scholarly journals Larval habitats and species diversity of mosquitoes (Diptera: Culicidae) in West Azerbaijan Province, Northwestern Iran

BMC Ecology ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Mojtaba Amini ◽  
Ahmad Ali Hanafi-Bojd ◽  
Ali Ahmad Aghapour ◽  
Ali Reza Chavshin

Abstract Background The characteristics of a larval habitat is an important factor which affects the breeding pattern and population growth of mosquitoes Information about the larval habitat characteristics and pupal productivity can be utilized for the surveillance of the level of population growth, species diversity, and preferred breeding sites of mosquitoes, which are important aspects of integrated vector control. In the present study, mosquito larvae were collected from 22 natural habitats in five counties of the West Azerbaijan Province in the Northwest of Iran during May–November 2018. Physicochemical characteristics of the habitats were investigated. These included alkalinity, chloride (Cl) content, water temperature (°C), turbidity (NTU), Total Dissolved Solids (TDS) (ppm), Electrical Conductivity (EC) (μS/cm), and acidity (pH). The index of affinity between the collected species was calculated using Fager & McGowan test. Results A total of 2715 specimens were collected and identified. Seven different species belonging to four genera were identified in our study sites. The species included, Culex pipiens Linnaeus 1758, Culex theileri Theobald 1903, Culex mimeticus Noé 1899, Culex modestus Ficalbi 1947, Culiseta longiareolata Macquart 1838, Anopheles maculipennis Meigen 1818complex, and Aedes caspius Pallas 1771. There was a significant difference in chloride content and water temperature preferences among the different species (P < 0.05). Also, there was no significant difference in pH, Alkalinity, Turbidity, TDS, and EC preferences among the different species (P > 0.05). The affinity between the pair of species Cx. mimeticus/Cs. longiareolata was 0.526. There was no affinity between other pairs of species or the affinity was very weak. Conclusions The physicochemical and biological characteristics of mosquito larval habitats play an important role in zoning of areas suitable for breeding and distribution. Surveillance of these characteristics can provide valuable information for entomological monitoring of mosquito vectors and for designing targeted control programs. Also, further studies should be undertaken in a wider geographical area, taking into account the complex characteristics of the physicochemical and ecological factors of the study area and their interaction with various mosquito species.

2017 ◽  
Vol 107 (5) ◽  
pp. 598-610 ◽  
Author(s):  
S.H. Nikookar ◽  
M. Fazeli-Dinan ◽  
S. Azari-Hamidian ◽  
S.N. Mousavinasab ◽  
M. Arabi ◽  
...  

AbstractMosquitoes transmit a variety of diseases to humans. Their abundance and distribution are related to the characteristics of larval habitats. Mosquito larvae were collected from 120 natural and artificial habitats in 30 villages of 16 counties using standard 350 ml dippers and pipette, on a monthly basis from May–December 2014 in Mazandaran Province, northern Iran. Larval habitat characteristics were recorded separately, based on the conditions of the habitats (permanent or temporary, stagnant or running), type of habitats (natural or artificial), vegetation, exposure to sun, type of bed, water condition (clear or turbid), expanse (m), depth (cm, m) and temperature (°C) of habitats. The relationship between larval density and environmental variables was assessed by Chi-square tests. Totally, 19,840 larvae from three genera and 16 species were collected and identified.Anopheles maculipennis s.l.andCulex pipienswere the dominant species and collected with the highest density in plain areas. The highest number of larvae were collected from natural habitats (60.34%), including; river edge, marsh, pit and wetlands; with temporary and stagnant water, expanse of 0–5 m, depth of 1–25 cm, without plant, shadow-sun, muddy floor, turbid water, temperature 20–25°C and in sunny conditions. River edge and rice fields forAn. maculipennis s.land, wetlands and discarded tires forCx. pipienswere the main larval habitats in the province. Statistical analysis revealed significant relation between occurrence ofAn. maculipennis s.l., Cx. pipiens, Culex torrentium, Culex mimeticusandCs. annulatawith each of the environmental variables (P< 0.001). These findings are essential in expanding our knowledge of the vectors ecology specially the type of habitat preference and will be beneficial in larval control programs.


Author(s):  
Tahereh Sadat Asgarian ◽  
Seyed Hassan Moosa-Kazemi ◽  
Mohammad Mehdi Sedaghat ◽  
Rouhullah Dehghani ◽  
Mohammad Reza Yaghoobi-Ershadi

Background: Mosquitoes are responsible for spreading devastating parasites and pathogens causing some important infectious diseases. The present study was done to better understand and update the fauna of Culicidae and to find out the distribution and the type of their larval habitats in Kashan County. Methods: This study was done in four districts of Kashan County (Central, Qamasr, Niasar and Barzok). Mosquito lar-vae were collected from 23 active larval habitats using a standard 350ml capacity mosquito dipper from April to late December 2019. The collected larvae were transferred to containers containing lactophenol, and after two weeks indi-vidually mounted in Berlese's fluid on a microscope slide and identified to species by morphological characters and valid keys. Results: In this study, a total of 9789 larvae were collected from urban and rural areas in Kashan County. The identified genera were Anopheles, Culiseta and Culex. In this study larvae of An. turkhudi, Cx. perexiguus, Cx. mimeticus, Cx. deserticola and Cs. subochrea were collected for the first time from Kashan County. Conclusion: The results of this study indicate the presence and activity of different mosquito species in Kashan County that some of them are vectors of arbovirus and other vector-borne diseases.


Author(s):  
Aioub Sofizadeh ◽  
Hamid Reza Shoraka ◽  
Fatemeh Mesgarian ◽  
Ghorban Mohammad Ozbaki ◽  
Abdolsamad Gharaninia ◽  
...  

Background: Mosquitoes (Diptera: Culicidae) is one of the most medically important families of Diptera. The aims of this study were to determine fauna and larval habitat characteristics of mosquitoes in Golestan Province, during 2014–15. Methods: This study was conducted in larval habitats of mosquitoes and installed ovitraps in 14 districts of Golestan Province, Northern Iran in 2015. Samples were collected with a scoop by ladle handling for entomology. The col­lected larvae were transferred to Laboratory of Medical Entomology in lactophenol solution. Then microscopic slides were prepared using de Faure's formula. Species of each sample was recognized using diagnostic criteria to identify the Culicidae species. Characteristics of larval breeding places were studied based on the habitat type (Permanent or temporary), water conditions (Clear or turbid, stagnant or running), vegetation (out, in, underwater vegetation or without vegetation), sunlight exposure (Full or partial sunlight) and so on. Data were analyzed using SPSS. Results: Overall, 5661 third- and fourth- instars larvae of mosquitoes were collected and 5 genera and 14 species were identified: Anopheles hyrcanus, An. maculipennis, An. pseudopictus, An. superpictus, Culex hortensis, Cx. mimiticus, Cx. perexiguus, Cx. pipiens, Cx. pusillus, Cx. theileri, Cx. tritaeniohynchus, Culiseta longiareolata, Och­lerotatus caspius, Uranotaenia unguiculata. Culex pipiens was recognized as predominant species of the family. Among the detected species, Cx. pusillus reported for the first time from Golestan Province. Conclusion: Due to the high species diversity of Culicidae, ecology of medical important species such as Cx. pipiens and Cx. tritaeniorhynchus needs more investigations.


2020 ◽  
Vol 3 (1) ◽  
pp. ACCEPTED
Author(s):  
Rho-Jeong Rae

This study investigated the boreal digging frog, Kaloula borealis, to determine the egg hatching period and whether the hatching period is affected by incubation temperature. The results of this study showed that all the eggs hatched within 48 h after spawning, with 28.1% (±10.8, n=52) hatching within 24 h and 99.9% (±0.23, n=49) within 48 h after spawning. A significant difference was noted in the mean hatching proportion of tadpoles at different water temperatures. The mean hatching rates between 15 and 24 h after spawning was higher at a water temperature of 21.1 (±0.2) °C than at 24.1 (±0.2) °C. These results suggest that incubation temperature affected the early life stages of the boreal digging frog, since they spawn in ponds or puddles that form during the rainy season.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ai-Ling Jiang ◽  
Ming-Chieh Lee ◽  
Guofa Zhou ◽  
Daibin Zhong ◽  
Dawit Hawaria ◽  
...  

AbstractLarval source management has gained renewed interest as a malaria control strategy in Africa but the widespread and transient nature of larval breeding sites poses a challenge to its implementation. To address this problem, we propose combining an integrated high resolution (50 m) distributed hydrological model and remotely sensed data to simulate potential malaria vector aquatic habitats. The novelty of our approach lies in its consideration of irrigation practices and its ability to resolve complex ponding processes that contribute to potential larval habitats. The simulation was performed for the year of 2018 using ParFlow-Common Land Model (CLM) in a sugarcane plantation in the Oromia region, Ethiopia to examine the effects of rainfall and irrigation. The model was calibrated using field observations of larval habitats to successfully predict ponding at all surveyed locations from the validation dataset. Results show that without irrigation, at least half of the area inside the farms had a 40% probability of potential larval habitat occurrence. With irrigation, the probability increased to 56%. Irrigation dampened the seasonality of the potential larval habitats such that the peak larval habitat occurrence window during the rainy season was extended into the dry season. Furthermore, the stability of the habitats was prolonged, with a significant shift from semi-permanent to permanent habitats. Our study provides a hydrological perspective on the impact of environmental modification on malaria vector ecology, which can potentially inform malaria control strategies through better water management.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Michelle C. Stanton ◽  
Patrick Kalonde ◽  
Kennedy Zembere ◽  
Remy Hoek Spaans ◽  
Christopher M. Jones

Abstract Background Spatio-temporal trends in mosquito-borne diseases are driven by the locations and seasonality of larval habitat. One method of disease control is to decrease the mosquito population by modifying larval habitat, known as larval source management (LSM). In malaria control, LSM is currently considered impractical in rural areas due to perceived difficulties in identifying target areas. High resolution drone mapping is being considered as a practical solution to address this barrier. In this paper, the authors’ experiences of drone-led larval habitat identification in Malawi were used to assess the feasibility of this approach. Methods Drone mapping and larval surveys were conducted in Kasungu district, Malawi between 2018 and 2020. Water bodies and aquatic vegetation were identified in the imagery using manual methods and geographical object-based image analysis (GeoOBIA) and the performances of the classifications were compared. Further, observations were documented on the practical aspects of capturing drone imagery for informing malaria control including cost, time, computing, and skills requirements. Larval sampling sites were characterized by biotic factors visible in drone imagery and generalized linear mixed models were used to determine their association with larval presence. Results Imagery covering an area of 8.9 km2 across eight sites was captured. Larval habitat characteristics were successfully identified using GeoOBIA on images captured by a standard camera (median accuracy = 98%) with no notable improvement observed after incorporating data from a near-infrared sensor. This approach however required greater processing time and technical skills compared to manual identification. Larval samples captured from 326 sites confirmed that drone-captured characteristics, including aquatic vegetation presence and type, were significantly associated with larval presence. Conclusions This study demonstrates the potential for drone-acquired imagery to support mosquito larval habitat identification in rural, malaria-endemic areas, although technical challenges were identified which may hinder the scale up of this approach. Potential solutions have however been identified, including strengthening linkages with the flourishing drone industry in countries such as Malawi. Further consultations are therefore needed between experts in the fields of drones, image analysis and vector control are needed to develop more detailed guidance on how this technology can be most effectively exploited in malaria control.


2021 ◽  
Vol 17 (5) ◽  
pp. 20210023
Author(s):  
Michael P. Moore

Natural selection on juveniles is often invoked as a constraint on adult evolution, but it remains unclear when such restrictions will have their greatest impact. Selection on juveniles could, for example, mainly limit the evolution of adult traits that mostly develop prior to maturity. Alternatively, selection on juveniles might primarily constrain the evolution of adult traits that experience weak or context-dependent selection in the adult stage. Using a comparative study of dragonflies, I tested these hypotheses by examining how a species’ larval habitat was related to the evolution of two adult traits that differ in development and exposure to selection: adult size and male ornamentation. Whereas adult size is fixed at metamorphosis and experiences consistent positive selection in the adult stage, ornaments develop throughout adulthood and provide context-dependent fitness benefits. My results show that species that develop in less stable larval habitats have smaller adult sizes and slower rates of adult size evolution. However, these risky larval habitats do not limit ornament expression or rates of ornament evolution. Selection on juveniles may therefore primarily affect the evolution of adult traits that mostly develop prior to maturity.


2018 ◽  
Vol 13 (2) ◽  
Author(s):  
Gaurav Kumar ◽  
Veena Pande ◽  
Shweta Pasi ◽  
Vijay P. Ojha ◽  
Ramesh C. Dhiman

The present study was planned to characterize the microclimate experienced by Aedes larvae in different breeding habitats by determining the temperature variations in water kept in containers during different months under natural conditions. The study was conducted in three municipal zones of Delhi. In each site, four types of container material (plastic, cement, iron and ceramic) were chosen for recording the water temperature in the containers. Daily air and water temperatures (mean, maximum and minimum values) recorded by HOBO and Tidbit data loggers, respectively, were compared using analysis of variance and Tukey’s honest significant difference (HSD) tests. Mean monthly temperature of water varied from 16.9 to 33.0 °C in tin containers, 17.3 to 35.6°C in plastic containers, 14.3 to 28.5°C in ceramic pots, 23.3 to 30.4°C in cemented underground tanks (UGT) and 15.8 to 35.1°C in cemented overhead tanks (OHTs). Corresponding values for the air temperature ranged from 17.7 to 36.1°C. The difference between temperature of water in the containers and air temperature was highest for ceramic pots. Daily mean, maximum and minimum temperatures recorded by different data loggers differed significantly (P<0.05). When Tukey HSD test was applied for data analysis, the daily mean air temperature differed significantly from the water temperature in tin and ceramic pots as well as cemented OHTs. The temperature of water in the different breeding habitats investigated was lower than the air temperature. Moreover, actual air temperature as recorded by HOBO was higher than the temperature recorded by local weather stations. Considering the ongoing climate change, cemented UGT and earthen pots may be more productive breeding habitats for the Aedes mosquito in the near future, while plastic and cemented OHTs might no longer be suitable for Aedes breeding.


2013 ◽  
Vol 33 (6) ◽  
pp. 741-744 ◽  
Author(s):  
Paulo H.D. Cançado ◽  
Taciany Ferreira ◽  
Eliane M. Piranda ◽  
Cleber O. Soares

Outbreaks of stable fly, Stomoxys calcitrans, cause losses for livestock producers located near sugarcane mills in Brazil, especially in southern Mato Grosso do Sul. The sugarcane mills are often pointed by local farmers as the primary source of these outbreaks; some mills also joined the farmers in combating the flies. Brazilian beef cattle production has great economic importance in similar level to bio-fuel production as ethanol. In this context, the wide-ranging knowledge on the biology and ecology of the stable fly, including larval habitats and their reproduction sites is extremely important for further development of control programs. This paper aims to report the occurrence and development of S. calcitrans larvae inside sugarcane stems in three municipalities of Mato Grosso do Sul. The sugarcane stems give protection against bad weather conditions and insecticide application. In this way, for sustainable sugarcane growth specific research concerning this situation should be conducted.


1970 ◽  
Vol 17 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Anita Pokharel ◽  
Madhu Chhetri ◽  
Chiranjibi P Upadhyaya

Limited information is available on the species composition, above ground biomass and its relations to grazing in a trans-Himalayan rangeland. Its assessment is essential for long term conservation and management. In the present study, we compared species composition, phenology, diversity index and biomass between controlled (without grazing) and open (free grazing) plots to assess the effects of grazing in the selected experimental sites of Upper Mustang during July and November 2005. Species encountered were classified as high, medium, low and non palatable and in three life form categories-grasses, shrubs and forbs. The experimental sites are dominated by forbs (80%) followed by grasses (15%) and shrubs (5%). Disturbance caused by grazing affects the phenological characteristics of the plant community. Result also reveals that species diversity, maximum possible diversity, evenness and species richness was higher in the grazed plots during July and November. A comparison of the aboveground biomass in July showed that mean percentage biomass of high, medium and low palatable species is higher in ungrazed plots. In November, the percentage biomass of only medium palatable species was higher in ungrazed plots and rest of the category is higher in grazed plots. Significant difference in July, a peak growing seasons for most of the plant species in the region reveals that the pasture has impact of livestock grazing. Keywords: Biomass, diversity, grazing effect, rangeland, species Banko Janakari: A journal of forestry information for Nepal Vol.17(1) 2007 pp.25-31


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