scholarly journals Distribution and diversity of mosquitoes and Oropouche-like virus infection rates in an Amazonian rural settlement

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246932
Author(s):  
Jordam William Pereira-Silva ◽  
Claudia María Ríos-Velásquez ◽  
Gervilane Ribeiro de Lima ◽  
Eric Fabrício Marialva dos Santos ◽  
Heliana Christy Matos Belchior ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Forest Canopy ◽  
Diversity Index ◽  
Mosquito Species ◽  
Natural Infection ◽  
Forest Edge ◽  
Rural Settlement ◽  
Vertical Stratification ◽  
Light Traps ◽  
Horizontal Stratification

Mosquito diversity and disease transmission are influenced by landscape modifications, i.e., vectors and pathogens previously found only in forests are now found close to human environments due to anthropic changes. This study determined the diversity and distribution of mosquitoes in forest environments in order to analyze the potential vectors of Amazonian forest arboviruses. Mosquitoes were collected by 1) vertical stratification from forest canopy and ground areas using Hooper Pugedo (HP) light traps and human attraction and 2) horizontal stratification using HP light traps in peridomicile, forest edge, and forest environments near the Rio Pardo rural settlement, Amazonas, Brazil. A total of 3,750 mosquitoes were collected, representing 46 species. 3,139 individuals representing 46 species were sampled by vertical stratification. Both the Shannon-Weaver diversity index (H’) and equitability (J’) were higher in the canopy than on the ground. 611 individuals representing 13 species were sampled by horizontal stratification. H’ decreased in the following order: forest edge > forest > peridomicile, and J’ was greater at the forest edge and smaller in the peridomicile environment. Moreover, H’ was higher for the human attraction collection method than the HP traps. A total of 671 pools were analyzed by RT-qPCR; three species were positive for Oropouche-like viruses (Ochlerotatus serratus, Psorophora cingulata, and Haemagogus tropicalis) and the minimum infection rate was 0.8%. The composition of mosquito species did not differ significantly between anthropic and forest environments in Rio Pardo. Some mosquito species, due to their abundance, dispersion in the three environments, and record of natural infection, were hypothesized to participate in the arbovirus transmission cycle in this Amazonian rural settlement.

scholarly journals Ecological characterization and infection of Anophelines (Diptera: Culicidae) of the Atlantic Forest in the southeast of Brazil over a 10 year period: Has the behaviour of the autochthonous malaria vector changed?

2017 ◽  
Author(s):  
Julyana Cerqueira Buery ◽  
Helder Ricas Rezende ◽  
Licia Natal ◽  
Leonardo Santana da Silva ◽  
Regiane Maria Tironi de Menezes ◽  
...  
Keyword(s):  
Atlantic Forest ◽  
Forest Canopy ◽  
Natural Infection ◽  
Specific Region ◽  
Forest Fragments ◽  
Light Traps ◽  
Espírito Santo ◽  
Espirito Santo ◽  
Pcr Techniques ◽  
Infection Study

ABSTRACTIn the south and southeast of Brazil, autochthonous malaria cases can be found near Atlantic Forest fragments. The transmission is not totally clarified; thus, the behaviour of the possible vectors in those regions must be observed. An entomological and natural infection study was performed on anophelines (Diptera: Culicidae) captured in the municipalities of the mountainous region of Espírito Santo state in 2004-2005. Similarly, between the years 2014 and 2015, 12 monthly collections were performed at the permanent trapping station of the study mentioned above (Valsugana Velha, Santa Teresa, ES). Light traps with CO2 (CO2-baited Center for Disease Control [CDC] traps) were set in open areas, at the edge of the forest (canopy and ground) and inside the forest (canopy and ground), whereas Shannon traps were set on the edge of the forest. A total of 1,414 anophelines were collected from 13 species. Anopheles (Kerteszia) cruzii Dyar and Knab remained the most captured species in the CO2-baited CDC traps set in the forest canopy and was also the vector with the highest prevalence of Plasmodium vivax infection according to molecular PCR techniques. Regarding mosquitoes of the subgenus Nyssorhynchus, P. vivax was found only in abdomens, weakening the hypothesis that this subgenus also plays a role in malaria transmission in this specific region.SponsorshipEspírito Santo Research Foundation (Fundação de Amparo à Pesquisa e Inovação do Espírito Santo – FAPES).

scholarly journals Biodiversity Pattern of Mosquitoes in Southeastern Senegal, Epidemiological Implication in Arbovirus and Malaria Transmission

2018 ◽  
Vol 56 (2) ◽  
pp. 453-463 ◽  
Author(s):  
Diawo Diallo ◽  
Cheikh T Diagne ◽  
Michaela Buenemann ◽  
Yamar Ba ◽  
Ibrahima Dia ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Land Cover ◽  
Forest Canopy ◽  
Diversity Index ◽  
Mosquito Species ◽  
Temporal Distribution ◽  
Abundant Species ◽  
Species Density ◽  
Maximum Temperature ◽  
Mosquito Abundance

Abstract The composition, density, diversity, and temporal distribution of mosquito species and the influence of temperature, relative humidity, and rainfall on these data were investigated in 50 sites across five land cover classes (forest, savannah, barren, village, and agriculture) in southeastern Senegal. Mosquitoes were collected monthly in each site between June 2009 and March 2011, with three people collecting mosquitoes landing on their legs for one to four consecutive days. In total, 81,219 specimens, belonging to 60 species and 7 genera, were collected. The most abundant species were Aedes furcifer (Edwards) (Diptera: Culicidae) (20.7%), Ae. vittatus (Bigot) (19.5%), Ae. dalzieli (Theobald) (14.7%), and Ae. luteocephalus (Newstead) (13.7%). Ae. dalzieli, Ae. furcifer, Ae. vittatus, Ae. luteocephalus, Ae. taylori Edwards, Ae. africanus (Theobald), Ae. minutus (Theobald), Anopheles coustani Laveran, Culex quinquefasciatus Say, and Mansonia uniformis (Theobald) comprised ≥10% of the total collection, in at least one land cover. The lowest species richness and Brillouin diversity index (HB = 1.55) were observed in the forest-canopy. The urban-indoor fauna showed the highest dissimilarity with other land covers and was most similar to the urban-outdoor fauna following Jaccard and Morisita index. Mosquito abundance peaked in June and October 2009 and July and October 2010. The highest species density was recorded in October. The maximum temperature was correlated positively with mean temperature and negatively with rainfall and relative humidity. Rainfall showed a positive correlation with mosquito abundance and species density. These data will be useful for understanding the transmission of arboviruses and human malaria in the region.

scholarly journals An Efficient Alternative to the CDC Gravid Trap for Southern House Mosquito (Diptera: Culicidae) Surveillance

2020 ◽  
Author(s):  
Timothy D McNamara ◽  
Thomas A O’Shea-Wheller ◽  
Nicholas DeLisi ◽  
Emily Dugas ◽  
Kevin A Caillouet ◽  
...  
Keyword(s):  
United States ◽  
Mosquito Species ◽  
Red Light ◽  
Light Trap ◽  
The United States ◽  
Light Traps ◽  
Efficient Alternative ◽  
Gravid Trap ◽  
Trapping Trials

Abstract West Nile virus (WNV) is the most prevalent arbovirus found throughout the United States. Surveillance of surface breeding Culex vectors involved in WNV transmission is primarily conducted using CDC Gravid traps. However, anecdotal claims from mosquito abatement districts in Louisiana assert that other trap types may be more suited to WNV surveillance. To test the validity of these assertions, we conducted a series of trapping trials and WNV surveillance over 3 yr to compare the efficacy of multiple trap types. First, we compared the CDC Gravid trap, CO2-baited New Standard Miniature Blacklight traps, and CO2-baited CDC light traps with either an incandescent light, a red light, or no light. We found that the CDC Gravid trap and CO2-baited no-light CDC Light trap collected the most mosquitoes. Second, we conducted additional, long-term trapping and WNV surveillance to compare these two trap types. We found that CO2-baited no-light CDC traps collected more of the local WNV vector, Culex quinquefasciatus (Say, Diptera, Culicidae), and detected WNV with greater sensitivity. Finally, we conducted trapping to compare the physiological states of Cx. quinquefasciatus and diversity of collected mosquitoes. CO2-baited no-light CDC light traps collected more unfed Cx. quinquefasciatus while Gravid traps collected more blooded Cx. quinquefasciatus; both traps collected the same number of gravid Cx. quinquefasciatus. Additionally, we found that CO2-baited no-light CDC light traps collected a larger diversity of mosquito species than Gravid traps.

NOTE ON THE UNIQUENESS OF AN ENDEMIC EQUILIBRIUM OF AN EPIDEMIC MODEL WITH BOOSTING OF IMMUNITY

2021 ◽  
pp. 1-12
Author(s):  
LIU YANG ◽  
YUKIHIKO NAKATA
Keyword(s):  
Epidemic Model ◽  
Disease Transmission ◽  
Immune Status ◽  
Natural Infection ◽  
Population Level ◽  
Qualitative Property ◽  
Endemic Equilibrium ◽  
Unique Existence ◽  
Nonlinear Version ◽  
Age Dependent

For some diseases, it is recognized that immunity acquired by natural infection and vaccination subsequently wanes. As such, immunity provides temporal protection to recovered individuals from an infection. An immune period is extended owing to boosting of immunity by asymptomatic re-exposure to an infection. An individual’s immune status plays an important role in the spread of infectious diseases at the population level. We study an age-dependent epidemic model formulated as a nonlinear version of the Aron epidemic model, which incorporates boosting of immunity by a system of delay equations and study the existence of an endemic equilibrium to observe whether boosting of immunity changes the qualitative property of the existence of the equilibrium. We establish a sufficient condition related to the strength of disease transmission from subclinical and clinical infective populations, for the unique existence of an endemic equilibrium.

scholarly journals Distance Effects on Diversity and Abundance of the Flower Visitors of Ocimum kilimandscharicum in the Kakamega Forest Ecosystem

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Hellen K. Mandela ◽  
Mugatsia H. Tsingalia ◽  
Mary Gikungu ◽  
Wilbur M. Lwande
Keyword(s):  
Species Diversity ◽  
Diversity Index ◽  
Land Use Changes ◽  
Species Abundance ◽  
Diversity Indices ◽  
Forest Edge ◽  
Flower Visitors ◽  
Kakamega Forest ◽  
Species Invasions ◽  
Wiener Diversity Index

Pollination is an important ecosystem service in the maintenance of biodiversity and most importantly in food production. Pollination is on the decline due to habitat loss, exotic species invasions, pollution, overharvesting, and land use changes. This study analyzed the abundance and diversity of flower visitors’ of Ocimum kilimandscharicum in Kakamega forest with increasing distance from the forest edge. Data were collected through direct observation and sweep netting. Six study sites were identified along two transects each 2.5 km long and labeled A to F. Distance in metres from the forest edge to each site was A=221, B=72, C=83, D=198, E=113, and F=50. Sampling was done from 7:30 am to 4:00 pm, three days in a week for five months consecutively. Diversity indices of different flower visitors were calculated using the Shannon-Wiener diversity index. One-way analysis of variance was used to compare differences between sites and a two-sample t-test was used to identify mean significant differences in species diversity between the closest and the furthest sites. A total of 645 individuals belonging to 35 species were captured from 4 families. The highest diversity was at site F (H’= 2.38) which was closest to the forest edge and the lowest diversity was from site A (H’=1.44) which was furthest from the forest edge. Distance from the forest edge significantly influenced species diversity (F(3, 20)=14.67, p=0.024). Distance from the forest edge also significantly influenced species abundance between the furthest sites A, D, and E and the nearest sites F, B, and C to the forest edge (t=4.177; p=0.0312) and species richness (t=3.2893; p=0.0187). This study clearly demonstrates that Ocimum kilimandscharicum flower visitors play essential roles in pollination and their higher number of visits translates into higher numbers of seeds set. Many of these pollinators are associated with the forest and hence the need to conserve the Kakamega forest as a source pool for pollinators.

scholarly journals Satellite Imaging and Long-Term Mosquito Surveillance Implicate the Influence of Rapid Urbanization on Culex Vector Populations

Insects ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 269
Author(s):  
Eleanor N. Field ◽  
Ryan E. Tokarz ◽  
Ryan C. Smith
Keyword(s):  
Land Use ◽  
Disease Transmission ◽  
Culex Pipiens ◽  
Management Practices ◽  
Mosquito Species ◽  
Land Use Changes ◽  
Mosquito Vector ◽  
Rapid Urbanization ◽  
Mosquito Surveillance

The ecology and environmental conditions of a habitat have profound influences on mosquito population abundance. As a result, mosquito species vary in their associations with particular habitat types, yet long-term studies showing how mosquito populations shift in a changing ecological landscape are lacking. To better understand how land use changes influence mosquito populations, we examined mosquito surveillance data over a thirty-four-year period for two contrasting sites in central Iowa. One site displayed increasing levels of urbanization over time and a dramatic decline in Culex pipiens group (an informal grouping of Culex restuans, Culex pipiens, and Culex salinarius, referred to as CPG), the primary vectors of West Nile virus in central Iowa. Similar effects were also shown for other mosquito vector populations, yet the abundance of Aedes vexans remained constant during the study period. This is in contrast to a second site, which reflected an established urban landscape. At this location, there were no significant changes in land use and CPG populations remained constant. Climate data (temperature, total precipitation) were compiled for each location to see if these changes could account for altered population dynamics, but neither significantly influence CPG abundance at the respective site locations. Taken together, our data suggest that increased landscape development can have negative impacts on Culex vector populations, and we argue that long-term surveillance paired with satellite imagery analysis are useful methods for measuring the impacts of rapid human development on mosquito vector communities. As a result, we believe that land use changes can have important implications for mosquito management practices, population modeling, and disease transmission dynamics.

scholarly journals Natural Regeneration of the Tree Stand in the Bilberry Spruce Forest—Clear-Cutting Ecotone Complex in the First Post-Logging Decade

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1542
Author(s):  
Nadezhda V. Genikova ◽  
Viktor N. Mamontov ◽  
Alexander M. Kryshen ◽  
Vladimir A. Kharitonov ◽  
Sergey A. Moshnikov ◽  
...  
Keyword(s):  
Natural Regeneration ◽  
Forest Canopy ◽  
Forest Cover ◽  
Forest Type ◽  
Ground Cover ◽  
Woody Species ◽  
Forest Edge ◽  
Tree Canopy ◽  
Clear Cut ◽  
Clear Cutting

Bilberry spruce forests are the most widespread forest type in the European boreal zone. Limiting the clear-cuttings size leads to fragmentation of forest cover and the appearance of large areas of ecotone complexes, composed of forest (F), a transition from forest to the cut-over site under tree canopy (FE), a transition from forest to the cut-over site beyond tree canopy (CE), and the actual clear-cut site (C). Natural regeneration of woody species (spruce, birch, rowan) in the bilberry spruce stand—clear-cut ecotone complex was studied during the first decade after logging. The effects produced by the time since cutting, forest edge aspect, and the ground cover on the emergence and growth of trees and shrubs under forest canopy and openly in the clear-cut were investigated. Estimating the amount and size of different species in the regeneration showed FE and CE width to be 8 m—roughly half the height of first-story trees. Typical forest conditions (F) feature a relatively small amount of regenerating spruce and birch. The most favorable conditions for natural regeneration of spruce in the clear-cut—mature bilberry spruce stand ecotone are at the forest edge in areas of transition both towards the forest and towards the clear-cut (FE and CE). Clear-cut areas farther from the forest edge (C) offer an advantage to regenerating birch, which grows densely and actively in this area.

scholarly journals The Arctiini (Lepidoptera, Erebidae, Arctiinae) fauna of the Serra do Pardo National Park, Pará, Brazil

Check List ◽  
2015 ◽  
Vol 11 (2) ◽  
pp. 1613 ◽  
Author(s):  
José Augusto Teston ◽  
Danilo Do C. V. Correa
Keyword(s):  
National Park ◽  
New Records ◽  
Diversity Index ◽  
Sampling Site ◽  
Brazilian Amazon ◽  
The State ◽  
Parametric Methods ◽  
Light Traps ◽  
Rarefaction Curve ◽  
Non Parametric

This study evaluated the Arctiini fauna of the Serra do Pardo National Park (Pará, Brazil) between 22 September and 3 October 2011. Light traps were left one night in each sampling site (SS) from 18:00 h to 6:00 h of the next day. The following parameters were evaluated: richness (S), abundance (N), diversity index (H’), Shannon uniformity (U) index, and Berger-Parker dominance (BP). Richness was estimated using the non-parametric methods Chao1, Chao2, ACE, ICE, Jackknife1, Jackknife2 and Bootstrap. A total of 3,247 specimens were captured, belonging to 221 Arctiini taxa; 32 of these are new records for the state of Pará and, of these, six are new records for the Brazilian Amazon. The Arctiini fauna is very rich and uniform. The richness estimator and rarefaction curve indicated the need for increased sampling efforts in the area.

scholarly journals Amblyomma tapirellum  (Acari: Ixodidae) collected from tropical forest canopy

F1000Research ◽  
2014 ◽  
Vol 2 ◽  
pp. 194
Author(s):  
Jose R Loaiza ◽  
Matthew J Miller ◽  
Eldredge Bermingham ◽  
Oris I Sanjur ◽  
Patrick A Jansen ◽  
...  
Keyword(s):  
Tropical Forests ◽  
Forest Canopy ◽  
Ground Level ◽  
Barro Colorado Island ◽  
Light Traps ◽  
Ecological Relationship ◽  
Questing Ticks ◽  
Free Ranging ◽  
Central Panama ◽  
Tropical Forest Canopy

Free-ranging ticks are widely known to be restricted to the ground level of vegetation. Here, we document the capture of the tick species Amblyomma tapirellum in light traps placed in the forest canopy of Barro Colorado Island, central Panama. A total of forty eight adults and three nymphs were removed from carbon dioxide–octenol baited CDC light traps suspended 20 meters above the ground during surveys for forest canopy mosquitoes. To our knowledge, this represents the first report of questing ticks from the canopy of tropical forests. Our finding suggests a novel ecological relationship between A. tapirellum and arboreal mammals, perhaps monkeys that come to the ground to drink or to feed on fallen fruits.

scholarly journals Effects of seasonality and land use on the abundance and distribution of mosquitoes on St. Kitts, West Indies

2020 ◽  
Author(s):  
Matthew J. Valentine ◽  
Brenda Ciraola ◽  
Gregory R. Jacobs ◽  
Charlie Arnot ◽  
Patrick J. Kelly ◽  
...  
Keyword(s):  
Land Cover ◽  
Disease Transmission ◽  
Negative Binomial ◽  
Mosquito Control ◽  
Mosquito Species ◽  
Negative Binomial Regression ◽  
Common Species ◽  
Negative Binomial Regression Model ◽  
Local Data ◽  
Land Covers

AbstractBackgroundHigh quality mosquito surveys that collect fine resolution local data on mosquito species’ abundances provide baseline data to help us understand potential host-pathogen-mosquito relationships, accurately predict disease transmission, and target mosquito control efforts in areas at risk of mosquito borne diseases.MethodsAs part of an investigation into arboviral sylvatic cycles on the Caribbean island of St. Kitts, we carried out an island wide mosquito survey from November 2017 to March 2019. Using Biogents Sentinel 2 and miniature CDC light traps that were set monthly and run for 48 hour intervals, we collected mosquitoes from a total of 30 sites distributed across the five common land covers on the island (agricultural, mangrove, rainforest, scrub, and urban). We developed a mixed effects negative binomial regression model to predict the effects of land cover, seasonality, and precipitation on observed counts of the most abundant mosquito species we found.ResultsWe captured 10 of the 14 mosquito species reported on the island, the four most abundant being Aedes taeniorhynchus, Culex quinquefasciatus, Aedes aegpyti, and Deinocerites magnus. Sampling in the mangroves yielded the most mosquitoes, with Ae. taeniorhynchus, Cx. quinquefasciatus, and De. magnus predominating. Aedes aegypti was recovered primarily from urban and agricultural habitats, but also at lower frequency in other land covers. Psorophora pygmaea and Toxorhynchites guadeloupensis were only captured in scrub habitat. Capture rates in rainforests were low. Our models indicated the relative abundance of the four most common species varied seasonally and with land cover. They also suggested that the extent to which monthly average precipitation influenced counts varied according to species.ConclusionsThis study demonstrates there is high seasonality in mosquito abundances and that land cover influenced the distribution and abundance of mosquito species on St. Kitts. Further, human-adapted mosquito species (e.g. Ae. aegypti and Cx. quinquefasciatus) that are known vectors for many human relevant pathogens are the most wide-spread (across land covers) and the least responsive to seasonal variation in precipitation.

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