Water PH Correlates With The Number of Mosquito Larvae in Nature Tourism Park

Mosquitoes go through four development phases: egg, larva, pupa and adult. The growth, survival, and adaptation of mosquito larvae are strongly influenced by the physical and chemical characteristics of the waters. Nature tourism parks have ecological and environmental potential for the development and spread of mosquitoes and vector diseases. This study aims to look at the correlation of the physical and chemical elements of water to the number of mosquito larvae. The study design was cross-sectional analytic observational. In TWA, 57 containers were found with 10 indoor and 47 outdoor locations. The container contains water with a salinity of 0-0.3, pH 4.5-8.3, TDS 3-899 ppm, and a temperature of 26 - 34℃. A total of 423 mosquito larvae consisting of Culex and Aedes species. Ae. albopictus is the dominant larval species found. Based on the Spearman test, there was no significant correlation between temperature, total dissolved solids and salinity with the number of mosquito larvae (p>0.05), while PH was positively correlated with the number of mosquito larvae (p = 0.019). Keywords: Chemical, Physical, Water, Mosquito larv

Seasonal assessment of pupal habitat productivity of malaria vector: Anopheles gambiae s.l as influence by physico-chemical conditions at selected breeding habitats in Niger, Nigeria

Malaria is the most significant protozoan disease in Africa and the principal vector-borne disease (VBD) in Nigeria, which is influenced by the quality of breeding habitats that are reflected through the stage preceding adult. Control of Anopheles gambiae s.l. populations through source reduction is still considered the most effective way of prevention and control, although it has proven unsustainable in Niger State. Physico-chemical cues were investigated. Samples were taken inside and outside 1m2 cages weekly by dipping and emptying the cages from May 2019 to March 2020. The data subjected to analysis of variance (one and two-way Anova). The findings revealed the mean pupae abundance (MPA), were significantly higher in Large Water bodies (624.50±217.81), and followed by Gutters (436.00±184.2) and Swamps (285.50±125.06). The mean pupae productivity (MPP), followed the order of descending rate >GT (717.50±219.38) >LW (677.21±145.10) >SW (530.40±136.97). The result also showed that emptying technique (ET) was more sufficient and reliable than dipping technique (DT). The peak abundance and productivity of the pupal stage was June to August then declined in March,2020 both habitats. However, MPP differed significantly (p<0.05) from one another across the months in all the habitat types. The physical and chemical cues of the breeding sites, varied significantly, except in temperature, total hardness, biochemical oxygen demands, conductivity, and pH in all the habitats. This study revealed high utilization of physico-chemical properties and poses increased risk of malaria. Thus, emphasis on the vector management strategies should be given specially on gutters and large water bodies as breeding habitats of malaria vectors (MV), in Niger Stat

The spatio-temporal distribution of acute encephalitis syndrome and its association with climate and landcover in Vietnam.

BackgroundAcute encephalitis syndrome (AES) differs in its spatio-temporal distribution in Vietnam with the highest incidence seen during the summer months in the northern provinces. AES has multiple aetiologies, and the cause remains unknown in many cases. While vector-borne disease such as Japanese encephalitis and dengue virus and non-vector-borne diseases such as influenza and enterovirus show evidence of seasonality, associations with climate variables and the spatio-temporal distribution in Vietnam differs between these. The aim of this study was therefore to understand the spatio-temporal distribution of, and risk factors for AES in Vietnam to help hypothesise the aetiology.MethodsThe number of monthly cases per province for AES, meningitis and diseases including dengue fever; influenza-like-illness (ILI); hand, foot, and mouth disease (HFMD); and Streptococcus suis were obtained from the General Department for Preventive Medicine (GDPM) from 1998-2016. Covariates including climate, normalized difference vegetation index (NDVI), elevation, the number of pigs, socio-demographics, JEV vaccination coverage and the number of hospitals were also collected. Spatio-temporal multivariable mixed-effects negative binomial Bayesian models with an outcome of the number of cases of AES, a combination of the covariates and harmonic terms to determine the magnitude of seasonality were developed.ResultsThe national monthly incidence of AES declined by 63.3% over the study period. However, incidence increased in some provinces, particularly in the Northwest region. In northern Vietnam, the incidence peaked in the summer months in contrast to the southern provinces where incidence remained relatively constant throughout the year. The incidence of meningitis, ILI and S. suis infection; temperature, relative humidity with no lag, NDVI at a lag of one month, and the number of pigs per 100,000 population were positively associated with the number of cases of AES in all models in which these covariates were included.ConclusionsThe positive correlation of AES with temperature and humidity suggest that a number of cases may be due to vector-borne diseases, suggesting a need to focus on vaccination campaigns. However, further surveillance and research are recommended to investigate other possible aetiologies such as S. suis or Orientia tsutsugamushi

Larval ecology and infestation indices of two major arbovirus vectors, Aedes aegypti and Aedes albopictus (Diptera: Culicidae), in Brazzaville, the capital city of the Republic of the Congo.

BACKGROUND Invasive mosquito species, such as Aedes albopictus in Congo can affect the distribution of native species, changing the vector composition and pattern of disease transmission. Here, we comparatively establish the geographical distribution and larval habitat preference of Ae. aegypti and Ae. albopictus and the risk of arbovirus disease outbreaks using Stegomyia indices in the city of Brazzaville, the capital of the Republic of the Congo. METHODS Human dwelling surveys of water-holding containers for immature stages of Aedes was carried out in December 2017 in Brazzaville through a random cluster sampling method. A total of 268 human dwellings distributed in 9 boroughs and 27 neighbourhoods were surveyed across the city. RESULTS Overall, 455 potential larval habitats were surveyed. Both Ae. aegypti and Ae. albopictus were collected across the city with an overall high prevalence of Ae. aegypti (53.1%) compared to Ae. albopictus (46.9%). Geographical distribution analysis showed that Ae. aegypti was more abundant (mean = 6.6 ± 1.4) in neighbourhoods located in downtown, while the abundance of Ae. albopictus was low (mean = 3.5 ± 0.6) in suburbs. Peridomestic containers, especially discarded tanks, were the most strongly colonized productive larval habitat for both mosquito species with the prevalence of 56.4% and 53.1% for Ae. aegypti and Ae. albopictus, respectively. Globally, the house index (HI), Breteau index (BI) and container index (CI) were high for Ae. aegypti (26.6%, 38.4% and 22.6%) and Ae. albopictus (33.3%, 49.6% and 26.6%) compared to the transmission risk threshold (5%, 5% and 20%) established by the WHO/PAHO. Overall, pupae-based indices (the pupae index and the pupae per person index) were not significantly different between Ae. aegypti (273.4% and 23.2%) and Ae. albopictus (228.8% and 19.5%). CONCLUSIONS The findings of this study suggest a high risk for transmission of arbovirus diseases in Brazzaville and call for an urgent need to implement vector control strategies against these vectors in the Republic of the Congo

Mosquitoes of Urban Oklahoma and Their Potential as Disease Vectors

The mosquito diversity of Oklahoma was last evaluated in a series of surveys conducted between 2003 and 2006 and before that, the previous survey was in 1965. Prior surveys targeted specific questions including the evaluation of West Nile virus. However, a systematic survey of the cities in Oklahoma was not conducted. In this study, mosquito populations were surveyed approximately bi-weekly at six different cities, including four with military bases, in central and southeastern Oklahoma between May and September 2016. Three different traps were used: CDC Mini Light traps with lights removed and baited with dry ice, CDC Gravid traps baited with Bermuda grass-conditioned water, and BG-Sentinel� traps baited with BG lure. A total of 11,980 adult female mosquitoes representing 34 species were collected over 834 trapping events. Mosquito communities differed significantly among trap type, with CDC Mini Light traps collecting the most individuals. Mosquito communities also differed significantly among cities sampled. These results show that urban areas in Oklahoma do not possess a homogenous mosquito community, and each city should be evaluated individually (at least within the same climate region). Aedes aegypti, an important disease vector was recorded in Oklahoma for the first time since 1940. Eighty-eight specimens of Ae. aegypti were collected in the cities of Altus, Ardmore, Frederick, and Lawton. CDC Mini Light traps were more attractive to Ae. aegypti than other two trap types. The most abundant mosquito species: Ae. albopictus, Ae. sollicitans, Ae. triseriatus, Cx. pipiens, and Cx. tarsalis were tested for presence of Dirolfilaria immitis, the causative agent for dog heartworm, and other parasitic nematodes. One mosquito pool tested was PCR positive for D. immitis, from a Cx. pipiens pool. Six other nematodes were collected in pools from Ae. albopictus. The D. immitis positive pool was collected from Idabel, OK, while four other positive pools were collected from Ardmore, OK, and one from Midwest City, OK. The information generated from this study provides insight into mosquito populations and potential for nematode transmission in Oklahoma. With increases in human populations living in cities, movement of people and global climate change, the results of this study serves as a baseline and informs mosquito management strategies for southern Oklahoma.Entomology & Plant Pathology (MS

Variação fenotípica e estrutura da comunidade de califorídeos (Diptera: Calliphoridae) necrófagos : perspectivas ecológicas e considerações para prática forense

Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Ecologia, 2019.A entomologia forense consiste na interpretação de vestígios entomológicos em casos criminais. Infere-se o intervalo pós-morte com base em características invividuais ou da comunidade de insetos. É importante que os profissionais conheçam o grau de variação dos fenótipos avaliados, bem como os fatores que levam a variação fenotípica e como eles operam. Fatores bióticos e abióticos interferem nos indivíduos levando à variabilidade de tamanhos e formas em insetos e que essas influências estão desigualmente distribuídas entre as espécies e os sexos. Este trabalho investigou como (1) a variação de tamanho e sua resposta à densidade estão estruturadas entre os sexos em três espécies de califorídeos necrófagos; (2) a morfologia alar dessas espécies de califorídeos reage a situações de competição intra- e interespecífica; (3) a comunidade de califorídeos necrófagos e suas variações fenotípicas estão temporalmente e espacialmente estruturadas em uma área ambientalmente protegida no Distrito Federal; e (4) a morfologia alar de duas espécies de califorídeos necrófagos (nativa X exótica) respondem à variação temporal (estação seca x chuvosa) e vegetacional (mata de galeria x campo sujo). O tamanho e a forma das asas de machos e fêmeas são diferentes e reagem de forma diversa ao aumento de densidade, e as três espécies analisadas reagem distintamente à competição interespecífica. A composição da comunidade de califorídeos necrófagos varia em função do tempo e das vegetação, com diferenças nas abundâncias e dominância de espécies em função do tempo e da cobertura vegetal, Algumas espécies têm potencial promissor como indicadores de ambientes. As duas espécies examinadas no Cerrado se comportaram de forma independente entre seca e chuva, porém não apresentaram níveis diferentes de assimetria flutuante em suas asas. Necessita-se de abordagens específicas para cada indicador forense e em função das suas respectivas trajetórias ecológicas e evolutivas para reduzir os graus de incerteza na prática forense.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).Forensic entomology consists in the interpretation of entomological evidence in criminal investigations. Forensic entomologists’ aim is to infer the postmortem interval based on individual or communitarian features of the specimens. For accurate prediction, it is important that entomologists know the degree of phenotypic variation and what factors influence it. Biotic and abiotic factor interfere in individuals, leading to morphological variation in insects, and this influence yield different results in males and females. The present work investigated (1) Sexual size dimorphism in three species of necrophagous calliphorids in response to density; (2) how those three species respond in wing morphology to intra and interspecific competition; (3) the temporal and spatial structure of necrophagous calliphorids community in an environmentally protected area in the Federal District and the morphological variation of two species (a native and an exotic) in different seasons and vegetation covers, and; (4) how these two species alter their wing morphology in response to temporal (dry and rainy season) and spatial (grassland and forest) heterogeneity. The results show that wing morphology in males and females of three species of necrophagous calliphorids display different responses to density, as well as interspecific competition. We also showed that community composition changes in response to time e vegetation cover, with abundance and dominance differences regarding both seasons and vegetation types, and some species have potential as indicators of environments. Furthermore, the two species examined in the Cerrado behave differently between the months of the dry and the rainy season, but display no differences in fluctuating asymmetry levels in their wing structures These results point to the necessity of individual approaches, specific for each forensic indicator due to its ecological and evolutionary trajectories. Only through a systematic analysis and clear delimitation of population it is going to be possible to reduce uncertainty in forensic practice