scholarly journals Mesures des indicateurs de prolifération des larves de moustiques au niveau des mares permanentes et semi permanentes de Saga, Niger

2020 ◽  
Vol 14 (4) ◽  
pp. 1188-1202
Author(s):  
Souleymane Mahamane Iro ◽  
Yaro Alpha Seydou ◽  
Ali Doumma
Keyword(s):  
Dissolved Oxygen ◽  
Mosquito Species ◽  
Larval Density ◽  
Principal Component ◽  
Wide Distribution ◽  
Oxygen Level ◽  
Temperature Conductivity ◽  
Breeding Sites ◽  
Group 2 ◽  
Gîtes Larvaires

Les Culicidae, communément appelés moustiques, par leur large distribution et leur abondance, sont impliqués dans la transmission de nombreuses maladies humaines et animales. La lutte contre ces insectes nécessite la connaissance de leurs lieux de développement dans lequel évoluent les stades pré imaginaux. La présente étude vise à caractériser ces gîtes larvaires en vue d’identifier les indicateurs entomologiques et écologiques de production de larves dans ces milieux. Pour ce faire, le pH, la température, la conductivité, la teneur en oxygène dissout et la densité larvaire des culicidae ont été estimés à la suite des prospections des gîtes larvaires effectuées de juillet 2007 à mars 2018 à Saga, un quartier périurbain de la Ville de Niamey. Au total, 17 gîtes ont été identifiés dont cinq (5) gîtes permanents (29,41%). Les surfaces d’eau artificielles ont été plus abondantes (64,71%). L’étude sur la caractérisation des gîtes par la méthode ACP (Analyse par Composantes Principales) a permis de grouper les gîtes en trois (3) catégories: le groupe 1 constitué par des gîtes qui présentent un pH légèrement acide (6,075 à 7,035) et un taux d’oxygène dissout élevé (1,11 à 2,32). Le groupe 2 qui est constitué par des gites qui présentent une conductivité plus élevée (compris entre 0,97 à 1,08) ainsi qu’un pH légèrement alcalin (7,51 à 7,83). Quant aux gîtes du groupe 3, ils appartiennent en effet, à une zone de transition ou les trois (3) paramètres sont élevés à savoir le pH (8,02 à 8,36), le taux d’oxygène dissout (1,43 mg/l à 2,54 mg/l) et de la conductivité (1170 μS/cm à 1370 μS/cm). L’étude a mis en évidence des affinités entre les espèces de moustiques et les conditions physico-chimiques des gîtes larvaires. C’est ainsi que An. gambiae s.l abonde dans les gîtes caractérisés par une température moins élevée, un pH neutre un taux d’oxygène dissout élevé alors que Culex pipens présente une affinité aux gîtes à forte conductivité et à taux d’oxygène dissout faible.Mots clès : Culicidae, Paramètres physico-chimiques, gîtes larvaires, Saga, Niger.   English Title: Measurements of mosquito larvae proliferation indicators in the permanent and semi-permanent ponds of Saga, Niger Culicidae, commonly known as mosquitoes, by their wide distribution and abundance, are involved in the transmission of many human and animal diseases. The fight against these insects requires knowledge of their places of development in which the pre-imaginary stages evolve. The present study aims to characterize these breeding sites in order to identify entomological and ecological indicators of larval production in these environments. To do this, the pH, temperature, conductivity, dissolved oxygen content and larval density of culicidae were estimated following surveys of the breeding sites carried out from July 2007 to March 2018 in Saga, a peri-urban area of the City of Niamey. In total, 17 lodgings have been identified, including five (5) permanent lodgings (29.41%). Artificial water surfaces were more abundant (64.71%). The study on the characterization of the deposits by the ACP method (Principal Component Analysis) made it possible to group the deposits in three (3) categories: group 1 consisting of deposits that have a slightly acidic pH (6.075 to 7.035) and a high dissolved oxygen level (1.11 to 2.32). Group 2 which consists of gites which have a higher conductivity (0.97 to 1.08) as well as a slightly alkaline pH (7.51 to 7.83). As for the group 3 deposits, they indeed belong to a transition zone where the three (3) parameters are high, namely the pH (8.02 to 8.36), the dissolved oxygen level (1.43 mg / l to 2.54 mg / l) and conductivity (1170 μS / cm to 1370 μS / cm). The study highlighted affinities between mosquito species and the physicochemical conditions of the breeding sites. This is how An. Gambiae sl abounds in deposits characterized by a lower temperature, a neutral pH a high dissolved oxygen level while Culex pipens has an affinity for deposits with high conductivity and low dissolved oxygen rate.Keywords: Culicidae, Physico-chemical parameters, breeding sites, Saga, Niger.  

scholarly journals Comparing sterile male releases and other methods for integrated control of the tiger mosquito in temperate and tropical climates

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Léa Douchet ◽  
Marion Haramboure ◽  
Thierry Baldet ◽  
Gregory L’Ambert ◽  
David Damiens ◽  
...  
Keyword(s):  
Vector Control ◽  
Mosquito Species ◽  
Integrated Control ◽  
Mass Trapping ◽  
Southwest Indian Ocean ◽  
Breeding Sites ◽  
Key Factor ◽  
Trapping Methods ◽  
Combination Of Methods ◽  
Tropical Climates

AbstractThe expansion of mosquito species worldwide is creating a powerful network for the spread of arboviruses. In addition to the destruction of breeding sites (prevention) and mass trapping, methods based on the sterile insect technique (SIT), the autodissemination of pyriproxyfen (ADT), and a fusion of elements from both of these known as boosted SIT (BSIT), are being developed to meet the urgent need for effective vector control. However, the comparative potential of these methods has yet to be explored in different environments. This is needed to propose and integrate informed guidelines into sustainable mosquito management plans. We extended a weather-dependent model of Aedes albopictus population dynamics to assess the effectiveness of these different vector control methods, alone or in combination, in a tropical (Reunion island, southwest Indian Ocean) and a temperate (Montpellier area, southern France) climate. Our results confirm the potential efficiency of SIT in temperate climates when performed early in the year (mid-March for northern hemisphere). In such a climate, the timing of the vector control action was the key factor in its success. In tropical climates, the potential of the combination of methods becomes more relevant. BSIT and the combination of ADT with SIT were twice as effective compared to the use of SIT alone.

scholarly journals SPATIAL EVALUATION OF THE WATER QUALITY FROM THE VELHAS RIVER CHANNEL, IN THE STATE OF MINAS GERAIS

2018 ◽  
Vol 15 (30) ◽  
pp. 75-86
Author(s):  
C. C. PINTO ◽  
K. B. ALMEIDA ◽  
S. C. OLIVEIRA
Keyword(s):  
Water Quality ◽  
Principal Component ◽  
Industrial Effluents ◽  
Metropolitan Region ◽  
Multivariate Statistical ◽  
Pollution Levels ◽  
Group 3 ◽  
Group 2 ◽  
Belo Horizonte ◽  
Monitoring Stations

This study presents an evaluation of the water quality variability of 19 monitoring stations located in the channel of the Velhas river, using multivariate statistical techniques - Cluster Analysis (CA) and Principal Component Analysis/Factor Analysis (PCA/FA). Sixteen physical-chemical parameters were evaluated between January 2009 and June 2016, totalizing 27,232 valid observations. The CA grouped the nineteen monitoring stations into three groups based on the pollution levels. The PCA/FA resulted in six latent factors for group 1, four for group 2 and five for group 3, accounting for 71.44%, 65.32% and 61.69% of the total variance in the respective water quality. The factors indicated that the parameters responsible for the variations in water quality are mainly related to the release of sanitary sewage and industrial effluents and also to agriculture and livestock activities. These results reflect different water quality conditions of the Velhas River in its extension but, in fact, it is verified a greater variability of the water in the Metropolitan Region of Belo Horizonte and its downstream, justified by the different loads of pollutants received in this region, mainly the releases of domestic sewage and industrial effluents.

Colonization patterns and life-history dynamics of Culex mosquitoes in artificial ponds of different character

1993 ◽  
Vol 71 (3) ◽  
pp. 568-578 ◽  
Author(s):  
D. Dudley Williams ◽  
Annette Tavares-Cromar ◽  
Donn J. Kushner ◽  
John R. Coleman
Keyword(s):  
Life History ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Larval Development ◽  
Development Time ◽  
Larval Density ◽  
Strong Relationship ◽  
Terrestrial Vegetation ◽  
Widespread Species ◽  
Artificial Ponds

The relationship between the biology and habitat of larval mosquitoes was studied in a series of artificial ponds of differing characteristics established across a terrestrial vegetation gradient from open fields to deep woods. The ponds were uniformly colonized by two widespread species of Culex, both characteristic of small bodies of water, including artificial, "container" habitats. First-instar larvae of Culex restuans were found within 2 days of filling the ponds with water and four or five generations were produced from May until the end of September. One very long generation occurred in July, which corresponded to maximum larval densities. Overall, there was a strong relationship between larval development time of C. restuans and larval density. A few larvae of Culex pipiens pipiens occurred sporadically throughout the summer, but numbers did not increase until C. restuans populations began to wane in late July. Thereafter two, or possibly three, generations were produced into the autumn. The patterns of colonization, synchrony of life history, and growth of these two species were remarkably consistent amongst the ponds, despite considerable variation in both their physical and biological environments (e.g., over the 2 years of study, conductivity ranged from 20 to 890 μS, pH from 6.4 to 10.7, dissolved oxygen from 0 to 13.5 ppm, and water temperature from 5 to 29.8 °C). Density of C. restuans was related to water temperature and pH at the "open" site and to water temperature, dissolved oxygen, percent algae, and percent detritus at the "edge of the woods" site. At the "deep woods" site, larval numbers were related to temperature, pH, conductivity, and dissolved oxygen. At both the edge and deep wood sites, larval development time of C. restuans increased with mean water temperature to 20 °C. Above this temperature, larval development time tended to decrease.

Seasonal distribution and movement of juvenile Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) in the lower Saint John River Basin, New Brunswick, Canada

2018 ◽  
Vol 75 (12) ◽  
pp. 2354-2363 ◽  
Author(s):  
Margaret M. Whitmore ◽  
Matthew K. Litvak
Keyword(s):  
River Basin ◽  
Movement Patterns ◽  
Principal Component ◽  
Wide Distribution ◽  
Atlantic Sturgeon ◽  
Coarse Scale ◽  
Brackish Waters ◽  
Single Location ◽  
Saint John ◽  
Acipenser Oxyrinchus

Juvenile Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) movement and distribution varies seasonally within the lower Saint John River Basin. We use acoustic telemetry to track coarse-scale movement and a network-based approach to develop metrics describing distribution and movement patterns of juvenile Atlantic sturgeon tagged in two rivers, the Saint John and Kennebecasis rivers. We use principal component analysis to develop indices of movement and residency and test for differences among seasons and between fish from each river. Juvenile Atlantic sturgeon exhibit higher residency during summer months compared with winter and spring. Juveniles are primarily concentrated in the brackish waters of the lower river reaches but make movements as far upriver as rkm 88. There was high variation in distribution and movement patterns exhibited by fish tagged in the Kennebecasis River, ranging from single-location occupancy to wide distribution. Three fish left the system during the study, indicating juveniles embark on brief marine excursions. Identifying spatiotemporal distributions of juvenile Atlantic sturgeon in their natal river systems is a crucial step towards identifying critical habitat and informing management decisions for this species.

LARVAL HABITAT CHARACTERISTICS OF COQUILLETTIDIA PERTURBANS (DIPTERA: CULICIDAE) IN MINNESOTA

1986 ◽  
Vol 118 (11) ◽  
pp. 1193-1198 ◽  
Author(s):  
Darold P. Batzer ◽  
Robert D. Sjogren
Keyword(s):  
Dissolved Oxygen ◽  
Water Column ◽  
Plant Species ◽  
Aquatic Vegetation ◽  
Larval Habitat ◽  
Habitat Characteristics ◽  
Breeding Sites ◽  
Organic Debris ◽  
Coquillettidia Perturbans ◽  
Hennepin County

AbstractLarvae of Coquillettidia pertubans (Walker) are found in some marshes of permanent water with stands of aquatic vegetation. Eighty-six marshes, located within a 400-km2 area of Hennepin County, Minnesota, were examined in the fall of 1984 to determine factors that characterize C. perturbans breeding sites. We found that C. perturbans larvae attached to the roots of primarily Typha species although other plant species were also used. The water in sites with larvae was significantly deeper, lower in dissolved oxygen, and contained a significantly thicker layer of organic debris than sites without larvae. Larvae were associated with sites where Typha had specialized structures called water roots, which grow in the water column. Larvae inhabiting floating mats of vegetation were associated with interior openings within the mats.

scholarly journals Surveillance of mosquitoes (Diptera: Culicidae) in Rajshahi, Bangladesh

2019 ◽  
Vol 6 (2) ◽  
pp. 329-336
Author(s):  
Md Tanvir Anjum Anik ◽  
Thahsin Farjana
Keyword(s):  
Public Health ◽  
Mosquito Species ◽  
Water Bodies ◽  
Polluted Water ◽  
Agricultural Fields ◽  
Light Traps ◽  
Anopheles Species ◽  
Breeding Sites ◽  
Arthropod Vectors ◽  
The World

Mosquitoes are considered the most important arthropod vectors in the world. Mosquito borne diseases are major public health problems in most of tropical and subtropical countries. An investigation was performed at Bagha upazila in Rajshahi district to identify the mosquito species and their breeding sites at the study area. Adult mosquitoes were collected by insect collecting net, light traps and human bait method and larvae were collected by dipper, mug, ladle spoon and dropper. A total of 1947 adult mosquitoes and 1376 larvae were collected and identified. Total ten species of adult mosquitoes and nine species of larvae under two genera were identified. The collected mosquitoes were belonging to two genera- Anopheles (An.) and Culex (Cx.). The identified species were Cx. quinquefasciatus, Cx. bitaeniorhynchus, Cx. tritaeniorhynchus, Cx. gelidus, Cx. pseudovishnui, Cx. whitmorei, Cx. fuscanus, Cx. fuscocephala, An. aconitus, An. vagus and An. barbirostris. In both cases of larvae and adult mosquitoes, Culex was found more prevalent than Anopheles. In case of larvae the prevalence was 75.8% and 24.2%, and in case of adult it was 71.2% and 28.8% for Culex and Anopheles, respectively. Among the all identified mosquitoes, Cx. quinquefasciatus showed the highest abundance in both cases of larval (23.5%) and adult mosquitoes (25.2%). From the survey it has been apparent that the Culex species may prefer the polluted water bodies in the locality like households, dairy sheds and drains whereas Anopheles species may prefer agricultural fields, and dairy sheds. This study will help to detect the breeding sites of mosquitoes in study areas and to take necessary steps to control mosquitoes and mosquito borne diseases. Res. Agric., Livest. Fish.6(2): 329-336, August 2019

Caractérisation écologique des milieux humides à larves de moustiques (Culicides) de la région subarctique continentale d'Opinaca (territoire de la Baie de James, Québec)

1978 ◽  
Vol 56 (11) ◽  
pp. 2377-2387 ◽  
Author(s):  
Yves Mailhot ◽  
Alain Maire
Keyword(s):  
Mosquito Species ◽  
Riparian Areas ◽  
Culex Restuans ◽  
Breeding Sites ◽  
Qualitative And Quantitative ◽  
Salix Planifolia ◽  
Quantitative Analyses ◽  
Aedes Communis ◽  
Culex Territans

Twenty mosquito species were collected in a low-subarctic area located between Eastmain River and Petit-Opinaca Lake, Quebec (52°15′ N, 76°38′ W). Qualitative and quantitative analyses of larval mosquito populations identified 20 ecological units that served as larval breeding sites. The data revealed typical larval associations such as Aedes canadensis – Aedes decticus, characteristic of the open bog series, Aedes communis – Aedes pionips of alder–willow groves (Salix planifolia – Alnus rugosa), Aedes intrudens and Aedes cinereus in flooded riparian areas. The ecology of species with summer larvae is also described: Culex restuans, Culex territans, Culiseta alaskaensis, and Culiseta impatiens.

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