the diversity of natural Wolbachia present in the wild mosquito populations. The adults and immature stages of mosquitoes were collected from urban, suburban and rural areas and were reared into adults and identified to species before being subjected to molecular analysis. We found that 22% out of 222 males and 34.6% of 543 females tested were carrying Wolbachia based on PCR amplification of the Wolbachia 16S rDNA genes technique. PCR digestion for Wolbachia supergrouping showed that most of the Ae. albopictus were superinfected with Wolbachia (52.41%), whereas 21% and 28% of the positive samples were singly infected with supergroup A and B, respectively. There is an indication that prevalence of Wolbachia varies between mosquito populations in different areas. However, further studies to incorporate both PCR amplication of the Wolbachia 16S rDNA and wsp genes with bigger sample size should be performed to measure exact infection of Wolbachia in Malaysia. The baseline data on diversity of Wolbachia supergroups is expected to facilitate Wolbachia strategy by helping us to better understand the patterns and impact of the bacteria’s transmission in the environment.

Mosquitoes and Bromeliads

Water can collect in the central tanks or axils of bromeliads, and immature stages of mosquitoes sometimes inhabit these small pools. This article provides recommendations for environmentally acceptable ways to control the production of nuisance mosquitoes in bromeliads; suggestions for planting species of bromeliads less likely to favor the production of mosquito-borne disease vectors; and general advice about personal protection against mosquito bites.

The effect of entomopathogenic fungi Metarhizium anisopliae var acridum and Beauveria bassiana on the survival of mosquito larvae of Anopheles arabiensis Patton and Culex quinquefasciatus Say

Because of environmental considerations and the development of resistance in vectors, efforts had been directed to microbial control. Immature stages of mosquito are useful components of malaria control program. The entomopathogenic hyphomycetous fungi Metarhizium anisopliaevar acridum and Beauveria bassiana were selected and tested against early (L1-2) and late (L3-4) stages of mosquito larvae (Anopheles arabiensis and Culex quinquefasciatus). Two concentrations of each fungual spores were used to perform the laboratory bioassays and time to death was determined for each mosquito species. Metarhizium anisopliae var acridum and Beauveria bassiana caused high mortality in An. arabiensis and C. quinquefasciatus. However, B. bassiana was less effective compared to M. anisopliae var acridum. Both An. arabiensis and C. quinquefasciatus were susceptible to the two fungi concentrations at the early stage. On the other hand, the older one were less susceptible.This research showed the potentiality of the two fungal species against mosquitoes in the larval stage, and the mortality percentage depends on fungus species itself and larval stage targeted. The increase in fungus concentration did not showed a proportional increase in mortality

Ecological, Social, and Other Environmental Determinants of Dengue Vector Abundance in Urban and Rural Areas of Northeastern Thailand.

Aedes aegypti is the main vector of dengue globally. The variables that influence the abundance of dengue vectors are numerous and complex. This has generated a need to focus on areas at risk of disease transmission, the spatial-temporal distribution of vectors, and the factors that modulate vector abundance. To help guide and improve vector-control efforts, this study identified the ecological, social, and other environmental risk factors that affect the abundance of adult female and immature Ae. aegypti in households in urban and rural areas of northeastern Thailand. A one-year entomological study was conducted in four villages of northeastern Thailand between January and December 2019. Socio-demographic; self-reported prior dengue infections; housing conditions; durable asset ownership; water management; characteristics of water containers; knowledge, attitudes, and practices (KAP) regarding climate change and dengue; and climate data were collected. Household crowding index (HCI), premise condition index (PCI), socio-economic status (SES), and entomological indices (HI, CI, BI, and PI) were calculated. Negative binomial generalized linear models (GLMs) were fitted to identify the risk factors associated with the abundance of adult females and immature Ae. aegypti. Urban sites had higher entomological indices and numbers of adult Ae. aegypti mosquitoes than rural sites. Overall, participants’ KAP about climate change and dengue were low in both settings. The fitted GLM showed that a higher abundance of adult female Ae. aegypti was significantly (p < 0.05) associated with many factors, such as a low education level of household respondents, crowded households, poor premise conditions, surrounding house density, bathrooms located indoors, unscreened windows, high numbers of wet containers, a lack of adult control, prior dengue infections, poor climate change adaptation, dengue, and vector-related practices. Many of the above were also significantly associated with a high abundance of immature mosquito stages. The GLM model also showed that maximum and mean temperature with four-and one-to-two weeks of lag were significant predictors (p < 0.05) of the abundance of adult and immature mosquitoes, respectively, in northeastern Thailand. The low KAP regarding climate change and dengue highlights the engagement needs for vector-borne disease prevention in this region. The identified risk factors are important for the critical first step toward developing routine Aedes surveillance and reliable early warning systems for effective dengue and other mosquito-borne disease prevention and control strategies at the household and community levels in this region and similar settings elsewhere.

Response of Mosquitoes Associated with Estuarine Wetlands to Bushfire in Australia.

The response of mosquitoes to bushfire is poorly understood. During the 2019-20 summer, many regions of Australia were impacted by devastating bushfires. An area of estuarine and brackish-water wetlands alongside the Georges River, Sydney, New South Wales, was burned in January 2020. Mosquito populations within the area were monitored as part of the local authority's mosquito management program, providing a unique opportunity to record the response of key mosquitoes of pest and public health concern to bushfire. Ground pools within a tidally influenced swamp oak forest dominated by Casuarina glauca and associated wetlands dominated by Phragmites australis and Bolboschoenus spp. had been identified as suitable habitat for a range of mosquitoes, including Aedes alternans, Ae. vigilax, and Verrallina funerea. Surveys of immature stages of mosquitoes within recently burned habitats inundated by tides demonstrated that mosquito eggs survived the direct and indirect impacts of fire and immature stages successfully completed development as reflected in concomitant changes in adult mosquito populations following the bushfire. This unique observation has implications for mosquito management following bushfire in Australia and internationally.

Characterization of Sites with Mosquito1 Larvae in the Metropolitan Region of Puebla, Mexico

Immature stages of mosquitoes (Diptera: Culicidae) were studied with the objective to characterize diversity and sites at the metropolitan region of Puebla, Mexico. Three weather periods (dry-cold, dry-hot, and wet) and two sampling methods (ovitraps and direct collection at larval habitats) were used. Seven species of mosquitoes were identified. Greatest richness and abundance were during the wet season with both sampling methods, but few mosquitoes were in ovitraps. Aedes epactius Dyar & Knab was dominant in the ovitraps. In larval habitats, dominant species were Ae. epactius and Culex quinquefasciatus Say. Sixty-one sites with developing mosquitoes were found and classified according to origin, location, and type. Characteristics such as insolation, organic matter, vegetation, and associated fauna of the sites were considered. Correspondence analysis determined preference patterns between species and sites. Ae. epactius, Culex restuans Theobald, and Cx. quinquefasciatus were opportunistic species, because they were found in a variety of larval habitats, whereas Culiseta particeps (Adams) and Culex stigmatosoma Dyar were generalist species. Cs. particeps was related to sites with accompanying fauna, and most individuals were collected in tires; Cx. stigmatosoma was associated with sites with vegetation in temporary puddles. Results can be important for improvement of entomological control and surveillance programs in the metropolitan region of Puebla.

A temperature-dependent mathematical model of malaria transmission with stage-structured mosquito population dynamics

Abstract In this paper, we formulate a temperature-dependent model for malaria transmission dynamics which includes immature stages of mosquitoes. The model is constructed by using ordinary differential equations with some parameters which are periodic functions. Two thresholds dynamics associated to the model have been derived: the vector reproduction ratio ℛ v and the basic reproduction ratio ℛ0. Through a rigorous analysis via theories and methods of dynamical systems, we prove that the global behavior of the model depends strongly on these two parameters. More precisely, we show that if ℛ v is greater than one and ℛ0 is less than one then, the disease-free periodic equilibrium is globally attractive. If ℛ v is greater than one and ℛ0 is greater than one, the disease remains persistent and the system admits at least one positive periodic solution. Finally, using the reported monthly mean temperature for Burkina Faso, numerical simulations are carried out to illustrate our mathematical results.

Nine years of mosquito monitoring in Germany, 2011\u20132019, with an updated inventory of German culicid species

Before the background of increasingly frequent outbreaks and cases of mosquito-borne diseases in various European countries, Germany recently realised the necessity of updating decade-old data on the occurrence and spatiotemporal distribution of culicid species. Starting in 2011, a mosquito monitoring programme was therefore launched with adult and immature mosquito stages being collected at numerous sites all over Germany both actively by trapping, netting, aspirating and dipping, and passively by the citizen science project ‘Mueckenatlas’. Until the end of 2019, about 516,000 mosquito specimens were analysed, with 52 (probably 53) species belonging to seven genera found, including several species not reported for decades due to being extremely rare (Aedes refiki, Anopheles algeriensis, Culex martinii) or local (Culiseta alaskaensis, Cs. glaphyroptera, Cs. ochroptera). In addition to 43 (probably 44 including Cs. subochrea) out of 46 species previously described for Germany, nine species were collected that had never been documented before. These consisted of five species recently established (Ae. albopictus, Ae. japonicus, Ae. koreicus, An. petragnani, Cs. longiareolata), three species probably introduced on one single occasion only and not established (Ae. aegypti, Ae. berlandi, Ae. pulcritarsis), and a newly described cryptic species of the Anopheles maculipennis complex (An. daciae) that had probably always been present but not been differentiated from its siblings. Two species formerly listed for Germany could not be documented (Ae. cyprius, Ae. nigrinus), while presence is likely for another species (Cs. subochrea), which could not be demonstrated in the monitoring programme as it can neither morphologically nor genetically be reliably distinguished from a closely related species (Cs. annulata) in the female sex. While Cs. annulata males were collected in the present programme, this was not the case with Cs. subochrea. In summary, although some species regarded endemic could not be found during the last 9 years, the number of culicid species that must be considered firmly established in Germany has increased to 51 (assuming Cs. subochrea and Ae. nigrinus are still present) due to several newly emerged ones but also to one species (Ae. cyprius) that must be considered extinct after almost a century without documentation. Most likely, introduction and establishment of the new species are a consequence of globalisation and climate warming, as three of them are native to Asia (Ae. albopictus, Ae. japonicus, Ae. koreicus) and three (Ae. albopictus, An. petragnani, Cs. longiareolata) are relatively thermophilic. Another thermophilic species, Uranotaenia unguiculata, which had been described for southwestern Germany in 1994 and had since been found only at the very site of its first detection, was recently documented at additional localities in the northeastern part of the country. As several mosquito species found in Germany are serious pests or potential vectors of disease agents and should be kept under permanent observation or even be controlled immediately on emergence, the German mosquito monitoring programme has recently been institutionalised and perpetuated.

Bio-efficacy of ultrasound exposure against immature stages of common house mosquitoes under laboratory conditions

Purpose: In southern Iran with a tropical climate, the above and underground cisterns of drinking water are the main habitats for immature stages of mosquitoes. The local people do not agree with using calcium hypochlorite granules in the water cisterns due to the change of water taste. Following the increased worldwide interest in using ultrasound technology for water disinfection, this study was conducted to assess the possible dual effects of ultrasound waves against immature mosquitoes.Materials and methods: Combinations of four power levels, two frequencies, three temperatures, and eight exposure times were applied to immature Culex pipiens. The exposure chamber of immature mosquitoes was the disposable cups placed inside a sonication bath containing tap water.Results: The mortality rate of immature mosquitos was 85–91% at 10–25 W, 30 °C and 130 kHz. The most effective ultrasound regimen for causing immature mortality included a fixed frequency of 130 kHz, a temperature of 30 °C, and a power level of 20–25 W. The lowest efficacy was observed in the egg stage. The median lethal time (LT50) and ninety percent lethal time (LT90) of sonication was 5.9 ± 0.6 min and 1.6 ± 0.1 min at 30 °C and a fixed frequency of 130 kHz.Conclusions: Evidence indicated effective ultrasound irradiation against immature mosquitoes in the water. This study provides a clear scientific basis for larvicidal properties induced by ultrasound emissions at laboratory conditions. The findings could be used for setting the ultrasound devices in the field investigations for achieving desired effectiveness.

WATER RESOURCES HELPS İN THE EXPANSİON OF MOSQUİTOES COLONİES

In Pakistan, water storage bodies are often the most plentiful and active habitats of immature stages of mosquitoes. Mosquitoes are blood feeding type of vectors that bite a particular host and suck blood. As a result, these vectors transmit disease causing agents to the host system. The most common mosquitoes borne viral diseases in Pakistan are Chicken gunya, Dengue fever, west nile and Zika fever. These diseases are common in low and poor living standard areas. Death rate increases due to more attack of these fatal diseases. Mosquitoes breeding sites are water bodies, discarded tyres, water tanks, bottles, cups and ant traps. Various environmental agents i.e. temperature fluctuations and water resources, now increase the rate of mosquitos in most areas of Pakistan. There is a lack of basic medical education and knowledge about its pervention techniques in mosquito affected areas in Pakistan. The purpose of this review is to highlight the current status of emerging mosquito borne viral diseases in Pakistan, i.e. Chicken gunya, Dengue fever, est nile and Zika fever. There is more need of prevention strategies and understanding about factors involved in spreading of mosquito borne diseases.

Investigation of Susceptibility Levels of Culex pipiens L. (Diptera: Culicidae) Populations to Synthetic Pyrethroids in Antalya Province of Turkey

Culex pipiens L. (Diptera: Culicidae) is an important vector of several pathogens. This mosquito is widely distributed throughout the world. We aimed to determine the susceptibility levels of Cx. pipiens populations to some synthetic pyrethroid insecticides in Antalya, Turkey. The immature stages of mosquitoes were collected from eight locations in Alanya, Döşemealtı, Kemer, Kumluca, and Manavgat districts of Antalya between Apr and Oct of 2017. Adult susceptibility tests were carried out according to a modified version of the Centers for Disease Control and Prevention bottle bioassay. In the tests, the World Health Organization recommended diagnostic doses; permethrin (0.75%), etofenprox (0.5%), deltamethrin (0.05%) and lambda-cyhalothrin (0.05%) were used. As a result of the susceptibility tests, deltamethrin was the least effective insecticide and it caused 58.78-97.56% mortalities on Cx. pipiens populations while permethrin was the most effective substance that caused 100% mortality on all populations. While all of the tested populations were found susceptible to permethrin, and possible resistant or resistant to deltamethrin. Etofenprox and lambda-cyhalothrin led to 91.54-100% and 93.1-100% mortalities, respectively. The possible resistance or resistance to deltamethrin in all the areas is caused by the widespread use of this chemical against pests in agriculture and public health applications for long-term. Moreover, a concordance was found between resistance levels and the intensity of pesticide application in agriculture and public health, and organic and chemical pollution levels in the sampled habitats.

Malaria Vector Abundance and the Incidence of Malaria Parasite amongst Students Living in Nnamdi Azikiwe University Hostels

Introduction: Malaria remains an important public health disease in both tropical and subtropical countries of Africa where transmission is mainly through the bite of an infected female Anopheles mosquito.&#x0D; Aim: The main aim of this study was to determine the prevalence of malaria parasite and the abundance of malaria vectors in and around the university hostels. &#x0D; Place and Duration of Study: The study was carried out in some selected hostels of Nnamdi Azikiwe University, Awka, from the month of March to September, 2018.&#x0D; Methodology: One hundred and fifty (150) students which volunteered from the selected hostels were tested for malaria parasite. Questionnaire on the frequency of clinical symptoms were distributed to these students. Indoor resting mosquitoes were collected through pyrethrum spray-sheet collection (PSC).Larval sampling was carried out for the immature stages of mosquitoes.&#x0D; Results: Of the students examined for malaria parasite, 135 (90%) showed positivity to the parasite. From the questionnaire distributed, 30 (20%) of the students were treated for malaria every 3months, 20(13.3%) every 6 months, 24 (16%) before resuming school, and 76(50.7%) only treated when they developed clinical malaria. Two hundred and two (202) mosquito larvae were collected from their breeding habitats during larval sampling and two hundred and four (204) adult mosquitoes of different species were collected indoors. However there was no significant difference between the number of rooms sampled and the number of mosquitoes collected at 5% level of significance (x2tab &gt; x2cal; 9.488 &gt;6.307).&#x0D; Conclusion: The study revealed that the students living in the hostels were highly exposed to malaria infection and a host of other mosquito borne diseases. The abundance of Anopheles gambiae sensu lacto in the university environment and the high prevalence rate of malaria is an indication of continuous transmission in the area. Therefore re-echoed awareness campaigns on the danger of malaria infection and its prevention and control through personal and environmental management should be carried out to educate all students especially those who attended medical check-ups during registration.