WorldWideScience

Sample records for below-ground mosquito breeding

  1. Divergent host preferences of above- and below-ground Culex pipiens mosquitoes and their hybrid offspring.

    Science.gov (United States)

    Fritz, M L; Walker, E D; Miller, J R; Severson, D W; Dworkin, I

    2015-06-01

    Culex pipiens form pipiens and Cx. pipiens form molestus (Diptera: Culicidae) belong to a cosmopolitan taxonomic group known as the Pipiens Assemblage. Hybridization between these forms is thought to contribute to human transmission of West Nile virus (WNV) in North America. Complementary choice and no-choice landing assays were developed to examine host acceptance by North American Cx. pipiens in the laboratory. Populations collected from above- and below-ground sites in suburban Chicago were identified as forms pipiens and molestus using a polymerase chain reaction-based assay. Avian and human host acceptance was then quantified for the two populations, as well as for their hybrid and backcross offspring. No-choice tests were used to demonstrate that both the pipiens and molestus forms were capable of feeding on human and avian hosts. Choice tests were used to demonstrate that form pipiens females were strongly avian-seeking; an individual's probability of accepting the chick host was 85%. Form molestus females were more likely to accept the human host (87%). Rates of host acceptance by F1 and backcross progeny were intermediate to those of their parents. The results suggest that host preferences in Cx. pipiens are genetically determined, and that ongoing hybridization between above- and below-ground populations is an important contributor to epizootic transmission of WNV in North America. © 2015 The Royal Entomological Society.

  2. [The biocontrol of container-breeding mosquitoes by using Toxorhynchites].

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    Yeh, C C

    1990-07-01

    Container-breeding mosquitoes not only bite people but also transmit many human and animal diseases. The problem with chemical control of these mosquitoes is that the breeding sites are always well dispersed and not easily located, and more manenergy and money are required to treat them individually. Since the adverse effects of pesticides on vector control have been recognized, Toxorhynchites mosquitoes are being reconsidered as a means of reducing the populations of other mosquito species. The bionomic interaction of predator and prey, mass rearing, and some examples of biological control of Toxorhynchites are discussed in this article. Integrated controls combining periodic mass release of gravid Toxorhynchites females and ULV pesticide applications can be used to suppress container-breeding mosquitoes.

  3. Simple intervention to reduce mosquito breeding in waste stabilisation ponds

    DEFF Research Database (Denmark)

    Ensink, Jeroen H J; Mukhtar, Muhammad; van der Hoek, Wim

    2007-01-01

    the control ponds had a significant number of positive samples. This suggests that a combination of simple low-cost interventions is a feasible environmental management strategy for vector control in WSP systems that are located in areas where medically important mosquitoes may breed in the shallow ponds.......Waste stabilisation ponds (WSP) are the preferred method for treatment of urban wastewater in low-income countries but, especially in arid regions, the pond systems can be important breeding sites for mosquitoes of medical importance. In a WSP system in Faisalabad, Pakistan, we assessed the impact...... of simple environmental interventions on mosquito occurrence and abundance. Reducing the amount of floating matter in the ponds, eliminating emergent vegetation and repairing cracks in the cement structure reduced the number of mosquito-positive samples in the intervention ponds to almost zero, whereas...

  4. A Statewide Survey for Container-Breeding Mosquitoes in Mississippi.

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    Goddard, Jerome; Moraru, Gail M; Mcinnis, Sarah J; Portugal, J Santos; Yee, Donald A; Deerman, J Hunter; Varnado, Wendy C

    2017-09-01

    Container-breeding mosquitoes are important in public health due to outbreaks of Zika, chikungunya, and dengue viruses. This paper documents the distribution of container-breeding mosquito species in Mississippi, with special emphasis on the genus Aedes. Five sites in each of the 82 Mississippi counties were sampled monthly between May 1 and August 31, 2016, and 50,109 mosquitoes in 14 species were collected. The most prevalent and widely distributed species found was Ae. albopictus, being found in all 82 counties, especially during July. A recent invasive, Ae. japonicus, seems to be spreading rapidly in Mississippi since first being discovered in the state in 2011. The most abundant Culex species collected were Cx. quinquefasciatus (found statewide), Cx. salinarius (almost exclusively in the southern portion of the state), and Cx. restuans (mostly central and southern Mississippi). Another relatively recent invasive species, Cx. coronator, was found in 20 counties, predominantly in the southern one-third of the state during late summer. Co-occurrence data of mosquito species found in the artificial containers were also documented and analyzed. Lastly, even though we sampled extensively in 410 sites across Mississippi, no larval Ae. aegypti were found. These data represent the first modern statewide survey of container species in Mississippi, and as such, allows for better public health readiness for emerging diseases and design of more effective vector control programs.

  5. Mosquito-disseminated pyriproxyfen yields high breeding-site coverage and boosts juvenile mosquito mortality at the neighborhood scale.

    Science.gov (United States)

    Abad-Franch, Fernando; Zamora-Perea, Elvira; Ferraz, Gonçalo; Padilla-Torres, Samael D; Luz, Sérgio L B

    2015-04-01

    Mosquito-borne pathogens pose major public health challenges worldwide. With vaccines or effective drugs still unavailable for most such pathogens, disease prevention heavily relies on vector control. To date, however, mosquito control has proven difficult, with low breeding-site coverage during control campaigns identified as a major drawback. A novel tactic exploits the egg-laying behavior of mosquitoes to have them disseminate tiny particles of a potent larvicide, pyriproxyfen (PPF), from resting to breeding sites, thus improving coverage. This approach has yielded promising results at small spatial scales, but its wider applicability remains unclear. We conducted a four-month trial within a 20-month study to investigate mosquito-driven dissemination of PPF dust-particles from 100 'dissemination stations' (DSs) deployed in a 7-ha sub-area to surveillance dwellings and sentinel breeding sites (SBSs) distributed over an urban neighborhood of about 50 ha. We assessed the impact of the trial by measuring juvenile mosquito mortality and adult mosquito emergence in each SBS-month. Using data from 1,075 dwelling-months, 2,988 SBS-months, and 29,922 individual mosquitoes, we show that mosquito-disseminated PPF yielded high coverage of dwellings (up to 100%) and SBSs (up to 94.3%). Juvenile mosquito mortality in SBSs (about 4% at baseline) increased by over one order of magnitude during PPF dissemination (about 75%). This led to a >10-fold decrease of adult mosquito emergence from SBSs, from approximately 1,000-3,000 adults/month before to about 100 adults/month during PPF dissemination. By expanding breeding-site coverage and boosting juvenile mosquito mortality, a strategy based on mosquito-disseminated PPF has potential to substantially enhance mosquito control. Sharp declines in adult mosquito emergence can lower vector/host ratios, reducing the risk of disease outbreaks. This approach is a very promising complement to current and novel mosquito control strategies

  6. British container breeding mosquitoes: the impact of urbanisation and climate change on community composition and phenology.

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    Susannah Townroe

    Full Text Available The proliferation of artificial container habitats in urban areas has benefitted urban adaptable mosquito species globally. In areas where mosquitoes transmit viruses and parasites, it can promote vector population productivity and fuel mosquito-borne disease outbreaks. In Britain, storage of water in garden water butts is increasing, potentially expanding mosquito larval habitats and influencing population dynamics and mosquito-human contact. Here we show that the community composition, abundance and phenology of mosquitoes breeding in experimental water butt containers were influenced by urbanisation. Mosquitoes in urban containers were less species-rich but present in significantly higher densities (100.4±21.3 per container than those in rural containers (77.7±15.1. Urban containers were dominated by Culex pipiens (a potential vector of West Nile Virus [WNV] and appear to be increasingly exploited by Anopheles plumbeus (a human-biting potential WNV and malaria vector. Culex phenology was influenced by urban land use type, with peaks in larval abundances occurring earlier in urban than rural containers. Among other factors, this was associated with an urban heat island effect which raised urban air and water temperatures by 0.9°C and 1.2°C respectively. Further increases in domestic water storage, particularly in urban areas, in combination with climate changes will likely alter mosquito population dynamics in the UK.

  7. British Container Breeding Mosquitoes: The Impact of Urbanisation and Climate Change on Community Composition and Phenology

    Science.gov (United States)

    Townroe, Susannah; Callaghan, Amanda

    2014-01-01

    The proliferation of artificial container habitats in urban areas has benefitted urban adaptable mosquito species globally. In areas where mosquitoes transmit viruses and parasites, it can promote vector population productivity and fuel mosquito-borne disease outbreaks. In Britain, storage of water in garden water butts is increasing, potentially expanding mosquito larval habitats and influencing population dynamics and mosquito-human contact. Here we show that the community composition, abundance and phenology of mosquitoes breeding in experimental water butt containers were influenced by urbanisation. Mosquitoes in urban containers were less species-rich but present in significantly higher densities (100.4±21.3) per container than those in rural containers (77.7±15.1). Urban containers were dominated by Culex pipiens (a potential vector of West Nile Virus [WNV]) and appear to be increasingly exploited by Anopheles plumbeus (a human-biting potential WNV and malaria vector). Culex phenology was influenced by urban land use type, with peaks in larval abundances occurring earlier in urban than rural containers. Among other factors, this was associated with an urban heat island effect which raised urban air and water temperatures by 0.9°C and 1.2°C respectively. Further increases in domestic water storage, particularly in urban areas, in combination with climate changes will likely alter mosquito population dynamics in the UK. PMID:24759617

  8. Mosquito Production and Associated Environmental and Chemical Parameters of Breeding Waters.

    Science.gov (United States)

    1983-05-01

    catch basins are also common breeding sites ( Carpenter and LaCasse 1955, King et al. 1960, Maddock et al. 1963). Cx. pipiens is considered the most... Carpenter , S. J. and W. J. LaCasse . 1955. Mosquitoes of North America north of Mexico. Univ. of Calif. Press, Berkely and Los Angeles. 360 pp. Chamberlain

  9. Role of wastewater irrigation in mosquito breeding in south Punjab, Pakistan

    DEFF Research Database (Denmark)

    Mukhtar, Muhammad; Herrel, Nathaly; Amerasinghe, Felix P

    2003-01-01

    Mosquito breeding within the wastewater irrigation system around the town of Haroonabad in the southern Punjab, Pakistan, was studied from July to September 2000 as part of a wider study of the costs and benefits of wastewater use in agriculture. The objective of this study was to assess the vect...

  10. Role of wastewater irrigation in mosquito breeding in south Punjab, Pakistan

    DEFF Research Database (Denmark)

    Mukhtar, Muhammad; Herrel, Nathaly; Amerasinghe, Felix P

    2003-01-01

    ) and Cx. quinquefasciatus (Bancroftian filariasis, West Nile fever) in the wastewater system indicated that such habitats could contribute to vector-borne disease risks for human communities that are dependent upon wastewater use for their livelihoods. Wastewater disposal and irrigation systems provide......Mosquito breeding within the wastewater irrigation system around the town of Haroonabad in the southern Punjab, Pakistan, was studied from July to September 2000 as part of a wider study of the costs and benefits of wastewater use in agriculture. The objective of this study was to assess the vector-borne...... human disease risks associated with mosquito species utilizing wastewater for breeding. Mosquito larvae were collected on a fortnightly basis from components of the wastewater disposal system and irrigated sites. In total, 133 samples were collected, about equally divided between agricultural sites...

  11. Targeting the breeding sites of malaria mosquitoes: biological and physical control of malaria mosquito larvae

    NARCIS (Netherlands)

    Bukhari, S.T.

    2011-01-01


    Malaria causes an estimated 225 million cases and 781,000 deaths every year. About 85% of the deaths are in children under five years of age. Malaria is caused by the Plasmodium parasite which is transmitted by the Anopheles mosquito vector. Mainly two methods of intervention are used for

  12. The fauna, monthly activity and species composition of anophelines mosquito larva in breeding places, Qom province

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    Abedin Saghafipour

    2013-09-01

    Full Text Available Background: There is need to develop updated database related to malaria mosquito, because there is back prevalence of malaria in the past two decades in some areas of north and northwest of Iran categorized as epidemiologically clean areas previously. Vectors control is one of the main strategies in controlling the epidemics. In this study, species composition and monthly activity of anopheles mosquito larva in different breeding places in Qom province was assessed. Material and Methods: The present study was a cross-sectional one. It was carried out in all 5 parts of geographical areas of Qom province. Samples were collected every 15 days from the natural and artificial breeding places from April to October 2010, using dipping standard method of WHO. Mosquito larvae conserved in lactophenol medium. In the laboratory, the specimens were mounted in likidophor medium and microscopic slides were prepared from larvae, and identified using illustrated keys for Iranian mosquitoes. Results: A total of 298 larvae samples were collected and identified from different breeding places in various areas of Qom province. This larvae belonged to two subgenus of Anopheles and Cellia and including four species of An.(Ano.marteri, An.(Ano.claviger, An.(Cel.superpictus, and An.(Cel.turkhudi. An.(Ano. claviger, An.(Ano.marteri, and An.(Cel.turkhudi are reported for the first time in this province. An.(Ano.claviger was dominant species of larvae in the breeding places in Qom province and found in different larva habitats. The peak of activity of recent species is in late July and early August and its seasonal activity is in late April to late October. Conclusion: An.(Cel.superpictus which is Malaria vector in different parts of the world and Iran is the dominant species of the area had the second frequency. Having high potential for transmission and possibility of establishing a transmission cycle with low abundance is the characteristics of first species. Anopheles

  13. Characterisation of breeding sites of anopheline mosquitoes in District Bannu, KPK, Pakistan.

    Science.gov (United States)

    Khan, Sadiq Ullah; Khan, Rahmat Ali

    2018-02-01

    To highlight the role of habitat evaluation in reducing the potential transmission risk of malaria. This study was conducted from January to June, 2015, in District Bannu in Khyber Pakhtunkhwa, Pakistan, where 64 larval habitats were characterised in 10 villages of the district. The larvae habitat features, like its permanent or temporary nature, artificial or natural, basic type, substrate type and vegetation, anopheline and culicine larval presence and density, were noted. ArcGIS 9.2 was used to map the mosquitoe breeding sites. Data was analysed related to the effect of temperature, rainfall and relative humidity on larval occurrence and density.. Of the 64 breeding habitats characterised, 26(40.6%) were temporary, while the remaining 38(59.4%) were permanent. Anopheline larvae were found in different types of habitats and occurred in man-made and temporary habitats with high population density. The marshlands (rice fields, sugarcane and open drains) were positive for anopheline larvae. The climatic factors like rain and humidity positively affected the larval density. The larval density was high in March and April at temperatures ranging from 16.1Co-23.45oC. Targeting the man-made and temporary larval habitats could results in the effective anopheline mosquitoes larvae control.

  14. The Highs and Lows of Making a Bucket List—Quantifying Potential Mosquito Breeding Habitats in Metropolitan Backyards

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    Ram Sharan Lamichhane

    2017-11-01

    Full Text Available While the development of land for residential housing along the Swan and Canning Rivers in Perth, WA, Australia has reduced natural mosquito breeding sites, the role of backyard container breeding remains a relatively unknown factor. Local Governments responsible for these areas focus management and control efforts on low lying, tidally driven mosquito habitats to control Aedes vigilax (Skuse and Aedes camptorhynchus (Thomson mosquitoes in an effort to reduce both the nuisance and disease risk to residents. In spite of their efforts, Local Governments continue to receive complaints regarding mosquito nuisance, even when environmental conditions do not favor hatching and development of the two species in the Swan River tidal flats. In this study, 150 backyard inspections were conducted in the residential suburb of Bassendean, Perth, WA, Australia, situated in close proximity to the Swan River tidal plain. The occurrence and species composition of the mosquito fauna found in residential backyards was documented. Of the backyards inspected, 94% were found to possess containers capable of breeding mosquitoes, although only 3% contained mosquito larvae. Nine species of mosquito were collected from containers ranging in capacity from 0.05 to 50 L across the study area. Additionally, encephalitis virus surveillance trapping was conducted within residential properties and compared to the tidally driven natural habitat at Ashfield Flats and a tidally influenced brackish creekline at Bindaring Park. The species composition of the fauna at the three habitat types differed significantly, with Aedes notoscriptus (Skuse dominating residential lots and A. vigilax more prevalent at the saltmarsh site. Bindaring Park had an adult composition at the mid-point of these two habitats, reflecting its proximity to both the Swan River and residential lots.

  15. Mapping of mosquito breeding sites in malaria endemic areas in Pos Lenjang, Kuala Lipis, Pahang, Malaysia.

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    Ahmad, Rohani; Ali, Wan N W M; Nor, Zurainee M; Ismail, Zamree; Hadi, Azahari A; Ibrahim, Mohd N; Lim, Lee H

    2011-12-13

    The application of the Geographic Information Systems (GIS) to the study of vector transmitted diseases considerably improves the management of the information obtained from the field survey and facilitates the study of the distribution patterns of the vector species. As part of a study to assess remote sensing data as a tool for vector mapping, geographical features like rivers, small streams, forest, roads and residential area were digitized from the satellite images and overlaid with entomological data. Map of larval breeding habitats distribution and map of malaria transmission risk area were developed using a combination of field data, satellite image analysis and GIS technique. All digital data in the GIS were displayed in the WGS 1984 coordinate system. Six occasions of larval surveillance were also conducted to determine the species of mosquitoes, their characteristics and the abundance of habitats. Larval survey studies showed that anopheline and culicine larvae were collected and mapped from 79 and 67 breeding sites respectively. Breeding habitats were located at 100-400 m from human settlement. Map of villages with 400 m buffer zone visualizes that more than 80% of Anopheles maculatus s.s. immature habitats were found within the buffer zone. This study amplifies the need for a broadening of the GIS approach which is emphasized with the aim of rejuvenating the dynamic aspect of entomological studies in Malaysia. In fact, the use of such basic GIS platforms promote a more rational basis for strategic planning and management in the control of endemic diseases at the national level.

  16. Breeding of Anopheles mosquitoes in irrigated areas of South Punjab, Pakistan

    DEFF Research Database (Denmark)

    Herrel, N; Amerasinghe, F P; Ensink, J

    2001-01-01

    As part of investigations on potential linkages between irrigation and malaria transmission, all surface water bodies in and around three villages along an irrigation distributary in South Punjab, Pakistan, were surveyed for anopheline mosquito larvae (Diptera: Culicidae) from April 1999 to March.......6%), An. pulcherrimus Theobald (1.8%), An. peditaeniatus Leicester (0.3%) and An. nigerrimus Giles (0.1%). The four most abundant species were significantly associated with waterlogged fields and communal village drinking-water tanks. Habitat characteristics most correlated with occurrence of anophelines......, mainly in irrigated and waterlogged fields. In South Punjab, where rainfall is very low, it should be possible to reduce anopheline breeding through water management, as larvae develop mainly in water bodies that are directly or indirectly related to the extensive canal-irrigation system....

  17. Immature Aedes mosquitoes colonize Culex quinquefasciatus breeding sites in neighborhoods in the municipality of Olinda, State of Pernambuco

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    Suzane Alves dos Santos

    2014-12-01

    Full Text Available Introduction The present study shows the colonization of Aedes mosquitoes in breeding sites specific for Culex quinquefasciatus in neighborhoods in the municipality of Olinda. Methods Samples were collected between May 2011 and June 2012 from breeding sites positive for Cx. quinquefasciatus by using a ladle and manual suction pump. Results Aedes aegypti (0.12%, Aedes albopictus (0.03%, and Cx. quinquefasciatus (99.8% were found across the breeding sites. Conclusions The presence of Aedes ssp. in several Cx. quinquefasciatus breeding sites with a heavy load of organic material demonstrates the need to review the concepts and methods used for treatment, as the use of specific larvicide for breeding sites of Culex.

  18. Increased container-breeding mosquito risk owing to drought-induced changes in water harvesting and storage in Brisbane, Australia.

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    Trewin, Brendan J; Kay, Brian H; Darbro, Jonathan M; Hurst, Tim P

    2013-12-01

    Extended drought conditions in south-east Queensland during the early 2000s have resulted in a culture of water harvesting and legislated water restrictions. Aedes notoscriptus is a container-breeding mosquito vector of Ross River and Barmah Forest viruses. From 2008-2009, the larval habitats and seasonal abundance of domestic container-breeding mosquitoes were recorded from three suburbs of Brisbane. A knowledge, attitudes and practice questionnaire was administered to householders. A low-cost, desktop methodology was used to predict the proportion of shaded premises compared with front-of-property estimates. We highlight changes in the frequency of container categories for A. notoscriptus as a response to human behavioural changes to drought. Garden accoutrements, discarded household items and water storage containers accounted for 66.2% (525/793) of positive containers and 77.5% (73 441/94 731) of all immature mosquitoes. Of all household premises surveyed, 52.6% (550/1046) contained rainwater tanks and 29.4% (308/1046) harvested water in other containers, contrasting with a previous 1995 survey where neither category was observed. Both Premise Condition Index and shade directly correlated with positive premises. Human response to drought has resulted in new habitats for domestic container-breeding mosquitoes. This recent trend of prolific water storage is similar to earlier years (1904-1943) in Brisbane when Aedes aegypti was present and dengue epidemics occurred.

  19. EnviroAtlas - Below Ground Live Tree Biomass Carbon Storage for the Conterminous United States- Forested

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    U.S. Environmental Protection Agency — This EnviroAtlas dataset includes the average below ground live tree root dry biomass estimate for the Watershed Boundary Dataset (WBD) 12-digit Hydrologic Unit...

  20. Transmission of Rift Valley fever virus from European-breed lambs to Culex pipiens mosquitoes.

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    Rianka P M Vloet

    2017-12-01

    Full Text Available Rift Valley fever virus (RVFV is a mosquito-borne bunyavirus of the genus Phlebovirus that is highly pathogenic to ruminants and humans. The disease is currently confined to Africa and the Arabian Peninsula, but globalization and climate change may facilitate introductions of the virus into currently unaffected areas via infected animals or mosquitoes. The consequences of such an introduction will depend on environmental factors, the availability of susceptible ruminants and the capacity of local mosquitoes to transmit the virus. We have previously demonstrated that lambs native to the Netherlands are highly susceptible to RVFV and we here report the vector competence of Culex (Cx. pipiens, the most abundant and widespread mosquito species in the country. Vector competence was first determined after artificial blood feeding of laboratory-reared mosquitoes using the attenuated Clone 13 strain. Subsequently, experiments with wild-type RVFV and mosquitoes hatched from field-collected eggs were performed. Finally, the transmission of RVFV from viremic lambs to mosquitoes was studied.Artificial feeding experiments using Clone 13 demonstrated that indigenous, laboratory-reared Cx. pipiens mosquitoes are susceptible to RVFV and that the virus can be transmitted via their saliva. Experiments with wild-type RVFV and mosquitoes hatched from field-collected eggs confirmed the vector competence of Cx. pipiens mosquitoes from the Netherlands. To subsequently investigate transmission of the virus under more natural conditions, mosquitoes were allowed to feed on RVFV-infected lambs during the viremic period. We found that RVFV is efficiently transmitted from lambs to mosquitoes, although transmission was restricted to peak viremia. Interestingly, in the mosquito-exposed skin samples, replication of RVFV was detected in previously unrecognized target cells.We here report the vector competence of Cx. pipiens mosquitoes from the Netherlands for RVFV. Both

  1. Transmission of Rift Valley fever virus from European-breed lambs to Culex pipiens mosquitoes.

    Science.gov (United States)

    Vloet, Rianka P M; Vogels, Chantal B F; Koenraadt, Constantianus J M; Pijlman, Gorben P; Eiden, Martin; Gonzales, Jose L; van Keulen, Lucien J M; Wichgers Schreur, Paul J; Kortekaas, Jeroen

    2017-12-01

    Rift Valley fever virus (RVFV) is a mosquito-borne bunyavirus of the genus Phlebovirus that is highly pathogenic to ruminants and humans. The disease is currently confined to Africa and the Arabian Peninsula, but globalization and climate change may facilitate introductions of the virus into currently unaffected areas via infected animals or mosquitoes. The consequences of such an introduction will depend on environmental factors, the availability of susceptible ruminants and the capacity of local mosquitoes to transmit the virus. We have previously demonstrated that lambs native to the Netherlands are highly susceptible to RVFV and we here report the vector competence of Culex (Cx.) pipiens, the most abundant and widespread mosquito species in the country. Vector competence was first determined after artificial blood feeding of laboratory-reared mosquitoes using the attenuated Clone 13 strain. Subsequently, experiments with wild-type RVFV and mosquitoes hatched from field-collected eggs were performed. Finally, the transmission of RVFV from viremic lambs to mosquitoes was studied. Artificial feeding experiments using Clone 13 demonstrated that indigenous, laboratory-reared Cx. pipiens mosquitoes are susceptible to RVFV and that the virus can be transmitted via their saliva. Experiments with wild-type RVFV and mosquitoes hatched from field-collected eggs confirmed the vector competence of Cx. pipiens mosquitoes from the Netherlands. To subsequently investigate transmission of the virus under more natural conditions, mosquitoes were allowed to feed on RVFV-infected lambs during the viremic period. We found that RVFV is efficiently transmitted from lambs to mosquitoes, although transmission was restricted to peak viremia. Interestingly, in the mosquito-exposed skin samples, replication of RVFV was detected in previously unrecognized target cells. We here report the vector competence of Cx. pipiens mosquitoes from the Netherlands for RVFV. Both laboratory

  2. Reclamation of mosquito breeding sites using Landsat-8 remote sensing data: A case study of Birnin Kebbi, Nigeria

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    Amusuk, Danboyi Joseph; Hashim, Mazlan; Beiranvand Pour, Amin

    2016-06-01

    It is believed by recent releases of World Health Organization (WHO) that more than half of the world's population (3.2 billion) live in areas that are at risk of malaria transmission. Although increased efforts are dramatically reducing the malaria burden in some places where the rate of new cases indicates a fall by 37% globally and 60% death rate. Unfortunately, the subSaharan Africa still shares 89% of malaria and 91% of malaria deaths. Essentially, attacking the causative vectors and reclamation of the vector breeding sites could be remarkable for the rolling back the malaria epidemic project. Consequently, it is essential to explore the possibility of using recent Landsat-8 data remote sensing data and applications of Geographic Information System (GIS) technique in contributing to the realization of this objective. This investigation used for identifying mosquito breeding habitat (Derelict Ponds) zones the application of supervised classification of the Landsat-8 image in conjunction with GIS layering which allowed identification of high risk prone regions for mosquito breeding habitat. The methodology delineated 10 spatial locations of the Derelict Ponds (DP) spread around the Birnin Kebbi urban environment. Moreover, the results combined with comparative analysis of the link between warm climatic (temperature and rainfall data) conditions and Malaria prevalence that is associated with urban poverty. This study indicates that the application of Landsat-8 data and GIS techniques can be a useful tool for planning and management of environmental health and mapping of hot spot environmental problem areas.

  3. An Educational Interventional Study to Assess Awareness about Mosquito Breeding, Diseases Caused and Protective Measures Against them among Families Residing in an Urban Slum of Indore City

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    Deepa Raghunath

    2013-08-01

    Full Text Available Background: Community participation plays an important role in control of Mosquito borne diseases. This study tries to assess impact of educational intervention on various aspects of mosquito borne diseases in an urban slum. Methodology: An educational interventional study was done in 200 families residing in a slum (Badi Gwaltoli which is in field practice area of Urban Health Centre attached to Department of Community Medicine of M.G.M.Medical College, Indore. A pretested semi-structured questionnaire was administered to the Head of the family which studied their awareness and perception regarding breeding sites and biting habits of mosquitoes, diseases spread by them and personal protective measures used, followed by an educational intervention and post assessment. Data was entered into Microsoft excel spread sheet and analysed using SPSS version 20 software. Results: 46% of study population knew the correct breeding season of mosquitoes (monsoon season during pre-intervention and 68% of the population post- intervention (p- value 0.004. When asked at what time mosquitoes bite the most, maximum number (92% of people said that mosquitoes bite most in the evening and night, while only 6% and 2% were for morning and noon, respectively. Only 3.5% of the population who knew about breeding sites knew about artificial collections of water. Majority said mosquito breed in dirty stagnant water (78.5%. About 96%of the study population was aware that mosquitoes spread diseases. However, only 33.3%of respondents knew correctly about the diseases spread which improved to 68% in the post-intervention period (p-value=.000. 46% knew all the protection measures against mosquitoes in the pre-intervention which increased to 86% in the post intervention (p.value-.005. Conclusion: Awareness about Aedes mosquitoes and its habits is quite poor and many people still believe that only dirty water serves as a breeding place in mosquitoes. Regular IEC sessions

  4. Root herbivory indirectly affects above- and below-ground community members and directly reduces plant performance

    NARCIS (Netherlands)

    Barber, N.A.; Milano, N.J.; Kiers, E.T.; Theis, N.; Bartolo, V.; Hazzard, R.V.; Adler, L.S.

    2015-01-01

    There is a widespread recognition that above- and below-ground organisms are linked through their interactions with host plants that span terrestrial subsystems. In addition to direct effects on plants, soil organisms such as root herbivores can indirectly alter interactions between plants and other

  5. Above-ground and below-ground plant responses to fertilization in two subarctic ecosystems

    NARCIS (Netherlands)

    Veen, G.F.; Sundqvist, Maja K.; Metcalfe, D.; Wilson, S.D.

    2015-01-01

    Soil nutrient supply is likely to change in the Arctic due to altered process rates associated with climate change. Here, we compare the responses of herbaceous tundra and birch forest understory to fertilization, considering both above- and below-ground responses. We added nitrogen and phosphorus

  6. Fertilization Increases Below-Ground Carbon Sequestration of Loblolly Pine Plantations

    Science.gov (United States)

    K.H. Johnsen; J.R. Butnor; C. Maier; R. Oren; R. Pangle; L. Samuelson; J. Seiler; S.E. McKeand; H.L. Allen

    2001-01-01

    The extent of fertilization of southern pine forests is increasing rapidly; industrial fertilization increased from 16,200 ha per year in 1988, to 344,250 ha in 1998. Fertilization increases stand productivity and can increase carbon (C) sequestration by: 1) increasing above-ground standing C; 2) increasing C stored in forest products; and 3) increasing below-ground...

  7. POLICY FRAMEWORK FOR UTILIZATION AND CONSERVATION OF BELOW-GROUND BIODIVERSITY IN KENYA

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    Celline Achieng

    2009-10-01

    Full Text Available The reasons for the lack of inclusion of below-ground biodiversity in the Kenyan policy and legal framework were sought. Gaps were identified in the relevant sectoral policies and laws in regard to the domestication of the Convention on Biological Diversity (CBD. Below -ground biodiversity had no specific schedule in any of the sectoral laws. Most sectoral laws were particular about the larger biodiversity and soils but had no mention of below-ground biodiversity. Material Transfer Agreements and Material Acquisition Agreements that are regarded as tools of domestication of the CBD to guide transfers, exchanges and acquisition of soil organisms lacked a regulating policy. The lack of regulating policy could be attributed to the delay in approval of draft regulations by the Ministry of Environment while the lack of inclusion of below-ground biodiversity in Kenya’s legal and policy framework could be as a result of lack of awareness and appreciation among stakeholders.

  8. Characterization of Mosquito Breeding Sites in and in the Vicinity of ...

    African Journals Online (AJOL)

    RESULTS: A total of 301 aquatic habitats were surveyed for mosquito larvae; in 32.56% (n=301) only Anopheles, in 27.91% only Culex, both genera were found mixed in 21.59% and no mosquito larvae were found in 17.94%. The findings depicted that dissolved oxygen (r = 0.34, p =0.04), pH (r = 0.35, p =0.03), conductivity ...

  9. Above- and below-ground net primary productivity across ten Amazonian forests on contrasting soils

    Directory of Open Access Journals (Sweden)

    L. E. O. C. Aragão

    2009-12-01

    Full Text Available The net primary productivity (NPP of tropical forests is one of the most important and least quantified components of the global carbon cycle. Most relevant studies have focused particularly on the quantification of the above-ground coarse wood productivity, and little is known about the carbon fluxes involved in other elements of the NPP, the partitioning of total NPP between its above- and below-ground components and the main environmental drivers of these patterns. In this study we quantify the above- and below-ground NPP of ten Amazonian forests to address two questions: (1 How do Amazonian forests allocate productivity among its above- and below-ground components? (2 How do soil and leaf nutrient status and soil texture affect the productivity of Amazonian forests? Using a standardized methodology to measure the major elements of productivity, we show that NPP varies between 9.3±1.3 Mg C ha−1 yr−1 (mean±standard error, at a white sand plot, and 17.0±1.4 Mg C ha−1 yr−1 at a very fertile Terra Preta site, with an overall average of 12.8±0.9 Mg C ha−1 yr−1. The studied forests allocate on average 64±3% and 36±3% of the total NPP to the above- and below-ground components, respectively. The ratio of above-ground and below-ground NPP is almost invariant with total NPP. Litterfall and fine root production both increase with total NPP, while stem production shows no overall trend. Total NPP tends to increase with soil phosphorus and leaf nitrogen status. However, allocation of NPP to below-ground shows no relationship to soil fertility, but appears to decrease with the increase of soil clay content.

  10. A below-ground herbivore shapes root defensive chemistry in natural plant populations

    Science.gov (United States)

    Huber, Meret; Bont, Zoe; Fricke, Julia; Brillatz, Théo; Aziz, Zohra; Gershenzon, Jonathan; Erb, Matthias

    2016-01-01

    Plants display extensive intraspecific variation in secondary metabolites. However, the selective forces shaping this diversity remain often unknown, especially below ground. Using Taraxacum officinale and its major native insect root herbivore Melolontha melolontha, we tested whether below-ground herbivores drive intraspecific variation in root secondary metabolites. We found that high M. melolontha infestation levels over recent decades are associated with high concentrations of major root latex secondary metabolites across 21 central European T. officinale field populations. By cultivating offspring of these populations, we show that both heritable variation and phenotypic plasticity contribute to the observed differences. Furthermore, we demonstrate that the production of the sesquiterpene lactone taraxinic acid β-d-glucopyranosyl ester (TA-G) is costly in the absence, but beneficial in the presence of M. melolontha, resulting in divergent selection of TA-G. Our results highlight the role of soil-dwelling insects for the evolution of plant defences in nature. PMID:27009228

  11. A below-ground herbivore shapes root defensive chemistry in natural plant populations.

    Science.gov (United States)

    Huber, Meret; Bont, Zoe; Fricke, Julia; Brillatz, Théo; Aziz, Zohra; Gershenzon, Jonathan; Erb, Matthias

    2016-03-30

    Plants display extensive intraspecific variation in secondary metabolites. However, the selective forces shaping this diversity remain often unknown, especially below ground. Using Taraxacum officinale and its major native insect root herbivore Melolontha melolontha, we tested whether below-ground herbivores drive intraspecific variation in root secondary metabolites. We found that high M. melolontha infestation levels over recent decades are associated with high concentrations of major root latex secondary metabolites across 21 central European T. officinale field populations. By cultivating offspring of these populations, we show that both heritable variation and phenotypic plasticity contribute to the observed differences. Furthermore, we demonstrate that the production of the sesquiterpene lactone taraxinic acid β-D-glucopyranosyl ester (TA-G) is costly in the absence, but beneficial in the presence of M. melolontha, resulting in divergent selection of TA-G. Our results highlight the role of soil-dwelling insects for the evolution of plant defences in nature. © 2016 The Author(s).

  12. Transmission of Rift Valley fever virus from European-breed lambs to Culex pipiens mosquitoes

    NARCIS (Netherlands)

    Vloet, Rianka P.M.; Vogels, Chantal B.F.; Koenraadt, Constantianus J.M.; Pijlman, Gorben P.; Eiden, Martin; Gonzales, Jose L.; Keulen, van Lucien J.M.; Wichgers Schreur, Paul J.; Kortekaas, Jeroen

    2017-01-01

    Background: Rift Valley fever virus (RVFV) is a mosquito-borne bunyavirus of the genus Phlebovirus that is highly pathogenic to ruminants and humans. The disease is currently confined to Africa and the Arabian Peninsula, but globalization and climate change may facilitate introductions of the virus

  13. Breeding of Anopheles mosquitoes in irrigated areas of South Punjab, Pakistan

    DEFF Research Database (Denmark)

    Herrel, N; Amerasinghe, F P; Ensink, J

    2001-01-01

    As part of investigations on potential linkages between irrigation and malaria transmission, all surface water bodies in and around three villages along an irrigation distributary in South Punjab, Pakistan, were surveyed for anopheline mosquito larvae (Diptera: Culicidae) from April 1999 to March...

  14. Sustainable urban development and human health: septic tank as a major breeding habitat of mosquito vectors of human diseases in south-eastern Nigeria.

    Science.gov (United States)

    Nwoke, B E; Nduka, F O; Okereke, O M; Ehighibe, O C

    1993-02-01

    Septic tank mosquitoes in Abia State University Okigwe, south-eastern Nigeria were studied using exit traps between November 1988 and April 1989. The results were revealing and striking. Apart from the common septic tank mosquitoes, Culex p. quinquefasciatus, Cu. cinereus and Aedes aegypti, which have been previously commonly found breeding in ammonia and nitrate-rich waters of latrines and septic tanks, the other species, Cu. horridus, Cu. tigripes and Aedes vittatus, have not been commonly reported as colonizing septic tanks in Nigeria. Three out of these six mosquito species observed are vectors of human diseases: Aedes aegypti and Aedes vittatus are vectors of Yellow fever and Cu. p. quinquefasciatus is a potential vector of Bancroftian filariasis and a world-wide vector of various arboviruses. The fact that these mosquito vectors are able to breed in highly polluted waters of septic tanks during the harsh dry months when most surface water bodies are dry is epidemiologically important. The breeding of these mosquito vectors of human diseases around human dwellings indicates an intense man-vector contact creating a high level risk to the crowded urban population. The public health implications of this urbanization/modernization problem and solutions are discussed.

  15. The effect of West Nile virus perceptions and knowledge on protective behavior and mosquito breeding in residential yards in Upstate New York

    NARCIS (Netherlands)

    Tuiten, W.; Koenraadt, C.J.M.; McComas, K.; Harrington, L.C.

    2009-01-01

    A knowledge, attitudes, and practices (KAP) questionnaire combined with entomological surveys of residential mosquito-breeding sites were conducted in two Upstate New York neighborhoods. We tested the hypothesis that “correct” West Nile virus (WNV) knowledge and perceptions correspond with the use

  16. Allometric scaling relationship between above- and below-ground biomass within and across five woody seedlings.

    Science.gov (United States)

    Cheng, Dongliang; Ma, Yuzhu; Zhong, Quanling; Xu, Weifeng

    2014-10-01

    Allometric biomass allocation theory predicts that leaf biomass (M L ) scaled isometrically with stem (M S ) and root (M R ) biomass, and thus above-ground biomass (leaf and stem) (M A ) and root (M R ) scaled nearly isometrically with below-ground biomass (root) for tree seedlings across a wide diversity of taxa. Furthermore, prior studies also imply that scaling constant should vary with species. However, litter is known about whether such invariant isometric scaling exponents hold for intraspecific biomass allocation, and how variation in scaling constants influences the interspecific scaling relationship between above- and below-ground biomass. Biomass data of seedlings from five evergreen species were examined to test scaling relationships among biomass components across and within species. Model Type II regression was used to compare the numerical values of scaling exponents and constants among leaf, stem, root, and above- to below-ground biomass. The results indicated that M L and M S scaled in an isometric or a nearly isometric manner with M R , as well as M A to M R for five woody species. Significant variation was observed in the Y-intercepts of the biomass scaling curves, resulting in the divergence for intraspecific scaling and interspecific scaling relationships for M L versus M S and M L versus M R , but not for M S versus M R and M A versus M R . We conclude, therefore, that a nearly isometric scaling relationship of M A versus M R holds true within each of the studied woody species and across them irrespective the negative scaling relationship between leaf and stem.

  17. Space sequestration below ground in old-growth spruce-beech forests – signs for facilitation?

    Directory of Open Access Journals (Sweden)

    Andreas eBolte

    2013-08-01

    Full Text Available Scientists are currently debating the effects of mixing tree species for the complementary resource acquisition in forest ecosystems. In four unmanaged old-growth spruce-beech forests in strict nature reserves in southern Sweden and northern Germany we assessed forest structure and fine rooting profiles and traits (≤ 2 mm by fine root sampling and the analysis of fine root morphology and biomass. These studies were conducted in selected tree groups with four different interspecific competition perspectives: (1 spruce as a central tree, (2 spruce as competitor, (3 beech as a central tree, and (4 beech as competitor. Mean values of life fine root attributes like biomass (FRB, length (FRL, and root area index (RAI were significantly lower for spruce than for beech in mixed stands. Vertical profiles of fine root attributes adjusted to one unit of basal area (BA exhibited partial root system stratification when central beech is growing with spruce competitors. In this constellation, beech was able to raise its specific root length (SRL and therefore soil exploration efficiency in the subsoil, while increasing root biomass partitioning into deeper soil layers. According to relative values of fine root attributes (rFRA, asymmetric below-ground competition was observed favoring beech over spruce, in particular when central beech trees are admixed with spruce competitors. We conclude that beech fine rooting is facilitated in the presence of spruce by lowering competitive pressure compared to intraspecific competition whereas the competitive pressure for spruce is increased by beech admixture. Our findings underline the need of spatially differentiated approaches to assess interspecific competition below ground. Single-tree approaches and simulations of below-ground competition are required to focus rather on microsites populated by tree specimens as the basic spatial study area.

  18. EnviroAtlas - Below Ground Live Tree Biomass Carbon Storage for the Conterminous United States- Forested

    Science.gov (United States)

    This EnviroAtlas dataset includes the average below ground live tree root dry biomass estimate for the Watershed Boundary Dataset (WBD) 12-digit Hydrologic Unit (HUC) in kg/m from the 2000 National Biomass and Carbon Dataset developed by the Woods Hole Research Center. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  19. ABOVE AND BELOW GROUND INTERACTIONS IN THE AGROFORESTAL ASSOCIATION 'RED CEDAR-PERSIAN LIME-CHAYA'

    Directory of Open Access Journals (Sweden)

    Jesús Mao Estanislao Aguilar-Luna

    2011-05-01

    Full Text Available Above and below ground interactions were analyzed in the agroforestal association 'red cedar-Persian lime-chaya', to know the initial optimum planting density (PD, in Quintana Roo, Mexico. Red cedar and Persian lime were placed in a 'Nelder' circle of 3154 m2 which consisted of 20 concentric circles alternating red cedars and Persian limes to 1.50 m apart and 10 plants per circle; chaya rectangular frame was set at 1.50 x 3.00 m, superimposed on the 'Nelder' circle. Defined eight PD 2602 to 3772 pl·ha-1 with 10 repetitions, to evaluate the length of main root (LMR, radical exploration range (RER, below ground interaction (BGI, plant height (PH, crown diameter (CD, above ground interaction (AGI and soil fertility (SF. The growth intraspecific he present statistical difference (P≤0.05 when moving from one PD to another PD, while the growth interespecific manifested different growth habit. The agroforestal association propitious in soil decreased phosphorous ±2 %, and increases organic matter ±14 % and nitrogen ±10 % on all PD. The BGI was increased in direct relation with the PD, reaching its highest value (64±5.8 % to 3772 pl·ha-1; the AGI also increased in direct relation with the PD, its highest value (52±3.1 % went to 3772 pl·ha-1; therefore, to higher PD increased BGI and AGI, at 20 months after planting.

  20. Mind the Roots: Phenotyping Below-Ground Crop Diversity and Its Influence on Final Yield

    Science.gov (United States)

    Nieters, C.; Guadagno, C. R.; Lemli, S.; Hosseini, A.; Ewers, B. E.

    2017-12-01

    Changes in global climate patterns and water regimes are having profound impacts on worldwide crop production. An ever-growing population paired with increasing temperatures and unpredictable periods of severe drought call for accurate modeling of future crop yield. Although novel approaches are being developed in high-throughput, above-ground image phenotyping, the below-ground plant system is still poorly phenotyped. Collection of plant root morphology and hydraulics are needed to inform mathematical models to reliably estimate yields of crops grown in sub-optimal conditions. We used Brassica rapa to inform our model as it is a globally cultivated crop with several functionally diverse cultivars. Specifically, we use 7 different accessions from oilseed (R500 and Yellow Sarson), leafy type (Pac choi and Chinese cabbage), a vegetable turnip, and two Wisconsin Fast Plants (Imb211 and Fast Plant self-compatible), which have shorter life cycles and potentially large differences in allocation to roots. Bi-weekly, we harvested above and below-ground biomass to compare the varieties in terms of carbon allocation throughout their life cycle. Using WinRhizo software, we analyzed root system length and surface area to compare and contrast root morphology among cultivars. Our results confirm that root structural characteristics are crucial to explain plant water use and carbon allocation. The root:shoot ratio reveals a significant (p physiological traits such as gas exchange, chlorophyll content, and chlorophyll a fluorescence. A thorough analysis of the root system will clarify carbon dynamics and hydraulics at the whole-plant level, improving final yield predictions.

  1. Comparison of Model Predictions and Laboratory Observations of Transgene Frequencies in Continuously-Breeding Mosquito Populations

    Directory of Open Access Journals (Sweden)

    Laura Valerio

    2016-09-01

    Full Text Available The persistence of transgenes in the environment is a consideration in risk assessments of transgenic organisms. Combining mathematical models that predict the frequency of transgenes and experimental demonstrations can validate the model predictions, or can detect significant biological deviations that were neither apparent nor included as model parameters. In order to assess the correlation between predictions and observations, models were constructed to estimate the frequency of a transgene causing male sexual sterility in simulated populations of a malaria mosquito Anopheles gambiae that were seeded with transgenic females at various proportions. Concurrently, overlapping-generation laboratory populations similar to those being modeled were initialized with various starting transgene proportions, and the subsequent proportions of transgenic individuals in populations were determined weekly until the transgene disappeared. The specific transgene being tested contained a homing endonuclease gene expressed in testes, I-PpoI, that cleaves the ribosomal DNA and results in complete male sexual sterility with no effect on female fertility. The transgene was observed to disappear more rapidly than the model predicted in all cases. The period before ovipositions that contained no transgenic progeny ranged from as little as three weeks after cage initiation to as long as 11 weeks.

  2. Culex pipiens s.l. and Culex torrentium (Culicidae) in Wrocław area (Poland): occurrence and breeding site preferences of mosquito vectors.

    Science.gov (United States)

    Weitzel, Thomas; Jawień, Piotr; Rydzanicz, Katarzyna; Lonc, Elzbieta; Becker, Norbert

    2015-01-01

    Both ornithophilic mosquito species, Culex pipiens s.l. (L.) and Culex torrentium (Martini, 1925), occur sympatric in temperate Europe. They are presumed to be primary vectors of West Nile and Sindbis viruses. Differentiation of these morphologically similar Culex species is essential for evaluation of different vector roles, for mosquito surveillance and integrated control strategies. Cx. torrentium has been neglected or erroneously determined as Cx. pipiens s.l. in some previous studies, because only males of both species can be diagnosed reliably by morphology. Thus, knowledge about species abundance, geographical distribution, breeding site preferences and the zoonotic risk assessment is incomplete also in Poland. In Wrocław area (Silesian Lowland), besides typical urban breeding sites, huge sewage irrigation fields provide suitable breeding conditions for Culex species. They are also inhabited by 180 resident and migratory bird species serving as potential virus reservoirs. In this study, morphology of larvae and males as well as species diagnostic enzyme markers, namely adenylate kinase (AK) and 2-hydroxybutyrate dehydrogenase (HBDH), were used to discriminate Cx. pipiens s.l. and Cx. torrentium. In a total of 650 Culex larvae from 24 natural and artificial breeding sites, Cx. pipiens s.l. had a proportion of 94.0% and Cx. torrentium only 6.0%. It could be shown that both species are well adapted to various breeding site types like ditches, catch basins, flower pots and buckets with diverse water quality. Cx. torrentium preferred more artificial water containers in urban surrounding (12% species proportion), whereas in semi-natural breeding sites, Cx. torrentium was rare (3%). In 12 of 24 breeding sites, larvae of both species have been found associated.

  3. Mapping urban and peri-urban breeding habitats of Aedes mosquitoes using a fuzzy analytical hierarchical process based on climatic and physical parameters

    Directory of Open Access Journals (Sweden)

    Muhammad Shahzad Sarfraz

    2014-12-01

    Full Text Available The spread of dengue fever depends mainly on the availability of favourable breeding sites for its mosquito vectors around human dwellings. To investigate if the various factors influencing breeding habitats can be mapped from space, dengue indices, such as the container index, the house index and the Breteau index, were calculated from Ministry of Public health data collected three times annually in Phitsanulok, Thailand between 2009 and 2011. The most influential factors were found to be temperature, humidity, rainfall, population density, elevation and land cover. Models were worked out using parameters mostly derived from freely available satellite images and fuzzy logic software with parameter synchronisation and a predication algorithm based on data mining and the Decision Tree method. The models developed were found to be sufficiently flexible to accommodate additional parameters and sampling data that might improve prediction of favourable breeding hotspots. The algorithm applied can not only be used for the prediction of near real-time scenarios with respect to dengue, but can also be applied for monitoring other diseases influenced by environmental and climatic factors. The multi-criteria model presented is a cost-effective way of identifying outbreak hotspots and early warning systems lend themselves for development based on this strategy. The proposed approach demonstrates the successful utilisation of remotely sensed images to map mosquito breeding habitats.

  4. Redefining fine roots improves understanding of below-ground contributions to terrestrial biosphere processes.

    Science.gov (United States)

    McCormack, M Luke; Dickie, Ian A; Eissenstat, David M; Fahey, Timothy J; Fernandez, Christopher W; Guo, Dali; Helmisaari, Heljä-Sisko; Hobbie, Erik A; Iversen, Colleen M; Jackson, Robert B; Leppälammi-Kujansuu, Jaana; Norby, Richard J; Phillips, Richard P; Pregitzer, Kurt S; Pritchard, Seth G; Rewald, Boris; Zadworny, Marcin

    2015-08-01

    Fine roots acquire essential soil resources and mediate biogeochemical cycling in terrestrial ecosystems. Estimates of carbon and nutrient allocation to build and maintain these structures remain uncertain because of the challenges of consistently measuring and interpreting fine-root systems. Traditionally, fine roots have been defined as all roots ≤ 2 mm in diameter, yet it is now recognized that this approach fails to capture the diversity of form and function observed among fine-root orders. Here, we demonstrate how order-based and functional classification frameworks improve our understanding of dynamic root processes in ecosystems dominated by perennial plants. In these frameworks, fine roots are either separated into individual root orders or functionally defined into a shorter-lived absorptive pool and a longer-lived transport fine-root pool. Using these frameworks, we estimate that fine-root production and turnover represent 22% of terrestrial net primary production globally - a c. 30% reduction from previous estimates assuming a single fine-root pool. Future work developing tools to rapidly differentiate functional fine-root classes, explicit incorporation of mycorrhizal fungi into fine-root studies, and wider adoption of a two-pool approach to model fine roots provide opportunities to better understand below-ground processes in the terrestrial biosphere. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  5. Quantifying below-ground nitrogen of legumes: Optimizing procedures for 15N shoot-labelling

    International Nuclear Information System (INIS)

    Khan, D.F.; Peoples, M.B.; Herridge, D.F.

    2003-01-01

    Quantifying below-ground nitrogen (N) of legumes is fundamental to understanding their effects on soil mineral N fertility and on the N economies of following or companion crops in legume-based rotations. Methodologies based on 15 N-labelling of whole plants with subsequent measurement of 15 N in recovered plant parts and in the root-zone soil have proved promising. We report four glasshouse experiments with objectives to develop appropriate protocols for in situ 15 N labelling of four pulses, faba bean (Vicia faba), chickpea (Cicer arietinum), mung bean (Vigna radiata) and pigeon pea (Cajanus cajan). Treatments included 15 N-urea concentration, feeding technique, leaflet/petiole position, and frequency of feeding. Nitrogen- 15 -labelling via the leaf-flap was best for faba bean, mung and pigeon pea, whilst petiole feeding was best for chickpea, in all cases using 0.2-mL volumes of 0.5% urea (98 atom% 15 N excess). The implications of uneven enrichment of the nodulated roots because of effects of the 15 N-depleted nodules when calculating root-derived N in soil are discussed. (author)

  6. Links between plant litter chemistry, species diversity, and below-ground ecosystem function.

    Science.gov (United States)

    Meier, Courtney L; Bowman, William D

    2008-12-16

    Decomposition is a critical source of plant nutrients, and drives the largest flux of terrestrial C to the atmosphere. Decomposing soil organic matter typically contains litter from multiple plant species, yet we lack a mechanistic understanding of how species diversity influences decomposition processes. Here, we show that soil C and N cycling during decomposition are controlled by the composition and diversity of chemical compounds within plant litter mixtures, rather than by simple metrics of plant species diversity. We amended native soils with litter mixtures containing up to 4 alpine plant species, and we used 9 litter chemical traits to evaluate the chemical composition (i.e., the identity and quantity of compounds) and chemical diversity of the litter mixtures. The chemical composition of the litter mixtures was the strongest predictor of soil respiration, net N mineralization, and microbial biomass N. Soil respiration and net N mineralization rates were also significantly correlated with the chemical diversity of the litter mixtures. In contrast, soil C and N cycling rates were poorly correlated with plant species richness, and there was no relationship between species richness and the chemical diversity of the litter mixtures. These results indicate that the composition and diversity of chemical compounds in litter are potentially important functional traits affecting decomposition, and simple metrics like plant species richness may fail to capture variation in these traits. Litter chemical traits therefore provide a mechanistic link between organisms, species diversity, and key components of below-ground ecosystem function.

  7. Arbuscular mycorrhizal fungi alter above- and below-ground chemical defense expression differentially among Asclepias species

    Directory of Open Access Journals (Sweden)

    Rachel L Vannette

    2013-09-01

    Full Text Available Belowground symbionts of plants can have substantial influence on plant growth and nutrition. Recent work demonstrates that mycorrhizal fungi can affect plant resistance to herbivory and the performance of above and belowground herbivores. Although these examples emerge from diverse systems, it is unclear if plant species that express similar defensive traits respond similarly to fungal colonization, but comparative work may inform this question. To examine the effects of arbuscular mycorrhizal fungi (AMF on the expression of chemical resistance, we inoculated 8 species of Asclepias (milkweed--which all produce toxic cardenolides--with a community of AMF. We quantified plant biomass, foliar and root cardenolide concentration and composition, and assessed evidence for a growth-defense tradeoff in the presence and absence of AMF. As expected, total foliar and root cardenolide concentration varied among milkweed species. Importantly, the effect of mycorrhizal fungi on total foliar cardenolide concentration also varied among milkweed species, with foliar cardenolides increasing or decreasing, depending on the plant species. We detected a phylogenetic signal to this variation; AMF fungi reduced foliar cardenolide concentrations to a greater extent in the clade including A. curassavica than in the clade including A. syriaca. Moreover, AMF inoculation shifted the composition of cardenolides in above- and below-ground plant tissues in a species-specific fashion. Mycorrhizal inoculation changed the relative distribution of cardenolides between root and shoot tissue in a species-specific fashion, but did not affect cardenolide diversity or polarity. Finally, a tradeoff between plant growth and defense in non-mycorrhizal plants was mitigated completely by AMF inoculation. Overall, we conclude that the effects of AMF inoculation on the expression of chemical resistance can vary among congeneric plant species, and ameliorate tradeoffs between growth and

  8. Arbuscular mycorrhizal fungi alter above- and below-ground chemical defense expression differentially among Asclepias species

    Science.gov (United States)

    Vannette, Rachel L.; Hunter, Mark D.; Rasmann, Sergio

    2013-01-01

    Below-ground (BG) symbionts of plants can have substantial influence on plant growth and nutrition. Recent work demonstrates that mycorrhizal fungi can affect plant resistance to herbivory and the performance of above- (AG) and BG herbivores. Although these examples emerge from diverse systems, it is unclear if plant species that express similar defensive traits respond similarly to fungal colonization, but comparative work may inform this question. To examine the effects of arbuscular mycorrhizal fungi (AMF) on the expression of chemical resistance, we inoculated 8 species of Asclepias (milkweed)—which all produce toxic cardenolides—with a community of AMF. We quantified plant biomass, foliar and root cardenolide concentration and composition, and assessed evidence for a growth-defense tradeoff in the presence and absence of AMF. As expected, total foliar and root cardenolide concentration varied among milkweed species. Importantly, the effect of mycorrhizal fungi on total foliar cardenolide concentration also varied among milkweed species, with foliar cardenolides increasing or decreasing, depending on the plant species. We detected a phylogenetic signal to this variation; AMF fungi reduced foliar cardenolide concentrations to a greater extent in the clade including A. curassavica than in the clade including A. syriaca. Moreover, AMF inoculation shifted the composition of cardenolides in AG and BG plant tissues in a species-specific fashion. Mycorrhizal inoculation changed the relative distribution of cardenolides between root and shoot tissue in a species-specific fashion, but did not affect cardenolide diversity or polarity. Finally, a tradeoff between plant growth and defense in non-mycorrhizal plants was mitigated completely by AMF inoculation. Overall, we conclude that the effects of AMF inoculation on the expression of chemical resistance can vary among congeneric plant species, and ameliorate tradeoffs between growth and defense. PMID:24065971

  9. A stable isotopic view on lianas' and trees' below ground competition for water

    Science.gov (United States)

    De Deurwaerder, Hannes; Hervé-Fernández, Pedro; Stahl, Clément; Bonal, Damien; Burban, Benoît; Petronelli, Pascal; Boeckx, Pascal; Verbeeck, Hans

    2017-04-01

    Various studies highlight an increase in liana abundance and biomass in the neotropics in the last decades. To date, the reason why this growth form expresses this trend is still unclear. One of the proposed hypotheses ascribes tropical lianas, in comparison to tropical trees, of being able to adapt better to increased drought conditions resulting from climate change. Moreover, lianas presumably have a deeper root system, providing access to deeper soil layers less susceptible for dehydration during drought events. A dual stable water isotopic approach (δ18O and δ2H) enables studying vegetation below ground competition and in combination with Bayesian mixing models can provide insight in the fractional contribution of distinct soil layer depths. In this perspective, precipitation (bulk and through fall), bulk soil (at different depths), stream and xylem water of both lianas and trees were sampled between October 7-13, 2015. The study focusses on two distinct plots differing in soil texture (sand and clay), localized in close vicinity of the Guyana flux tower at Paracou (French Guyana). Our study highlights the erroneous of the deep tap root hypothesis and provides new insights in water and nutrient competition between tropical lianas and trees during dry season. Lianas isotopic signature is enriched compared to those of trees. This can be linked to water source depth and soil seasonal replenishment. Moreover, liana displaying a very active soil surface root activity, efficiently capturing the low amount of dry season precipitation, while trees show to tap the deeper and less drought susceptible soil layers. A strategy, which not only results in a spatial niche separation in the underground competition for water, but it also provides lianas with a definite advantage in nutrient competition.

  10. Mapping Above- and Below-Ground Carbon Pools in Boreal Forests: The Case for Airborne Lidar.

    Science.gov (United States)

    Kristensen, Terje; Næsset, Erik; Ohlson, Mikael; Bolstad, Paul V; Kolka, Randall

    2015-01-01

    A large and growing body of evidence has demonstrated that airborne scanning light detection and ranging (lidar) systems can be an effective tool in measuring and monitoring above-ground forest tree biomass. However, the potential of lidar as an all-round tool for assisting in assessment of carbon (C) stocks in soil and non-tree vegetation components of the forest ecosystem has been given much less attention. Here we combine the use airborne small footprint scanning lidar with fine-scale spatial C data relating to vegetation and the soil surface to describe and contrast the size and spatial distribution of C pools within and among multilayered Norway spruce (Picea abies) stands. Predictor variables from lidar derived metrics delivered precise models of above- and below-ground tree C, which comprised the largest C pool in our study stands. We also found evidence that lidar canopy data correlated well with the variation in field layer C stock, consisting mainly of ericaceous dwarf shrubs and herbaceous plants. However, lidar metrics derived directly from understory echoes did not yield significant models. Furthermore, our results indicate that the variation in both the mosses and soil organic layer C stock plots appears less influenced by differences in stand structure properties than topographical gradients. By using topographical models from lidar ground returns we were able to establish a strong correlation between lidar data and the organic layer C stock at a stand level. Increasing the topographical resolution from plot averages (~2000 m2) towards individual grid cells (1 m2) did not yield consistent models. Our study demonstrates a connection between the size and distribution of different forest C pools and models derived from airborne lidar data, providing a foundation for future research concerning the use of lidar for assessing and monitoring boreal forest C.

  11. Speciation below ground: Tempo and mode of diversification in a radiation of endogean ground beetles.

    Science.gov (United States)

    Andújar, Carmelo; Pérez-González, Sergio; Arribas, Paula; Zaballos, Juan P; Vogler, Alfried P; Ribera, Ignacio

    2017-11-01

    Dispersal is a critical factor determining the spatial scale of speciation, which is constrained by the ecological characteristics and distribution of a species' habitat and the intrinsic traits of species. Endogean taxa are strongly affected by the unique qualities of the below-ground environment and its effect on dispersal, and contrasting reports indicate either high dispersal capabilities favoured by small body size and mediated by passive mechanisms, or low dispersal due to restricted movement and confinement inside the soil. We studied a species-rich endogean ground beetle lineage, Typhlocharina, including three genera and more than 60 species, as a model for the evolutionary biology of dispersal and speciation in the deep soil. A time-calibrated molecular phylogeny generated from >400 individuals was used to delimit candidate species, to study the accumulation of lineages through space and time by species-area-age relationships and to determine the geographical structure of the diversification using the relationship between phylogenetic and geographic distances across the phylogeny. Our results indicated a small spatial scale of speciation in Typhlocharina and low dispersal capacity combined with sporadic long distance, presumably passive dispersal events that fuelled the speciation process. Analysis of lineage growth within Typhlocharina revealed a richness plateau correlated with the range of distribution of lineages, suggesting a long-term species richness equilibrium mediated by density dependence through limits of habitat availability. The interplay of area- and age-dependent processes ruling the lineage diversification in Typhlocharina may serve as a general model for the evolution of high species diversity in endogean mesofauna. © 2017 John Wiley & Sons Ltd.

  12. Above- and below-ground methane fluxes and methanotrophic activity in a landfill-cover soil.

    Science.gov (United States)

    Schroth, M H; Eugster, W; Gómez, K E; Gonzalez-Gil, G; Niklaus, P A; Oester, P

    2012-05-01

    Landfills are a major anthropogenic source of the greenhouse gas methane (CH(4)). However, much of the CH(4) produced during the anaerobic degradation of organic waste is consumed by methanotrophic microorganisms during passage through the landfill-cover soil. On a section of a closed landfill near Liestal, Switzerland, we performed experiments to compare CH(4) fluxes obtained by different methods at or above the cover-soil surface with below-ground fluxes, and to link methanotrophic activity to estimates of CH(4) ingress (loading) from the waste body at selected locations. Fluxes of CH(4) into or out of the cover soil were quantified by eddy-covariance and static flux-chamber measurements. In addition, CH(4) concentrations at the soil surface were monitored using a field-portable FID detector. Near-surface CH(4) fluxes and CH(4) loading were estimated from soil-gas concentration profiles in conjunction with radon measurements, and gas push-pull tests (GPPTs) were performed to quantify rates of microbial CH(4) oxidation. Eddy-covariance measurements yielded by far the largest and probably most representative estimates of overall CH(4) emissions from the test section (daily mean up to ∼91,500μmolm(-2)d(-1)), whereas flux-chamber measurements and CH(4) concentration profiles indicated that at the majority of locations the cover soil was a net sink for atmospheric CH(4) (uptake up to -380μmolm(-2)d(-1)) during the experimental period. Methane concentration profiles also indicated strong variability in CH(4) loading over short distances in the cover soil, while potential methanotrophic activity derived from GPPTs was high (v(max)∼13mmolL(-1)(soil air)h(-1)) at a location with substantial CH(4) loading. Our results provide a basis to assess spatial and temporal variability of CH(4) dynamics in the complex terrain of a landfill-cover soil. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Above- and below-ground microclimate of grow tubes in an organic mulch-incorporated, raised bed system for blueberry

    Science.gov (United States)

    Grow tubes are well established in forestry and are gaining attention in establishing some woody perennial crops. To date, microclimate descriptions have addressed the above-ground environment, but a mulched raised bed system with organic mulch-incorporated soil requires both above- and below-ground...

  14. Above- and below-ground competition in high and low irradiance: tree seedling responses to a competing liana Byttneria grandifolia

    NARCIS (Netherlands)

    Chen, J.Y.; Bongers, F.; Cao, K.F.; Cai, Z.Q.

    2008-01-01

    Abstract: In tropical forests, trees compete not only with other trees, but also with lianas, which may limit tree growth and regeneration. Liana effects may depend on the availability of above- and below-ground resources and differ between tree species. We conducted a shade house experiment to test

  15. Competitive responses of seedlings and understory plants in longleaf pine woodlands: separating canopy influences above and below ground

    Science.gov (United States)

    Stephen D. Pecot; Robert J. Mitchell; Brian J. Palik; Barry Moser; J. Kevin Hiers

    2007-01-01

    A trenching study was used to investigate above- and below-ground competition in a longleaf pine (Pinus palustris P. Mill.) woodland. Trenched and nontrenched plots were replicated in the woodland matrix, at gap edges, and in gap centers representing a range of overstory stocking. One-half of each plot received a herbicide treatment to remove the...

  16. Effects of above- and below-ground competition from shrubs on photosynthesis, transpiration and growth in Quercus robur L

    Science.gov (United States)

    Anna M. Jensen; Magnus Lof; Emile S. Gardiner

    2011-01-01

    For a tree seedling to successfully establish in dense shrubbery, it must maintain function under heterogeneous resource availability. We evaluated leaf-level acclimation in photosynthetic capacity, seedling-level transpiration, and seedling morphology and growth to gain an understanding of the effects of above- and below-ground competition on Quercus robur seedlings....

  17. Below-ground process responses to elevated CO2 and temperature: a discussion of observations, measurement methods, and models

    Science.gov (United States)

    Elise Pendall; Scott Bridgham; Paul J. Hanson; Bruce Hungate; David W. Kicklighter; Dale W. Johnson; Beverly E. Law; Yiqi Luo; J. Patrick Megonigal; Maria Olsrud; Michael G. Ryan; Shiqiang Wan

    2004-01-01

    Rising atmospheric CO2 and temperatures are probably altering ecosystem carbon cycling, causing both positive and negative feedbacks to climate. Below-ground processes play a key role in the global carbon (C) cycle because they regulate storage of large quantities of C, and are potentially very sensitive to direct and indirect effects of elevated...

  18. Diversity of mosquitoes and larval breeding preference based on physico-chemical parameters in Western Ghats, Tamilnadu, India

    Directory of Open Access Journals (Sweden)

    Periyasamy Senthamarai Selvan

    2015-06-01

    Full Text Available Objective: To study the diversity and distribution of mosquitoes in Western Ghats of Coimbatore and Nilgiris District, Tamilnadu, India. Methods: Random collections were carried out during August-2013 to July-2014 in cesspits, animal footprints, rock holes, tree holes, drainages at study areas of Marudhamalai, Valparai, Mettupalayam in Coimbatore District and Dhottapeta, Coonoor, Gudalur in Nilgiris District of Tamilnadu, India by using suction tube and kerosene pump. Mosquitoes were identified by standard entomological procedures. Results: A total of 1 018 mosquitoes (larvae and pupae were collected from all over the study areas comprising 6 genera and 23 species. They are, Culex mimulus, Culex pseudovishnui, Culex quinquefasciatus, Culex vishnui, Culex khazani, Culex uniformis, Heizmannia chandi, Heizmannia grenii, Heizmannia indica, Oclerotatus anureostriatus, Oclerotatus albotaeniatis, Oclerotatus deccanus, Oclerotatus gubernatoris, Aedes aegypti, Aedes albopictus, Aedes edwardsi, Aedes krombeini, Toxorhynchites minimus, Toxorhynchites splendens, Anopheles aitkenii, Anopheles barbirostris, Anopheles culiciformis and Anopheles maculatus. ShannonWeaver diversity index, Margalef’s index of richness and Simpsons dominance index was also studied. From 6 sites, the highest mosquitoes were collected from Marudhamalai (309 and the least mosquitoes were collected in Mettupalayam (68. The study determined whether physicochemical characteristics differ between habitats with high and low presence of mosquito larvae. Based on Margalef’s index of richness (Dmg, the highest values were present in Mettupalayam (5.214 study area and the lowest in Marudhamalai (3.837. It can be concluded from Shanon-Weaver index of diversity that, the highest values were present in Mettupalayam (2.947 and the least value were in Gudalur (2.410 during the study period. Conclusions: In areas with reservoirs of disease, mosquito abundance information can help to identify the

  19. Biological control of container-breeding mosquitoes, Aedes albopictus and Culex quinquefasciatus, in a Japanese island by release of Toxorhynchites splendens adults.

    Science.gov (United States)

    Miyagi, I; Toma, T; Mogi, M

    1992-07-01

    To control container-breeding mosquitoes in the small island of Minnajima (0.56 km2), northern Okinawa, Japan, laboratory-reared adults (aged 7-10 days) of Toxorhynchites splendens (Palawan strain), a mosquito with predatory larvae, were released repeatedly during 1984, 1986 and 1987. Thirteen species of mosquitoes (Diptera: Culicidae) occurred in artificial containers, ground pools or crab-holes on the island, the predominant species being Aedes (Stegomyia) albopictus and Culex (Culex) quinquefasciatus. Predatory mosquito larvae of Culex (Lutzia) fuscanus and Cx (Lt.) halifaxii were found commonly in wet containers. In the first year of study, during a period of 54 days from 13 May to 5 July 1984, totals of 879 female and 806 male adults of Tx.splendens were released on six occasions. Similarly, between 29 April and 30 August 1986, totals of 2920 female and 2878 male adult Tx.splendens were released. In the third study year, totals of 2041 female and 1783 male Tx.splendens were released on eight occasions during 199 days from 23 April to 7 November 1987. After adult releases at two sites, the immature stages of Tx.splendens were found in 164 out of 502 traps in 1984, 421 out of 933 traps in 1986, and 151 out of 502 traps in 1987. The number of immatures of Tx.splendens present in each trap varied from 1 to 40 in 1984, 1 to 29 in 1986 and 1 to 9 in 1987. Numbers of immatures of the target species found in the traps during August-September averaged 71.9/trap/month in 1984, 114.7/trap/month in 1986 and 36.0/trap/month in 1987, significantly less in the traps with Tx.splendens than in those without them. The present field studies indicated that, in this small island, approximately 250 adult female and 200 male Tx.splendens per month should be released from April to November, and the releases should be carried out every year, in order to control effectively the target mosquitoes Ae.albopictus and Cx quinquefasciatus breeding in artificial containers in Minnajima.

  20. Household survey of container-breeding mosquitoes and climatic factors influencing the prevalence of Aedes aegypti (Diptera: Culicidae) in Makkah City, Saudi Arabia

    Science.gov (United States)

    Aziz, Al Thabiany; Dieng, Hamady; Ahmad, Abu Hassan; Mahyoub, Jazem A; Turkistani, Abdulhafis M; Mesed, Hatabbi; Koshike, Salah; Satho, Tomomitsu; Salmah, MR Che; Ahmad, Hamdan; Zuharah, Wan Fatma; Ramli, Ahmad Saad; Miake, Fumio

    2012-01-01

    Objective To investigate the prevalence of container breeding mosquitoes with emphasis on the seasonality and larval habitats of Aedes aegypti (Ae. aegypti) in Makkah City, adjoining an environmental monitoring and dengue incidence. Methods Monthly visits were performed between April 2008 and March 2009 to randomly selected houses. During each visit, mosquito larvae were collected from indoors and outdoors containers by either dipping or pipetting. Mosquitoes were morphologically identified. Data on temperature, relative humidity, rain/precipitations during the survey period was retrieved from governmental sources and analyzed. Results The city was warmer in dry season (DS) than wet season (WS). No rain occurred at all during DS and even precipitations did fall, wetting events were much greater during WS. Larval survey revealed the co-breeding of Aedes, Culex and Anopheles in a variety of artificial containers in and around homes. 32 109 larvae representing 1st , 2nd, 3rd, and 4th stages were collected from 22 618 container habitats. Culicines was far the commonest and Aedes genus was as numerous as the Culex population. Ae. aegypti larval abundance exhibited marked temporal variations, overall, being usually more abundant during WS. Ten types of artificial containers were found with developing larvae. 70% of these habitats were located indoors. 71.42% of indoor containers were permanent and 28.58% was semi-permanent during WS. Cement tanks was the only container type permanent during DS. Ae. aegypti larval indices (CI, HI, BI) recorded were greater during WS. Conclusions Taken together, these results indicate a high risk of dengue transmission in the holy city. PMID:23569860

  1. UV-B-mediated changes on below-ground communities associated with the roots of Acer saccharum

    International Nuclear Information System (INIS)

    Klironomos, J.N.; Allen, M.F.

    1995-01-01

    1. Little is known about how exposure to UV-B radiation affects rhizosphere microbes. Rhizosphere organisms are fed primarily by root-derived substrates and fulfil functions such as mineralization, immobilization, decomposition, pathogeneity and improvement of plant nutrition; they form the base of the below-ground food web. 2. In this study, we exposed Sugar Maple (Acer saccharum) seedlings to UV-B radiation in order to determine if UV-B influences the activities of mycorrhizal and non-mycorrhizal fungi, bacteria and microbe-feeding arthropods in the rhizosphere. 3. Below-ground organisms are greatly affected by UV-B radiation. Overall, carbon-flow in the plant soil system was shifted from a mutualistic-closed, mycorrhizal-dominated system to an opportunist-open, saprobe/pathogen-dominated one. (author)

  2. Contribution of above- and below-ground plant traits to the structure and function of grassland soil microbial communities.

    Science.gov (United States)

    Legay, N; Baxendale, C; Grigulis, K; Krainer, U; Kastl, E; Schloter, M; Bardgett, R D; Arnoldi, C; Bahn, M; Dumont, M; Poly, F; Pommier, T; Clément, J C; Lavorel, S

    2014-10-01

    Abiotic properties of soil are known to be major drivers of the microbial community within it. Our understanding of how soil microbial properties are related to the functional structure and diversity of plant communities, however, is limited and largely restricted to above-ground plant traits, with the role of below-ground traits being poorly understood. This study investigated the relative contributions of soil abiotic properties and plant traits, both above-ground and below-ground, to variations in microbial processes involved in grassland nitrogen turnover. In mountain grasslands distributed across three European sites, a correlative approach was used to examine the role of a large range of plant functional traits and soil abiotic factors on microbial variables, including gene abundance of nitrifiers and denitrifiers and their potential activities. Direct effects of soil abiotic parameters were found to have the most significant influence on the microbial groups investigated. Indirect pathways via plant functional traits contributed substantially to explaining the relative abundance of fungi and bacteria and gene abundances of the investigated microbial communities, while they explained little of the variance in microbial activities. Gene abundances of nitrifiers and denitrifiers were most strongly related to below-ground plant traits, suggesting that they were the most relevant traits for explaining variation in community structure and abundances of soil microbes involved in nitrification and denitrification. The results suggest that consideration of plant traits, and especially below-ground traits, increases our ability to describe variation in the abundances and the functional characteristics of microbial communities in grassland soils. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Impacts of Jatropha-based biodiesel production on above and below-ground carbon stocks: A case study from Mozambique

    International Nuclear Information System (INIS)

    Vang Rasmussen, Laura; Rasmussen, Kjeld; Bech Bruun, Thilde

    2012-01-01

    The need to mitigate climate change makes production of liquid biofuels a high priority. Substituting fossil fuels by biodiesel produced from Jatropha curcas has gained widespread attention as Jatropha cultivation is claimed to offer green house gas emission reductions. Farmers respond worldwide to this increasing demand by converting forests into Jatropha, but whether Jatropha-based biodiesel offers carbon savings depends on the carbon emissions that occur when land use is changed to Jatropha. This paper provides an impact assessment of a small-scale Jatropha project in Cabo Delgado, Mozambique. The paper outlines the estimated impacts on above and below-ground carbon stocks when land use is changed to increase Jatropha production. The results show that expansion of Jatropha production will most likely lead to the conversion of miombo forest areas to Jatropha, which implies a reduction in above and below-ground carbon stocks. The carbon debts created by the land use change can be repaid by replacing fossil fuels with Jatropha-based biodiesel. A repayment time of almost two centuries is found with optimistic estimates of the carbon debt, while the use of pessimistic values results in a repayment time that approaches the millennium. - Highlights: ► Demands for biofuels make production of Jatropha-based biodiesel a priority. ► Farmers in Northern Mozambique are likely to convert un-logged miombo to Jatropha. ► Converting miombo to Jatropha creates reductions in above and below-ground carbon. ► It takes 187–966 years to repay emissions from above and below-ground carbon stocks.

  4. Below-ground plant–fungus network topology is not congruent with above-ground plant–animal network topology

    Science.gov (United States)

    Toju, Hirokazu; Guimarães, Paulo R.; Olesen, Jens M.; Thompson, John N.

    2015-01-01

    In nature, plants and their pollinating and/or seed-dispersing animals form complex interaction networks. The commonly observed pattern of links between specialists and generalists in these networks has been predicted to promote species coexistence. Plants also build highly species-rich mutualistic networks below ground with root-associated fungi, and the structure of these plant–fungus networks may also affect terrestrial community processes. By compiling high-throughput DNA sequencing data sets of the symbiosis of plants and their root-associated fungi from three localities along a latitudinal gradient, we uncovered the entire network architecture of these interactions under contrasting environmental conditions. Each network included more than 30 plant species and hundreds of mycorrhizal and endophytic fungi belonging to diverse phylogenetic groups. The results were consistent with the notion that processes shaping host-plant specialization of fungal species generate a unique linkage pattern that strongly contrasts with the pattern of above-ground plant–partner networks. Specifically, plant–fungus networks lacked a “nested” architecture, which has been considered to promote species coexistence in plant–partner networks. Rather, the below-ground networks had a conspicuous “antinested” topology. Our findings lead to the working hypothesis that terrestrial plant community dynamics are likely determined by the balance between above-ground and below-ground webs of interspecific interactions. PMID:26601279

  5. Effects of Grazing on Above- vs. Below-Ground Biomass Allocation of Alpine Grasslands on the Northern Tibetan Plateau.

    Directory of Open Access Journals (Sweden)

    Chaoxu Zeng

    Full Text Available Biomass allocation is an essential concept for understanding above- vs. below-ground functions and for predicting the dynamics of community structure and ecosystem service under ongoing climate change. There is rare available knowledge of grazing effects on biomass allocation in multiple zonal alpine grassland types along climatic gradients across the Northern Tibetan Plateau. We collected the peak above- and below-ground biomass (AGB and BGB values at 106 pairs of well-matched grazed vs. fenced sites during summers of 2010-2013, of which 33 pairs were subject to meadow, 52 to steppe and 21 to desert-steppe. The aboveground net primary productivity (ANPP was represented by the peak AGB while the belowground net primary productivity (BNPP was estimated from ANPP, the ratio of living vs. dead BGB, and the root turnover rate. Two-ways analyses of variance (ANOVA and paired samples comparisons with t-test were applied to examine the effects of pasture managements (PMS, i.e., grazed vs. fenced and zonal grassland types on both ANPP and BNPP. Allometric and isometric allocation hypotheses were also tested between logarithmically transformed ANPP and BNPP using standardized major axis (SMA analyses across grazed, fenced and overall sites. In our study, a high community-dependency was observed to support the allometric biomass allocation hypothesis, in association with decreased ANPP and a decreasing-to-increasing BNPP proportions with increasing aridity across the Northern Tibetan Plateau. Grazing vs. fencing seemed to have a trivial effect on ANPP compared to the overwhelming influence of different zonal grassland types. Vegetation links above- and below-ground ecological functions through integrated meta-population adaptive strategies to the increasing severity of habitat conditions. Therefore, more detailed studies on functional diversity are essentially to achieve conservation and sustainability goals under ongoing climatic warming and intensifying

  6. Effects of Grazing on Above- vs. Below-Ground Biomass Allocation of Alpine Grasslands on the Northern Tibetan Plateau.

    Science.gov (United States)

    Zeng, Chaoxu; Wu, Jianshuang; Zhang, Xianzhou

    2015-01-01

    Biomass allocation is an essential concept for understanding above- vs. below-ground functions and for predicting the dynamics of community structure and ecosystem service under ongoing climate change. There is rare available knowledge of grazing effects on biomass allocation in multiple zonal alpine grassland types along climatic gradients across the Northern Tibetan Plateau. We collected the peak above- and below-ground biomass (AGB and BGB) values at 106 pairs of well-matched grazed vs. fenced sites during summers of 2010-2013, of which 33 pairs were subject to meadow, 52 to steppe and 21 to desert-steppe. The aboveground net primary productivity (ANPP) was represented by the peak AGB while the belowground net primary productivity (BNPP) was estimated from ANPP, the ratio of living vs. dead BGB, and the root turnover rate. Two-ways analyses of variance (ANOVA) and paired samples comparisons with t-test were applied to examine the effects of pasture managements (PMS, i.e., grazed vs. fenced) and zonal grassland types on both ANPP and BNPP. Allometric and isometric allocation hypotheses were also tested between logarithmically transformed ANPP and BNPP using standardized major axis (SMA) analyses across grazed, fenced and overall sites. In our study, a high community-dependency was observed to support the allometric biomass allocation hypothesis, in association with decreased ANPP and a decreasing-to-increasing BNPP proportions with increasing aridity across the Northern Tibetan Plateau. Grazing vs. fencing seemed to have a trivial effect on ANPP compared to the overwhelming influence of different zonal grassland types. Vegetation links above- and below-ground ecological functions through integrated meta-population adaptive strategies to the increasing severity of habitat conditions. Therefore, more detailed studies on functional diversity are essentially to achieve conservation and sustainability goals under ongoing climatic warming and intensifying human

  7. Nitrogen mediates above-ground effects of ozone but not below-ground effects in a rhizomatous sedge

    International Nuclear Information System (INIS)

    Jones, M.L.M.; Hodges, G.; Mills, G.

    2010-01-01

    Ozone and atmospheric nitrogen are co-occurring pollutants with adverse effects on natural grassland vegetation. Plants of the rhizomatous sedge Carex arenaria were exposed to four ozone regimes representing increasing background concentrations (background-peak): 10-30, 35-55, 60-80 and 85-105 ppb ozone at two nitrogen levels: 12 and 100 kg N ha -1 yr -1 . Ozone increased the number and proportion of senesced leaves, but not overall leaf number. There was a clear nitrogen x ozone interaction with high nitrogen reducing proportional senescence in each treatment and increasing the ozone dose (AOT40) at which enhanced senescence occurred. Ozone reduced total biomass due to significant effects on root biomass. There were no interactive effects on shoot:root ratio. Rhizome tissue N content was increased by both nitrogen and ozone. Results suggest that nitrogen mediates above-ground impacts of ozone but not impacts on below-ground resource translocation. This may lead to complex interactive effects between the two pollutants on natural vegetation. - Nitrogen alters threshold of ozone-induced senescence, but not below-ground resource allocation.

  8. Detecting Below-Ground Processes, Diversity, and Ecosystem Function in a Savanna Ecosystem Using Spectroscopy Across Different Vegetation Layers

    Science.gov (United States)

    Cavender-Bares, J.; Schweiger, A. K.; Madritch, M. D.; Gamon, J. A.; Hobbie, S. E.; Montgomery, R.; Townsend, P. A.

    2017-12-01

    Above-and below-ground plant traits are important for substrate input to the rhizosphere. The substrate composition of the rhizosphere, in turn, affects the diversity of soil organisms, influences soil biochemistry, and water content, and resource availability for plant growth. This has substantial consequences for ecosystem functions, such as above-ground productivity and stability. Above-ground plant chemical and structural traits can be linked to the characteristics of other plant organs, including roots. Airborne imaging spectroscopy has been successfully used to model and predict chemical and structural traits of the above-ground vegetation. However, remotely sensed images capture, almost exclusively, signals from the top of the canopy, providing limited direct information about understory vegetation. Here, we use a data set collected in a savanna ecosystem consisting of spectral measurements gathered at the leaf, the whole plant, and vegetation canopy level to test for hypothesized linkages between above- and below-ground processes that influence root biomass, soil biochemistry, and the diversity of the soil community. In this environment, consisting of herbaceous vegetation intermixed with shrubs and trees growing at variable densities, we investigate the contribution of different vegetation strata to soil characteristics and test the ability of imaging spectroscopy to detect these in plant communities with contrasting vertical structure.

  9. Similar below-ground carbon cycling dynamics but contrasting modes of nitrogen cycling between arbuscular mycorrhizal and ectomycorrhizal forests.

    Science.gov (United States)

    Lin, Guigang; McCormack, M Luke; Ma, Chengen; Guo, Dali

    2017-02-01

    Compared with ectomycorrhizal (ECM) forests, arbuscular mycorrhizal (AM) forests are hypothesized to have higher carbon (C) cycling rates and a more open nitrogen (N) cycle. To test this hypothesis, we synthesized 645 observations, including 22 variables related to below-ground C and N dynamics from 100 sites, where AM and ECM forests co-occurred at the same site. Leaf litter quality was lower in ECM than in AM trees, leading to greater forest floor C stocks in ECM forests. By contrast, AM forests had significantly higher mineral soil C concentrations, and this result was strongly mediated by plant traits and climate. No significant differences were found between AM and ECM forests in C fluxes and labile C concentrations. Furthermore, inorganic N concentrations, net N mineralization and nitrification rates were all higher in AM than in ECM forests, indicating 'mineral' N economy in AM but 'organic' N economy in ECM trees. AM and ECM forests show systematic differences in mineral vs organic N cycling, and thus mycorrhizal type may be useful in predicting how different tree species respond to multiple environmental change factors. By contrast, mycorrhizal type alone cannot reliably predict below-ground C dynamics without considering plant traits and climate. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  10. Mosquito control in Dar es Salaam. II. Impact of expanded polystyrene beads and pyriproxyfen treatment of breeding sites on Culex quinquefasciatus densities.

    Science.gov (United States)

    Chavasse, D C; Lines, J D; Ichimori, K; Majala, A R; Minjas, J N; Marijani, J

    1995-04-01

    In two contrasting areas of Dar es Salaam (Ilala and Mikocheni) all enclosed breeding sites of Culex quinquefasciatus, such as latrines and septic tanks, were treated with a floating layer of expanded polystyrene beads. 7 months later checks in both study areas revealed only one site (from which the polystyrene had been removed during emptying) containing immature stages of Cx quinquefasciatus. Open breeding sites such as areas of flooded land and blocked drains were treated with pyriproxyfen (an insect growth regulator) at a concentration of 0.1 ppm. Emergence of Cx quinquefasciatus adults from these sites was inhibited for 4 weeks during the rainy season and for up to 11 weeks during the dry season. The problem of mosquito breeding sites caused by bathroom sullage water was addressed through a combination of health education and indirect pressure from the Urban Malaria Control Project (UMCP) via local community leaders. Households responsible for these sites were encouraged to eliminate them by diverting the water into an enclosed drainage structure, usually a pit latrine. After two weekly visits 64.7% of households had complied and 93.4% had complied after five visits. 5 months later, only 15.7% had reverted to allowing sullage water to collect into puddles. Densities of Cx quinquefasciatus adults dropped by 76.7% in Mikocheni and by 46.2% in Ilala following intervention, but increased by 84.9% and 25.6% in two untreated comparison areas. The reasons for differential success of the combined interventions in the two treated areas are discussed.

  11. Above- and below-ground carbon stocks in an indigenous tree (Mytilaria laosensis) plantation chronosequence in subtropical China.

    Science.gov (United States)

    Ming, Angang; Jia, Hongyan; Zhao, Jinlong; Tao, Yi; Li, Yuanfa

    2014-01-01

    More than 60% of the total area of tree plantations in China is in subtropical, and over 70% of subtropical plantations consist of pure stands of coniferous species. Because of the poor ecosystem services provided by pure coniferous plantations and the ecological instability of these stands, a movement is under way to promote indigenous broadleaf plantation cultivation as a promising alternative. However, little is known about the carbon (C) stocks in indigenous broadleaf plantations and their dependence on stand age. Thus, we studied above- and below-ground biomass and C stocks in a chronosequence of Mytilaria laosensis plantations in subtropical China; stands were 7, 10, 18, 23, 29 and 33 years old. Our assessments included tree, shrub, herb and litter layers. We used plot-level inventories and destructive tree sampling to determine vegetation C stocks. We also measured soil C stocks by analyses of soil profiles to 100 cm depth. C stocks in the tree layer dominated the above-ground ecosystem C pool across the chronosequence. C stocks increased with age from 7 to 29 years and plateaued thereafter due to a reduction in tree growth rates. Minor C stocks were found in the shrub and herb layers of all six plantations and their temporal fluctuations were relatively small. C stocks in the litter and soil layers increased with stand age. Total above-ground ecosystem C also increased with stand age. Most increases in C stocks in below-ground and total ecosystems were attributable to increases in soil C content and tree biomass. Therefore, considerations of C sequestration potential in indigenous broadleaf plantations must take stand age into account.

  12. Mosquito breeding site water temperature observations and simulations towards improved vector-borne disease models for Africa.

    Science.gov (United States)

    Asare, Ernest O; Tompkins, Adrian M; Amekudzi, Leonard K; Ermert, Volker; Redl, Robert

    2016-03-31

    An energy budget model is developed to predict water temperature of typical mosquito larval developmental habitats. It assumes a homogeneous mixed water column driven by empirically derived fluxes. The model shows good agreement at both hourly and daily time scales with 10-min temporal resolution observed water temperatures, monitored between June and November 2013 within a peri-urban area of Kumasi, Ghana. There was a close match between larvae development times calculated using either the model-derived or observed water temperatures. The water temperature scheme represents a significant improvement over assuming the water temperature to be equal to air temperature. The energy budget model requires observed minimum and maximum temperatures, information that is generally available from weather stations. Our results show that hourly variations in water temperature are important for the simulation of aquatic-stage development times. By contrast, we found that larval development is insensitive to sub-hourly variations. Modelling suggests that in addition to water temperature, accurate estimation of degree-day development time is very important to correctly predict the larvae development times. The results highlight the potential of the model to predict water temperature of temporary bodies of surface water. Our study represents an important contribution towards the improvement of weatherdriven dynamical disease models, including those designed for malaria early forecasting systems.

  13. Laboratory evaluation of Mesocyclops annulatus (Wierzejski, 1892 (Copepoda: Cyclopidea as a predator of container-breeding mosquitoes in Argentina

    Directory of Open Access Journals (Sweden)

    María V Micieli

    2002-09-01

    Full Text Available In laboratory bioassays we tested the predatory capacity of the copepod Mesocyclops annulatus on Aedes aegypti and Culex pipiens larvae. A single adult female of M. annulatus caused 51.6% and 52.3% mortality of 50 first instar larvae of Ae. aegypti and Cx. pipiens respectively, in a 72 h test period. When alternative food was added to the containers, mortality rates declined to 16% and 10.3% for Ae. aegypti and Cx. pipiens respectively. When 50 first instar larvae of each of the two mosquito species tested were placed together with a single adult female of M. annulatus, mortality rates were 75.5% for Ae. aegypti larvae and 23.5% for Cx. pipiens larvae in a three day test period. Different density of adult females of M. annulatus ranged from 5 to 25 females produced mortality rates of Ae. aegypti first instar larvae from 50% to 100% respectively. When a single adult female of M. annulatus was exposed to an increasing number of first-instar Ae. aegypti larvae ranging from 10 to 100, 100% mortality was recorded from 1 to 25 larvae, then mortality declined to 30% with 100 larvae. The average larvae killed per 24 h period by a single copepod were 29.

  14. Effect of food on immature development, consumption rate, and relative growth rate of Toxorhynchites splendens (Diptera: Culicidae, a predator of container breeding mosquitoes

    Directory of Open Access Journals (Sweden)

    D Dominic Amalraj

    2005-12-01

    Full Text Available Food utilization by the larvae of Toxorhynchites splendens (Wiedemann was studied in the laboratory by offering larvae of Aedes aegypti Linnaeus, Anopheles stephensi (Liston, and Culex quinquefasciatus (Say. Quantitative analyses of data indicated that immature development was significantly faster with increase in food availability. The regression analysis showed that the degrees of the relationship between immature duration (Id and food availability were higher when offered early instars of prey (first and second instars than late instars. Consumption rate (Cr of the predator increased with increase in food availability and this relationship was highly significant when larvae of An. stephensi were offered as food. Consumption rate to food level decreased with increase in the age class of the prey. There was a significant negative correlation between Id and Cr. This aspect helps to increase population turnover of T. splendens in a shorter period when the prey is abundant. Conversely, the predator compensated the loss in daily food intake at low food level by extending Id thereby attains the minimum threshold pupal weight for adult emergence. There was an increase in the relative growth rate (RGR of the predator when An. stephensi was offered as prey and this was related to the high protein content of the prey per body weight. There was a positive correlation between Cr and RGR. This adaptive life characteristic strategy of this predator is useful for mass-rearing for large scale field release programmes in the control of container breeding mosquitoes is discussed.

  15. Effect of food on immature development, consumption rate, and relative growth rate of Toxorhynchites splendens (Diptera: Culicidae), a predator of container breeding mosquitoes.

    Science.gov (United States)

    Dominic Amalraj, D; Sivagnaname, N; Das, P K

    2005-12-01

    Food utilization by the larvae of Toxorhynchites splendens (Wiedemann) was studied in the laboratory by offering larvae of Aedes aegypti Linnaeus, Anopheles stephensi (Liston), and Culex quinquefasciatus (Say). Quantitative analyses of data indicated that immature development was significantly faster with increase in food availability. The regression analysis showed that the degrees of the relationship between immature duration (Id) and food availability were higher when offered early instars of prey (first and second instars) than late instars. Consumption rate (Cr) of the predator increased with increase in food availability and this relationship was highly significant when larvae of An. stephensi were offered as food. Consumption rate to food level decreased with increase in the age class of the prey. There was a significant negative correlation between Id and Cr. This aspect helps to increase population turnover of T. splendens in a shorter period when the prey is abundant. Conversely, the predator compensated the loss in daily food intake at low food level by extending Id thereby attains the minimum threshold pupal weight for adult emergence. There was an increase in the relative growth rate (RGR) of the predator when An. stephensi was offered as prey and this was related to the high protein content of the prey per body weight. There was a positive correlation between Cr and RGR. This adaptive life characteristic strategy of this predator is useful for mass-rearing for large scale field release programmes in the control of container breeding mosquitoes is discussed.

  16. Land-use type and intensity differentially filter traits in above- and below-ground arthropod communities.

    Science.gov (United States)

    Birkhofer, Klaus; Gossner, Martin M; Diekötter, Tim; Drees, Claudia; Ferlian, Olga; Maraun, Mark; Scheu, Stefan; Weisser, Wolfgang W; Wolters, Volkmar; Wurst, Susanne; Zaitsev, Andrey S; Smith, Henrik G

    2017-05-01

    Along with the global decline of species richness goes a loss of ecological traits. Associated biotic homogenization of animal communities and narrowing of trait diversity threaten ecosystem functioning and human well-being. High management intensity is regarded as an important ecological filter, eliminating species that lack suitable adaptations. Below-ground arthropods are assumed to be less sensitive to such effects than above-ground arthropods. Here, we compared the impact of management intensity between (grassland vs. forest) and within land-use types (local management intensity) on the trait diversity and composition in below- and above-ground arthropod communities. We used data on 722 arthropod species living above-ground (Auchenorrhyncha and Heteroptera), primarily in soil (Chilopoda and Oribatida) or at the interface (Araneae and Carabidae). Our results show that trait diversity of arthropod communities is not primarily reduced by intense local land use, but is rather affected by differences between land-use types. Communities of Auchenorrhyncha and Chilopoda had significantly lower trait diversity in grassland habitats as compared to forests. Carabidae showed the opposite pattern with higher trait diversity in grasslands. Grasslands had a lower proportion of large Auchenorrhyncha and Carabidae individuals, whereas Chilopoda and Heteroptera individuals were larger in grasslands. Body size decreased with land-use intensity across taxa, but only in grasslands. The proportion of individuals with low mobility declined with land-use intensity in Araneae and Auchenorrhyncha, but increased in Chilopoda and grassland Heteroptera. The proportion of carnivorous individuals increased with land-use intensity in Heteroptera in forests and in Oribatida and Carabidae in grasslands. Our results suggest that gradients in management intensity across land-use types will not generally reduce trait diversity in multiple taxa, but will exert strong trait filtering within

  17. Below-ground biomass production and allometric relationships of eucalyptus coppice plantation in the central highlands of Madagascar

    International Nuclear Information System (INIS)

    Razakamanarivo, Ramarson H.; Razakavololona, Ando; Razafindrakoto, Marie-Antoinette; Vieilledent, Ghislain; Albrecht, Alain

    2012-01-01

    Short rotations of Eucalyptus plantations under coppice regime are extensively managed for wood production in Madagascar. Nevertheless, little is known about their biomass production and partitioning and their potential in terms of carbon sequestration. If above-ground biomass (AGB) can be estimated based on established allometric relations, below-ground (BGB) estimates are much less common. The aim of this work was to develop allometric equations to estimate biomass of these plantations, mainly for the root components. Data from 9 Eucalyptus robusta stands (47–87 years of plantation age, 3–5 years of coppice-shoot age) were collected and analyzed. Biomass of 3 sampled trees per stand was determined destructively. Dry weight of AGB components (leaves, branches and stems) were estimated as a function of basal area of all shoots per stump and dry weight for BGB components (mainly stump, coarse root (CR) and medium root (MR)) were estimated as a function of stump circumference. Biomass was then computed using allometric equations from stand inventory data. Stand biomass ranged from 102 to 130 Mg ha −1 with more than 77% contained in the BGB components. The highest dry weight was allocated in the stump and in the CR (51% and 42% respectively) for BGB parts and in the stem (69%) for AGB part. Allometric relationships developed herein could be applied to other Eucalyptus plantations which present similar stand density and growing conditions; anyhow, more is needed to be investigated in understanding biomass production and partitioning over time for this kind of forest ecosystem. -- Highlights: ► We studied the potential of old eucalyptus coppices in Madagascar to mitigate global warming. ► Biomass measurement, mainly for below-ground BGB (stump, coarse-medium-and fine roots) was provided. ► BGB allometry relationships for short rotation forestry under coppice were established. ► BGB were found to be important with their 102-130MgC ha -1 (<77% of the C in

  18. Mosquito Control

    Science.gov (United States)

    ... Protection Agency Search Search Contact Us Share Mosquito Control About Mosquitoes General Information Life Cycle Information from ... Repellent that is Right for You DEET Mosquito Control Methods Success in mosquito control: an integrated approach ...

  19. Disentangling above- and below-ground facilitation drivers in arid environments: the role of soil microorganisms, soil properties and microhabitat.

    Science.gov (United States)

    Lozano, Yudi M; Armas, Cristina; Hortal, Sara; Casanoves, Fernando; Pugnaire, Francisco I

    2017-12-01

    Nurse plants promote establishment of other plant species by buffering climate extremes and improving soil properties. Soil biota plays an important role, but an analysis to disentangle the effects of soil microorganisms, soil properties and microclimate on facilitation is lacking. In three microhabitats (gaps, small and large Retama shrubs), we placed six microcosms with sterilized soil, two per soil origin (i.e. from each microhabitat). One in every pair received an alive, and the other a sterile, inoculum from its own soil. Seeds of annual plants were sown into the microcosms. Germination, survival and biomass were monitored. Soil bacterial communities were characterized by pyrosequencing. Germination in living Retama inoculum was nearly double that of germination in sterile inoculum. Germination was greater under Retama canopies than in gaps. Biomass was up to three times higher in nurse than in gap soils. Soil microorganisms, soil properties and microclimate showed a range of positive to negative effects on understory plants depending on species identity and life stage. Nurse soil microorganisms promoted germination, but the effect was smaller than the positive effects of soil properties and microclimate under nurses. Nurse below-ground environment (soil properties and microorganisms) promoted plant growth and survival more than nurse microhabitat. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  20. Disease ecology across soil boundaries: effects of below-ground fungi on above-ground host-parasite interactions.

    Science.gov (United States)

    Tao, Leiling; Gowler, Camden D; Ahmad, Aamina; Hunter, Mark D; de Roode, Jacobus C

    2015-10-22

    Host-parasite interactions are subject to strong trait-mediated indirect effects from other species. However, it remains unexplored whether such indirect effects may occur across soil boundaries and connect spatially isolated organisms. Here, we demonstrate that, by changing plant (milkweed Asclepias sp.) traits, arbuscular mycorrhizal fungi (AMF) significantly affect interactions between a herbivore (the monarch butterfly Danaus plexippus) and its protozoan parasite (Ophryocystis elektroscirrha), which represents an interaction across four biological kingdoms. In our experiment, AMF affected parasite virulence, host resistance and host tolerance to the parasite. These effects were dependent on both the density of AMF and the identity of milkweed species: AMF indirectly increased disease in monarchs reared on some species, while alleviating disease in monarchs reared on other species. The species-specificity was driven largely by the effects of AMF on both plant primary (phosphorus) and secondary (cardenolides; toxins in milkweeds) traits. Our study demonstrates that trait-mediated indirect effects in disease ecology are extensive, such that below-ground interactions between AMF and plant roots can alter host-parasite interactions above ground. In general, soil biota may play an underappreciated role in the ecology of many terrestrial host-parasite systems. © 2015 The Author(s).

  1. Disease ecology across soil boundaries: effects of below-ground fungi on above-ground host–parasite interactions

    Science.gov (United States)

    Tao, Leiling; Gowler, Camden D.; Ahmad, Aamina; Hunter, Mark D.; de Roode, Jacobus C.

    2015-01-01

    Host–parasite interactions are subject to strong trait-mediated indirect effects from other species. However, it remains unexplored whether such indirect effects may occur across soil boundaries and connect spatially isolated organisms. Here, we demonstrate that, by changing plant (milkweed Asclepias sp.) traits, arbuscular mycorrhizal fungi (AMF) significantly affect interactions between a herbivore (the monarch butterfly Danaus plexippus) and its protozoan parasite (Ophryocystis elektroscirrha), which represents an interaction across four biological kingdoms. In our experiment, AMF affected parasite virulence, host resistance and host tolerance to the parasite. These effects were dependent on both the density of AMF and the identity of milkweed species: AMF indirectly increased disease in monarchs reared on some species, while alleviating disease in monarchs reared on other species. The species-specificity was driven largely by the effects of AMF on both plant primary (phosphorus) and secondary (cardenolides; toxins in milkweeds) traits. Our study demonstrates that trait-mediated indirect effects in disease ecology are extensive, such that below-ground interactions between AMF and plant roots can alter host–parasite interactions above ground. In general, soil biota may play an underappreciated role in the ecology of many terrestrial host–parasite systems. PMID:26468247

  2. The Rate and Process of Mangrove Forest Expansion on Above and Below Ground Carbon Relations in Coastal Louisiana

    Science.gov (United States)

    Doyle, T. W.; Pham, T. H.; Reyes, M. R.; Meriwether, J. R.

    2016-02-01

    Recent field studies have documented measureable mangrove expansion landward in tropical zones and poleward in temperate saltmarsh around the northern Gulf of Mexico. Louisiana, in particular, has been recolonized by black mangrove, Avicennia germinans, over a large spatial extent since complete dieback from freeze dating back two decades. Study sites were established near Fourchon, Louisiana to account for the rate and process of marsh/mangrove dominance on carbon burial and elevation change over the past 50 years. Transects were oriented perpendicular from waterway berm of tall and scrub mangrove cover on higher ground grading to low marsh settings of saltmarsh and mixed mangrove ingrowth. Elevation mapping, plant cover and biomass sampling, and soil core dating were conducted to evaluate carbon relations above and below ground. Results showed that sites with tall mangrove have significantly higher above ground biomass than Spartina marsh and mixed marsh/mangrove zone. AG biomass was positively correlated with soil surface elevation and negatively with tidal flood frequency. In addition, tall mangrove zones recorded a twofold increase in soil accretion and carbon burial rates compared with saltmarsh soils based on 137Cs dating. These findings support a positive feedback of mangrove ingrowth and persistence on carbon production and burial allowing higher accretion rates and elevation gains when favored by warmer climate periods lacking or following episodic freeze events.

  3. The presence of a below-ground neighbour alters within-plant seed size distribution in Phaseolus vulgaris.

    Science.gov (United States)

    Chen, Bin J W; During, Heinjo J; Vermeulen, Peter J; Anten, Niels P R

    2014-10-01

    Considerable variation in seed size commonly exists within plants, and is believed to be favoured under natural selection. This study aims to examine the extent to which seed size distribution depends on the presence of competing neighbour plants. Phaseolus vulgaris plants rooting with or without a conspecific neighbour were grown in soil with high or low nutrient availability. Seeds were harvested at the end of the growth cycle, the total nitrogen and phosphorus invested in seed production were measured and within-plant seed size distribution was quantified using a set of statistical descriptors. Exposure to neighbours' roots induced significant changes in seed size distribution. Plants produced proportionally more large seeds and fewer small ones, as reflected by significant increases in minimal seed size, mean seed size, skewness and Lorenz asymmetry coefficient. These effects were different from, and in several cases opposite to, the responses when the soil nutrient level was reduced, and were significant after correction for the amount of resources invested in seed production. Below-ground neighbour presence affects within-plant seed size distribution in P. vulgaris. This effect appears to be non-resource-mediated, i.e. to be independent of neighbour-induced effects on resource availability. It implies that, based on current environmental cues, plants can make an anticipatory adjustment of their investment strategy in offspring as an adaptation to the local environment in the future. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. Recognition of Orobanche cumana Below-Ground Parasitism Through Physiological and Hyper Spectral Measurements in Sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Cochavi, Amnon; Rapaport, Tal; Gendler, Tania; Karnieli, Arnon; Eizenberg, Hanan; Rachmilevitch, Shimon; Ephrath, Jhonathan E

    2017-01-01

    Broomrape ( Orobanche and Phelipanche spp.) parasitism is a severe problem in many crops worldwide, including in the Mediterranean basin. Most of the damage occurs during the sub-soil developmental stage of the parasite, by the time the parasite emerges from the ground, damage to the crop has already been done. One feasible method for sensing early, below-ground parasitism is through physiological measurements, which provide preliminary indications of slight changes in plant vitality and productivity. However, a complete physiological field survey is slow, costly and requires skilled manpower. In recent decades, visible to-shortwave infrared (VIS-SWIR) hyperspectral tools have exhibited great potential for faster, cheaper, simpler and non-destructive tracking of physiological changes. The advantage of VIS-SWIR is even greater when narrow-band signatures are analyzed with an advanced statistical technique, like a partial least squares regression (PLS-R). The technique can pinpoint the most physiologically sensitive wavebands across an entire spectrum, even in the presence of high levels of noise and collinearity. The current study evaluated a method for early detection of Orobanche cumana parasitism in sunflower that combines plant physiology, hyperspectral readings and PLS-R. Seeds of susceptible and resistant O. cumana sunflower varieties were planted in infested (15 mg kg -1 seeds) and non-infested soil. The plants were examined weekly to detect any physiological or structural changes; the examinations were accompanied by hyperspectral readings. During the early stage of the parasitism, significant differences between infected and non-infected sunflower plants were found in the reflectance of near and shortwave infrared areas. Physiological measurements revealed no differences between treatments until O. cumana inflorescences emerged. However, levels of several macro- and microelements tended to decrease during the early stage of O. cumana parasitism. Analysis of

  5. Recognition of Orobanche cumana Below-Ground Parasitism Through Physiological and Hyper Spectral Measurements in Sunflower (Helianthus annuus L.

    Directory of Open Access Journals (Sweden)

    Amnon Cochavi

    2017-06-01

    Full Text Available Broomrape (Orobanche and Phelipanche spp. parasitism is a severe problem in many crops worldwide, including in the Mediterranean basin. Most of the damage occurs during the sub-soil developmental stage of the parasite, by the time the parasite emerges from the ground, damage to the crop has already been done. One feasible method for sensing early, below-ground parasitism is through physiological measurements, which provide preliminary indications of slight changes in plant vitality and productivity. However, a complete physiological field survey is slow, costly and requires skilled manpower. In recent decades, visible to-shortwave infrared (VIS-SWIR hyperspectral tools have exhibited great potential for faster, cheaper, simpler and non-destructive tracking of physiological changes. The advantage of VIS-SWIR is even greater when narrow-band signatures are analyzed with an advanced statistical technique, like a partial least squares regression (PLS-R. The technique can pinpoint the most physiologically sensitive wavebands across an entire spectrum, even in the presence of high levels of noise and collinearity. The current study evaluated a method for early detection of Orobanche cumana parasitism in sunflower that combines plant physiology, hyperspectral readings and PLS-R. Seeds of susceptible and resistant O. cumana sunflower varieties were planted in infested (15 mg kg-1 seeds and non-infested soil. The plants were examined weekly to detect any physiological or structural changes; the examinations were accompanied by hyperspectral readings. During the early stage of the parasitism, significant differences between infected and non-infected sunflower plants were found in the reflectance of near and shortwave infrared areas. Physiological measurements revealed no differences between treatments until O. cumana inflorescences emerged. However, levels of several macro- and microelements tended to decrease during the early stage of O. cumana

  6. Allometry and partitioning of above- and below-ground biomass in farmed eucalyptus species dominant in Western Kenyan agricultural landscapes

    International Nuclear Information System (INIS)

    Kuyah, Shem; Dietz, Johannes; Muthuri, Catherine; Noordwijk, Meine van; Neufeldt, Henry

    2013-01-01

    Farmers in developing countries are one of the world's largest and most efficient producers of sequestered carbon. However, measuring, monitoring and verifying how much carbon trees in smallholder farms are removing from the atmosphere has remained a great challenge in developing nations. Devising a reliable way for measuring carbon associated with trees in agricultural landscapes is essential for helping smallholder farmers benefit from emerging carbon markets. This study aimed to develop biomass equations specific to dominant eucalyptus species found in agricultural landscapes in Western Kenya. Allometric relationships were developed by regressing diameter at breast height (DBH) alone or DBH in combination with height, wood density or crown area against the biomass of 48 trees destructively sampled from a 100 km 2 site. DBH alone was a significant predictor variable and estimated aboveground biomass (AGB) with over 95% accuracy. The stems, branches and leaves formed up to 74, 22 and 4% of AGB, respectively, while belowground biomass (BGB) of the harvested trees accounted for 21% of the total tree biomass, yielding an overall root-to-shoot ratio (RS) of 0.27, which varied across tree size. Total tree biomass held in live Eucalyptus trees was estimated to be 24.4 ± 0.01 Mg ha −1 , equivalent to 11.7 ± 0.01 Mg of carbon per hectare. The equations presented provide useful tools for estimating tree carbon stocks of Eucalyptus in agricultural landscapes for bio-energy and carbon accounting. These equations can be applied to Eucalyptus in most agricultural systems with similar agro-ecological settings where tree growth parameters would fall within ranges comparable to the sampled population. -- Highlights: ► Equation with DBH alone estimated aboveground biomass with about 95% accuracy. ► Local generic equations overestimated above- and below-ground biomass by 10 and 48%. ► Height, wood density and crown area data did not improve model accuracy. ► Stems

  7. Production dynamics of fine roots in beech forests: possible mechanism of resource allocation between above- and below-ground production

    Science.gov (United States)

    Nakahata, R.; Osawa, A.; Naramoto, M.; Mizunaga, H.; Sato, M.

    2017-12-01

    The masting phenomenon that seed production has large annual variation with spatial synchrony appears generally in beeches. Therefore, net primary production and carbon allocation mechanism in beech forests may differ among several years in relation to annual variation of seed production. On the other hand, fine roots play key roles in carbon dynamics and nutrient and water acquisition of an ecosystem. Evaluation of fine root dynamics is essential to understand long-term dynamics of production in forest ecosystems. Moreover, the influence of mast seeding on resource allocation should be clarified in such beech forests. The aim of this study is to clarify possible relationships between the patterns of above- and below-ground production in relation to the masting events using observation data of litter fall and fine root dynamics. We applied the litter trap method and a minirhizotron method in a cool-temperate natural forest dominated by beech (Fagus crenata Blume). Ten litter traps were set from 2008 to 2016, then annual leaf and seed production were estimated. Four minirhizotron tubes were buried in Aug. 2008 and soil profiles were scanned monthly until Nov. 2016 during the periods of no snow covering. The scanned soil profiles were analyzed for calculating fine root production using the WinRHIZO Tron software. In the present study site, rich production of mast seeding occurred biennially and fine root production showed various seasonal patterns. There was no significant correlation between seed production and annual fine root production in the same year. However, seed production had a positive correlation with fine root production in autumn in the previous year and indicated a negative correlation with that in autumn in the current year. These results indicate that higher fine root production has led to increased nutrient acquisition, which resulted in rich seed production in the next year. It is also suppressed after the masting events due to shortage in

  8. Luxury consumption of soil nutrients: a possible competitive strategy in above-ground and below-ground biomass allocation and root morphology for slow-growing arctic vegetation?

    NARCIS (Netherlands)

    Wijk, van M.T.; Williams, M.; Gough, L.; Hobbie, S.E.; Shaver, G.R.

    2003-01-01

    1 A field-experiment was used to determine how plant species might retain dominance in an arctic ecosystem receiving added nutrients. We both measured and modelled the above-ground and below-ground biomass allocation and root morphology of non-acidic tussock tundra near Toolik Lake, Alaska, after 4

  9. Impacts of an Invasive Non-Native Annual Weed, Impatiens glandulifera, on Above- and Below-Ground Invertebrate Communities in the United Kingdom

    Science.gov (United States)

    Tanner, Robert A.; Varia, Sonal; Eschen, René; Wood, Suzy; Murphy, Sean T.; Gange, Alan C.

    2013-01-01

    Vegetation community composition and the above- and below-ground invertebrate communities are linked intrinsically, though few studies have assessed the impact of non-native plants on both these parts of the community together. We evaluated the differences in the above- (foliage- and ground-dwelling) and below-ground invertebrate communities in nine uninvaded plots and nine plots invaded by the annual invasive species Impatiens glandulifera, in the UK during 2007 and 2008. Over 139,000 invertebrates were identified into distinct taxa and categorised into functional feeding groups. The impact of I. glandulifera on the vegetation and invertebrate community composition was evaluated using multivariate statistics including principal response curves (PRC) and redundancy analysis (RDA). In the foliage-dwelling community, all functional feeding groups were less abundant in the invaded plots, and the species richness of Coleoptera and Heteroptera was significantly reduced. In the ground-dwelling community, herbivores, detritivores, and predators were all significantly less abundant in the invaded plots. In contrast, these functional groups in the below-ground community appeared to be largely unaffected, and even positively associated with the presence of I. glandulifera. Although the cover of I. glandulifera decreased in the invaded plots in the second year of the study, only the below-ground invertebrate community showed a significant response. These results indicate that the above- and below-ground invertebrate communities respond differently to the presence of I. glandulifera, and these community shifts can potentially lead to a habitat less biologically diverse than surrounding native communities; which could have negative impacts on higher trophic levels and ecosystem functioning. PMID:23840648

  10. The effect of shade on the container index and pupal productivity of the mosquitoes Aedes aegypti and Culex pipiens breeding in artificial containers.

    Science.gov (United States)

    Vezzani, D; Albicócco, A P

    2009-03-01

    The aim of this study was to assess whether certain attributes of larval breeding sites are correlated with pupal productivity (i.e. numbers of pupae collected per sampling period), so that these could be used as the focus for control measures to enhance control efficiency. Therefore, the objectives were to identify the months of highest pupal productivity of Aedes aegypti (L.) and Culex pipiens L. (Diptera: Culicidae) in an urban temperate cemetery in Argentina where artificial containers of containers and to determine whether the composition of the containers affected pupal productivity. Over a period of 9 months, 200 randomly chosen water-filled containers (100 sunlit and 100 shaded), out of approximately 3738 containers present (approximately 54% in shade), were examined each month within a cemetery (5 ha) in Buenos Aires (October 2006 to June 2007). In total, 3440 immatures of Cx pipiens and 1974 of Ae. aegypti were collected. The larvae : pupae ratio was 10 times greater for the former, indicating that larval mortality was greater for Cx pipiens. Both mosquito species showed a higher container index (CI) in shaded than in sunlit containers (Ae. aegypti: 12.8% vs. 6.9% [chi(2) = 17.6, P container and the number of pupae per pupa-positive container did not differ significantly between sunlit and shaded containers for either species. Therefore, the overall relative productivity of pupae per ha of Ae. aegypti and Cx pipiens was 2.3 and 1.8 times greater, respectively, in shaded than in sunlit areas as a result of the greater CIs of containers in shaded areas. Neither the CI nor the number of immatures per infested container differed significantly among container types of different materials in either lighting condition. The maximum CI and total pupal counts occurred in March for Ae. aegypti and in January and February for Cx pipiens. The estimated peak abundance of pupae in the whole cemetery reached a total of approximately 4388 in the middle of March for Ae

  11. Epiphyte-cover on seagrass (Zostera marina L. leaves impedes plant performance and radial O2 loss from the below-ground tissue

    Directory of Open Access Journals (Sweden)

    Kasper Elgetti Brodersen

    2015-08-01

    Full Text Available The O2 budget of seagrasses is a complex interaction between several sources and sinks, which is strongly regulated by light availability and mass transfer over the diffusive boundary layer (DBL surrounding the plant. Epiphyte growth on leaves may thus strongly affect the O2 availability of the seagrass plant and its capability to aerate its rhizosphere as a defence against plant toxins.We used electrochemical and fiber-optic microsensors to quantify the O2 flux, DBL and light microclimate around leaves with and without filamentous algal epiphytes. We also quantified the below-ground radial O2 loss from roots (~1 mm from the root-apex to elucidate how this below-ground oxic microzone was affected by the presence of epiphytes.Epiphyte-cover on seagrass leaves (~21% areal cover resulted in reduced light quality and quantity for photosynthesis, thus leading to reduced plant fitness. A ~4 times thicker diffusive boundary layer around leaves with epiphyte-cover impeded gas (and nutrient exchange with the surrounding water-column and thus the amount of O2 passively diffusing into the leaves in darkness. During light exposure of the leaves, radial oxygen loss from the below-ground tissue was ~2 times higher from plants without epiphyte-cover. In contrast, no O2 was detectable at the surface of the root-cap tissue of plants with epiphyte-cover during darkness, leaving the plants more susceptible to sulphide intrusion.Epiphyte growth on seagrass leaves thus negatively affects the light climate and O2 uptake in darkness, hampering the plants performance and thereby reducing the oxidation capability of its below-ground tissue.

  12. Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta Forests.

    Directory of Open Access Journals (Sweden)

    Anne C S McIntosh

    Full Text Available Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs and multiple carbon-source substrate-induced respiration (MSIR of the forest floor microbial community environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis showed that two above-ground (mean tree diameter, litter cover and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs properties were associated with variation in understory plant community composition. These results provide

  13. Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta) Forests.

    Science.gov (United States)

    McIntosh, Anne C S; Macdonald, S Ellen; Quideau, Sylvie A

    2016-01-01

    Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand) scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover) and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs) and multiple carbon-source substrate-induced respiration (MSIR) of the forest floor microbial community) environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis) showed that two above-ground (mean tree diameter, litter cover) and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs) properties were associated with variation in understory plant community composition. These results provide novel insights

  14. Identifying qualitative effects of different grazing types on below-ground communities and function in a long-term field experiment

    DEFF Research Database (Denmark)

    Macdonald, Catriona A.; Crawley, Michael J.; Wright, Denis J.

    2015-01-01

    for ecosystem functions. The mechanism behind these impacts are likely to be driven by both direct effects of grazing altering the pattern of nutrient inputs and by indirect effects through changes in plant species composition. However, we could not entirely discount that the pesticide used to exclude...... invertebrates may have affected some microbial community measures. Nevertheless, our work illustrates that human activity that affects grazing intensity may affect ecosystem functioning and sustainability, as regulated by multi-trophic interactions between above- and below-ground communities....

  15. Investigation of Comparative Mosquito Breeding in Dredged Material Disposal Sites Used in the Maintenance Dredging of the Atlantic Intra-Coastal Waterway in South Carolina.

    Science.gov (United States)

    1978-01-01

    time is highly dependent on water temperature. Floodwater mosquito broods are usually S closely synchronized and emergence of all adults in a brood is...warm-blooded hosts, taking blood about as often from birds as from mammals. Crans S (1968) reported similar results from host preference studies in...implicated A. bradZleyi as a possible vector of encephalitis (Buescher et al., 1970). Both bradleyi and atropcs have been infected with malaria * parasites

  16. Recommendations to the NRC for review criteria for alternative methods of low-level radioactive waste disposal: Task 2a, Below-ground vaults

    International Nuclear Information System (INIS)

    Denson, R.H.; Bennett, R.D.; Wamsley, R.M.; Bean, D.L.; Ainsworth, D.L.

    1987-12-01

    The US Army Engineer Waterways Experiment Station (WES) and the US Army Engineer Division, Huntsville (HNDED) have developed general design criteria and specific design review criteria for the below-ground vault (BGV) alternative method of low-level radioactive waste (LLW) disposal. A BGV is a reinforced concrete vault (floor, walls, and roof) placed underground below the frost line, and above the water table, surrounded by filter blanket and drainage zones and covered with a low permeability earth layer and top soil with vegetation. Eight major review criteria categories have been developed ranging from the loads imposed on the BGV structure through material quality and durability considerations. Specific design review criteria have been developed in detail for seven of the eight major categories. 59 refs., 14 figs., 2 tabs

  17. The roots of diversity: below ground species richness and rooting distributions in a tropical forest revealed by DNA barcodes and inverse modeling.

    Directory of Open Access Journals (Sweden)

    F Andrew Jones

    Full Text Available Plants interact with each other, nutrients, and microbial communities in soils through extensive root networks. Understanding these below ground interactions has been difficult in natural systems, particularly those with high plant species diversity where morphological identification of fine roots is difficult. We combine DNA-based root identification with a DNA barcode database and above ground stem locations in a floristically diverse lowland tropical wet forest on Barro Colorado Island, Panama, where all trees and lianas >1 cm diameter have been mapped to investigate richness patterns below ground and model rooting distributions.DNA barcode loci, particularly the cpDNA locus trnH-psba, can be used to identify fine and small coarse roots to species. We recovered 33 species of roots from 117 fragments sequenced from 12 soil cores. Despite limited sampling, we recovered a high proportion of the known species in the focal hectare, representing approximately 14% of the measured woody plant richness. This high value is emphasized by the fact that we would need to sample on average 13 m(2 at the seedling layer and 45 m(2 for woody plants >1 cm diameter to obtain the same number of species above ground. Results from inverse models parameterized with the locations and sizes of adults and the species identifications of roots and sampling locations indicates a high potential for distal underground interactions among plants.DNA barcoding techniques coupled with modeling approaches should be broadly applicable to studying root distributions in any mapped vegetation plot. We discuss the implications of our results and outline how second-generation sequencing technology and environmental sampling can be combined to increase our understanding of how root distributions influence the potential for plant interactions in natural ecosystems.

  18. Biomass and morphology of fine roots in temperate broad-leaved forests differing in tree species diversity: is there evidence of below-ground overyielding?

    Science.gov (United States)

    Meinen, Catharina; Hertel, Dietrich; Leuschner, Christoph

    2009-08-01

    Biodiversity effects on ecosystem functioning in forests have only recently attracted increasing attention. The vast majority of studies in forests have focused on above-ground responses to differences in tree species diversity, while systematic analyses of the effects of biodiversity on root systems are virtually non-existent. By investigating the fine root systems in 12 temperate deciduous forest stands in Central Europe, we tested the hypotheses that (1) stand fine root biomass increases with tree diversity, and (2) 'below-ground overyielding' of species-rich stands in terms of fine root biomass is the consequence of spatial niche segregation of the roots of different species. The selected stands represent a gradient in tree species diversity on similar bedrock from almost pure beech forests to medium-diverse forests built by beech, ash, and lime, and highly-diverse stands dominated by beech, ash, lime, maple, and hornbeam. We investigated fine root biomass and necromass at 24 profiles per stand and analyzed species differences in fine root morphology by microscopic analysis. Fine root biomass ranged from 440 to 480 g m(-2) in the species-poor to species-rich stands, with 63-77% being concentrated in the upper 20 cm of the soil. In contradiction to our two hypotheses, the differences in tree species diversity affected neither stand fine root biomass nor vertical root distribution patterns. Fine root morphology showed marked distinctions between species, but these root morphological differences did not lead to significant differences in fine root surface area or root tip number on a stand area basis. Moreover, differences in species composition of the stands did not alter fine root morphology of the species. We conclude that 'below-ground overyielding' in terms of fine root biomass does not occur in the species-rich stands, which is most likely caused by the absence of significant spatial segregation of the root systems of these late-successional species.

  19. Below-ground abiotic and biotic heterogeneity shapes above-ground infection outcomes and spatial divergence in a host-parasite interaction.

    Science.gov (United States)

    Tack, Ayco J M; Laine, Anna-Liisa; Burdon, Jeremy J; Bissett, Andrew; Thrall, Peter H

    2015-09-01

    We investigated the impact of below-ground and above-ground environmental heterogeneity on the ecology and evolution of a natural plant-pathogen interaction. We combined field measurements and a reciprocal inoculation experiment to investigate the potential for natural variation in abiotic and biotic factors to mediate infection outcomes in the association between the fungal pathogen Melampsora lini and its wild flax host, Linum marginale, where pathogen strains and plant lines originated from two ecologically distinct habitat types that occur in close proximity ('bog' and 'hill'). The two habitat types differed strikingly in soil moisture and soil microbiota. Infection outcomes for different host-pathogen combinations were strongly affected by the habitat of origin of the plant lines and pathogen strains, the soil environment and their interactions. Our results suggested that tradeoffs play a key role in explaining the evolutionary divergence in interaction traits among the two habitat types. Overall, we demonstrate that soil heterogeneity, by mediating infection outcomes and evolutionary divergence, can contribute to the maintenance of variation in resistance and pathogenicity within a natural host-pathogen metapopulation. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  20. Uprooting force balance for pioneer woody plants: A quantification of the relative contribution of above- and below-ground plant architecture to uprooting susceptibility

    Science.gov (United States)

    Bywater-Reyes, S.; Wilcox, A. C.; Lightbody, A.; Skorko, K.; Stella, J. C.

    2012-12-01

    Cottonwood (Populus), willow (Salix), and tamarisk (Tamarix) populate riparian areas in many dryland regions, and their recruitment depends heavily on hydrogeomorphic conditions. The survival of pioneer woody seedlings depends in part on the establishment of root systems capable of anchoring plants in subsequent floods, and this root system development in turn influences the cohesion that plants provide to bars. The factors influencing the anchoring ability and resistance to scour of woody seedlings include plant frontal area and flexibility, root structure, and water table elevation. This study aims to quantify the factors comprising the force balance to uproot woody seedlings and saplings in two field sites characterized by different hydrologic conditions. The Bill Williams River (AZ) is an impounded river with elevated water table elevations produced by dam-released base flows. The Bitterroot River (MT) is an unimpounded river with a snowmelt hydrograph and seasonal fluctuations in river and water table elevation. We simulate uprooting from flooding events by saturating substrates and applying force near the base of the plant in a lateral, downstream direction until uprooting occurs, for a range of plant sizes but with a focus on small (plants, with cottonwood and tamarisk seedlings showing greater variability than willow. In contrast, root length and stem diameter are only weakly correlated with pull-out force. By combining pull test results with measurements of geomorphic and groundwater conditions, this study provides insights into the relative contribution of a plant's above-ground and below-ground architecture to uprooting potential and into the feedbacks between vegetation and morphodynamics on river bars.

  1. No consistent effect of plant species richness on resistance to simulated climate change for above- or below-ground processes in managed grasslands.

    Science.gov (United States)

    Dormann, Carsten F; von Riedmatten, Lars; Scherer-Lorenzen, Michael

    2017-06-17

    Species richness affects processes and functions in many ecosystems. Since management of temperate grasslands is directly affecting species composition and richness, it can indirectly govern how systems respond to fluctuations in environmental conditions. Our aim in this study was to investigate whether species richness in managed grasslands can buffer the effects of drought and warming manipulations and hence increase the resistance to climate change. We established 45 plots in three regions across Germany, each with three different management regimes (pasture, meadow and mown pasture). We manipulated spring warming using open-top chambers and summer drought using rain-out shelters for 4 weeks. Measurements of species richness, above- and below-ground biomass and soil carbon and nitrogen concentrations showed significant but inconsistent differences among regions, managements and manipulations. We detected a three-way interaction between species richness, management and region, indicating that our study design was sensitive enough to detect even intricate effects. We could not detect a pervasive effect of species richness on biomass differences between treatments and controls, indicating that a combination of spring warming and summer drought effects on grassland systems are not consistently moderated by species richness. We attribute this to the relatively high number of species even at low richness levels, which already provides the complementarity required for positive biodiversity-ecosystem functioning relationships. A review of the literature also indicates that climate manipulations largely fail to show richness-buffering, while natural experiments do, suggesting that such manipulations are milder than reality or incur treatment artefacts.

  2. Assessment of Above- and Below-ground Competition between Sesame (Sesamume indicum L. and Pigweed (Amaranthus retroflexus and Its Effects on Sesame Yield and Yield Components

    Directory of Open Access Journals (Sweden)

    A.J Yanegh

    2013-08-01

    Full Text Available This study carried out in a factorial layout on completely randomaized block design with three replications, to evaluate the above- and below- ground competition between sesame (Sesamum indicum and pigweed (Amaranthus retroflexus, and their impacts on sesame yield and yield component. The experimental treatments were all combination of crop-weed competition (shoot competition, root competition and root-shoot competition and sesame plant densitys (1, 2 and 4 plant per pot. Plants were sown in plastic pots (24 cm diameter and 28 cm height in year 2010, at feild of Ferdowsi University of Mashhad. For study the shoot competition of sesame-pigweed, the roots were separated by plastic when the pots were filled with soil before sowing the seeds. Three weeks after emerging, shoots of plants were separated vertical barrier (30 x 70 cm for studing root competition. Results showed that competition treatments had a significant effect on seed weight per plant and yield components except 1000 seed weight. Among competition produced higher yield and yield components compared to othere treatments. However, sesame and pigweed biological weight in root-shoot competition was 2.6 and 13.7 respectively, that was higher than other competition treatments and was significant. Capsule number in main and sub branches, capsule number in plant, seed number in capsule and seed number in plant in complete competition treatment was 15, 2.58, 17.5, 43.7 and 693.89 respectively, that was higher than other treatments and differences among them was significant. Sesame density also had a significant effect on seed weight per plant and yield components. When low density were used (one plant, yield and yield components was more, therefore in one plant per pot density biological weight of sesame was 3.82 gr, and in higher densities the mentioned traits decreased significantly.

  3. Evaluation of carbon stocks in above- and below-ground biomass in Central Africa: case study of Lesio-louna tropical rainforest of Congo

    Science.gov (United States)

    Liu, X.; Ekoungoulou, R.; Loumeto, J. J.; Ifo, S. A.; Bocko, Y. E.; Koula, F. E.

    2014-07-01

    The study was aimed to estimate the carbon stocks of above- and below-ground biomass in Lesio-louna forest of Congo. The methodology of allometric equations was used to measure the carbon stocks of Lesio-louna natural forest. We are based precisely on the model II which is also called non-destructive method or indirect method of measuring carbon stocks. While there has been use of parameters such as the DBH and wood density. The research was done with 22 circular plots each 1256 m2. In the 22 plots studied, 19 plots are in the gallery forest and three plots in the secondary forest. Also, 22 circular plots were distributed in 5 sites studies of Lesio-louna forest, including: Inkou forest island, Iboubikro, Ngoyili, Blue lake and Ngambali. So, there are two forest types (secondary forest and gallery forest) in this forest ecosystem. In the 5 sites studied, we made measurements on a total of 347 trees with 197 trees for the class of 10-30 cm diameter, 131 trees for the class of 30-60 cm diameter and 19 trees in the diameter class > 60 cm. The results show that in the whole forest, average carbon stock for the 22 plots of the study was 168.601 t C ha-1 for AGB, or 81% and 39.551 t C ha-1 for BGB, or 19%. The total carbon stocks in all the biomass was 3395.365 t C for AGB, which is 3.395365 × 10-6 Gt C and 909.689934 t C for BGB, which was 9.09689934 × 10-7 Gt C. In this forest, the carbon stock was more important in AGB compared to BGB with respectively 3395.365 t C against 909.689934 t C. Plot10 (AGB = 363.899 t C ha-1 and BGB = 85.516 t C ha-1) was the most dominant in terms of carbon quantification in Lesio-louna.

  4. Evidence that acidification-induced declines in plant diversity and productivity are mediated by changes in below-ground communities and soil properties in a semi-arid steppe

    Science.gov (United States)

    Chen, Dima; Lan, Zhichun; Bai, Xue; Grace, James B.; Bai, Yongfei

    2013-01-01

    Anthropogenic acid deposition–induced soil acidification is one of the major threats to biodiversity, ecosystem functioning and services. Few studies, however, have explored in detail how above-ground changes in plant species richness and productivity resulting from soil acidification are mediated by effects on below-ground biota and soil properties.

  5. Mosquito Traps: An Innovative, Environmentally Friendly Technique to Control Mosquitoes

    Directory of Open Access Journals (Sweden)

    Brigitte Poulin

    2017-03-01

    Full Text Available We tested the use of mosquito traps as an alternative to spraying insecticide in Camargue (France following the significant impacts observed on the non-target fauna through Bti persistence and trophic perturbations. In a village of 600 inhabitants, 16 Techno Bam traps emitting CO2 and using octenol lures were set from April to November 2016. Trap performance was estimated at 70% overall based on mosquitoes landing on human bait in areas with and without traps. The reduction of Ochlerotatus caspius and Oc. detritus, the two species targeted by Bti spraying, was, respectively, 74% and 98%. Traps were less efficient against Anopheles hyrcanus (46%, which was more attracted by lactic acid than octenol lures based on previous tests. Nearly 300,000 mosquitoes from nine species were captured, with large variations among traps, emphasizing that trap performance is also influenced by surrounding factors. Environmental impact, based on the proportion of non-target insects captured, was mostly limited to small chironomids attracted by street lights. The breeding success of a house martin colony was not significantly affected by trap use, in contrast to Bti spraying. Our experiment confirms that the deployment of mosquito traps can offer a cost-effective alternative to Bti spraying for protecting local populations from mosquito nuisance in sensitive natural areas.

  6. The occurrences and habitat characteristics of mosquitoes in Accra ...

    African Journals Online (AJOL)

    A study to assess mosquito species occurrences and the effects of some ecological characteristics on their breeding was undertaken in Accra. Five species of mosquitoes, Anopheles gambiae s.l, Culex decens, Culex quinquefasciatus, Anopheles melas and Aedes aegyptii were found occurring in a wide variety of places.

  7. Mosquito larval habitats and public health implications in Abeokuta ...

    African Journals Online (AJOL)

    The larval habitats of mosquitoes were investigated in Abeokuta, Nigeria in order to determine the breeding sites of the existing mosquito fauna and its possible public health implications on the residents of the City. The habitats were sampled between August 2005 and July 2006 using plastic dippers and a pipette.

  8. Biodiversity and ecosystem risks arising from using guppies to control mosquitoes

    Science.gov (United States)

    Rana W. El-Sabaawi; Therese C. Frauendorf; Piata S. Marques; Richard A. Mackenzie; Luisa R. Manna; Rosana Mazzoni; Dawn A. T. Phillip; Misha L. Warbanski; Eugenia Zandon

    2016-01-01

    Deploying mosquito predators such as the guppy (Poecilia reticulata) into bodies of water where mosquitoes breed is a common strategy for limiting the spread of disease-carrying mosquitoes. Here, we draw on studies from epidemiology, conservation, ecology and evolution to show that the evidence for the effectiveness of guppies in controlling...

  9. Mosquito, egg raft (image)

    Science.gov (United States)

    Mosquitoes of the Culex species lay their eggs in the form of egg rafts that float in still or stagnant water. The mosquito ... mosquitoes. (Image courtesy of the Centers for Disease Control and Prevention.)

  10. [Reevaluation of the biological control of vector mosquitoes using predatory larvae of Toxorhynchites mosquitoes].

    Science.gov (United States)

    Tsukamoto, M; Horio, M

    1985-09-01

    Attempts to control mosquito-borne disease using predatory mosquitoes such as Toxorhynchites larvae have led to indefinite results for many years, mainly because of the lack of adequate species or strains of Toxorhynchites. Recent improvements of natural and artificial matings of adults in the laboratory and of mass breeding of larvae, however, have made it possible to establish laboratory colonies of most Toxorhynchites species whenever and wherever necessary. Effects of biological control by releasing large numbers of Toxorhynchites mosquitoes should be reevaluated from a new concept of comparing the usual chemical insecticides with the living and flying "insecticides" which cause no environmental pollution.

  11. Biodiversity and ecosystem risks arising from using guppies to control mosquitoes

    OpenAIRE

    El-Sabaawi, Rana W.; Frauendorf, Therese C.; Marques, Piata S.; Mackenzie, Richard A.; Manna, Luisa R.; Mazzoni, Rosana; Phillip, Dawn A. T.; Warbanski, Misha L.; Zandonà, Eugenia

    2016-01-01

    Deploying mosquito predators such as the guppy (Poecilia reticulata) into bodies of water where mosquitoes breed is a common strategy for limiting the spread of disease-carrying mosquitoes. Here, we draw on studies from epidemiology, conservation, ecology and evolution to show that the evidence for the effectiveness of guppies in controlling mosquitoes is weak, that the chances of accidental guppy introduction into local ecosystems are large, and that guppies can easily establish populations ...

  12. Physico-chemical characteristics of Anopheles breeding sites ...

    African Journals Online (AJOL)

    Mosquitoes exploit almost all types of aquatic habitats for breeding. Prevailing physicochemical parameters in these habitats are important factors for survival and development of mosquito. Here, six water samples from Atlantic Ocean, River, well, distilled (control), rain and borehole water were used to culture Anopheline ...

  13. Pond dyes are Culex mosquito oviposition attractants

    Directory of Open Access Journals (Sweden)

    Natali Ortiz Perea

    2017-05-01

    successful, with significantly higher numbers of pupae, in the habitat where they had vegetation cover and shade. Discussion Our study has raised some interesting possibilities; one is that where used, pond dyes may be encouraging mosquitoes to breed in gardens in close proximity to people. Considering the concerns over potential future spread of disease in urban environments, this as well as shading of ponds and water butts, should inform future advice over reducing mosquito breeding and spread.

  14. Avoid Mosquito Bites

    Science.gov (United States)

    ... protect yourself from mosquitoes inside your home or hotel, sleep under a mosquito bed net. For more ... Jobs Funding LEGAL Policies Privacy FOIA No Fear Act OIG 1600 Clifton Road Atlanta , GA 30329-4027 ...

  15. Controlling Mosquitoes Outside

    Centers for Disease Control (CDC) Podcasts

    2016-08-09

    Mosquitoes can carry viruses, like West Nile, Zika, dengue, and chikungunya. In this podcast, Mr. Hubbard will teach you and his neighbor, Laura, ways to help reduce the number of mosquitoes outside your home. Tips include eliminating areas of standing water where mosquitoes lay eggs and using larvicides to kill young mosquitoes.  Created: 8/9/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 8/9/2016.

  16. [Progress on transgenic mosquitoes].

    Science.gov (United States)

    Yang, Pin

    2011-04-30

    The genetically modified mosquitoes have been developed aiming to control mosquito-borne diseases by either reducing population sizes or replacing existing populations with vectors unable to transmit the disease. introduces some progress on the generation of transgenic mosquitoes and their fitness in wild population. This paper

  17. Above- and Below-ground Biomass, Net Ecosystem Carbon Exchange, and Soil Respiration in a Poplar Populus deltoides Bartr.) stand : Changes after 3 years of Growth under Elevated CO2

    Science.gov (United States)

    Barron-Gafford, G. A.; Grieve, K.; Bil, K.; Kudeyarov, V.; Handley, L.; Murthy, R.

    2003-12-01

    Stands of cottonwood (Populus deltoides Bartr.) trees were grown as a coppiced system under ambient (40 Pa), twice ambient (80 Pa), and three times ambient (120 Pa) partial pressure CO2 for the past three years in the Intensively-managed Forest Mesocosm (IFM) of the Biosphere 2 Center. Over three years Net Ecosystem CO2 exchange (NECE) was measured continuously and in the third year, nine whole trees were harvested from each CO2 treatment over the growing season. Both above- and below-ground parameters were measured. Three years of growth under elevated CO2 showed the expected stimulation in foliar biomass (8.7, 11.9, and 13.1 kg for the 40, 80, and 120 Pa treatments, respectively). Rates of NECE also followed an expected increase with elevated atmospheric CO2 concentrations, with maximum CO2 uptake rates reaching 10.5, 15.6, and 19.6 μ moles m-2 s-1 in the 40, 80, and 120 Pa treatments, respectively. However, above ground woody biomass and root biomass were not much stimulated beyond 80 Pa CO2. Wood/foliage and above/below ground biomass ratios reflect this decline. Under conditions of non-limiting nutrients and water, we found consistent increases in the above/below ground biomass ratio and wood to foliage biomass ratios in the 80 compared to the 40 Pa pCO2. Woody biomass production and the above/below ground biomass ratio were lower under the 120 Pa than any other treatment. Although biomass production did not change appreciably between 80 and 120 Pa CO2 treatments, both substrate induced and in-situ soil respiration values are also significantly higher in the 120Pa treatment, though no differences were present prior to CO2 treatments (Murthy et al. 2003). The unique closed-system operation of the IFM allowed for measures of soil CO2 efflux to be measured at both the soil collar and stand scales using a box model that takes into account all inputs and outputs from the stand. In-situ soil respiration rates increased significantly with increased atmospheric CO2

  18. The influence of water stress on biomass and N accumulation, N partitioning between above and below ground parts and on N rhizodeposition during reproductive growth of pea (Pisum sativum L.)

    DEFF Research Database (Denmark)

    Mahieu, S.; Germont, Florent; Aveline, A.

    2009-01-01

    rhizodeposition by a pea (Pisum sativum L.) when influenced by water stress. In a controlled environment, pea plants were exposed to a severe drought or not stressed, either at flowering or during pod filling. N rhizodeposition was measured using the split root method and plants were harvested at the end...... of flowering (59 days after sowing, DAS 59), at the end of the drought period applied during pod filling (DAS 74) and at maturity (DAS 101). Water stress strongly affected pea dry weight and N accumulation. In both stressed treatments, nodule biomass and N content were reduced by about 65% in the absence...... in rhizodeposits represented around 30% of the total BGN and increased to around 60% at maturity though BGN decreased from around 20 to 13% of the total plant N between DAS 74 and maturity. The results suggest that water stress has no specific effect on N partitioning between above and below ground parts....

  19. The most common mosquitoes at Al- Rayyan municipality (Qatar state) and their potential for transmitting malaria

    OpenAIRE

    Ahmed, Rabab Ibrahim

    2015-01-01

    During the period from December 2014 to April 2015, a mosquito survey (Diptera: Culicidae) was conducted at Al Rayyan Municipality, western region of Qatar. The survey aimed to identify the most common mosquitoes species in the study area and assess their potential in transmitting malaria. In all, 37 collection sites were visited throughout the study period revealing 312 mosquitoes. Larvae were collected as well as adults. The pH of larvae breeding sites was also measured in the laboratory. A...

  20. Slave Breeding

    OpenAIRE

    Sutch, Richard

    1986-01-01

    This paper reviews the historical work on slave breeding in the ante-bellum United States. Slave breeding consisted of interference in the sexual life of slaves by their owners with the intent and result of increasing the number of slave children born. The weight of evidence suggests that slave breeding occurred in sufficient force to raise the rate of growth of the American slave population despite evidence that only a minority of slave-owners engaged in such practices.

  1. Artificial Diets for Mosquitoes

    Directory of Open Access Journals (Sweden)

    Kristina K. Gonzales

    2016-12-01

    Full Text Available Mosquito-borne diseases are responsible for more than a million human deaths every year. Modern mosquito control strategies such as sterile insect technique (SIT, release of insects carrying a dominant lethal (RIDL, population replacement strategies (PR, and Wolbachia-based strategies require the rearing of large numbers of mosquitoes in culture for continuous release over an extended period of time. Anautogenous mosquitoes require essential nutrients for egg production, which they obtain through the acquisition and digestion of a protein-rich blood meal. Therefore, mosquito mass production in laboratories and other facilities relies on vertebrate blood from live animal hosts. However, vertebrate blood is expensive to acquire and hard to store for longer times especially under field conditions. This review discusses older and recent studies that were aimed at the development of artificial diets for mosquitoes in order to replace vertebrate blood.

  2. Tips to Prevent Mosquito Bites

    Science.gov (United States)

    Using the right insect repellent and other preventive actions can discourage mosquitoes from landing on you. Tips include removing mosquito habitats such as standing water, minimizing exposed skin, and staying indoors while mosquitoes are most active.

  3. Exploring methods to minimize the risk of mosquitoes in rainwater harvesting systems

    Science.gov (United States)

    Moglia, Magnus; Gan, Kein; Delbridge, Nathan

    2016-12-01

    Rainwater harvesting in residential homes is emerging as an important complement to centralized water supplies in urban centres around the world. Domestic rainwater harvesting systems provide a variety of benefits for water management and contribute to sustainable and integrated urban water management. There are however risks associated with rainwater harvesting that requires appropriate mitigation. One such risk is that systems can become breeding grounds for mosquitoes. This can constitute a significant health risk through the spread of mosquito-borne diseases (i.e. arbovirus and malaria). This paper explores the extent to which mosquitoes breed in rainwater harvesting systems as well as the effectiveness of different risk mitigation actions. Data were sourced from a large-scale domestic rainwater tank inspection survey undertaken in Melbourne and were analysed using simple Bayesian Network models. The observed rate of mosquito breeding was too high and was identified as a serious concern for health officials and water managers. The most common access routes into the tank system were found to be through the tank inlet or overflow. By exploring different system set-ups it was found that in order to mitigate the risk of mosquito breeding in tanks, all potential access routes must be adequately sealed. The complete eradication of mosquitos in rainwater tanks, however, may need further investigation, as 4% of systems with adequate protection at the inlet and overflow were still found to have mosquitoes in them.

  4. Mosquito inspired medical needles

    DEFF Research Database (Denmark)

    Lenau, Torben Anker; Hesselberg, Thomas; Drakidis, Alexandros Dimitrios

    2017-01-01

    The stinging proboscis in mosquitos have diameters of only 40-100 μm which is much less than the thinnest medical needles and the mechanics of these natural stinging mechanisms have therefore attracted attention amongst developers of injection devises. The mosquito use a range of different...

  5. Controlling Mosquitoes Indoors

    Centers for Disease Control (CDC) Podcasts

    2016-08-23

    Mosquitoes can carry viruses, like West Nile and Zika. In this podcast, Mr. Hubbard teaches his neighbors, the Smith family, ways to help reduce the number of mosquitoes inside their home.  Created: 8/23/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 8/23/2016.

  6. The risk of a mosquito-borne infection in a heterogeneous environment.

    Directory of Open Access Journals (Sweden)

    David L Smith

    2004-11-01

    Full Text Available A common assumption about malaria, dengue, and other mosquito-borne infections is that the two main components of the risk of human infection--the rate at which people are bitten (human biting rate and the proportion of mosquitoes that are infectious--are positively correlated. In fact, these two risk factors are generated by different processes and may be negatively correlated across space and time in heterogeneous environments. Uneven distribution of blood-meal hosts and larval habitat creates a spatial mosaic of demograPhic sources and sinks. Moreover, mosquito populations fluctuate temporally, forced by environmental variables such as rainfall, temperature, and humidity. These sources of spatial and temporal heterogeneity in the distribution of mosquito populations generate variability in the human biting rate, in the proportion of mosquitoes that are infectious, and in the risk of human infection. To understand how heterogeneity affects the epidemiology of mosquito-borne infections, we developed a set of simple models that incorporate heterogeneity in a stepwise fashion. These models predict that the human biting rate is highest shortly after the mosquito densities peak, near breeding sites where adult mosquitoes emerge, and around the edges of areas where humans are aggregated. In contrast, the proportion of mosquitoes that are infectious reflects the age structure of mosquito populations; it peaks where old mosquitoes are found, far from mosquito breeding habitat, and when mosquito population density is declining. Finally, we show that estimates for the average risk of infection that are based on the average entomological inoculation rate are strongly biased in heterogeneous environments.

  7. UV light and urban pollution: Bad cocktail for mosquitoes?

    Energy Technology Data Exchange (ETDEWEB)

    Tetreau, Guillaume, E-mail: guillaume.tetreau@gmail.com [Laboratoire d’Ecologie Alpine, LECA-UMR 5553, Université de Grenoble 1, BP 53, 38041 Grenoble cedex 09 (France); Department of Entomology, Cornell University, New York State Agricultural Experiment Station, Geneva, NY 14456 (United States); Chandor-Proust, Alexia; Faucon, Frédéric; Stalinski, Renaud; Akhouayri, Idir; Prud’homme, Sophie M.; Régent-Kloeckner, Myriam; Raveton, Muriel; Reynaud, Stéphane [Laboratoire d’Ecologie Alpine, LECA-UMR 5553, Université de Grenoble 1, BP 53, 38041 Grenoble cedex 09 (France)

    2014-01-15

    Highlights: •Mosquito tolerance to temephos is induced by PAHs and UV exposure. •Toxicity of fluoranthene for mosquito Malpighian tubules cells is induced by UV. •Fluoranthene crystallizes in mosquito Malpighian tubules upon UV exposure. •Mixture of two PAHs is less toxic for mosquitoes than each PAHs separately. •Combination of abiotic parameters (PAHs and UV) affect mosquito physiology. -- Abstract: Mosquito breeding sites consist of water pools, which can either be large open areas or highly covered ponds with vegetation, thus with different light exposures combined with the presence in water of xenobiotics including polycyclic aromatic hydrocarbons (PAHs) generated by urban pollution. UV light and PAHs are abiotic factors known to both affect the mosquito insecticide resistance status. Nonetheless, their potential combined effects on the mosquito physiology have never been investigated. The present article aims at describing the effects of UV exposure alongside water contamination with two major PAH pollutants (fluoranthene and benzo[a]pyrene) on a laboratory population of the yellow fever mosquito Aedes aegypti. To evaluate the effects of PAH exposure and low energetic UV (UV-A) irradiation on mosquitoes, different parameters were measured including: (1) The PAH localization and its impact on cell mortality by fluorescent microscopy; (2) The detoxification capacities (cytochrome P450, glutathione-S-transferase, esterase); (3) The responses to oxidative stress (Reactive Oxygen Species–ROS) and (4) The tolerance of mosquito larvae to a bioinsecticide (Bacillus thuringiensis subsp. israelensis–Bti) and to five chemical insecticides (DDT, imidacloprid, permethrin, propoxur and temephos). Contrasting effects regarding mosquito cell mortality, detoxification and oxidative stress were observed as being dependent on the pollutant considered, despite the fact that the two PAHs belong to the same family. Moreover, UV is able to modify pollutant effects on

  8. UV light and urban pollution: Bad cocktail for mosquitoes?

    International Nuclear Information System (INIS)

    Tetreau, Guillaume; Chandor-Proust, Alexia; Faucon, Frédéric; Stalinski, Renaud; Akhouayri, Idir; Prud’homme, Sophie M.; Régent-Kloeckner, Myriam; Raveton, Muriel; Reynaud, Stéphane

    2014-01-01

    Highlights: •Mosquito tolerance to temephos is induced by PAHs and UV exposure. •Toxicity of fluoranthene for mosquito Malpighian tubules cells is induced by UV. •Fluoranthene crystallizes in mosquito Malpighian tubules upon UV exposure. •Mixture of two PAHs is less toxic for mosquitoes than each PAHs separately. •Combination of abiotic parameters (PAHs and UV) affect mosquito physiology. -- Abstract: Mosquito breeding sites consist of water pools, which can either be large open areas or highly covered ponds with vegetation, thus with different light exposures combined with the presence in water of xenobiotics including polycyclic aromatic hydrocarbons (PAHs) generated by urban pollution. UV light and PAHs are abiotic factors known to both affect the mosquito insecticide resistance status. Nonetheless, their potential combined effects on the mosquito physiology have never been investigated. The present article aims at describing the effects of UV exposure alongside water contamination with two major PAH pollutants (fluoranthene and benzo[a]pyrene) on a laboratory population of the yellow fever mosquito Aedes aegypti. To evaluate the effects of PAH exposure and low energetic UV (UV-A) irradiation on mosquitoes, different parameters were measured including: (1) The PAH localization and its impact on cell mortality by fluorescent microscopy; (2) The detoxification capacities (cytochrome P450, glutathione-S-transferase, esterase); (3) The responses to oxidative stress (Reactive Oxygen Species–ROS) and (4) The tolerance of mosquito larvae to a bioinsecticide (Bacillus thuringiensis subsp. israelensis–Bti) and to five chemical insecticides (DDT, imidacloprid, permethrin, propoxur and temephos). Contrasting effects regarding mosquito cell mortality, detoxification and oxidative stress were observed as being dependent on the pollutant considered, despite the fact that the two PAHs belong to the same family. Moreover, UV is able to modify pollutant effects on

  9. Observations on anopheline breeding in relation to aquatic plants in different breeding habitats of Kheda (Gujarat).

    Science.gov (United States)

    Kant, Rajni; Srivastava, H C

    2004-09-01

    Water bodies infested with aquatic vegetations may pose problems in mosquito control through bio-environmental methods. Paucity of information pertaining to association of mosquito breeding with aquatic vegetation was the basis for present investigation. The mosquito breeding sites infested with solitary/dominating plant community viz., Eichhornia crassipes, Ipomoea aquatica, Hydrilla verticillata, Nymphea neuchali, Trapa bispinosa, Lemna paucicostata, Trachelomonas spp., Azolla pinnata, Algae spp. and Cynodon dactylon were selected for the study. The investigation revealed that breeding of eleven anopheline species was associated with Eichhornia in different habitats followed by Hydrilla, algae and Cynodon (8 each), Ipomoea and Trapa (6), Lemna. and Nymphea (5), Azolla and Trachelomonas (4). An. subpictus was associated with all types of vegetation. An. annularis, An. nigerrimus and An. barbirostris were associated with nine plant species. An. culicifacies, the principal malaria vector was found breeding in association with seven aquatic plants and showed strong association with Cynodon, Hydrilla and algae. The species diversity in habitats infested with Hydrilla, algae and Cynodon seems to be most favourable for the breeding of An. culicifacies. It is suggested that thinning or removal of such vegetations at regular interval may help to reduce vector population and enhance the efficacy of biological control agents particularly the larvivorous fishes in such habitats.

  10. Studies on mosquitoes (Diptera: Culicidae and anthropic environment: 6 - Breeding in empty conditions of rice fields in South-Eastern Brazil Estudos sobre mosquitos (Diptera: Culicidae e ambiente antrópico: 6 - Observações em campos de arroz não cultivados, na região sudeste do Brasil

    Directory of Open Access Journals (Sweden)

    Oswaldo Paulo Forattini

    1994-12-01

    Full Text Available Studies on culicid breeding in empty rice fields were carried out during the cultivation cycle from May to November 1993. This period corresponded to stages 1 and 2, when empty conditions prevailed. Breeding occurred in stage 1 and the first part of stage 2, corresponding respectively to fallow uncultivated and ploughing situations. No breeding was found to take place during the second part of stage 2 when transient floods and harrowing occurred. The predominant species were Aedes scapularis, Culex nigripalpus and Cx. mollis. The Pilosus Group of Culex (Melanoconion was found at lower densities. Some epidemiological considerations are presented.Apresentam-se os resultados obtidos com a pesquisa sistemática de criadouros nas fases não cultivadas dos campos de arroz, correspondendo ao período de maio a novembro de 1993. Esse lapso de tempo foi o referente aos estádios de repouso, de aradura do terreno e de gradeamento. Este foi realizado mediante inundações transitórias e a homogeneização mecânica da terra. O primeiro correspondeu ao estádio 1, enquanto os outros dois, ao estádio 2. Foram encontrados criadouros nas etapas concernentes aos estados de repouso e de aradura. Foram negativas as pesquisas referentes às fases de gradeamento. As espécies predominantes foram Aedes scapularis, Culex nigripalpus e Cx. mollis. Observou-se a existência de associações com o ritmo local das precipitações atmosféricas. São apresentadas considerações sobre o potencial epidemiológico desses encontros.

  11. UV light and urban pollution: bad cocktail for mosquitoes?

    Science.gov (United States)

    Tetreau, Guillaume; Chandor-Proust, Alexia; Faucon, Frédéric; Stalinski, Renaud; Akhouayri, Idir; Prud'homme, Sophie M; Régent-Kloeckner, Myriam; Raveton, Muriel; Reynaud, Stéphane

    2014-01-01

    Mosquito breeding sites consist of water pools, which can either be large open areas or highly covered ponds with vegetation, thus with different light exposures combined with the presence in water of xenobiotics including polycyclic aromatic hydrocarbons (PAHs) generated by urban pollution. UV light and PAHs are abiotic factors known to both affect the mosquito insecticide resistance status. Nonetheless, their potential combined effects on the mosquito physiology have never been investigated. The present article aims at describing the effects of UV exposure alongside water contamination with two major PAH pollutants (fluoranthene and benzo[a]pyrene) on a laboratory population of the yellow fever mosquito Aedes aegypti. To evaluate the effects of PAH exposure and low energetic UV (UV-A) irradiation on mosquitoes, different parameters were measured including: (1) The PAH localization and its impact on cell mortality by fluorescent microscopy; (2) The detoxification capacities (cytochrome P450, glutathione-S-transferase, esterase); (3) The responses to oxidative stress (Reactive Oxygen Species-ROS) and (4) The tolerance of mosquito larvae to a bioinsecticide (Bacillus thuringiensis subsp. israelensis-Bti) and to five chemical insecticides (DDT, imidacloprid, permethrin, propoxur and temephos). Contrasting effects regarding mosquito cell mortality, detoxification and oxidative stress were observed as being dependent on the pollutant considered, despite the fact that the two PAHs belong to the same family. Moreover, UV is able to modify pollutant effects on mosquitoes, including tolerance to three insecticides (imidacloprid, propoxur and temephos), cell damage and response to oxidative stress. Taken together, our results suggest that UV and pollution, individually or in combination, are abiotic parameters that can affect the physiology and insecticide tolerance of mosquitoes; but the complexity of their direct effect and of their interaction will require further

  12. The mosquito problem in Oxidation Pounds

    CSIR Research Space (South Africa)

    Loedolff, C.J

    2011-01-20

    Full Text Available accepted iii Southern Airica for nianv reasons, the most important hieing the low cost when compared with the conventional sewage works. Va nous aspects tf the system Inn e been investigated, (lie work having been co ordinated by (lie South Airic...~ui Council for Scientific and Industrial Research. In tropical and sub—tropical areas, such as in Southern Africa, (lie problem of mosquito breeding is of considerable importance and requires i,itinediate solution. \\iosquitoes are an i iitercstiig group...

  13. Mosquitoes of Middle America.

    Science.gov (United States)

    1976-09-30

    adeloupe, 1964-1966. S Cova Garcia, Pablo, Division de Endemias Rurales, Ministerio de Sanidad y Asistencia Social , Mara- cay, Venezuela...Central America. Diaz Najerra , Alfonso, Laboratorio de En tomologia, Instituto de Salubridad y Enfermedades Trop- icales.— Mosquitoes of Mexico , loan of...Saneamiento Ambiental. Minister io de Sanidad y Asistencia Social , Caracas , Venezuela. — Organization of topotypic survey of mosquitoes in Vene zuela

  14. MosquitoNet: investigating the use of UAV and artificial neural networks for integrated mosquito management

    Science.gov (United States)

    Case, E.; Ren, Y.; Shragai, T.; Erickson, D.

    2017-12-01

    Integrated mosquito control is expensive and resource intensive, and changing climatic factors are predicted to expand the habitable range of disease-carrying mosquitoes into new regions in the United States. Of particular concern in the northeastern United States are aedes albopictus, an aggressive, invasive species of mosquito that can transmit both native and exotic disease. Ae. albopictus prefer to live near human populations and breed in artificial containers with as little as two millimeters of standing water, exponentially increasing the difficulty of source control in suburban and urban areas. However, low-cost unmanned aerial vehicles (UAVs) can be used to photograph large regions at centimeter-resolution, and can image containers of interest in suburban neighborhoods. While proofs-of-concepts have been shown using UAVs to identify naturally occurring bodies of water, they have not been used to identify mosquito habitat in more populated areas. One of the primary challenges is that post-processing high-resolution aerial imagery is still time intensive, often labelled by hand or with programs built for satellite imagery. Artificial neural networks have been highly successful at image recognition tasks; in the past five years, convolutional neural networks (CNN) have surpassed or aided trained humans in identification of skin cancer, agricultural crops, and poverty levels from satellite imagery. MosquitoNet, a dual classifier built from the Single Shot Multibox Detector and VGG16 architectures, was trained on UAV­­­­­ aerial imagery taken during a larval study in Westchester County in southern New York State in July and August 2017. MosquitoNet was designed to assess the habitat risk of suburban properties by automating the identification and counting of containers like tires, toys, garbage bins, flower pots, etc. The SSD-based architecture marked small containers and other habitat indicators while the VGG16-based architecture classified the type of

  15. GLOBE Observer Mosquito Habitat Mapper: Geoscience and Public Health Connections

    Science.gov (United States)

    Low, R.; Boger, R. A.

    2017-12-01

    The global health crisis posed by vector-borne diseases is so great in scope that it is clearly insurmountable without the active help of tens-or hundreds- of thousands of individuals, working to identify and eradicate risk in communities around the world. Mobile devices equipped with data collection capabilities and visualization opportunities are lowering the barrier for participation in data collection efforts. The GLOBE Observer Mosquito Habitat Mapper (MHM) provides citizen scientists with an easy to use mobile platform to identify and locate mosquito breeding sites in their community. The app also supports the identification of vector taxa in the larvae development phase via a built-in key, which provides important information for scientists and public health officials tracking the rate of range expansion of invasive vector species and associated health threats. GO Mosquito is actively working with other citizen scientist programs across the world to ensure interoperability of data through standardization of metadata fields specific to vector monitoring, and through the development of APIs that allow for data exchange and shared data display through a UN-sponsored proof of concept project, Global Mosquito Alert. Avenues of application for mosquito vector data-both directly, by public health entities, and by modelers who employ remotely sensed environmental data to project mosquito population dynamics and epidemic disease will be featured.

  16. Study of mosquito attractants for photo catalytic mosquito trap

    OpenAIRE

    Dewi Tristantini; Slamet -; Angela Jessica Stephanie

    2014-01-01

    Photo catalytic mosquito trap is made of TiO2-Activated Carbon (AC) with a certain composition of AC. Research concerns on the heat spectrum which is produced by combination process of existing CO2 and humid air. The purpose of performance testing is to observe capability of this device in trapping mosquitoes related to the air temperature profile for heat spectrum is play important role for attracting mosquitoes. Result shows photo catalytic mosquito trap is more effective than devices which...

  17. Repelling mosquitoes with essential oils

    Science.gov (United States)

    Riley, L.

    2017-12-01

    Mosquitoes carry diseases than can lead to serious illness and death. According to the World Health Organization, mosquitoes infect over 300 million people a year with Malaria and Dengue Fever, two life threatening diseases vectored by mosquitoes. Although insecticides are the most effective way to control mosquitoes, they are not always environmentally friendly. Therefore, alternative tactics should be considered. In this study, we looked at the repellency of various essential oils on female Aedes aegypti through a series of laboratory assays.

  18. Mosquitoes, models, and dengue.

    Science.gov (United States)

    Lifson, A R

    1996-05-04

    In the last 10 years dengue has spread markedly through Latin America and the Caribbean (Dominican Republic, Jamaica, Barbados, Mexico, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama, Ecuador, Colombia, Venezuela, and Brazil). The mosquito Aedes aegypti has taken advantage of increased urbanization and crowding to transmit the dengue virus. The mosquito infests tires, cans, and water jars near dwellings. The female mosquito practices multiple, interrupted feeding. Thus, mosquito infesting and feeding practices facilitate dengue transmission in crowded conditions. Factors contributing to the spread of dengue include numbers of infected and susceptible human hosts, strain of dengue virus, size of mosquito population, feeding habits, time from infection to ability to transmit virus for both vector and host, likelihood of virus transmission from human to mosquito to human, and temperature (which affects vector distribution, size, feeding habits, and extrinsic incubation period). Public health models may use simulation models to help them plan or evaluate the potential impact of different intervention strategies and/or of environmental changes (e.g., global warming). Other factors contributing to the dengue epidemic are international travel, urbanization, population growth, crowding, poverty, a weakened public health infrastructure, and limited support for sustained disease control programs. Molecular epidemiology by nucleic acid sequence analysis is another sophisticated technique used to study infectious diseases. It showed that dengue type 3 isolated from Panama and Nicaragua in 1994 was identical to that responsible for the major dengue hemorrhagic fever epidemics in Sri Lanka and India in the 1980s. Public health officials must remember three priorities relevant to dengue and other emerging infections: the need to strengthen surveillance efforts, dedicated and sustained involvement in prevention and control needs at the local level, and a strong

  19. Flavivirus-Mosquito Interactions

    Directory of Open Access Journals (Sweden)

    Yan-Jang S. Huang

    2014-11-01

    Full Text Available The Flavivirus genus is in the family Flaviviridae and is comprised of more than 70 viruses. These viruses have a broad geographic range, circulating on every continent except Antarctica. Mosquito-borne flaviviruses, such as yellow fever virus, dengue virus serotypes 1–4, Japanese encephalitis virus, and West Nile virus are responsible for significant human morbidity and mortality in affected regions. This review focuses on what is known about flavivirus-mosquito interactions and presents key data collected from the field and laboratory-based molecular and ultrastructural evaluations.

  20. Transfer of toxin genes to alternate bacterial hosts for mosquito control

    Directory of Open Access Journals (Sweden)

    Sergio Orduz

    1995-02-01

    Full Text Available Mosquitoes are vector of serious human and animal diseases, such as malaria, dengue, yellow fever, among others. The use of biological control agents has provide an environmentally safe and highly specific alternative to the use of chemical insecticides in the control of vector borne diseases. Bacillus thuringiensis and B. sphaericus produce toxic proteins to mosquito larvae. Great progress has been made on the biochemical and molecular characterization of such proteins and the genes encoding them. Nevertheless, the low residuality of these biological insecticides is one of the major drawbacks. This article present some interesting aspects of the mosquito larvae feeding habits and review the attempts that have been made to genetically engineer microorganisms that while are used by mosquito larvae as a food source should express the Bacillus toxin genes in order to improve the residuality and stability in the mosquito breeding ponds.

  1. Biodiversity and ecosystem risks arising from using guppies to control mosquitoes.

    Science.gov (United States)

    El-Sabaawi, Rana W; Frauendorf, Therese C; Marques, Piata S; Mackenzie, Richard A; Manna, Luisa R; Mazzoni, Rosana; Phillip, Dawn A T; Warbanski, Misha L; Zandonà, Eugenia

    2016-10-01

    Deploying mosquito predators such as the guppy (Poecilia reticulata) into bodies of water where mosquitoes breed is a common strategy for limiting the spread of disease-carrying mosquitoes. Here, we draw on studies from epidemiology, conservation, ecology and evolution to show that the evidence for the effectiveness of guppies in controlling mosquitoes is weak, that the chances of accidental guppy introduction into local ecosystems are large, and that guppies can easily establish populations and damage these aquatic ecosystems. We highlight several knowledge and implementation gaps, and urge that this approach is either abandoned in favour of more effective strategies or that it is used much more rigorously. Controlling mosquitoes does not need to come at the expense of freshwater biodiversity. © 2016 The Author(s).

  2. Mediation of oviposition responses in the malaria mosquito Anopheles stephensi Liston by certain fatty acid esters.

    Science.gov (United States)

    Sharma, Kavita R; Seenivasagan, T; Rao, A N; Ganesan, K; Agrawal, O P; Prakash, Shri

    2009-01-01

    The chemical factors involved in oviposition site selection by mosquitoes have become the focus of interest in recent years, and considerable attention is paid to the chemical cues influencing mosquito oviposition. Studies on synthetic oviposition attractants/repellents of long-chain fatty acid esters against Anopheles stephensi are limited. Screening and identification of chemicals which potentially attract/repel the gravid females to/or from oviposition site could be exploited for eco-friendly mosquito management strategies. The ester compounds demonstrated their ability to repel and attract the gravid A. stephensi females in the treated substrates. Significant level of concentration-dependent negative oviposition response of mosquitoes to octadecyl propanoate, heptadecyl butanoate, hexadecyl pentanoate, and tetradecyl heptanoate were observed. In contrast, decyl undecanoate, nonyl dodecanoate, pentyl hexadecanoate, and propyl octadecanoate elicited concentration-dependent positive oviposition responses from the gravid mosquitoes. Forcing a female to retain her eggs due to unavailability of a suitable oviposition site and attracting them to lay the eggs in a baited ovitraps shall ensure effective control of mosquito breeding and population buildup because the oviposition bioassay target the most susceptible stage of an insect life cycle. Treating relatively smaller natural breeding sites with an effective repellent and placing ovitraps containing an attractant in combination with insect-growth regulator (IGR)/insecticide would be a promising method of mosquito management.

  3. Transposable elements in mosquitoes.

    Science.gov (United States)

    Boulesteix, M; Biémont, C

    2005-01-01

    We describe the current state of knowledge about transposable elements (TEs) in different mosquito species. DNA-based elements (class II elements), non-LTR retrotransposons (class I elements), and MITEs (Miniature Inverted Repeat Transposable Elements) are found in the three genera, Anopheles, Aedes and Culex, whereas LTR retrotransposons (class I elements) are found only in Anopheles and Aedes. Mosquitoes were the first insects in which MITEs were reported; they have several LTR retrotransposons belonging to the Pao family, which is distinct from the Gypsy-Ty3 and Copia-Ty1 families. The number of TE copies shows huge variations between classes of TEs within a given species (from 1 to 1000), in sharp contrast to Drosophila, which shows only relatively minor differences in copy number between elements (from 1 to 100). The genomes of these insects therefore display major differences in the amount of TEs and therefore in their structure and global composition. We emphasize the need for more population genetic data about the activity of TEs, their distribution over chromosomes and their frequencies in natural populations of mosquitoes, to further the current attempts to develop a transgenic mosquito unable to transmit malaria that is intended to replace the natural populations.

  4. Mosquito Bites are Bad!

    Centers for Disease Control (CDC) Podcasts

    2016-08-11

    In this podcast for kids, the Kidtastics talk about the dangers of mosquito bites and how to prevent getting them.  Created: 8/11/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 8/11/2016.

  5. Mosquito Life Cycle

    Science.gov (United States)

    ... flies short time after emerging and after its body parts have hardened. The first three stages occur in water, but the adult is an active flying insect. Only the female mosquito bites and feeds on the blood of humans or other animals. After she obtains a blood ...

  6. Resource Limitation, Controphic Ostracod Density and Larval Mosquito Development.

    Directory of Open Access Journals (Sweden)

    Raylea Rowbottom

    Full Text Available Aquatic environments can be restricted with the amount of available food resources especially with changes to both abiotic and biotic conditions. Mosquito larvae, in particular, are sensitive to changes in food resources. Resource limitation through inter-, and intra-specific competition among mosquitoes are known to affect both their development and survival. However, much less is understood about the effects of non-culicid controphic competitors (species that share the same trophic level. To address this knowledge gap, we investigated and compared mosquito larval development, survival and adult size in two experiments, one with different densities of non-culicid controphic conditions and the other with altered resource conditions. We used Aedes camptorhynchus, a salt marsh breeding mosquito and a prominent vector for Ross River virus in Australia. Aedes camptorhynchus usually has few competitors due to its halo-tolerance and distribution in salt marshes. However, sympatric ostracod micro-crustaceans often co-occur within these salt marshes and can be found in dense populations, with field evidence suggesting exploitative competition for resources. Our experiments demonstrate resource limiting conditions caused significant increases in mosquito developmental times, decreased adult survival and decreased adult size. Overall, non-culicid exploitation experiments showed little effect on larval development and survival, but similar effects on adult size. We suggest that the alterations of adult traits owing to non-culicid controphic competition has potential to extend to vector-borne disease transmission.

  7. RELATIVE ABUNDANCE AND SPECIES COMPOSITION OF MOSQUITO POPULATIONS (DIPTERA:CULICIDAE) IN A LA CROSSE VIRUS- ENDEMIC AREA IN WESTERN NORTH CAROLINA

    Science.gov (United States)

    Container surveys were conducted in 5 communities on the Cherokee Indian Reservation, an area of western North Carolina endemic for transmission of La Crosse (LAC) virus, to determine the potential for peridomestic mosquito breeding, the relative abundance of mosquito species, an...

  8. Web mapping GIS: GPS under the GIS umbrella for Aedes species dengue and chikungunya vector mosquito surveillance and control

    Directory of Open Access Journals (Sweden)

    M. Palaniyandi

    2014-09-01

    Full Text Available The mosquito nuisance and the mosquito borne diseases have become major important challenging public health problems in India especially in the fast developing city like Pondicherry urban agglomeration. The Pondicherry government has been implemented full-fledged mosquito control measures, however, dengue and chikungunya epidemics was accelerating trend in Pondicherry for the recent years, and therefore, the directorate of public health, Pondicherry was requested vector control research centre (VCRC, to conduct a mosquito control evaluation survey. A team of field staff of VCRC headed by the author, Pondicherry, have conducted a detailed reconnaissance survey for collecting the site specifications of houses and the streetwise mosquito data for analyzing the density of vector mosquitoes in the wards / blocks and delineating the areas vulnerable to disease epidemics in the urban areas. The GPS GARMIN 12 XL was used to collect the field data. The ARC GIS 10.0 software was used to map the site locations (houses with mosquito’s data. The digital map of block boundary of Pondicherry was used for mapping purpose. A systematic grid sampling was applied to conduct a rapid survey for mapping Aedes species mosquito genic condition in the urban areas and the coordinates of sites of house information with breeding habitats positive in the grid sectors was collected using GPS, and the mean value of positive habitats was analyzed by quintiles method for mapping. The four blocks were selected for Aedes mosquito survey where the mosquito problem was identified as comparatively high, four numbers of wards were selected from each block, and the 40 number of houses was selected with 100 meter interval distance for mosquito breeding survey in the domestic and peripheral domestic areas in each wards. The problematic areas were identified, highlighted and recommended for web mapping GIS for Aedes mosquito surveillance continuously for monitoring the mosquito control

  9. Capitalizing on Citizen Science Data for Validating Models and Generating Hypotheses Describing Meteorological Drivers of Mosquito-Borne Disease Risk

    Science.gov (United States)

    Boger, R. A.; Low, R.; Paull, S.; Anyamba, A.; Soebiyanto, R. P.

    2017-12-01

    Temperature and precipitation are important drivers of mosquito population dynamics, and a growing set of models have been proposed to characterize these relationships. Validation of these models, and development of broader theories across mosquito species and regions could nonetheless be improved by comparing observations from a global dataset of mosquito larvae with satellite-based measurements of meteorological variables. Citizen science data can be particularly useful for two such aspects of research into the meteorological drivers of mosquito populations: i) Broad-scale validation of mosquito distribution models and ii) Generation of quantitative hypotheses regarding changes to mosquito abundance and phenology across scales. The recently released GLOBE Observer Mosquito Habitat Mapper (GO-MHM) app engages citizen scientists in identifying vector taxa, mapping breeding sites and decommissioning non-natural habitats, and provides a potentially useful new tool for validating mosquito ubiquity projections based on the analysis of remotely sensed environmental data. Our early work with GO-MHM data focuses on two objectives: validating citizen science reports of Aedes aegypti distribution through comparison with accepted scientific data sources, and exploring the relationship between extreme temperature and precipitation events and subsequent observations of mosquito larvae. Ultimately the goal is to develop testable hypotheses regarding the shape and character of this relationship between mosquito species and regions.

  10. Breeds of cattle

    NARCIS (Netherlands)

    Buchanan, David S.; Lenstra, Johannes A.|info:eu-repo/dai/nl/067852335

    2015-01-01

    This chapter gives an overview on the different breeds of cattle (Bos taurus and B. indicus). Cattle breeds are presented and categorized according to utility and mode of origin. Classification and phylogeny of breeds are also discussed. Furthermore, a description of cattle breeds is provided.

  11. Evidence for regular ongoing introductions of mosquito disease vectors into the Galapagos Islands.

    Science.gov (United States)

    Bataille, Arnaud; Cunningham, Andrew A; Cedeño, Virna; Cruz, Marilyn; Eastwood, Gillian; Fonseca, Dina M; Causton, Charlotte E; Azuero, Ronal; Loayza, Jose; Martinez, Jose D Cruz; Goodman, Simon J

    2009-11-07

    Wildlife on isolated oceanic islands is highly susceptible to the introduction of pathogens. The recent establishment in the Galápagos Islands of the mosquito Culex quinquefasciatus, a vector for diseases such as avian malaria and West Nile fever, is considered a serious risk factor for the archipelago's endemic fauna. Here we present evidence from the monitoring of aeroplanes and genetic analysis that C. quinquefasciatus is regularly introduced via aircraft into the Galápagos Archipelago. Genetic population structure and admixture analysis demonstrates that these mosquitoes breed with, and integrate successfully into, already-established populations of C. quinquefasciatus in the Galápagos, and that there is ongoing movement of mosquitoes between islands. Tourist cruise boats and inter-island boat services are the most likely mechanism for transporting Culex mosquitoes between islands. Such anthropogenic mosquito movements increase the risk of the introduction of mosquito-borne diseases novel to Galápagos and their subsequent widespread dissemination across the archipelago. Failure to implement and maintain measures to prevent the human-assisted transport of mosquitoes to and among the islands could have catastrophic consequences for the endemic wildlife of Galápagos.

  12. Oviposition and vertical dispersal of Aedes mosquitoes in multiple storey buildings in Colombo district, Sri Lanka.

    Science.gov (United States)

    Jayathilake, T A Hasini D G; Wickramasinghe, Mervyn B; de Silva, B G D Nissanka K

    2015-09-01

    The Colombo City in Sri Lanka is experiencing tremendous development and construction of multiple storey buildings and high rise apartments. The change in housing types and microhabitats might have altered the flight and breeding behaviour of Aedes mosquito population. This study was carried out to determine the vertical dispersal and abundance of Aedes mosquitoes in multiple storey buildings in the Colombo district, with respect to abiotic factors such as rainfall, humidity and wind speed. Hence, this study is of paramount importance, particularly for planning and implementation of control measures against Aedes mosquitoes. An ovitrap based study was carried out at four selected multiple storey buildings in four residential areas located in Colombo, Sri Lanka, from August to December 2013. Results were analyzed using four indices; ovitrap index, mean number of larvae, mean number of eggs and mean number of larvae per ovipaddle. The results implied that Aedes mosquitoes could be found in different elevations from ground floor to the highest floor (130 ft). There was a significant difference between height and ovitrap index (pvertical dispersal of Aedes mosquitoes (pvertical dispersal with respect to abundance seemed to be statistically non-significant (p>0.05) with height which indicates high abundance of Aedes mosquitoes at higher floors. Abiotic factors also seemed to cause significant effect to the vertical dispersal of Aedes mosquitoes in high rise buildings.

  13. Organic breeding: New trend in plant breeding

    Directory of Open Access Journals (Sweden)

    Berenji Janoš

    2009-01-01

    Full Text Available Organic breeding is a new trend in plant breeding aimed at breeding of organic cultivars adapted to conditions and expectations of organic plant production. The best proof for the need of organic cultivars is the existence of interaction between the performances of genotypes with the kind of production (conventional or organic (graph. 1. The adaptation to low-input conditions of organic production by more eddicient uptake and utilization of plant nutrients is especially important for organic cultivars. One of the basic mechanism of weed control in organic production is the competition of organic cultivars and weeds i.e. the enhanced ability of organic cultivars to suppress the weeds. Resistance/tolerance to diseases and pests is among the most important expectations toward the organic cultivars. In comparison with the methods of conventional plant breeding, in case of organic plant breeding limitations exist in choice of methods for creation of variability and selection classified as permitted, conditionally permitted and banned. The use of genetically modified organisms and their derivated along with induced mutations is not permitted in organic production. The use of molecular markers in organic plant breeding is the only permitted modern method of biotechnology. It is not permitted to patent the breeding material of organic plant breeding or the organic cultivars. .

  14. Mosquitoes as a Part of Wetland Biodiversity

    OpenAIRE

    Schäfer, Martina

    2004-01-01

    Wetlands contain both aquatic and terrestrial environments which generates high biodiversity. However, they are commonly associated with mosquitoes (Diptera: Culicidae), and mosquitoes are usually regarded as negative by humans because they can cause nuisance and transmit diseases. This thesis aimed to clarify the association between mosquitoes and wetlands and to achieve a more balanced view of biodiversity in wetlands by including mosquito diversity. Studies on adult mosquito diversity and ...

  15. Perspectives of people in Mali toward genetically-modified mosquitoes for malaria control

    Directory of Open Access Journals (Sweden)

    Famenini Shannon

    2010-05-01

    Full Text Available Abstract Background Genetically-modified (GM mosquitoes have been proposed as part of an integrated vector control strategy for malaria control. Public acceptance is essential prior to field trials, particularly since mosquitoes are a vector of human disease and genetically modified organisms (GMOs face strong scepticism in developed and developing nations. Despite this, in sub-Saharan Africa, where the GM mosquito effort is primarily directed, very little data is available on perspectives to GMOs. Here, results are presented of a qualitative survey of public attitudes to GM mosquitoes for malaria control in rural and urban areas of Mali, West Africa between the months of October 2008 and June 2009. Methods The sample consisted of 80 individuals - 30 living in rural communities, 30 living in urban suburbs of Bamako, and 20 Western-trained and traditional health professionals working in Bamako and Bandiagara. Questions were asked about the cause of malaria, heredity and selective breeding. This led to questions about genetic alterations, and acceptable conditions for a release of pest-resistant GM corn and malaria-refractory GM mosquitoes. Finally, participants were asked about the decision-making process in their community. Interviews were transcribed and responses were categorized according to general themes. Results Most participants cited mosquitoes as one of several causes of malaria. The concept of the gene was not widely understood; however selective breeding was understood, allowing limited communication of the concept of genetic modification. Participants were open to a release of pest-resistant GM corn, often wanting to conduct a trial themselves. The concept of a trial was reapplied to GM mosquitoes, although less frequently. Participants wanted to see evidence that GM mosquitoes can reduce malaria prevalence without negative consequences for human health and the environment. For several participants, a mosquito control programme was

  16. Perspectives of people in Mali toward genetically-modified mosquitoes for malaria control.

    Science.gov (United States)

    Marshall, John M; Touré, Mahamoudou B; Traore, Mohamed M; Famenini, Shannon; Taylor, Charles E

    2010-05-14

    Genetically-modified (GM) mosquitoes have been proposed as part of an integrated vector control strategy for malaria control. Public acceptance is essential prior to field trials, particularly since mosquitoes are a vector of human disease and genetically modified organisms (GMOs) face strong scepticism in developed and developing nations. Despite this, in sub-Saharan Africa, where the GM mosquito effort is primarily directed, very little data is available on perspectives to GMOs. Here, results are presented of a qualitative survey of public attitudes to GM mosquitoes for malaria control in rural and urban areas of Mali, West Africa between the months of October 2008 and June 2009. The sample consisted of 80 individuals - 30 living in rural communities, 30 living in urban suburbs of Bamako, and 20 Western-trained and traditional health professionals working in Bamako and Bandiagara. Questions were asked about the cause of malaria, heredity and selective breeding. This led to questions about genetic alterations, and acceptable conditions for a release of pest-resistant GM corn and malaria-refractory GM mosquitoes. Finally, participants were asked about the decision-making process in their community. Interviews were transcribed and responses were categorized according to general themes. Most participants cited mosquitoes as one of several causes of malaria. The concept of the gene was not widely understood; however selective breeding was understood, allowing limited communication of the concept of genetic modification. Participants were open to a release of pest-resistant GM corn, often wanting to conduct a trial themselves. The concept of a trial was reapplied to GM mosquitoes, although less frequently. Participants wanted to see evidence that GM mosquitoes can reduce malaria prevalence without negative consequences for human health and the environment. For several participants, a mosquito control programme was preferred; however a transgenic release that satisfied

  17. Incorporating the effects of humidity in a mechanistic model of Anopheles gambiae mosquito population dynamics in the Sahel region of Africa.

    Science.gov (United States)

    Yamana, Teresa K; Eltahir, Elfatih A B

    2013-08-09

    Low levels of relative humidity are known to decrease the lifespan of mosquitoes. However, most current models of malaria transmission do not account for the effects of relative humidity on mosquito survival. In the Sahel, where relative humidity drops to levels Sahel region of Africa, which are presented in this paper. We apply this equation to the environmental data and conduct numerical simulations of mosquito populations using the Hydrology, Entomology and Malaria Transmission Simulator (HYDREMATS). Relative humidity drops to levels that are uncomfortable for mosquitoes at the end of the rainy season. In one village, Banizoumbou, water pools dried up and interrupted mosquito breeding shortly after the end of the rainy season. In this case, relative humidity had little effect on the mosquito population. However, in the other village, Zindarou, the relatively shallow water table led to water pools that persisted several months beyond the end of the rainy season. In this case, the decrease in mosquito survival due to relative humidity improved the model's ability to reproduce the seasonal pattern of observed mosquito abundance. We proposed a new equation to describe Anopheles gambiae s.l. mosquito survival as a function of temperature and relative humidity. We demonstrated that relative humidity can play a significant role in mosquito population and malaria transmission dynamics. Future modeling work should account for these effects of relative humidity.

  18. Dynamics of radon-222 near below ground surface

    International Nuclear Information System (INIS)

    Fukui, Masami; Katsurayama, Kousuke; Nishimura, Susumu.

    1986-01-01

    The concentrations and variation of 222 Rn were investigated both in unconfined groundwater and in the aerated zone to obtain information as to the behavior of Rn close to ground surface. The Rn concentrations in unconfined groundwater near the surface were depletive by the extent of about 50 % compared with that of lower part in a borehole, then the continuous extraction of groundwater causes pronounced increase of the concentration. The method, which monitors continuously the Rn concentration in such surroundings, was developed, where the unconfined groundwater extracted was injected into another borehole and sprayed gas was measured using an ionization chamber. The read-out values of this system well followed the variation of concentrations caused by the meteorological parameter, especially infiltrating water. The increase of 222 Rn concentration in the aerated zone above the water level was clearly observed following the ascendant of groundwater level caused by the infiltrating water, whereas the change of concentration in soil air just below the ground surface obeyed mainly to the wetness of soil and unconfined groundwater level rather than atmospheric pressure. (author)

  19. Otidea subterranea sp. nov.: Otidea goes below ground.

    Science.gov (United States)

    Smith, Matthew E; Healy, Rosanne A

    2009-08-01

    Evidence suggests that truffle-like sporocarp forms have evolved many times in the Pezizales, but primarily from epigeous ancestors within ectomycorrhizal clades. There are several ectomycorrhizal clades, however, that contain no known hypogeous species. We collected specimens of an unusual unidentified truffle from mixed oak woodlands in Iowa. Although clearly a member of the Pezizales (Ascomycota), this hypogeous species did not belong to any of the described truffle genera. Based on a combination of ecological, phylogenetic, and morphological evidence we determined that this new truffle is a hypogeous member of the genus Otidea (Pyronemataceae), a lineage with no described truffle species. We describe it here as a new species, Otidea subterranea.

  20. Plant defense below ground and spatiotemporal processes in natural vegetation

    NARCIS (Netherlands)

    Van der Putten, W.H.

    2003-01-01

    Root herbivores and pathogens play an important role in driving plant abundance, species diversity, and succession in natural vegetation. Subterranean plant feeders and pathogenic microorganisms interfere with basic functions of plant roots, such as resource uptake, storage of reserves, and

  1. Mitigating Mosquito Disease Vectors with Citizen Science: a Review of the GLOBE Observer Mosquito Habitat Mapper Pilot and Implications for Wide-scale Implementation

    Science.gov (United States)

    Riebeek Kohl, H.; Low, R.; Boger, R. A.; Schwerin, T. G.; Janney, D. W.

    2017-12-01

    The spread of disease vectors, including mosquitoes, is an increasingly significant global environmental issue driven by a warming climate. In 2017, the GLOBE Observer Program launched a new citizen science initiative to map mosquito habitats using the free GLOBE Observer App for smart phones and tablets. The app guides people to identify mosquito larvae and breeding sites, and then once documented, to eliminate or treat the site to prevent further breeding. It also gives citizen scientists the option to identify the mosquito larvae species to determine whether it is one of three genera that potentially could transmit Zika, dengue fever, yellow fever, chikungunya, and other diseases. This data is uploaded to an international database that is freely available to the public and science community. GLOBE Observer piloted the initiative with educators in the United States, Brazil, and Peru, and it is now open for global participation. This presentation will discuss lessons learned in the pilot phase as well as plans to implement the initiative worldwide in partnership with science museums and science centers. GLOBE Observer is the non-student citizen science arm of the Global Learning and Observations to Benefit the Environment (GLOBE) Program, a long-standing, international science and education program that provides students and citizen scientists with the opportunity to participate in data collection and the scientific process, and contribute meaningfully to our understanding of the Earth system and global environment. GLOBE Observer data collection also includes cloud cover and cloud type and land cover/land use (in late 2017).

  2. Mosquito-borne West Nile virus (WNV) surveillance in the Upper Rhine Valley, Germany.

    Science.gov (United States)

    Timmermann, Ute; Becker, Norbert

    2010-06-01

    West Nile virus (WNV) could be introduced into Germany via migratory birds originating from Africa or southern Europe and subsequently transmitted to indigenous birds, humans, or horses by mosquitoes. Neither the virus itself nor antibodies against WNV have yet to be found in mosquitoes and horses, whereas antibodies have been detected in migrating birds and in humans that were in close contact with birds. At present, the West Nile virus itself has yet to be detected in Germany. This investigation was conducted primarily in major bird breeding, resting, and roosting habitats (hotspots) in the Upper Rhine Valley. Adult mosquitoes were trapped using CO2-baited Encephalitis Vector Surveillance (EVS)-traps and were tested for WNV by the VecTest WNV Antigen Assay. In 2007 and 2008, a total of 11,073 host-seeking adult female mosquitoes (13 species) were tested, and all tests were negative for WNV. Statistical calculations could be performed only where sufficient numbers of mosquitoes were trapped. For these sites, WNV infection among mosquitoes could be ruled out with 80% certainty. For the evaluation of the WNV situation in Germany, the results of this investigation are a further indication that the virus has not yet arrived.

  3. Larval habitats of mosquito fauna in Osogbo metropolis, Southwestern Nigeria.

    Science.gov (United States)

    Adeleke, Monsuru Adebayo; Adebimpe, Wasiu Olalekan; Hassan, AbdulWasiu Oladele; Oladejo, Sunday Olukayode; Olaoye, Ismail; Olatunde, Ganiyu Olatunji; Adewole, Taiwo

    2013-09-01

    To determine the larval habitats of mosquito fauna and possible impact of land use/ land cover changes on the epidemiology of mosquito-borne diseases in Osogbo metropolis, Southwestern, Nigeria. All accessible larval habitats were surveyed between May and September, 2011 in Osogbo metropolis while Land Use/ Land cover of the city was analyzed using 2 Lansat Multispectral Scanner satellite imagery of SPOT 1986 and LANDSAT TM 2009. A total of six species namely, Aedes aegypti, Aedes albopictus, Aedes vittatus, Anopheles gambiae complex, Culex quinquefasciatus and Eretmapodite chrysogaster were encountered during the study. The occurrence and contribution of disused tyres was significantly higher (P0.05). The accessible land use/ land covered of the study area between 1986 and 2009 showed that the wet land coverage and settlement area increased from 0.19 to 9.09 hectare and 1.00 to 2.01 hectare respectively while the forest area decreased from 60.18 to 50.14 hectare. The contribution of the habitats coupled with the increasing rate of flooded environment which could provide ample breeding sites for mosquitoes call for sustained environmental sanitation and management in Osogbo metropolis.

  4. Cooler temperatures destabilize RNA interference and increase susceptibility of disease vector mosquitoes to viral infection.

    Science.gov (United States)

    Adelman, Zach N; Anderson, Michelle A E; Wiley, Michael R; Murreddu, Marta G; Samuel, Glady Hazitha; Morazzani, Elaine M; Myles, Kevin M

    2013-01-01

    The impact of global climate change on the transmission dynamics of infectious diseases is the subject of extensive debate. The transmission of mosquito-borne viral diseases is particularly complex, with climatic variables directly affecting many parameters associated with the prevalence of disease vectors. While evidence shows that warmer temperatures often decrease the extrinsic incubation period of an arthropod-borne virus (arbovirus), exposure to cooler temperatures often predisposes disease vector mosquitoes to higher infection rates. RNA interference (RNAi) pathways are essential to antiviral immunity in the mosquito; however, few experiments have explored the effects of temperature on the RNAi machinery. We utilized transgenic "sensor" strains of Aedes aegypti to examine the role of temperature on RNA silencing. These "sensor" strains express EGFP only when RNAi is inhibited; for example, after knockdown of the effector proteins Dicer-2 (DCR-2) or Argonaute-2 (AGO-2). We observed an increase in EGFP expression in transgenic sensor mosquitoes reared at 18°C as compared with 28°C. Changes in expression were dependent on the presence of an inverted repeat with homology to a portion of the EGFP sequence, as transgenic strains lacking this sequence, the double stranded RNA (dsRNA) trigger for RNAi, showed no change in EGFP expression when reared at 18°C. Sequencing small RNAs in sensor mosquitoes reared at low temperature revealed normal processing of dsRNA substrates, suggesting the observed deficiency in RNAi occurs downstream of DCR-2. Rearing at cooler temperatures also predisposed mosquitoes to higher levels of infection with both chikungunya and yellow fever viruses. This data suggest that microclimates, such as those present in mosquito breeding sites, as well as more general climactic variables may influence the dynamics of mosquito-borne viral diseases by affecting the antiviral immunity of disease vectors.

  5. Cooler temperatures destabilize RNA interference and increase susceptibility of disease vector mosquitoes to viral infection.

    Directory of Open Access Journals (Sweden)

    Zach N Adelman

    Full Text Available The impact of global climate change on the transmission dynamics of infectious diseases is the subject of extensive debate. The transmission of mosquito-borne viral diseases is particularly complex, with climatic variables directly affecting many parameters associated with the prevalence of disease vectors. While evidence shows that warmer temperatures often decrease the extrinsic incubation period of an arthropod-borne virus (arbovirus, exposure to cooler temperatures often predisposes disease vector mosquitoes to higher infection rates. RNA interference (RNAi pathways are essential to antiviral immunity in the mosquito; however, few experiments have explored the effects of temperature on the RNAi machinery.We utilized transgenic "sensor" strains of Aedes aegypti to examine the role of temperature on RNA silencing. These "sensor" strains express EGFP only when RNAi is inhibited; for example, after knockdown of the effector proteins Dicer-2 (DCR-2 or Argonaute-2 (AGO-2. We observed an increase in EGFP expression in transgenic sensor mosquitoes reared at 18°C as compared with 28°C. Changes in expression were dependent on the presence of an inverted repeat with homology to a portion of the EGFP sequence, as transgenic strains lacking this sequence, the double stranded RNA (dsRNA trigger for RNAi, showed no change in EGFP expression when reared at 18°C. Sequencing small RNAs in sensor mosquitoes reared at low temperature revealed normal processing of dsRNA substrates, suggesting the observed deficiency in RNAi occurs downstream of DCR-2. Rearing at cooler temperatures also predisposed mosquitoes to higher levels of infection with both chikungunya and yellow fever viruses.This data suggest that microclimates, such as those present in mosquito breeding sites, as well as more general climactic variables may influence the dynamics of mosquito-borne viral diseases by affecting the antiviral immunity of disease vectors.

  6. Radiation biology of mosquitoes.

    Science.gov (United States)

    Helinski, Michelle E H; Parker, Andrew G; Knols, Bart G J

    2009-11-16

    There is currently renewed interest in assessing the feasibility of the sterile insect technique (SIT) to control African malaria vectors in designated areas. The SIT relies on the sterilization of males before mass release, with sterilization currently being achieved through the use of ionizing radiation. This paper reviews previous work on radiation sterilization of Anopheles mosquitoes. In general, the pupal stage was irradiated due to ease of handling compared to the adult stage. The dose-response curve between the induced sterility and log (dose) was shown to be sigmoid, and there was a marked species difference in radiation sensitivity. Mating competitiveness studies have generally been performed under laboratory conditions. The competitiveness of males irradiated at high doses was relatively poor, but with increasing ratios of sterile males, egg hatch could be lowered effectively. Males irradiated as pupae had a lower competitiveness compared to males irradiated as adults, but the use of partially-sterilizing doses has not been studied extensively. Methods to reduce somatic damage during the irradiation process as well as the use of other agents or techniques to induce sterility are discussed. It is concluded that the optimal radiation dose chosen for insects that are to be released during an SIT programme should ensure a balance between induced sterility of males and their field competitiveness, with competitiveness being determined under (semi-) field conditions. Self-contained 60Co research irradiators remain the most practical irradiators but these are likely to be replaced in the future by a new generation of high output X ray irradiators.

  7. Radiation biology of mosquitoes

    Directory of Open Access Journals (Sweden)

    Knols Bart GJ

    2009-11-01

    Full Text Available Abstract There is currently renewed interest in assessing the feasibility of the sterile insect technique (SIT to control African malaria vectors in designated areas. The SIT relies on the sterilization of males before mass release, with sterilization currently being achieved through the use of ionizing radiation. This paper reviews previous work on radiation sterilization of Anopheles mosquitoes. In general, the pupal stage was irradiated due to ease of handling compared to the adult stage. The dose-response curve between the induced sterility and log (dose was shown to be sigmoid, and there was a marked species difference in radiation sensitivity. Mating competitiveness studies have generally been performed under laboratory conditions. The competitiveness of males irradiated at high doses was relatively poor, but with increasing ratios of sterile males, egg hatch could be lowered effectively. Males irradiated as pupae had a lower competitiveness compared to males irradiated as adults, but the use of partially-sterilizing doses has not been studied extensively. Methods to reduce somatic damage during the irradiation process as well as the use of other agents or techniques to induce sterility are discussed. It is concluded that the optimal radiation dose chosen for insects that are to be released during an SIT programme should ensure a balance between induced sterility of males and their field competitiveness, with competitiveness being determined under (semi- field conditions. Self-contained 60Co research irradiators remain the most practical irradiators but these are likely to be replaced in the future by a new generation of high output X ray irradiators.

  8. Transgenic mosquitoes and malaria transmission.

    Science.gov (United States)

    Christophides, George K

    2005-03-01

    As the malaria burden persists in most parts of the developing world, the concept of implementation of new strategies such as the use of genetically modified mosquitoes to control the disease continues to gain support. In Africa, which suffers most from malaria, mosquito vector populations are spread almost throughout the entire continent, and the parasite reservoir is big and continuously increasing. Moreover, malaria is transmitted by many species of anophelines with specific seasonal and geographical patterns. Therefore, a well designed, evolutionarily robust and publicly accepted plan aiming at population reduction or replacement is required. The task is twofold: to engineer mosquitoes with a genetic trait that confers resistance to malaria or causes population suppression; and, to drive the new trait through field populations. This review examines these two issues, and describes the groundwork that has been done towards understanding of the complex relation between the parasite and its vector.

  9. Transgenic Mosquitoes - Fact or Fiction?

    Science.gov (United States)

    Wilke, André B B; Beier, John C; Benelli, Giovanni

    2018-03-08

    Technologies for controlling mosquito vectors based on genetic manipulation and the release of genetically modified mosquitoes (GMMs) are gaining ground. However, concrete epidemiological evidence of their effectiveness, sustainability, and impact on the environment and nontarget species is lacking; no reliable ecological evidence on the potential interactions among GMMs, target populations, and other mosquito species populations exists; and no GMM technology has yet been approved by the WHO Vector Control Advisory Group. Our opinion is that, although GMMs may be considered a promising control tool, more studies are needed to assess their true effectiveness, risks, and benefits. Overall, several lines of evidence must be provided before GMM-based control strategies can be used under the integrated vector management framework. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. The association of environmental changes and the replacement of mosquito fauna in the Colombo District, Sri Lanka

    Directory of Open Access Journals (Sweden)

    BAS Priyangika

    2014-06-01

    Full Text Available The mosquito survey was carried out for 8 months between October 2009 and May 2010. Investigations included 12 randomly selected urban (6 and semi-urban (6 areas in the Colombo District of Sri Lanka. Thirty eight mosquito species were found and Anopheles interruptus, An. pseudojamesii, Aedes stenovensoni, Ae. edwardsi, Ae. vittatus, Culex  barraudi, Cx. fatigans, Cx. univittatus, Cx. aculeatus, Cx. purplexus, Cx. spiculosus, Cx. quadripalpis, Cx. halifaxi, Uranotaenia atra, Ur. unguiculata were new findings that were not recorded  previously in the period 1981-1982 from the same locations although 11 different breeding habitats were examined. Rainfall had a direct relation (P=0.000 with the distribution and the density of mosquitoes. Unplanned urbanization, human activities and irregular or non-disposal of domestic waste products have led to a population replacement of the mosquito fauna in these locations.

  11. GLOBE Goes GO with Mosquitoes

    Science.gov (United States)

    Boger, R. A.; Low, R.

    2016-12-01

    The GLOBE Mosquito Larvae protocol and a new citizen science initiative, GLOBE Observers (GO), were both launched in Summer 2016. While the GLOBE Mosquito Larvae Protocol and associated educational materials target K-16 student inquiry and research, the GO protocol version is simplified to enable citizen scientists of all ages from all walks of life to participate. GO allows citizen scientists to collect and submit environmental data through an easy-to-use smart phone app available for both Apple and Android mobile devices. GO mosquito asks for photos of larvae mosquito genus or species, location, and type of water source (e.g., container or pond) where the larvae were found. To initiate the new mosquito GLOBE/GO opportunities, workshops have been held in Barbuda, Thailand, West Indies, US Gulf Coast, New York City, and at the GLOBE Annual Meeting in Colorado. Through these venues, the protocols have been refined and a field campaign has been initiated so that GO and GLOBE citizen scientists (K-16 students and all others) can contribute data. Quality assurance measures are taken through the online training required to participate and the validation of identification by other citizen sciences and mosquito experts. Furthermore, initial research is underway to develop optical recognition software starting with the species that carry the Zika virus (Aedes aegypti and A. albopictus). With this launch, we plan to move forward by providing opportunities throughout the world to engage people in meaningful environmental and public health data collection and to promote citizen scientists to become agents of change in their communities.

  12. A small scale field trial with expanded polystyrene beads for mosquito control in septic tanks.

    Science.gov (United States)

    Chang, M S; Lian, S; Jute, N

    1995-01-01

    A field trial of the use of expanded polystyrene beads (EPSB) to control the breeding of mosquito larvae in household septic tanks was conducted in Sarawak. One week after treatment, the breeding of Culex quinquefasciatus and Aedes albopictus was reduced by 100% and 68.7% respectively. For both species combined, a 57.25% reduction in the adult emergence rate was achieved. No adult was caught in the emergence trap one month after treatment. A reduction in mosquito biting rates was reported by 87.3% of respondents. All households regarded the EPSB treatment as effective. This study has reduced the relatively high infestation rate of A. albopictus in the septic tanks to 16-20%. The EPSB treatment is feasible and practical. Post-treatment assessment using adult emergence traps and the implications for the vector control programme of the local authority are discussed.

  13. Tritium breeding in fusion reactors

    International Nuclear Information System (INIS)

    Abdou, M.A.

    1982-10-01

    Key technological problems that influence tritium breeding in fusion blankets are reviewed. The breeding potential of candidate materials is evaluated and compared to the tritium breeding requirements. The sensitivity of tritium breeding to design and nuclear data parameters is reviewed. A framework for an integrated approach to improve tritium breeding prediction is discussed with emphasis on nuclear data requirements

  14. Hydrology and Mosquito Population Dynamics around a Hydropower Reservoir in Africa

    Science.gov (United States)

    Endo, N.; Eltahir, E. A.

    2013-12-01

    Malaria is associated with dams because their reservoirs provide mosquitoes, the vector of malaria, with permanent breeding sites. The risk of contracting malaria is likely to be enhanced following the increasing trend of hydropower dam construction to satisfy the expanding energy needs in developing countries. A close examination of its adverse health impacts is critical in the design, construction, and operation phases. We will present results of extensive field studies in 2012 and 2013 around the Koka Reservoir, Ethiopia. The results uncover the importance of reservoir management especially after the rainy seasons. Furthermore, we show the capability of a newly modified hydrology, entomology and malaria transmission simulator, HYDREMATS (Bomblies et al, 2008), and its potential as a tool for evaluating environmental management strategies to control malaria. HYDREMATS was developed to represent how the hydrology in nearby villages is impacted by the reservoir system, and the role of different types of vector ecologies associated with different Anopheles mosquito species. The hydrology component of HYDREMATS simulates three different mosquito breeding habitats: rain-fed pools, groundwater pools, and shoreline water. The entomology component simulates the life cycles of An. funestus and An. arabiensis, the two main vectors around the reservoir. The model was calibrated over the 2012-2013 period. The impact of reservoir water level management on the mosquito population is explored based on numerical model simulations and field experiments.

  15. Implementation in breeding programmes

    NARCIS (Netherlands)

    Coffey, M.P.; McParland, S.; Bastin, C.; Wall, E.; Berry, D.P.; Veerkamp, R.F.

    2013-01-01

    Genetic improvement is easy when selecting for one heritable and well-recorded trait at a time. Many industrialised national dairy herds have overall breeding indices that incorporate a range of traits balanced by their known or estimated economic value. Future breeding goals will contain more

  16. Genomic dairy cattle breeding

    DEFF Research Database (Denmark)

    Mark, Thomas; Sandøe, Peter

    2010-01-01

    , unfavourable genetic trends for metabolic, reproductive, claw and leg diseases indicate that these attempts have been insufficient. Today, novel genome-wide sequencing techniques are revolutionising dairy cattle breeding; these enable genetic changes to occur at least twice as rapidly as previously. While......, a number of potential risks are discussed, including detrimental genetic trends for non-measured welfare traits, the increased chance of spreading unfavourable mutations, reduced sharing of information arising from concerns over patents, and an increased monopoly within dairy cattle breeding that may make...... negative effects on animal welfare and to invest in breeding for increased animal welfare. Researchers are encouraged to further investigate the long-term effects of various breeding schemes that rely on genomic breeding values....

  17. Mosquito Bite Prevention For Travelers

    Science.gov (United States)

    ... bites. Here’s how: Keep mosquitoes out of your hotel room or lodging Š Choose a hotel or lodging with air conditioning or screens on ... percentages of active ingredient provide longer protection Some brand name examples* (Insect repellents may be sold under ...

  18. Looking Backward, Looking Forward: The Long, Torturous Struggle with Mosquitoes

    Directory of Open Access Journals (Sweden)

    Gordon M. Patterson

    2016-10-01

    Full Text Available The American anti-mosquito movement grew out of the discovery of the role of mosquitoes in transferring pathogens and public concern about pest and nuisance mosquitoes in the late 1800s. In the 20th century, organized mosquito control in the United States passed through three eras: mechanical, chemical, and integrated mosquito control. Mosquito control in the 21st century faces the challenge of emerging pathogens, invasive mosquito species, and balancing concerns about the environment with effective control strategies.

  19. Rural buyers' perception about mosquito repellants

    Directory of Open Access Journals (Sweden)

    D. MEHTA

    2010-06-01

    Full Text Available Mosquito repellants prevent mosquito bites and prevention of "man-mosquito contact" is a critical factor in transmission and spread of any disease through mosquitoes particularly in rural area. There has been a long standing 'bias' towards rural buyers. The rural markets are considered rigid in the nature but it is not the case in real sense. Marketing to rural buyers is not only a challenge to the marketers but to the manufacturers, communicators, national planners and economists as well. That is why it has been necessary to understand the various aspects of selected rural areas and consumption pattern for such a fast growing market i.e. mosquito repellants and rural buyers’ perception towards such urban products. The present paper aims to find out the factors influencing the purchase decisions of rural buyers for mosquito repellants and to study the perceptions of present and potential rural buyers' of selected mosquito repellant brands.

  20. Gender, mosquitos and malaria: implications for community development programs in Laputta, Myanmar.

    Science.gov (United States)

    Tin-Oo; Pe-Thet-Htoon; Khin-Thet-Wai; Parks, W; Bryan, J

    2001-09-01

    This paper examines the gender roles linked to division of labor and potential exposure to mosquitos and malaria prevention activities. A "Human Development Initiative" (HDI) Project has been launched in Laputta, a mangrove delta region of Myanmar assisted by United Nations Development Program since 1994. The project aims to improve rural community access to primary health care and provide micro-credit programs, income generation schemes, and educational opportunities as a basis for community empowerment. Women and children of low-income households are the target beneficiaries. Prior to self-care training program and distribution of self-care manuals, altogether 20 focus group discussions (separately assigned to men and women) were conducted in eight study villages between January to February 2000. The primary vector for malaria in study area is Anopheles sundaicus. Rural women were prone to malaria due to exposure to mosquitos within the peak biting period at night because of their gender assigned roles. Both men and women perceived that mosquitos commonly bite before midnight, more at dusk. Lack of awareness of correlation between mosquitos and malaria together with lack of affordability enhance either non-use or shared use of bed-nets at home. Rural women did not consider destruction of breeding places of mosquitos as their major concern. Thus, it is essential for program planners to motivate local women for more active participation in vector control measures within and beyond their households in the context of community development programs.

  1. Assessment of Clarias gariepinus as a biological control agent against mosquito larvae.

    Science.gov (United States)

    Chala, Buze; Erko, Berhanu; Animut, Abebe; Degarege, Abraham; Petros, Beyene

    2016-05-31

    The emergence and spread of insecticide resistant mosquitoes renewed interest in investigating the use of larvivorous fish as a biological control agent. The potential of Clarias gariepinus fish in controlling Anopheles arabiensis and culicine larvae was assessed under laboratory and semi-field conditions. Small size (15-20 cm) C. gariepinus fish consumed greater number of mosquito larvae than the large size fish (25-40 cm) in the multivariate regression model (β = 13.36, 95 % CI = 4.57, 22.15). The Anopheles larvae consumed was greater in number than the culicines larvae consumed by the fish (β = 12.10, 95 % CI = 3.31, 20.89). The number of larvae consumed was greater during the night hours than during the light hours (β = 30.06, 95 % CI = 21.27, 38.85). Amount of supplementary fish food did not cause significant differences in the number of mosquito larvae consumed by the fish among different groups. C. gariepinus was observed to feed on mosquito larvae under laboratory and semi-field conditions. C. gariepinus fed on the larvae of An. arabiensis and culicines readily. Hence, it can be used as an alternative mosquito control agent in Ethiopia where the breeding habitats are small and localized.

  2. Monthly prevalence and diversity of mosquitoes (Diptera: Culicidae in Fars Province, Southern Iran

    Directory of Open Access Journals (Sweden)

    Davood Keshavarzi

    2017-02-01

    Full Text Available Objective: To get new data about the ecology of mosquitoes, which would be valuable to develop programs for future provision of mosquito controls in the study area. Methods: During April to September 2012, larvae of mosquitoes were collected from six counties in south of Fars Province using dipping method. Characteristics of larval breeding places were considered based on water conditions. Species diversity was examined in terms of alpha and beta measures, with the intent of comparing mosquito diversity according to the typology of regions. Results: During this investigation, totally, 5 057 larvae of mosquitoes belonging to 5 genera and 17 different mosquito species were recognized, namely, Anopheles dthali, Anopheles fluviatilis, Anopheles stephensi, Anopheles superpictus, Culex quinquefasciatus (Cx. quinquefasciatus, Culex mimeticus, Culex perexiguus, Culex pipiens (Cx. pipiens, Culex tritaeniorhynchus, Culex theileri (Cx. theileri, Culex tritaeniorhynchus, Culex sinaiticus, Culex torrentium, Culex modestus, Ochlerotatus caspius, Culiseta longiareolata and Aedes vexans (Ae. vexans. This is the first record of Ae. vexans, Culex perexiguus and Culex modestus in the Province. Cx. pipiens (27.3%, Cx. theileri (15.9% and Cx. quinquefasciatus (9.4% were the most abundant species found respectively. Cx. pipiens reached the highest density in August and July, while Cx. theileri, Cx. quinquefasciatus and Ae. vexans were found in high numbers in June. Diversity analysis indicated the highest species diversity in the Mohr County (Margalef index of 1.41 and Shannon index of 1.7 and the lowest species diversity in the Lamerd County (Margalef index of 0.33 and Shannon index of 0.38. Conclusions: Regarding to this research, there are some potential vectors of medical and veterinary importance in Fars Province. Results of the present study may serve as a basis for risk assessment of emerging mosquito-borne diseases.

  3. Mosquitoes established in Lhasa city, Tibet, China

    Science.gov (United States)

    2013-01-01

    Background In 2009, residents of Lhasa city, Tibet Autonomous Region (TAR), China reported large numbers of mosquitoes and bites from these insects. It is unclear whether this was a new phenomenon, which species were involved, and whether these mosquitoes had established themselves in the local circumstances. Methods The present study was undertaken in six urban sites of Chengguan district Lhasa city, Tibet. Adult mosquitoes were collected by bed net trap, labor hour method and light trap in August 2009 and August 2012. The trapped adult mosquitoes were initially counted and identified according to morphological criteria, and a proportion of mosquitoes were examined more closely using a multiplex PCR assay. Results 907 mosquitoes of the Culex pipiens complex were collected in this study. Among them, 595 were females and 312 were males. There was no significant difference in mosquito density monitored by bed net trap and labor hour method in 2009 and 2012. Of 105 mosquitoes identified by multiplex PCR, 36 were pure mosquitoes (34.29%) while 69 were hybrids (65.71%). The same subspecies of Culex pipiens complex were observed by bed net trap, labor hour method and light trap in 2009 and 2012. Conclusion The local Culex pipiens complex comprises the subspecies Cx. pipiens pipiens, Cx. pipiens pallens, Cx. pipiens quinquefasciatus and its hybrids. Mosquitoes in the Cx. pipiens complex, known to be, potentially, vectors of periodic filariasis and encephalitis, are now present from one season to the next, and appear to be established in Lhasa City, TAR. PMID:24060238

  4. Approaches to passive mosquito surveillance in the EU

    NARCIS (Netherlands)

    Kampen, H.; Medlock, J.M.; Vaux, A.G.C.; Koenraadt, C.J.M.; Vliet, van A.J.H.; Bartumeus, F.; Oltra, A.; Sousa, C.A.; Chouin, S.; Werner, D.

    2015-01-01

    The recent emergence in Europe of invasive mosquitoes and mosquito-borne disease associated with both invasive and native mosquito species has prompted intensified mosquito vector research in most European countries. Central to the efforts are mosquito monitoring and surveillance activities in order

  5. Birds - Breeding [ds60

    Data.gov (United States)

    California Natural Resource Agency — This data set provides access to information gathered on annual breeding bird surveys in California using a map layer developed by the Department. This data layer...

  6. Garlic breeding system innovations

    NARCIS (Netherlands)

    Zheng, S.J.; Kamenetsky, R.; Féréol, L.; Barandiaran, X.; Rabinowitch, H.D.; Chovelon, V.; Kik, C.

    2007-01-01

    This review outlines innovative methods for garlic breeding improvement and discusses the techniques used to increase variation like mutagenesis and in vitro techniques, as well as the current developments in florogenesis, sexual hybridization, genetic transformation and mass propagation. Sexual

  7. Metallic copper spray--a new control technique to combat invasive container-inhabiting mosquitoes.

    Science.gov (United States)

    Becker, Norbert; Oo, Thin Thin; Schork, Nino

    2015-11-09

    The control of container-inhabiting mosquitoes is mainly based on environmental management with special emphasis on community participation e.g. source reduction by elimination or modification of water bodies. However, citizens are often not aware of the problems related to urban mosquito control or just ignore the advice provided during anti-mosquito control campaigns. In particular, cemeteries contain favourite breeding sites for container-inhabiting mosquitoes like Ochlerotatus j. japonicus, Culex pipiens s.l./Cx. torrentium, Aedes aegypti or Aedes albopictus. In our study, we investigated whether metallic copper e.g. in form of copper spray can be a suitable and cost-effective tool to combat mosquito breeding in vases or other similar small containers where no commonly used insecticides can be applied. The effect of metallic copper spray in comparison to 5 Euro cent coins or copper tubes at different dosages and water qualities applied in small water collections such as widely used plastic grave vases were evaluated by assessing the mortality rates of larvae of Oc.j. japonicus, Cx. pipiens s.l./Cx. torrentium and Ae.aegypti. Different water qualities were tested to assess the influence of pH on the solubility of the copper ions. The copper concentrations were quantified using ICP/MS (Inductively coupled plasma/Mass spectrometry) in relation to the exposure time and mortality rates of mosquito larvae. All statistical analyses were computed using JMP 10.0.2 (SAS Institute Inc., 2012, Cary, NC, USA). Dosages of less than 500 ppb of copper in the water of small containers led to a 100% mortality rate after 2 weeks for all tested mosquito species by using one or more 5 Euro cent coins/vase. When the interior surface of plastic grave vases was covered by metallic copper spray, all of the tested larvae died after 7-10 days in the laboratory and under field conditions the reduction rate was 99.44% for Oc.j. japonicus and 99.6% for Culex pipiens s.l./Cx. torrentium

  8. What drives cooperative breeding?

    Directory of Open Access Journals (Sweden)

    Walter D Koenig

    2017-06-01

    Full Text Available Cooperative breeding, in which more than a pair of conspecifics cooperate to raise young at a single nest or brood, is widespread among vertebrates but highly variable in its geographic distribution. Particularly vexing has been identifying the ecological correlates of this phenomenon, which has been suggested to be favored in populations inhabiting both relatively stable, productive environments and in populations living under highly variable and unpredictable conditions. Griesser et al. provide a novel approach to this problem, performing a phylogenetic analysis indicating that family living is an intermediate step between nonsocial and cooperative breeding birds. They then examine the ecological and climatic conditions associated with these different social systems, concluding that cooperative breeding emerges when family living is favored in highly productive environments, followed secondarily by selection for cooperative breeding when environmental conditions deteriorate and within-year variability increases. Combined with recent work addressing the fitness consequences of cooperative breeding, Griesser et al.'s contribution stands to move the field forward by demonstrating that the evolution of complex adaptations such as cooperative breeding may only be understood when each of the steps leading to it are identified and carefully integrated.

  9. Ornamental Plant Breeding

    Directory of Open Access Journals (Sweden)

    Flávia Barbosa Silva Botelho

    2015-04-01

    Full Text Available World’s ornamental plant market, including domestic market of several countries and its exports, is currently evaluated in 107 billion dollars yearly. Such estimate highlights the importance of the sector in the economy of the countries, as well as its important social role, as it represents one of the main activities, which contributes to income and employment. Therefore a well-structured plant breeding program, which is connected with consumers’ demands, is required in order to fulfill these market needs globally. Activities related to pre-breeding, conventional breeding, and breeding by biotechnological techniques constitute the basis for the successful development of new ornamental plant cultivars. Techniques that involve tissue culture, protoplast fusion and genetic engineering greatly aid conventional breeding (germplasm introduction, plant selection and hybridization, aiming the obtention of superior genotypes. Therefore it makes evident, in the literature, the successful employment of genetic breeding, since it aims to develop plants with commercial value that are also competitive with the ones available in the market.

  10. Studies on Deltamethrin Treated Mosquito Net

    Directory of Open Access Journals (Sweden)

    A. Tyagi

    2010-01-01

    Full Text Available The focus of the present studies is to characterize mosquito net for its material of construction and qualitative as well as quantitative determination of the mosquito repellent chemical deltamethrin present in it. Further, the assessment of the mode of incorporation of the deltamethrin in the fabric of the mosquito net was done, i.e. whether the deltamethrin was present as a coating on the surface of the mosquito net or it was incorporated in the bulk of the material of construction of the mosquito net. The chromatographic technique has been used for quantitative estimation of deltamethrin extracted by two different solvents from the net. It has been found that the determination of deltamethrin in mosquito nets can vary with the method of extraction used. While extraction with acetone is good enough for estimating the chemical adsorbed on the surface, extraction with xylene provides complete information about the chemical present even in the bulk of the material.

  11. Distribution and occurrence of mosquito species in the municipal areas of Imo State, Nigeria

    Directory of Open Access Journals (Sweden)

    Ifeyinwa Celestina MGBEMENA

    2012-05-01

    Full Text Available A study of the ecology of drainage - breeding mosquito vectors was conducted in the three urban centers (Owerri, Orlu and Okigwe of Imo State, Nigeria. Four drainage sites located around markets, residential, stream and hotel premises were selected in each urban centre. Dipping method of sampling was employed and a total of 8,820 mosquitoes comprising eight species namely; Aedes aegypti, Aedes vittatus, Culex quinquefasciatus, Culex tigripes, Culex horridus, Culex cinereus, Culex annuliorus and Anopheles gambiae were encountered; in Owerri and Orlu with Cx. cinereus being completely absent in Okigwe. Cx. quinquefasciatus was predominantly present in all drainage sites with the highest occurrence of 4,474(50.74% followed by Aedes aegypti 1814 (20.57%, An .gambiae 945(10.71%, Cx. tigripes 484 (5.48% Ae. vittatus 420 (4.76%, Cx. horridus 264 (02.99%, Cx. cinereus 261 (2.96%, Cx. annuliorus 159 (1.88%. Of all sites sampled, market drainages had the highest abundance of mosquitoes which was significantly higher than (ANOVA, P≤ 0.05 those found in the residential, streams and hotel premises. Residential drainages recorded the second highest density followed by stream/vegetation drainages and hotel drainages which had the least. The abundance and distribution of mosquitoes in Owerri (130.06 the State Capital was significantly higher (ANOVA, P≤ 0.05 than those for Orlu (93.44 and Okigwe (52.13. The mosquito species identified in this study are of public health importance and there is an urgent need to desilt and clean up these drainages for free flow of water. This will not only rid these species of breeding sites but also free the State of the diseases associated with these organisms.

  12. North American Wetlands and Mosquito Control

    Directory of Open Access Journals (Sweden)

    Gabrielle E. Sakolsky-Hoopes

    2012-12-01

    Full Text Available Wetlands are valuable habitats that provide important social, economic, and ecological services such as flood control, water quality improvement, carbon sequestration, pollutant removal, and primary/secondary production export to terrestrial and aquatic food chains. There is disagreement about the need for mosquito control in wetlands and about the techniques utilized for mosquito abatement and their impacts upon wetlands ecosystems. Mosquito control in wetlands is a complex issue influenced by numerous factors, including many hard to quantify elements such as human perceptions, cultural predispositions, and political climate. In spite of considerable progress during the last decades, habitat protection and environmentally sound habitat management still remain inextricably tied to politics and economics. Furthermore, the connections are often complex, and occur at several levels, ranging from local businesses and politicians, to national governments and multinational institutions. Education is the key to lasting wetlands conservation. Integrated mosquito abatement strategies incorporate many approaches and practicable options, as described herein, and need to be well-defined, effective, and ecologically and economically sound for the wetland type and for the mosquito species of concern. The approach will certainly differ in response to disease outbreaks caused by mosquito-vectored pathogens versus quality of life issues caused by nuisance-biting mosquitoes. In this contribution, we provide an overview of the ecological setting and context for mosquito control in wetlands, present pertinent information on wetlands mosquitoes, review the mosquito abatement options available for current wetlands managers and mosquito control professionals, and outline some necessary considerations when devising mosquito control strategies. Although the emphasis is on North American wetlands, most of the material is applicable to wetlands everywhere.

  13. North American Wetlands and Mosquito Control

    Science.gov (United States)

    Rey, Jorge R.; Walton, William E.; Wolfe, Roger J.; Connelly, Roxanne; O’Connell, Sheila M.; Berg, Joe; Sakolsky-Hoopes, Gabrielle E.; Laderman, Aimlee D.

    2012-01-01

    Wetlands are valuable habitats that provide important social, economic, and ecological services such as flood control, water quality improvement, carbon sequestration, pollutant removal, and primary/secondary production export to terrestrial and aquatic food chains. There is disagreement about the need for mosquito control in wetlands and about the techniques utilized for mosquito abatement and their impacts upon wetlands ecosystems. Mosquito control in wetlands is a complex issue influenced by numerous factors, including many hard to quantify elements such as human perceptions, cultural predispositions, and political climate. In spite of considerable progress during the last decades, habitat protection and environmentally sound habitat management still remain inextricably tied to politics and economics. Furthermore, the connections are often complex, and occur at several levels, ranging from local businesses and politicians, to national governments and multinational institutions. Education is the key to lasting wetlands conservation. Integrated mosquito abatement strategies incorporate many approaches and practicable options, as described herein, and need to be well-defined, effective, and ecologically and economically sound for the wetland type and for the mosquito species of concern. The approach will certainly differ in response to disease outbreaks caused by mosquito-vectored pathogens versus quality of life issues caused by nuisance-biting mosquitoes. In this contribution, we provide an overview of the ecological setting and context for mosquito control in wetlands, present pertinent information on wetlands mosquitoes, review the mosquito abatement options available for current wetlands managers and mosquito control professionals, and outline some necessary considerations when devising mosquito control strategies. Although the emphasis is on North American wetlands, most of the material is applicable to wetlands everywhere. PMID:23222252

  14. Mosquito age and avian malaria infection.

    Science.gov (United States)

    Pigeault, Romain; Nicot, Antoine; Gandon, Sylvain; Rivero, Ana

    2015-09-30

    The immune system of many insects wanes dramatically with age, leading to the general prediction that older insects should be more susceptible to infection than their younger counterparts. This prediction is however challenged by numerous studies showing that older insects are more resistant to a range of pathogens. The effect of age on susceptibility to infections is particularly relevant for mosquitoes given their role as vectors of malaria and other diseases. Despite this, the effect of mosquito age on Plasmodium susceptibility has been rarely explored, either experimentally or theoretically. Experiments were carried out using the avian malaria parasite Plasmodium relictum and its natural vector in the field, the mosquito Culex pipiens. Both innate immune responses (number and type of circulating haemocytes) and Plasmodium susceptibility (prevalence and burden) were quantified in seven- and 17-day old females. Whether immunity or Plasmodium susceptibility are modulated by the previous blood feeding history of the mosquito was also investigated. To ensure repeatability, two different experimental blocks were carried out several weeks apart. Haemocyte numbers decrease drastically as the mosquitoes age. Despite this, older mosquitoes are significantly more resistant to a Plasmodium infection than their younger counterparts. Crucially, however, the age effect is entirely reversed when old mosquitoes have taken one previous non-infected blood meal. The results agree with previous studies showing that older insects are often more resistant to infections than younger ones. These results suggest that structural and functional alterations in mosquito physiology with age may be more important than immunity in determining the probability of a Plasmodium infection in old mosquitoes. Possible explanations for why the effect is reversed in blood-fed mosquitoes are discussed. The reversal of the age effect in blood fed mosquitoes implies that age is unlikely to have a

  15. The impact of transgenic mosquitoes on dengue virulence to humans and mosquitoes.

    Science.gov (United States)

    Medlock, Jan; Luz, Paula M; Struchiner, Claudio J; Galvani, Alison P

    2009-10-01

    Dengue is a major public health concern in the tropics and subtropics. Innovative transgenic strategies to render Aedes aegypti mosquitoes, the primary vector of dengue, incompetent for dengue transmission are under development. We modeled the evolutionary impact of different transgenic mosquito strategies on dengue-induced mortality, that is, dengue virulence, to both humans and mosquitoes. This model incorporates various evolutionary trade-offs in dengue virus epidemiological traits, for example, a trade-off between dengue transmission rate and its virulence to humans. Our results indicate that strategies that block transmission or reduce mosquito biting impose selection on dengue virulence in humans. This selection can be for either higher or lower virulence, depending on the interaction between the effect of the transgene and the trade-offs in epidemiological traits, highlighting the need for detailed quantitative data to understand more fully the impact of mosquito transgenesis on dengue virulence. Dengue virulence in mosquitoes can be selected on by transgenic strategies of blocking transmission, decreased mosquito biting, increased mosquito background mortality, and increased mosquito infection-induced mortality. Our results suggest that dengue control strategies that raise mosquito background mortality or mosquito infection-induced mortality pose less risk of causing increased virulence to humans than strategies that block transmission or reduce mosquito biting.

  16. Studies on Deltamethrin Treated Mosquito Net

    OpenAIRE

    A. Tyagi; T. Sharma; M. Singh; K. Fatma; V. S. Rawat; M. Aggarwal; R. K. Khandal

    2010-01-01

    The focus of the present studies is to characterize mosquito net for its material of construction and qualitative as well as quantitative determination of the mosquito repellent chemical deltamethrin present in it. Further, the assessment of the mode of incorporation of the deltamethrin in the fabric of the mosquito net was done, i.e. whether the deltamethrin was present as a coating on the surface of the mosquito net or it was incorporated in the bulk of the material of construction of the m...

  17. Anopheline (Diptera:Culicidae) breeding in a traditional tank-based village ecosystem in north central Sri Lanka

    DEFF Research Database (Denmark)

    Amerasinghe, F P; Konradsen, F; Fonseka, K T

    1997-01-01

    A 13-mo survey of immature anopheline mosquitoes breeding in surface water habitats was done at Mahameegaswewa village within the Huruluwewa watershed in north central Sri Lanka as part of a multidisciplinary study on malaria epidemiology. The watershed is representative of the ancient small tank...

  18. Breeding-assisted genomics.

    Science.gov (United States)

    Poland, Jesse

    2015-04-01

    The revolution of inexpensive sequencing has ushered in an unprecedented age of genomics. The promise of using this technology to accelerate plant breeding is being realized with a vision of genomics-assisted breeding that will lead to rapid genetic gain for expensive and difficult traits. The reality is now that robust phenotypic data is an increasing limiting resource to complement the current wealth of genomic information. While genomics has been hailed as the discipline to fundamentally change the scope of plant breeding, a more symbiotic relationship is likely to emerge. In the context of developing and evaluating large populations needed for functional genomics, none excel in this area more than plant breeders. While genetic studies have long relied on dedicated, well-structured populations, the resources dedicated to these populations in the context of readily available, inexpensive genotyping is making this philosophy less tractable relative to directly focusing functional genomics on material in breeding programs. Through shifting effort for basic genomic studies from dedicated structured populations, to capturing the entire scope of genetic determinants in breeding lines, we can move towards not only furthering our understanding of functional genomics in plants, but also rapidly improving crops for increased food security, availability and nutrition. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Septic tank mosquitoes: competition between species in central Nigeria.

    Science.gov (United States)

    Irving-Bell, R J; Okoli, E I; Diyelong, D Y; Lyimo, E O; Onyia, O C

    1987-07-01

    Exit traps, placed over the air vents of septic tanks, were used to examine species diversity and relative abundance of mosquitoes breeding in ammonia-rich waters of septic tanks. Of the six species found, Culex decens Theobald and Culex cinereus Theobald appeared to be competing successfully with Culex quinquefasciatus Say during the wet season but not during the long dry season. The seasonal timing of their displacement by Cx quinquefasciatus was variable and did not correlate well with climatic factors. The three other species present, generally during the wet season and early dry season, were Culex tigripes G. & C., Culex horridus Edwards and Aedes aegypt (L.). Experimental bucket ovitraps were used to assess preference towards covered (dark) septic tank water in comparison with sunlit septic tank water, covered and sunlit compost water. These were colonized by Cx quinquefasciatus, Cx decens, Ae. aegypti and Ae. vittatus Bigot. The covered septic tank water was more abundantly colonized by Cx quinquefasciatus and marginally so by the two Aedes species. Cx decens appeared to colonize the exposed compost water more readily in the dry season, but changed to the covered septic tank water in the wet season. The discussion centres around competition between these mosquitos species and concludes that it would be useful to know what environmental factors, or what aspects of competition, lead to severe natural reductions in the abundance of the major pest species Cx quinquefasciatus.

  20. Native Argentinean cyclopoids (Crustacea: Copepoda as predators of Aedes aegypti and Culex pipiens (Diptera: Culicidae mosquitoes

    Directory of Open Access Journals (Sweden)

    María C Tranchida

    2009-12-01

    Full Text Available Copepods from La Plata, Argentina were investigated to characterize the local community of larvivorous copepods inhabiting mosquito breeding sites and to identify new predator species of the mosquitoes which occur in artificial containers, Aedes aegypti and Culex pipiens. Diversity of larvivorous cyclopoids was highest in permanent pools. Predation by sex and age, selectivity on mosquito species, and daily predation rate during five days were studied for Acanthocyclops robustus, Diacyclops uruguayensis, Macrocyclops albidus and Mesocyclops longisetus. Female copepods presented the highest predatory capacity. No predatory preference for mosquito species was found. According to overall predation potential, copepods were ranked as follows: D. uruguayensis Se hizo una prospección de copépodos en La Plata, Argentina, con los objetivos de caracterizar la comunidad local de copépodos larvívoros en sitios de cría de mosquitos, e identificar nuevas especies depredadoras de los mosquitos de contenedores artificiales Aedes aegypti y Culex pipiens. La diversidad de ciclopoides larvívoros fue máxima en charcos permanentes. Se examinó la depredación por sexos y edad, la selectividad por especies de mosquito, y la tasa de depredación diaria durante cinco días en Acanthocyclops robustus, Diacyclops uruguayensis, Macrocyclops albidus y Mesocyclops longisetus. Los copépodos hembra presentaron la capacidad depredadora más alta. No se encontró preferencia por alguna especie de mosquito. De acuerdo al potencial de depredación en general, los copépodos se ordenan así: D. uruguayensis < A. robustus < M. albidus < M. longisetus. También se evaluó la tolerancia a la desecación del hábitat y la capacidad de resistir en agua de contenedores artificiales. D. uruguayensis y A. robustus sobrevivieron en condiciones de sequía, pero D. uruguayensis presentó menor supervivencia en agua de floreros de cementerio. M. albidus no sobrevivió condiciones de

  1. The Influence of Antibodies to Selected Mosquito Immunogens on Mosquitoes Following Ingestion of Blood from an Immune Vertebrate Host.

    Science.gov (United States)

    1992-08-05

    mosquito parts. Female Aedes aegypt ] (Rockefeller Strain) mosquitoes were used in this study. They were reared from eggs hatched In deoxygenated water... Aedes aegypti. We immunized mice with mosquito antigens prepared from sugar-fed and blood-fed mosquitoes as follows: heads and thoraces, abdomens, and...34 antigens on the life processes of Aedes aegypti. We have immunized mice with mosquito antigens prepared from both sugar-fed and blood-fed mosquitoes

  2. Inter-epidemic abundance and distribution of potential mosquito vectors for Rift Valley fever virus in Ngorongoro district, Tanzania.

    Science.gov (United States)

    Mweya, Clement N; Kimera, Sharadhuli I; Mellau, Lesakit S B; Mboera, Leonard E G

    2015-01-01

    Rift Valley fever (RVF) is a mosquito-borne viral zoonosis that primarily affects ruminants but also has the capacity to infect humans. To determine the abundance and distribution of mosquito vectors in relation to their potential role in the virus transmission and maintenance in disease epidemic areas of Ngorongoro district in northern Tanzania. A cross-sectional entomological investigation was carried out before the suspected RVF outbreak in October 2012. Mosquitoes were sampled both outdoors and indoors using the Centre for Disease Control (CDC) light traps and Mosquito Magnets baited with attractants. Outdoor traps were placed in proximity with breeding sites and under canopy in banana plantations close to the sleeping places of animals. A total of 1,823 mosquitoes were collected, of which 87% (N=1,588) were Culex pipiens complex, 12% (N=226) Aedes aegypti, and 0.5% (N=9) Anopheles species. About two-thirds (67%; N=1,095) of C. pipiens complex and nearly 100% (N=225) of A. aegypti were trapped outdoors using Mosquito Magnets. All Anopheles species were trapped indoors using CDC light traps. There were variations in abundance of C. pipiens complex and A. aegypti among different ecological and vegetation habitats. Over three quarters (78%) of C. pipiens complex and most (85%) of the A. aegypti were trapped in banana and maize farms. Both C. pipiens complex and A. aegypti were more abundant in proximity with cattle and in semi-arid thorn bushes and lower Afro-montane. The highest number of mosquitoes was recorded in villages that were most affected during the RVF epidemic of 2007. Of the tested 150 pools of C. pipiens complex and 45 pools of A. aegypti, none was infected with RVF virus. These results provide insights into unique habitat characterisation relating to mosquito abundances and distribution in RVF epidemic-prone areas of Ngorongoro district in northern Tanzania.

  3. Inter-epidemic abundance and distribution of potential mosquito vectors for Rift Valley fever virus in Ngorongoro district, Tanzania

    Directory of Open Access Journals (Sweden)

    Clement N. Mweya

    2015-01-01

    Full Text Available Background: Rift Valley fever (RVF is a mosquito-borne viral zoonosis that primarily affects ruminants but also has the capacity to infect humans. Objective: To determine the abundance and distribution of mosquito vectors in relation to their potential role in the virus transmission and maintenance in disease epidemic areas of Ngorongoro district in northern Tanzania. Methods: A cross-sectional entomological investigation was carried out before the suspected RVF outbreak in October 2012. Mosquitoes were sampled both outdoors and indoors using the Centre for Disease Control (CDC light traps and Mosquito Magnets baited with attractants. Outdoor traps were placed in proximity with breeding sites and under canopy in banana plantations close to the sleeping places of animals. Results: A total of 1,823 mosquitoes were collected, of which 87% (N=1,588 were Culex pipiens complex, 12% (N=226 Aedes aegypti, and 0.5% (N=9 Anopheles species. About two-thirds (67%; N=1,095 of C. pipiens complex and nearly 100% (N=225 of A. aegypti were trapped outdoors using Mosquito Magnets. All Anopheles species were trapped indoors using CDC light traps. There were variations in abundance of C. pipiens complex and A. aegypti among different ecological and vegetation habitats. Over three quarters (78% of C. pipiens complex and most (85% of the A. aegypti were trapped in banana and maize farms. Both C. pipiens complex and A. aegypti were more abundant in proximity with cattle and in semi-arid thorn bushes and lower Afro-montane. The highest number of mosquitoes was recorded in villages that were most affected during the RVF epidemic of 2007. Of the tested 150 pools of C. pipiens complex and 45 pools of A. aegypti, none was infected with RVF virus. Conclusions: These results provide insights into unique habitat characterisation relating to mosquito abundances and distribution in RVF epidemic-prone areas of Ngorongoro district in northern Tanzania.

  4. Review: Improving our knowledge of male mosquito biology in relation to genetic control programmes.

    Science.gov (United States)

    Lees, Rosemary Susan; Knols, Bart; Bellini, Romeo; Benedict, Mark Q; Bheecarry, Ambicadutt; Bossin, Hervé Christophe; Chadee, Dave D; Charlwood, Jacques; Dabiré, Roch K; Djogbenou, Luc; Egyir-Yawson, Alexander; Gato, René; Gouagna, Louis Clément; Hassan, Mo'awia Mukhtar; Khan, Shakil Ahmed; Koekemoer, Lizette L; Lemperiere, Guy; Manoukis, Nicholas C; Mozuraitis, Raimondas; Pitts, R Jason; Simard, Frederic; Gilles, Jeremie R L

    2014-04-01

    The enormous burden placed on populations worldwide by mosquito-borne diseases, most notably malaria and dengue, is currently being tackled by the use of insecticides sprayed in residences or applied to bednets, and in the case of dengue vectors through reduction of larval breeding sites or larviciding with insecticides thereof. However, these methods are under threat from, amongst other issues, the development of insecticide resistance and the practical difficulty of maintaining long-term community-wide efforts. The sterile insect technique (SIT), whose success hinges on having a good understanding of the biology and behaviour of the male mosquito, is an additional weapon in the limited arsenal against mosquito vectors. The successful production and release of sterile males, which is the mechanism of population suppression by SIT, relies on the release of mass-reared sterile males able to confer sterility in the target population by mating with wild females. A five year Joint FAO/IAEA Coordinated Research Project brought together researchers from around the world to investigate the pre-mating conditions of male mosquitoes (physiology and behaviour, resource acquisition and allocation, and dispersal), the mosquito mating systems and the contribution of molecular or chemical approaches to the understanding of male mosquito mating behaviour. A summary of the existing knowledge and the main novel findings of this group is reviewed here, and further presented in the reviews and research articles that form this Acta Tropica special issue. Copyright © 2013 International Atomic Energy Agency 2013. Published by Elsevier B.V. All rights reserved.

  5. Welfare in horse breeding

    DEFF Research Database (Denmark)

    Campbell, M.L.H.; Sandøe, Peter

    2015-01-01

    Welfare problems related to the way horses are bred, whether by coitus or by the application of artificial reproduction techniques (ARTs), have been given no discrete consideration within the academic literature. This paper reviews the existing knowledge base about welfare issues in horse breeding...... and identifies areas in which data is lacking. We suggest that all methods of horse breeding are associated with potential welfare problems, but also that the judicious use of ARTs can sometimes help to address those problems. We discuss how negative welfare effects could be identified and limited and how...

  6. Anopheles plumbeus (Diptera: Culicidae in Europe: a mere nuisance mosquito or potential malaria vector?

    Directory of Open Access Journals (Sweden)

    Schaffner Francis

    2012-11-01

    Full Text Available Abstract Background Anopheles plumbeus has been recognized as a minor vector for human malaria in Europe since the beginning of the 20th century. In recent years this tree hole breeding mosquito species appears to have exploited novel breeding sites, including large and organically rich man-made containers, with consequently larger mosquito populations in close vicinity to humans. This lead to investigate whether current populations of An. plumbeus would be able to efficiently transmit Plasmodium falciparum, the parasite responsible for the most deadly form of malaria. Methods Anopheles plumbeus immatures were collected from a liquid manure pit in Switzerland and transferred as adults to the CEPIA (Institut Pasteur, France where they were fed on P. falciparum gametocytes produced in vitro. Anopheles gambiae mosquitoes served as controls. Development of P. falciparum in both mosquito species was followed by microscopical detection of oocysts on mosquito midguts and by sporozoite detection in the head/thorax by PCR and microscopy. Results A total of 293 wild An. plumbeus females from four independent collections successfully fed through a membrane on blood containing P. falciparum gametocytes. Oocysts were observed in mosquito midguts and P. falciparum DNA was detected in head-thorax samples in all four experiments, demonstrating, on a large mosquito sample, that An. plumbeus is indeed receptive to P. falciparum NF54 and able to produce sporozoites. Importantly, the proportion of sporozoites-infected An. plumbeus was almost similar to that of An. gambiae (31 to 88% An. plumbeus versus 67 to 97% An. gambiae. However, the number of sporozoites produced was significantly lower in infected An. plumbeus. Conclusion The results show that a sample of field-caught An. plumbeus has a moderate to high receptivity towards P. falciparum. Considering the increased mobility of humans between Europe and malaria endemic countries and changes in environment and

  7. Host preferences of blood-feeding mosquitoes

    NARCIS (Netherlands)

    Takken, W.; Verhulst, N.O.

    2013-01-01

    Mosquitoes use plant sugars and vertebrate blood as nutritional resources. When searching for blood hosts, some mosquitoes express preferential behavior for selected species. Here, we review the available knowledge on host preference, as this is expected to affect the life history and transmission

  8. Microorganism-mediated behaviour of malaria mosquitoes

    NARCIS (Netherlands)

    Busula, Annette O.

    2017-01-01

    Host-seeking is an important component of mosquito vectorial capacity on which the success of the other behavioural determinants depends. Blood-seeking mosquitoes are mainly guided by chemical cues released by their blood hosts. This thesis describes results of a study that determined the effect

  9. Livestock: An alternative mosquito control measure | Yakubu ...

    African Journals Online (AJOL)

    It was observed that the population density of mosquitoes was higher in the animal pen than the human room and among the preventive measures employed by the respondents, most used smoke to repel mosquitoes from both animal pen and human room. It can therefore be concluded that there exists a link between ...

  10. Hey! A Mosquito Bit Me! (For Kids)

    Science.gov (United States)

    ... First Aid & Safety Doctors & Hospitals Videos Recipes for Kids Kids site Sitio para niños How the Body Works ... Español Hey! A Mosquito Bit Me! KidsHealth / For Kids / Hey! A Mosquito Bit Me! Print en español ¡ ...

  11. The use of annual killifish in the biocontrol of the aquatic stages of mosquitoes in temporary bodies of fresh water; a potential new tool in vector control

    Science.gov (United States)

    2010-01-01

    Background Mosquitoes that breed in temporary pools in remote areas that dry up seasonally are especially difficult to control through chemical or biological means. The annual killifish has been suggested as a means of eradicating the aquatic stages of mosquitoes in transient pools because they can maintain permanent populations in such habitats by undergoing suspended animation or diapause during the embryonic stages to survive periodic drought. However, very little is known about the predatory activity of annual killifish and their usefulness in mosquito control. Results The annual killifish, Nothobranchius guentheri, native to Tanzania, was used in this investigation. Food preference was tested under laboratory conditions by feeding juvenile killifish with 2nd instar mosquito larvae of Culex quinquefasciatus in the presence of alternative food sources, such as rotifers and chironomid larvae. Semi-field tests were conducted by introduction of hibernating killifish embryos and juvenile fish to artificial ponds in an outdoor open environment that allowed natural oviposition of Cx. quinquefasciatus. Food preference studies show that N. guentheri preferred to prey on mosquito larvae than either chironomid or rotifers. When hibernating killifish embryos were added to ponds simultaneously with the addition of freshwater, the embryos hatched and fed on mosquito larval population resulting in complete elimination of the immature stages. The introduction of juvenile fish to ponds with high density of mosquito larvae resulted in total eradication of the mosquito population due to predation by fish. Complete biocontrol of the mosquito larval population was achieved in the presence of 3 fish per m2 of pond surface area. Conclusions The annual killifish provides yet another tool that may be employed in the eradication diseases carried by mosquitoes through vector control, particularly in temporary bodies of freshwater. The fish can be conveniently transported in the absence

  12. The use of annual killifish in the biocontrol of the aquatic stages of mosquitoes in temporary bodies of fresh water; a potential new tool in vector control

    Directory of Open Access Journals (Sweden)

    Adrias Araceli Q

    2010-05-01

    Full Text Available Abstract Background Mosquitoes that breed in temporary pools in remote areas that dry up seasonally are especially difficult to control through chemical or biological means. The annual killifish has been suggested as a means of eradicating the aquatic stages of mosquitoes in transient pools because they can maintain permanent populations in such habitats by undergoing suspended animation or diapause during the embryonic stages to survive periodic drought. However, very little is known about the predatory activity of annual killifish and their usefulness in mosquito control. Results The annual killifish, Nothobranchius guentheri, native to Tanzania, was used in this investigation. Food preference was tested under laboratory conditions by feeding juvenile killifish with 2nd instar mosquito larvae of Culex quinquefasciatus in the presence of alternative food sources, such as rotifers and chironomid larvae. Semi-field tests were conducted by introduction of hibernating killifish embryos and juvenile fish to artificial ponds in an outdoor open environment that allowed natural oviposition of Cx. quinquefasciatus. Food preference studies show that N. guentheri preferred to prey on mosquito larvae than either chironomid or rotifers. When hibernating killifish embryos were added to ponds simultaneously with the addition of freshwater, the embryos hatched and fed on mosquito larval population resulting in complete elimination of the immature stages. The introduction of juvenile fish to ponds with high density of mosquito larvae resulted in total eradication of the mosquito population due to predation by fish. Complete biocontrol of the mosquito larval population was achieved in the presence of 3 fish per m2 of pond surface area. Conclusions The annual killifish provides yet another tool that may be employed in the eradication diseases carried by mosquitoes through vector control, particularly in temporary bodies of freshwater. The fish can be conveniently

  13. History of Aedes mosquitoes in Hawaii.

    Science.gov (United States)

    Winchester, Jonathan C; Kapan, Durrell D

    2013-06-01

    As a geographically isolated island chain with no native mosquitoes, Hawaii is a model for examining the mechanisms behind insect vector invasions and their subsequent interactions with each other and with human populations. The yellow fever mosquito, Aedes aegypti, and the Asian tiger mosquito, Ae. albopictus, have been responsible for epidemics of dengue in Hawaii. As one of the world's earliest locations to be invaded by both species, Hawaii's history is particularly relevant because both species are currently invading new areas worldwide and are implicated in outbreaks of emergent or reemergent pathogens such as dengue, chikungunya, and yellow fever. Here we analyze the historical records of mosquito introductions in order to understand the factors that have led to the current distribution of these 2 mosquitoes in the Hawaiian Islands.

  14. Relevant microclimate for determining the development rate of malaria mosquitoes and possible implications of climate change.

    Science.gov (United States)

    Paaijmans, Krijn P; Imbahale, Susan S; Thomas, Matthew B; Takken, Willem

    2010-07-09

    The relationship between mosquito development and temperature is one of the keys to understanding the current and future dynamics and distribution of vector-borne diseases such as malaria. Many process-based models use mean air temperature to estimate larval development times, and hence adult vector densities and/or malaria risk. Water temperatures in three different-sized water pools, as well as the adjacent air temperature in lowland and highland sites in western Kenya were monitored. Both air and water temperatures were fed into a widely-applied temperature-dependent development model for Anopheles gambiae immatures, and subsequently their impact on predicted vector abundance was assessed. Mean water temperature in typical mosquito breeding sites was 4-6 degrees C higher than the mean temperature of the adjacent air, resulting in larval development rates, and hence population growth rates, that are much higher than predicted based on air temperature. On the other hand, due to the non-linearities in the relationship between temperature and larval development rate, together with a marginal buffering in the increase in water temperature compared with air temperature, the relative increases in larval development rates predicted due to climate change are substantially less. Existing models will tend to underestimate mosquito population growth under current conditions, and may overestimate relative increases in population growth under future climate change. These results highlight the need for better integration of biological and environmental information at the scale relevant to mosquito biology.

  15. School-based health education in Yucatan, Mexico about the Chikungunya virus and mosquito illness prevention

    Directory of Open Access Journals (Sweden)

    Monica Seungah Choo

    2017-05-01

    Full Text Available The Chikungunya virus (CHIKV has been rapidly spreading throughout Latin America, utilizing pre-existing vectors to infiltrate the immunologically naïve populations. With the current rise of the Zika Virus, there is an urgent need for more rigorous vector control efforts to prevent further Zika breakout. We designed a schoolbased education module on CHIKV and mosquito prevention and presented it to the local students of ages of 6-18 in a rural town called Sudzal in Yucatan, Mexico. We distributed questionnaires before and after education to test the students’ knowledge of CHIKV and mosquito prevention. Chisquared test was performed to determine the efficacy of the presentation in increasing their knowledge. The education presentation has proven to effectively educate the local residents in several critical methods of mosquito prevention, increasing the average test scores by 67% post-education. These include applying repellent, staying hydrated during recuperation, and cleaning indoor water containers to eliminate breeding sites (P<0.001. Furthermore, the questionnaire captured the residents’ behavioral patterns regarding CHIKV and mosquito prevention and identified cultural, ecological, and socioeconomic factors hindering effective implementation of vector control.

  16. Influence of breeding site availability on the oviposition behaviour of Aedes aegypti

    Science.gov (United States)

    de Abreu, Filipe Vieira Santos; Morais, Maira Moreira; Ribeiro, Sérvio Pontes; Eiras, Álvaro Eduardo

    2015-01-01

    Despite the importance of the mosquito Aedes aegypti in the transmission of arboviruses, such as yellow fever, Chikungunya fever and dengue fever, some aspects of their behaviour remain unknown. In the present study, the oviposition behaviour of Ae. aegypti females that were exposed to different densities of breeding sites (2, 4, 8 and 16) was evaluated in laboratory and semi-field conditions. The number of breeding sites that were used was proportional to the number available, but tended towards stabilisation. Females used four-six breeding sites on average, with a maximum of 11. A high percentage of eggs was observed in the water, along with the presence of a breeding site termed “favourite”, which received at least 40% of the eggs. The results are discussed in ecological, evolutionary and epidemiological approaches. PMID:26154742

  17. Influence of breeding site availability on the oviposition behaviour of Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Filipe Vieira Santos de Abreu

    2015-08-01

    Full Text Available Despite the importance of the mosquito Aedes aegypti in the transmission of arboviruses, such as yellow fever, Chikungunya fever and dengue fever, some aspects of their behaviour remain unknown. In the present study, the oviposition behaviour of Ae. aegypti females that were exposed to different densities of breeding sites (2, 4, 8 and 16 was evaluated in laboratory and semi-field conditions. The number of breeding sites that were used was proportional to the number available, but tended towards stabilisation. Females used four-six breeding sites on average, with a maximum of 11. A high percentage of eggs was observed in the water, along with the presence of a breeding site termed “favourite”, which received at least 40% of the eggs. The results are discussed in ecological, evolutionary and epidemiological approaches.

  18. Sugar beet breeding

    Science.gov (United States)

    Sugar beet is a recent crop developed solely for extraction of the sweetener sucrose. Breeding and improvement of Beta vulgaris for sugar has a rich historical record. Sugar beet originated from fodder beet in the 1800s, and selection has increased sugar content from 4 to 6% then to over 18% today. ...

  19. Mutation breeding in mangosteen

    International Nuclear Information System (INIS)

    Mohd Khalid Mohd Zain

    2002-01-01

    Mangosteen the queen of the tropical fruits is apomitic and only a cultivar is reported and it reproduces asexually. Conventional breeding is not possible and the other methods to create variabilities are through genetic engineering and mutation breeding. The former technique is still in the infantry stage in mangosteen research while the latter has been an established tool in breeding to improve cultivars. In this mutation breeding seeds of mangosteen were irradiated using gamma rays and the LD 50 for mangosteen was determined and noted to be very low at 10 Gy. After sowing in the seedbed, the seedlings were transplanted in polybags and observed in the nursery bed for about one year before planted in the field under old oil palm trees in Station MARDI, Kluang. After evaluation and screening, about 120 mutant mangosteen plants were selected and planted in Kluang. The plants were observed and some growth data taken. There were some mutant plants that have good growth vigour and more vigorous that the control plants. The trial are now in the fourth year and the plants are still in the juvenile stage. (Author)

  20. Plant Breeding Goes Microbial

    NARCIS (Netherlands)

    Wei, Zhong; Jousset, Alexandre|info:eu-repo/dai/nl/370632656

    Plant breeding has traditionally improved traits encoded in the plant genome. Here we propose an alternative framework reaching novel phenotypes by modifying together genomic information and plant-associated microbiota. This concept is made possible by a novel technology that enables the

  1. Plant breeding and genetics

    Science.gov (United States)

    The ultimate goal of plant breeding is to develop improved crops. Improvements can be made in crop productivity, crop processing and marketing, and/or consumer quality. The process of developing an improved cultivar begins with intercrossing lines with high performance for the traits of interest, th...

  2. Organic crop breeding

    NARCIS (Netherlands)

    Lammerts Van Bueren, E.; Myers, J.R.

    2012-01-01

    This book provides readers with a thorough review of the latest efforts by crop breeders and geneticists to develop improved varieties for organic production. The book opens with chapters looking at breeding efforts that focus on specific valuable traits such as quality, pest and disease resistance

  3. Penguin breeding in Edinburgh

    NARCIS (Netherlands)

    Gillespie, T.H.; F.R.S.E.,; F.Z.S.,

    1939-01-01

    The Scottish National Zoological Park at Edinburgh has been notably successful in keeping and breeding penguins. It is happy in possessing as a friend and benefactor, Mr Theodore E. Salvesen, head of the firm of Christian Salvesen & Co., Leith, to whose interest and generosity it owes the great

  4. Ovipositional Behavior of Anopheles gambiae Mosquitoes.

    Science.gov (United States)

    Agyapong, Jeffrey; Chabi, Joseph; Ablorde, Aikins; Kartey, Worlasi D; Osei, Joseph H N; de Souza, Dziedzom K; Dadzie, Samuel; Boakye, Daniel A; Ohta, Nobuo; Hadi, Melinda P; Suzuki, Takashi

    2014-12-01

    Mosquito eggs laid within two hours are necessary for transgenic (injection) studies, because mosquito eggs become hard after that period. Thus, in order to have eggs available within this two-hour window, it is important to understand the ovipositional behavior of Anopheles gambiae s.s.. In the present study, the ovipositional behavior of An. gambiae s.s. (Kisumu) was investigated in several different conditions: age of mosquitoes, time post blood meal to access oviposition substrate, and light conditions. Two groups of mosquitoes, 3-5 days old and 9-11 days old were blood-fed. For those mosquito groups, an oviposition dish was set either at 48 hours or 72 hours after the blood meal either in a light condition or in an artificial dark condition. The number of laid eggs was compared among the different conditions. The 3-5 day-old mosquitoes apparently produced a higher number of eggs than 9-11 day-old mosquitoes, while there was no significant difference between the two groups. The number of laid eggs per one surviving blood-fed mosquito in the dark condition was significantly higher than that in the light condition (p = 0.03). Providing an oviposition dish at 72 hours after blood meal resulted in a significantly higher number of laid eggs per one surviving blood-fed mosquito than at 48 hours after blood meal (p = 0.03). In conclusion, the optimal condition to have readily available egg supply for transgenic analysis was as follows: 3-5 day-old mosquitoes with an oviposition dish placed at 72 hours after the blood meal in a dark environment.

  5. Green Nanoparticles for Mosquito Control

    Directory of Open Access Journals (Sweden)

    Namita Soni

    2014-01-01

    Full Text Available Here, we have used the green method for synthesis of silver and gold nanoparticles. In the present study the silver (Ag and gold (Au nanoparticles (NPs were synthesized by using the aqueous bark extract of Indian spice dalchini (Cinnamomum zeylanicum (C. zyelanicum or C. verum J. Presl. Additionally, we have used these synthesized nanoparticles for mosquito control. The larvicidal activity has been tested against the malaria vector Anopheles stephensi and filariasis vector Culex quinquefasciatus. The results were obtained using UV-visible spectrophotometer and the images were recorded with a transmission electron microscope (TEM. The efficacy tests were then performed at different concentrations and varying numbers of hours by probit analysis. The synthesized AgNPs were in spherical shape and average sizes (11.77 nm AgNPs and 46.48 nm AuNPs. The larvae of An. stephensi were found highly susceptible to the synthesized AgNPs and AuNPs than the Cx. quinquefasciatus. These results suggest that the C. zeylanicum synthesized silver and gold nanoparticles have the potential to be used as an ideal ecofriendly approach for the control of mosquito.

  6. Mutation breeding newsletter. No. 45

    International Nuclear Information System (INIS)

    2001-07-01

    This issue of the Mutation Breeding newsletter contains 39 articles dealing with radiation induced mutations and chemical mutagenesis techniques in plant breeding programs with the aims of improving crop productivity and disease resistance as well as exploring genetic variabilities

  7. Culex Species Mosquitoes and Zika Virus.

    Science.gov (United States)

    Huang, Yan-Jang S; Ayers, Victoria B; Lyons, Amy C; Unlu, Isik; Alto, Barry W; Cohnstaedt, Lee W; Higgs, Stephen; Vanlandingham, Dana L

    2016-10-01

    Recent reports of Zika virus (ZIKV) isolates from Culex species mosquitoes have resulted in concern regarding a lack of knowledge on the number of competent vector species for ZIKV transmission in the new world. Although observations in the field have demonstrated that ZIKV isolation can be made from Culex species mosquitoes, the detection of ZIKV in these mosquitoes is not proof of their involvement in a ZIKV transmission cycle. Detection may be due to recent feeding on a viremic vertebrate, and is not indicative of replication in the mosquito. In this study, susceptibility of recently colonized Culex species mosquitoes was investigated. The results showed a high degree of refractoriness among members of Culex pipiens complex to ZIKV even when exposed to high-titer bloodmeals. Our finding suggests that the likelihood of Culex species mosquitoes serving as secondary vectors for ZIKV is very low, therefore vector control strategies for ZIKV should remain focused on Aedes species mosquitoes. Our demonstration that Culex quinquefasciatus from Vero Beach, FL, is refractory to infection with ZIKV is especially important and timely. Based on our data, we would conclude that the autochthonous cases of Zika in Florida are not due to transmission by C. quinquefasciatus, and so control efforts should focus on other species, logically Aedes aegypti and Aedes albopictus.

  8. Wolbachia-a foe for mosquitoes

    Directory of Open Access Journals (Sweden)

    Nadipinayakanahalli Munikrishnappa Guruprasad

    2014-02-01

    Full Text Available Mosquitoes act as vectors for a wide range of viral and parasitic infectious diseases such as malaria, dengue, Chickungunya, lymphatic filariasis, Japanese encephalitis and West Nile virus in humans as well as in animals. Although a wide range of insecticides are used to control mosquitoes, it has only resulted in development of resistance to such insecticides. The evolution of insecticide resistance and lack of vaccines for many mosquito-borne diseases have made these arthropods highly harmful vectors. Recently, a novel approach to control mosquitoes by transinfection of life shortening maternally transmitted endo-symbiont Wolbachia wMelPop strain from fruitfly Drosophila into mosquito population has been developed by researchers. The wMelPop strain up-regulated the immune gene expression in mosquitoes thereby reducing the dengue and Chickungunya viral replication in Aedes aegypti, and also it significantly reduced the Plasmodium level in Anopheles gambiae. Here, we discuss the strategy of using Wolbachia in control of vector-borne diseases of mosquitoes.

  9. Identification of Essential Containers for Aedes Larval Breeding to Control Dengue in Dhaka, Bangladesh.

    Science.gov (United States)

    Ferdousi, Farhana; Yoshimatsu, Shoji; Ma, Enbo; Sohel, Nazmul; Wagatsuma, Yukiko

    2015-12-01

    Dengue fever (DF), one of the most important emerging arboviral diseases, is transmitted through the bite of container breeding mosquitoes Aedes aegypti and Aedes albopictus. A household entomological survey was conducted in Dhaka from August through October 2000 to inspect water-holding containers in indoor, outdoor, and rooftop locations for Aedes larvae. The objective of this study was to determine mosquito productivity of each container type and to identify some risk factors of households infested with Aedes larvae. Of 9,222 households inspected, 1,306 (14.2%) were positive for Aedes larvae. Of 38,777 wet containers examined, 2,272 (5.8%) were infested with Aedes larvae. Containers used to hold water, such as earthen jars, tanks, and drums were the most common containers for larval breeding. Tires in outdoor and rooftop locations of the households were also important for larval breeding. Although present in abundance, buckets were of less importance. Factors such as independent household, presence of a water storage system in the house, and fully/partly shaded outdoors were found to be significantly associated with household infestation of Aedes larvae. Identification and subsequent elimination of the most productive containers in a given area may potentially reduce mosquito density to below a level at which dengue transmission may be halted.

  10. Registros de mayor altitud para mosquitos (Diptera: Culicidae en Venezuela

    Directory of Open Access Journals (Sweden)

    Juan-Carlos Navarro

    2010-03-01

    Full Text Available Los mosquitos (Diptera: Culicidae son insectos holometábolos con estadios inmaduros acuáticos que utilizan una amplia variedad de hábitats larvales, desde cuerpos de agua en el suelo hasta Fitotelmata (depósitos de agua en las plantas y depósitos artificiales. La disponibilidad de sitios de reproducción a menudo determina el límite superior del ámbito de los mosquitos. Nosotros construimos una base de datos de 9 607 registros, 432 localidades, 19 géneros y 254 especies. La coordillera Andina posee el 77% de los registros con mayor altitud incluyendo Aedes euris con un registro a 3 300 m, seguido por tres especies de Anopheles -subgénero Kerteszia- con una altitud máxima de 2 680 m. Wyeomyia bicornis y Culex daumastocampa a 2 550 m fueron los registros de mayor altitud en la cordillera Costera- Central, mientras que el record más alto en Pantepui fue Wyeomyia zinzala a 2 252 m. El 60% de los registros de máxima altitud están representados por especies asociadas con fitotelmata (Bromeliaceae y Sarraceniaceae. Los límites superiores de Culex quinquefasciatus y Anopheles (Kerteszia podría representar el límite teórico para la transmisión de filariasis o arbovirus, por Culex y malaria por Anopheles (Kerteszia en Venezuela. Del mismo modo, un vector del dengue, Aedes aegypti, no ha sido registrado por encima de 2 000 m.Highest mosquito records (Diptera: Culicidae in Venezuela. Mosquitoes (Diptera: Culicidae are holometabolous insects with aquatic immature stages, which use a broad variety of larval habitats, from ground water bodies to Phytothelmata (water deposits in plants and artificial deposits. The availability of breeding sites often determines the upper limits of mosquito ranges. We built a database with 9 607 records with 432 localities, 19 genera and 254 species. The Andean mountains have 77% of the highest mosquito records including Aedes euris with record at 3 133 m, followed by three species of Anopheles -subgenera

  11. Mosquito immune defenses against Plasmodium infection.

    Science.gov (United States)

    Cirimotich, Chris M; Dong, Yuemei; Garver, Lindsey S; Sim, Shuzhen; Dimopoulos, George

    2010-04-01

    The causative agent of malaria, Plasmodium, has to undergo complex developmental transitions and survive attacks from the mosquito's innate immune system to achieve transmission from one host to another through the vector. Here we discuss recent findings on the role of the mosquito's innate immune signaling pathways in preventing infection by the Plasmodium parasite, the identification and mechanistic description of novel anti-parasite molecules, the role that natural bacteria harbored in the mosquito midgut might play in this immune defense and the crucial parasite and vector molecules that mediate midgut infection.

  12. Mutation breeding in peas

    International Nuclear Information System (INIS)

    Jaranowski, J.; Micke, A.

    1985-01-01

    The pea as an ancient crop plant still today has wide uses and is an import source of food protein. It is also an important object for genetic studies and as such has been widely used in mutation induction experiments. However, in comparison with cereals this ancient crop plant (like several other grain legumes) has gained relatively little from advances in breeding. The review focuses on the prospects of genetic improvement of pea by induced mutations, discusses principles and gives methodological information. (author)

  13. The ecology of Anopheles mosquitoes under climate change: case studies from the effects of deforestation in East African highlands.

    Science.gov (United States)

    Afrane, Yaw A; Githeko, Andrew K; Yan, Guiyun

    2012-02-01

    Climate change is expected to lead to latitudinal and altitudinal temperature increases. High-elevation regions such as the highlands of Africa and those that have temperate climate are most likely to be affected. The highlands of Africa generally exhibit low ambient temperatures. This restricts the distribution of Anopheles mosquitoes, the vectors of malaria, filariasis, and O'nyong'nyong fever. The development and survival of larval and adult mosquitoes are temperature dependent, as are mosquito biting frequency and pathogen development rate. Given that various Anopheles species are adapted to different climatic conditions, changes in climate could lead to changes in species composition in an area that may change the dynamics of mosquito-borne disease transmission. It is important to consider the effect of climate change on rainfall, which is critical to the formation and persistence of mosquito breeding sites. In addition, environmental changes such as deforestation could increase local temperatures in the highlands; this could enhance the vectorial capacity of the Anopheles. These experimental data will be invaluable in facilitating the understanding of the impact of climate change on Anopheles. © 2012 New York Academy of Sciences.

  14. Combining hydrology and mosquito population models to identify the drivers of Rift Valley fever emergence in semi-arid regions of West Africa.

    Directory of Open Access Journals (Sweden)

    Valérie Soti

    Full Text Available BACKGROUND: Rift Valley fever (RVF is a vector-borne viral zoonosis of increasing global importance. RVF virus (RVFV is transmitted either through exposure to infected animals or through bites from different species of infected mosquitoes, mainly of Aedes and Culex genera. These mosquitoes are very sensitive to environmental conditions, which may determine their presence, biology, and abundance. In East Africa, RVF outbreaks are known to be closely associated with heavy rainfall events, unlike in the semi-arid regions of West Africa where the drivers of RVF emergence remain poorly understood. The assumed importance of temporary ponds and rainfall temporal distribution therefore needs to be investigated. METHODOLOGY/PRINCIPAL FINDINGS: A hydrological model is combined with a mosquito population model to predict the abundance of the two main mosquito species (Aedes vexans and Culex poicilipes involved in RVFV transmission in Senegal. The study area is an agropastoral zone located in the Ferlo Valley, characterized by a dense network of temporary water ponds which constitute mosquito breeding sites. The hydrological model uses daily rainfall as input to simulate variations of pond surface areas. The mosquito population model is mechanistic, considers both aquatic and adult stages and is driven by pond dynamics. Once validated using hydrological and entomological field data, the model was used to simulate the abundance dynamics of the two mosquito species over a 43-year period (1961-2003. We analysed the predicted dynamics of mosquito populations with regards to the years of main outbreaks. The results showed that the main RVF outbreaks occurred during years with simultaneous high abundances of both species. CONCLUSION/SIGNIFICANCE: Our study provides for the first time a mechanistic insight on RVFV transmission in West Africa. It highlights the complementary roles of Aedes vexans and Culex poicilipes mosquitoes in virus transmission, and recommends

  15. Combining hydrology and mosquito population models to identify the drivers of Rift Valley fever emergence in semi-arid regions of West Africa.

    Science.gov (United States)

    Soti, Valérie; Tran, Annelise; Degenne, Pascal; Chevalier, Véronique; Lo Seen, Danny; Thiongane, Yaya; Diallo, Mawlouth; Guégan, Jean-François; Fontenille, Didier

    2012-01-01

    Rift Valley fever (RVF) is a vector-borne viral zoonosis of increasing global importance. RVF virus (RVFV) is transmitted either through exposure to infected animals or through bites from different species of infected mosquitoes, mainly of Aedes and Culex genera. These mosquitoes are very sensitive to environmental conditions, which may determine their presence, biology, and abundance. In East Africa, RVF outbreaks are known to be closely associated with heavy rainfall events, unlike in the semi-arid regions of West Africa where the drivers of RVF emergence remain poorly understood. The assumed importance of temporary ponds and rainfall temporal distribution therefore needs to be investigated. A hydrological model is combined with a mosquito population model to predict the abundance of the two main mosquito species (Aedes vexans and Culex poicilipes) involved in RVFV transmission in Senegal. The study area is an agropastoral zone located in the Ferlo Valley, characterized by a dense network of temporary water ponds which constitute mosquito breeding sites. The hydrological model uses daily rainfall as input to simulate variations of pond surface areas. The mosquito population model is mechanistic, considers both aquatic and adult stages and is driven by pond dynamics. Once validated using hydrological and entomological field data, the model was used to simulate the abundance dynamics of the two mosquito species over a 43-year period (1961-2003). We analysed the predicted dynamics of mosquito populations with regards to the years of main outbreaks. The results showed that the main RVF outbreaks occurred during years with simultaneous high abundances of both species. Our study provides for the first time a mechanistic insight on RVFV transmission in West Africa. It highlights the complementary roles of Aedes vexans and Culex poicilipes mosquitoes in virus transmission, and recommends the identification of rainfall patterns favourable for RVFV amplification.

  16. Using Stable Isotopes of Carbon and Nitrogen to Mark Wild Populations of Anopheles and Aedes Mosquitoes in South-Eastern Tanzania.

    Directory of Open Access Journals (Sweden)

    Mercy A Opiyo

    Full Text Available Marking wild mosquitoes is important for understanding their ecology, behaviours and role in disease transmission. Traditional insect marking techniques include using fluorescent dyes, protein labels, radioactive labels and tags, but such techniques have various limitations; notably low marker retention and inability to mark wild mosquitoes at source. Stable isotopes are gaining wide spread use for non-invasive marking of arthropods, permitting greater understanding of mosquito dispersal and responses to interventions. We describe here a simple technique for marking naturally-breeding malaria and dengue vectors using stable isotopes of nitrogen (15N and carbon (13C, and describe potential field applications.We created man-made aquatic mosquito habitats and added either 15N-labelled potassium nitrate or 13C-labelled glucose, leaving non-adulterated habitats as controls. We then allowed wild mosquitoes to lay eggs in these habitats and monitored their development in situ. Pupae were collected promptly as they appeared and kept in netting cages. Emergent adults (in pools of ~4 mosquitoes/pool and individually stored pupae were desiccated and analysed using Isotope Ratio Mass Spectrometry (IRMS.Anopheles gambiae s.l and Aedes spp. from enriched 13C and enriched 15N larval habitats had significantly higher isotopic levels than controls (P = 0.005, and both isotopes produced sufficient distinction between marked and unmarked mosquitoes. Mean δ15N for enriched females and males were 275.6±65.1 and 248.0±54.6, while mean δ15N in controls were 2.1±0.1 and 3.9±1.7 respectively. Similarly, mean δ13C for enriched females and males were 36.08±5.28 and 38.5±6.86, compared to -4.3±0.2 and -7.9±3.6 in controls respectively. Mean δ15N and δ13C was significantly higher in any pool containing at least one enriched mosquito compared to pools with all unenriched mosquitoes, P<0.001. In all cases, there were variations in standardized isotopic ratios

  17. Using Stable Isotopes of Carbon and Nitrogen to Mark Wild Populations of Anopheles and Aedes Mosquitoes in South-Eastern Tanzania.

    Science.gov (United States)

    Opiyo, Mercy A; Hamer, Gabriel L; Lwetoijera, Dickson W; Auckland, Lisa D; Majambere, Silas; Okumu, Fredros O

    2016-01-01

    Marking wild mosquitoes is important for understanding their ecology, behaviours and role in disease transmission. Traditional insect marking techniques include using fluorescent dyes, protein labels, radioactive labels and tags, but such techniques have various limitations; notably low marker retention and inability to mark wild mosquitoes at source. Stable isotopes are gaining wide spread use for non-invasive marking of arthropods, permitting greater understanding of mosquito dispersal and responses to interventions. We describe here a simple technique for marking naturally-breeding malaria and dengue vectors using stable isotopes of nitrogen (15N) and carbon (13C), and describe potential field applications. We created man-made aquatic mosquito habitats and added either 15N-labelled potassium nitrate or 13C-labelled glucose, leaving non-adulterated habitats as controls. We then allowed wild mosquitoes to lay eggs in these habitats and monitored their development in situ. Pupae were collected promptly as they appeared and kept in netting cages. Emergent adults (in pools of ~4 mosquitoes/pool) and individually stored pupae were desiccated and analysed using Isotope Ratio Mass Spectrometry (IRMS). Anopheles gambiae s.l and Aedes spp. from enriched 13C and enriched 15N larval habitats had significantly higher isotopic levels than controls (P = 0.005), and both isotopes produced sufficient distinction between marked and unmarked mosquitoes. Mean δ15N for enriched females and males were 275.6±65.1 and 248.0±54.6, while mean δ15N in controls were 2.1±0.1 and 3.9±1.7 respectively. Similarly, mean δ13C for enriched females and males were 36.08±5.28 and 38.5±6.86, compared to -4.3±0.2 and -7.9±3.6 in controls respectively. Mean δ15N and δ13C was significantly higher in any pool containing at least one enriched mosquito compared to pools with all unenriched mosquitoes, Pisotopic ratios between mosquito species. Enrichment of semi-natural mosquito larval

  18. Entomopathogenic fungi for mosquito control: A review

    NARCIS (Netherlands)

    Scholte, E.J.; Knols, B.G.J.; Samson, R.A.; Takken, W.

    2004-01-01

    Fungal diseases in insects are common and widespread and can decimate their populations in spectacular epizootics. Virtually all insect orders are susceptible to fungal diseases, including Dipterans. Fungal pathogens such as Lagenidium, Coelomomyces and Culicinomyces are known to affect mosquito

  19. Distributional Records for Aedes Mosquitoes from the U.S. Force Ovitrapping Program--1992

    Science.gov (United States)

    1993-01-01

    figures become 8.8, 32.6 and bases, the prevalence was30.7% (401/l,308). It’ 54.1%. the 139 Aedes (Stegomyia)-positive ovipaddles Aedes aegypt was...S. FUNDING NUMBERS Distributional records for Aedes mosquitoes from the U.S. Air Force ovitrapping program - 1992 62 AUTHOR(S) Chad P. McHugh 7...public release; distribution is unlimited 13. ABSTRACT (Maximum 200 words) During 1992, ovitrapping to sample container-breeding Aedes was conducted at

  20. Nanoparticles for mosquito control: Challenges and constraints

    Directory of Open Access Journals (Sweden)

    Giovanni Benelli

    2017-10-01

    Full Text Available Mosquito control programs are facing important and timely challenges, including the recent outbreaks of novel arbovirus, the development of resistance in several Culicidae species, and the rapid spreading of highly invasive mosquitoes worldwide. Current control tools mainly rely on the employment of (i synthetic or microbial pesticides, (ii insecticide-treated bed nets, (iii adult repellents, (iv biological control agents against mosquito young instars (mainly fishes, amphibians and copepods (v Sterile Insect Technique (SIT, (vi “boosted SIT”, (vii symbiont-based methods and (viii transgenic mosquitoes. Currently, none of these single strategies is fully successful. Novel eco-friendly strategies to manage mosquito vectors are urgently needed. The plant-mediated fabrication of nanoparticles is advantageous over chemical and physical methods, since it is cheap, single-step, and does not require high pressure, energy, temperature, or the use of highly toxic chemicals. In the latest years, a growing number of plant-borne compounds have been proposed for efficient and rapid extracellular synthesis of metal nanoparticles effective against mosquitoes at very low doses (i.e. 1–30 ppm. In this review, we focused on the promising potential of green-fabricated nanoparticles as toxic agents against mosquito young instars, and as adult oviposition deterrents. Furthermore, we analyzed current evidences about non-target effects of these nanocomposites used for mosquito control, pointing out their moderate acute toxicity for non-target aquatic organisms, absence of genotoxicity at the doses tested against mosquitoes, and the possibility to boost the predation rates of biological control agents against mosquitoes treating the aquatic environment with ultra-low doses (e.g. 1–3 ppm of green-synthesized nanoparticles, which reduce the motility of mosquito larvae. Challenges for future research should shed light on (i the precise mechanism(s of action of

  1. Pathogenesis of Dengue Vaccine Viruses in Mosquitoes.

    Science.gov (United States)

    1980-01-01

    per ml. . h Tabl , Yellow fever virus infection rates obtained with heparinized Vertebrate bloods Blood Source Rabbit Guinea g Chicken tk~nkcy Aedes ...were similar. A mosquito inoculation-headsquash-immuno]uflorosecncr te(hni(que was found to L be more sensitive than Aedes albopictus cells(C6/306...12 B. Efficiency of per os infection studies . . . . . .. 13 C. Comparison of Aedes albopictus (C6/3A) cell line and mosquito

  2. Reverse breeding: a novel breeding approach based on engineered meiosis.

    Science.gov (United States)

    Dirks, Rob; van Dun, Kees; de Snoo, C Bastiaan; van den Berg, Mark; Lelivelt, Cilia L C; Voermans, William; Woudenberg, Leo; de Wit, Jack P C; Reinink, Kees; Schut, Johan W; van der Zeeuw, Eveline; Vogelaar, Aat; Freymark, Gerald; Gutteling, Evert W; Keppel, Marina N; van Drongelen, Paul; Kieny, Matthieu; Ellul, Philippe; Touraev, Alisher; Ma, Hong; de Jong, Hans; Wijnker, Erik

    2009-12-01

    Reverse breeding (RB) is a novel plant breeding technique designed to directly produce parental lines for any heterozygous plant, one of the most sought after goals in plant breeding. RB generates perfectly complementing homozygous parental lines through engineered meiosis. The method is based on reducing genetic recombination in the selected heterozygote by eliminating meiotic crossing over. Male or female spores obtained from such plants contain combinations of non-recombinant parental chromosomes which can be cultured in vitro to generate homozygous doubled haploid plants (DHs). From these DHs, complementary parents can be selected and used to reconstitute the heterozygote in perpetuity. Since the fixation of unknown heterozygous genotypes is impossible in traditional plant breeding, RB could fundamentally change future plant breeding. In this review, we discuss various other applications of RB, including breeding per chromosome.

  3. Materials for breeding blankets

    International Nuclear Information System (INIS)

    Mattas, R.F.; Billone, M.C.

    1995-09-01

    There are several candidate concepts for tritium breeding blankets that make use of a number of special materials. These materials can be classified as Primary Blanket Materials, which have the greatest influence in determining the overall design and performance, and Secondary Blanket Materials, which have key functions in the operation of the blanket but are less important in establishing the overall design and performance. The issues associated with the blanket materials are specified and several examples of materials performance are given. Critical data needs are identified

  4. Why are anopheline mosquitoes not present in the Seychelles?

    Directory of Open Access Journals (Sweden)

    Goodman Steven M

    2011-02-01

    Full Text Available Abstract Background Species of anopheline mosquitoes are largely distributed over emerged lands around the world and, within the tropics, few areas are without these insects, which are vectors of malaria parasites. Among the exceptions is the Seychelles archipelago in the western Indian Ocean. However, in the Aldabra island group, located in the extreme western portion of the archipelago, Anopheles gambiae s.l. was introduced, leading to massive proliferation and then elimination, with the most recent autochthonous malaria cases recorded in 1931. Methods In order to re-examine the absence of anopheline mosquitoes in the Seychelles, an entomological field survey was conducted in December 2008 at 17 sites on four granitic islands, including Mahé and Praslin, and ten sites on coralline atolls in the extreme west, including Aldabra. Results No evidence of larval or adult anophelines was found at the surveyed sites, which supports their absence in the Seychelles. Conclusions In the granitic islands of the Seychelles, the climate is favourable for anophelines. However, these islands are protected by their remoteness and prevailing seasonal winds. In addition, stagnant freshwater, required in anopheline larval development, is relatively uncommon on the granitic islands because of the steep slopes. In the southwestern atolls (Aldabra and Providence-Farquhar groups, the presence of a long dry season of up to nine months and the total absence of permanent natural freshwater prevents the breeding of anophelines and their successful colonization. The Seychelles does not have any native land mammals and like in other parts of the world (Antarctica, Iceland, New Caledonia, Central Pacific islands their absence is associated with the lack of anophelines. This suggests an obligatory relationship for anophelines to feed on terrestrial mammals, without alternative for blood-feeding sources, such as bats, birds and reptiles.

  5. The Potential Use of Wolbachia-Based Mosquito Biocontrol Strategies for Japanese Encephalitis.

    Directory of Open Access Journals (Sweden)

    Claire L Jeffries

    Full Text Available Japanese encephalitis virus (JEV is a zoonotic pathogen transmitted by the infectious bite of Culex mosquitoes. The virus causes the development of the disease Japanese encephalitis (JE in a small proportion of those infected, predominantly affecting children in eastern and southern Asia. Annual JE incidence estimates range from 50,000-175,000, with 25%-30% of cases resulting in mortality. It is estimated that 3 billion people live in countries in which JEV is endemic. The virus exists in an enzootic transmission cycle, with mosquitoes transmitting JEV between birds as reservoir hosts and pigs as amplifying hosts. Zoonotic infection occurs as a result of spillover events from the main transmission cycle. The reservoir avian hosts include cattle egrets, pond herons, and other species of water birds belonging to the family Ardeidae. Irrigated rice fields provide an ideal breeding ground for mosquitoes and attract migratory birds, maintaining the transmission of JEV. Although multiple vaccines have been developed for JEV, they are expensive and require multiple doses to maintain efficacy and immunity. As humans are a "dead-end" host for the virus, vaccination of the human population is unlikely to result in eradication. Therefore, vector control of the principal mosquito vector, Culex tritaeniorhynchus, represents a more promising strategy for reducing transmission. Current vector control strategies include intermittent irrigation of rice fields and space spraying of insecticides during outbreaks. However, Cx. Tritaeniorhynchus is subject to heavy exposure to pesticides in rice fields, and as a result, insecticide resistance has developed. In recent years, significant advancements have been made in the potential use of the bacterial endosymbiont Wolbachia for mosquito biocontrol. The successful transinfection of Wolbachia strains from Drosophila flies to Aedes (Stegomyia mosquitoes has resulted in the generation of "dengue-refractory" mosquito

  6. International forum for surveillance and control of mosquitoes and mosquito-borne diseases

    Science.gov (United States)

    This manuscript provides highlights of presentations given at the 1st International Forum for Surveillance and Control of Mosquitoes and Mosquito-borne Disease in Beijing, China. Topics covered in this 4-day forum included: diseases, surveillance, insecticides, physiology and ecology, behavior, inv...

  7. 2nd International Forum for Surveillance and Control of Mosquitoes and Mosquito-borne Diseases

    Science.gov (United States)

    The Entomological Society of China (ESC) and Beijing Institute of Microbiology and Epidemiology (BIME) hosted the 2nd International Forum for Surveillance and Control of Mosquitoes and Mosquito-borne Diseases in Beijing, China, May 23-27, 2011. The theme of the Forum was “Impact of global climate ch...

  8. Research Contributing to Improvements in Controlling Florida’s Mosquitoes and Mosquito-Borne Diseases

    Science.gov (United States)

    Tabachnick, Walter J.

    2016-01-01

    Research on mosquitoes and mosquito-borne diseases has contributed to improvements in providing effective, efficient, and environmentally proper mosquito control. Florida has benefitted from several research accomplishments that have increased the state’s mosquito control capabilities. Research with Florida’s mosquitoes has resulted in the development of ecologically sound management of mosquito impoundments on Florida’s east coast. This strategy, called Rotational Impoundment Management (RIM), has improved the ability to target the delivery of pesticides and has helped to reduce non-target effects and environmental damage. Research has led to the development of an arbovirus surveillance system which includes sentinel chicken surveillance, real time use of environmental contributing factors like meteorology and hydrology to target mosquito control, as well as public health efforts to mitigate disease outbreaks to areas with risk of disease. These research driven improvements have provided substantial benefits to all of Florida. More research is needed to meet the future challenges to reduce emerging pathogens like Zika virus and the consequences of environmental changes like global climate change that are likely to influence the effects of mosquito-borne pathogens on human health and well-being. PMID:27690112

  9. Research Contributing to Improvements in Controlling Florida’s Mosquitoes and Mosquito-borne Diseases

    Directory of Open Access Journals (Sweden)

    Walter J. Tabachnick

    2016-09-01

    Full Text Available Research on mosquitoes and mosquito-borne diseases has contributed to improvements in providing effective, efficient, and environmentally proper mosquito control. Florida has benefitted from several research accomplishments that have increased the state’s mosquito control capabilities. Research with Florida’s mosquitoes has resulted in the development of ecologically sound management of mosquito impoundments on Florida’s east coast. This strategy, called Rotational Impoundment Management (RIM, has improved the ability to target the delivery of pesticides and has helped to reduce non-target effects and environmental damage. Research has led to the development of an arbovirus surveillance system which includes sentinel chicken surveillance, real time use of environmental contributing factors like meteorology and hydrology to target mosquito control, as well as public health efforts to mitigate disease outbreaks to areas with risk of disease. These research driven improvements have provided substantial benefits to all of Florida. More research is needed to meet the future challenges to reduce emerging pathogens like Zika virus and the consequences of environmental changes like global climate change that are likely to influence the effects of mosquito-borne pathogens on human health and well-being.

  10. Radiation mutation breeding

    Energy Technology Data Exchange (ETDEWEB)

    Song, Hi Sup; Kim, Jae Sung; Kim, Jin Kyu; Shin, In Chul; Lim, Young Taek

    1998-04-01

    In order to develop an advanced technical knowledge for the selection of better mutants, some of the crops were irradiated and the mutation rate, the survival rate and the method for selction of a mutant were studied. Furthermore, this study aimed to obtain basic data applicable to the development of genetic resources by evaluation and analysis the specific character for selection of the superior mutant and its plant breeding. 1. selection of the mutant with a superior resistance against environment in the principal crops 1) New varieties of mutant rices such as Wonpyeongbyeo, Wongwangbyeo, Winmibyeo, and heogseon chalbeyeo (sticky forma) were registered in the national variety list and made an application to crop variety protection right. They are under review now. 2) We also keep on studying on the number of a grain of 8 lines of excellent mutant rice for the purpose of improvement of breeding . 3) We selected 3 lines which have a resistance to pod and stem blight in large soybean, 31 lines with small grain size and higher yield, 112 lines of soybean of cooking, 7 lines of low lipoxygenase content, and 12 lines with decreased phytic acid content by 20 % compared to the previous level. 2. Selection of advanced Mugunwha (Rose of Sharon) mutant 1) Bagseul, a new variety of mutant, was developed and 30 plantlets of it are being proliferated. 2) Fifty-three lines of a mutant having a various morphologies were selected.

  11. Biotechnology in soybean breeding

    Directory of Open Access Journals (Sweden)

    Sudarić Aleksandra

    2010-01-01

    Full Text Available Biotechnology can be defined broadly as a set of tools that allows scientists to genetically characterize or improve living organisms. Several emerging technologies, such as molecular characterization and genetic transformation, are already being used extensively for the purpose of plant improvement. Other emerging sciences, including genomics and proteomics, are also starting to impact plant improvement. Tools provided by biotechnology will not replace classical breeding methods, but rather will help provide new discoveries and contribute to improved nutritional value and yield enhancement through greater resistance to disease, herbicides and abiotic factors. In soybeans, biotechnology has and will continue to play a valuable role in public and private soybean breeding programs. Based on the availability and combination of conventional and molecular technologies, a substantial increase in the rate of genetic gain for economically important soybean traits can be predicted in the next decade. In this paper, a short review of technologies for molecular markers analysis in soybean is given as well as achievements in the area of genetic transformation in soybean.

  12. Engineered mosquitoes to fight mosquito borne diseases: not a merely technical issue.

    Science.gov (United States)

    Favia, Guido

    2015-01-01

    Malaria, dengue and other mosquito-borne diseases pose dramatic problems of public health, particularly in tropical and sub-tropical countries. Historically, vector control has been one of the most successfully strategies to eradicate some mosquito-borne diseases, as witnessed by malaria eradication in Mediterranean regions such as Italy and Greece. Vector control through insecticides has been used worldwide; unfortunately, it is losing effectiveness due to spread of resistances. Control of mosquito-borne diseases through field-releases of genetically engineered mosquitoes is an innovative and now feasible approach. Genetically modified mosquitoes have already been released into the wild in some regions, and protocols for this release are on hand in others. Local authorities are vigilant that transgenic insects in the field are safe for human and animal populations, and the public engagement in every control program is assuming a central role.

  13. Controle los mosquitos que están en el exterior (Controlling Mosquitoes Outside)

    Centers for Disease Control (CDC) Podcasts

    2016-07-11

    Los mosquitos pueden transmitir virus como el del zika. En este podcast, el Sr. Francisco le enseñará a usted y a su vecina Adriana diferentes maneras para ayudar a reducir la cantidad de mosquitos fuera de su casa. Los consejos incluyen eliminar áreas de agua estancada donde los mosquitos ponen sus huevos, usar larvicidas para matar mosquitos jóvenes, y reparar grietas y cubrir las ventilaciones de los pozos sépticos. También aprenderá cómo se usan los aviones que ayudan a rociar insecticida para los mosquitos.  Created: 7/11/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 7/11/2016.

  14. Breeds in danger of extintion and biodiversity

    OpenAIRE

    A. Blasco

    2008-01-01

    Some arguments currently used to support breed conservation are examined. The central point is that we cannot conserve all breeds because we do not have financial resources enough to keep everything (mainly in developing countries) and in many cases we do not have special reasons to conserve breeds. A breed is a human product and it should not be confused with specie. A breed can be generated or transformed. We can create synthetic breeds with the best characteristics of several breeds. Selec...

  15. Mutation breeding newsletter. No. 43

    International Nuclear Information System (INIS)

    1997-10-01

    This issue of the Newsletter includes articles dealing with radiation induced mutation based plant breeding research findings aimed at improving productivity, disease resistance and tolerance of stress conditions

  16. The fog of war: Why the environmental crusade for anadromous fish species in California could disarm the State’s local vector control districts in their war against mosquitoes

    Directory of Open Access Journals (Sweden)

    Stephen M. Siptroth

    2011-12-01

    Full Text Available In California, local mosquito and vector control districts have successfully controlled mosquito and vector-borne diseases by improving drainage patterns and applying pesticides. The Bay-Delta Conservation Plan, which is a proposed habitat conservation plan for the Sacramento-San Joaquin Bay-Delta estuary, proposes to add over 70,000 acres of habitat in the Delta to improve conditions for threatened and endangered aquatic and terrestrial species. This habitat could also be a suitable mosquito breeding habitat, which will be located in close proximity to urban and suburban communities. Wetland management practices and continued pesticide applications in the Delta could mitigate the effects of a new mosquito breeding habitat. Recent legal developments, however, require districts to obtain and comply with Clean Water Act permits, which restrict the application of pesticides in or near waters of the United States. Moreover, the U.S. Environmental Protection Agency has taken the first step in a rulemaking process that could further limit or prohibit the use of certain vector control pesticides in the Delta. In the near term and until less harmful methods for mosquito control are available, local vector control districts’ application of mosquito control pesticides should be exempt from Clean Water Act permit requirements.

  17. Textbook animal breeding : animal breeding andgenetics for BSc students

    NARCIS (Netherlands)

    Oldenbroek, Kor; Waaij, van der Liesbeth

    2014-01-01

    This textbook contains teaching material on animal breeding and genetics for BSc students. The text book started as an initiative of the Dutch Universities for Applied (Agricultural) Sciences. The textbook is made available by the Animal Breeding and Genomics Centre (ABGC) of Wageningen UR

  18. Mosquito consumption by insectivorous bats: does size matter?

    Directory of Open Access Journals (Sweden)

    Leroy Gonsalves

    Full Text Available Insectivorous bats have often been touted as biological control for mosquito populations. However, mosquitoes generally represent only a small proportion of bat diet. Given the small size of mosquitoes, restrictions imposed on prey detectability by low frequency echolocation, and variable field metabolic rates (FMR, mosquitoes may not be available to or profitable for all bats. This study investigated whether consumption of mosquitoes was influenced by bat size, which is negatively correlated with echolocation frequency but positively correlated with bat FMR. To assess this, we investigated diets of five eastern Australian bat species (Vespadelus vulturnus Thomas, V. pumilus Gray, Miniopterus australis Tomes, Nyctophilus gouldi Tomes and Chalinolobus gouldii Gray ranging in size from 4-14 g in coastal forest, using molecular analysis of fecal DNA. Abundances of potential mosquito and non-mosquito prey were concurrently measured to provide data on relative prey abundance. Aedes vigilax was locally the most abundant mosquito species, while Lepidoptera the most abundant insect order. A diverse range of prey was detected in bat feces, although members of Lepidoptera dominated, reflecting relative abundance at trap sites. Consumption of mosquitoes was restricted to V. vulturnus and V. pumilus, two smaller sized bats (4 and 4.5 g. Although mosquitoes were not commonly detected in feces of V. pumilus, they were present in feces of 55 % of V. vulturnus individuals. To meet nightly FMR requirements, Vespadelus spp. would need to consume ~600-660 mosquitoes on a mosquito-only diet, or ~160-180 similar sized moths on a moth-only diet. Lower relative profitability of mosquitoes may provide an explanation for the low level of mosquito consumption among these bats and the absence of mosquitoes in feces of larger bats. Smaller sized bats, especially V. vulturnus, are likely to be those most sensitive to reductions in mosquito abundance and should be monitored

  19. Does mosquito control have an effect on mosquito-borne disease? The case of Ross River virus disease and mosquito management in Queensland, Australia.

    Science.gov (United States)

    Tomerini, Deanna M; Dale, Pat E; Sipe, Neil

    2011-03-01

    We examined the relationship between types of mosquito control programs and the mosquito-borne Ross River virus (RRV) disease in Queensland, Australia. Mosquito control information was collected through a survey of the responsible agencies (local governments), and RRV disease notification data were provided by the Queensland state health authority. The study developed a typology of mosquito control programs, based on the approaches used. Based on the analysis of data on RRV disease rates between mosquito control types within 4 climatic regions, each region had different combinations of mosquito control strategies in their programs; there were also general similarities in the relationship between program types and RRV rates between the regions. The long-term RRV disease rates were lower in areas where the mosquito control program included pre-emptive (rather than reactive) surveillance based on an extensive (rather than incomplete) knowledge of mosquito habitats, and where treatment of both saltwater and freshwater habitats (compared to only saltwater habitats, in coastal areas) occurred. The data indicate that mosquito control is an effective public health intervention to reduce mosquito-borne disease; hence, climate change adaptation strategies should ensure that adequate resources are available for effective vector control so as to manage the risk of mosquito-borne diseases.

  20. Spectroscopic Studies of Mosquito Iridescent Virus, its Capsid Proteins, Lipids, and DNA

    International Nuclear Information System (INIS)

    Kravchenko, V.M.; Rud, Yu.P.; Buchatski, L.P.; Melnik, V.I.; Mogylchak, K.Yu.; Ladan, S.P.; Yashchuk, V.M.

    2012-01-01

    Mosquito iridescent virus (MIV) is an icosahedric lipid-containing virus which affects mosquitoes of Aedes, Culex, Culizeta genera. Apart from mosquitoes and other insects, iridoviruses cause the mass death of fish and can cause huge losses for industrial fish breedings. The MIV virion consists of a core of the genetic material (double-stranded viral DNA) surrounded by a capsid (icosahedral protein shell) and further encased in a lipid envelope. The aim of the work was to determine the role of MIV virion constituents (lipids, capsid proteins, and viral DNA) in the formation of spectral properties of the whole MIV virions. Measured are UV-Vis absorption, fluorescence, fluorescence excitation, and phosphorescence spectra of MIV virions, their capsid proteins, lipids, and viral DNA dissolved in various buffers. It is shown that the UV absorption of MIV virions is caused by the absorption of all virion constituents such as capsid proteins, lipids, and viral DNA. The fluorescence of MIV virions at room temperature is mainly due to the fluorescence of capsid proteins. The spectra measured at low temperatures make it possible to identify the type of a nucleic acid (DNA or RNA) inside the virion thanks to the fact that the DNA and RNA phosphorescence spectra are radically different.

  1. Over-breeding

    International Nuclear Information System (INIS)

    Schuh, S.A.

    1991-01-01

    The Greenhouse Effect has fuzzy parameters, as do the consequences of acid rain, accidental nuclear fallout, deforestation, even the depletion of oil and natural gas reserves, and other threatening calamities. But the consequences of human over-breeding do not fall within fuzzy parameters. Reliable demographic studies predict a world population by the year 2020 of twice the present four billion or so living human beings. Some of us will see that year. But the population will again have doubled by the year 2090: sixteen billion people. The author suggests in this paper some morally permissible steps that might be taken to circumvent what otherwise is most assuredly an impending world tragedy. We have an ethical obligation to future generations. They have the moral right to a qualitatively fulfilling life, not just on allotted number of years. Some of my suggestions will not be palatable to some readers. But I urge those readers seriously to consider and if possible, hopefully, to propose alternatives

  2. Next generation breeding.

    Science.gov (United States)

    Barabaschi, Delfina; Tondelli, Alessandro; Desiderio, Francesca; Volante, Andrea; Vaccino, Patrizia; Valè, Giampiero; Cattivelli, Luigi

    2016-01-01

    The genomic revolution of the past decade has greatly improved our understanding of the genetic make-up of living organisms. The sequencing of crop genomes has completely changed our vision and interpretation of genome organization and evolution. Re-sequencing allows the identification of an unlimited number of markers as well as the analysis of germplasm allelic diversity based on allele mining approaches. High throughput marker technologies coupled with advanced phenotyping platforms provide new opportunities for discovering marker-trait associations which can sustain genomic-assisted breeding. The availability of genome sequencing information is enabling genome editing (site-specific mutagenesis), to obtain gene sequences desired by breeders. This review illustrates how next generation sequencing-derived information can be used to tailor genomic tools for different breeders' needs to revolutionize crop improvement. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  3. Beyond breeding area management

    DEFF Research Database (Denmark)

    Pedersen, Lykke; Thorup, Kasper; Tøttrup, Anders P.

    . Perhaps as a consequence, long-distance migratory songbirds are declining rapidly compared to their sedentary counterparts. To understand what is driving these declines in European-Afrotropical migratory bird populations we need to understand the full annual migration cycle of these birds. Recent...... technological advances are currently enabling us to track yet smaller songbirds throughout their migration cycle providing valuable insight into the life cycle of individual birds. However, direct tracking of migratory birds has so far mainly been conducted on single populations and our understanding of entire......) in the period 2009-2015. We found that populations used the same migration routes and staging sites, but segregated spatially at the main non-breeding grounds in southern Africa. This finding suggest a far more complex migration pattern than what has recently been described for European-Afrotropical migrants...

  4. Field performance of engineered male mosquitoes.

    Science.gov (United States)

    Harris, Angela F; Nimmo, Derric; McKemey, Andrew R; Kelly, Nick; Scaife, Sarah; Donnelly, Christl A; Beech, Camilla; Petrie, William D; Alphey, Luke

    2011-10-30

    Dengue is the most medically important arthropod-borne viral disease, with 50-100 million cases reported annually worldwide. As no licensed vaccine or dedicated therapy exists for dengue, the most promising strategies to control the disease involve targeting the predominant mosquito vector, Aedes aegypti. However, the current methods to do this are inadequate. Various approaches involving genetically engineered mosquitoes have been proposed, including the release of transgenic sterile males. However, the ability of laboratory-reared, engineered male mosquitoes to effectively compete with wild males in terms of finding and mating with wild females, which is critical to the success of these strategies, has remained untested. We report data from the first open-field trial involving a strain of engineered mosquito. We demonstrated that genetically modified male mosquitoes, released across 10 hectares for a 4-week period, mated successfully with wild females and fertilized their eggs. These findings suggest the feasibility of this technology to control dengue by suppressing field populations of A. aegypti.

  5. Assessing the sustainability of individual behavior change against mosquitoes after the outbreak of a vector-borne disease in Mauritius: a case study

    Directory of Open Access Journals (Sweden)

    Smita Goorah

    2013-01-01

    Full Text Available The island of Mauritius had not experienced any mosquito-borne diseases since the last malaria outbreak in the early 1980s. When the chikungunya fever epidemic affected the island in 2005-2006, the local population was unprepared against this mosquito-borne infection and officially 11, 000 people were affected. Authorities promptly set up public health campaigns and actively encouraged the public to take preventive actions against the mosquito vector. This study has been carried out to investigate whether the individual preventive interventions adopted to combat mosquitoes during the outbreak have been sustained two years following the outbreak in a specific rural locality. Ethical clearance was obtained from the Research Ethics Committee of the University of Mauritius. Data was collected using a door-to-door household survey in a small rural locality of Mauritius in December 2008 and January 2009. One person per household was interviewed and the sample size was 172. Sustainability of individual preventive interventions was determined by assessing the preventive measures adopted by people against mosquitoes prior to, during, and two years following the outbreak. Elimination of mosquito breeding places was the most practiced preventive measure adopted by people in all outbreak periods as compared to preventive measures against mosquito bites within and outside the house. An increase in all individual preventive measures was observed during the outbreak followed by a slow decline two years following the outbreak. An important finding was that all post-outbreak preventive measures were sustained above the pre-outbreak levels, especially so in the case of source reduction interventions. Individual efforts in the inter-epidemic period are important to mitigate the spread of a mosquito-borne infection and it is encouraging to observe in this case study that although individual preventive measures decline with time after an outbreak they are still

  6. Biotechnology in maize breeding

    Directory of Open Access Journals (Sweden)

    Mladenović-Drinić Snežana

    2004-01-01

    Full Text Available Maize is one of the most important economic crops and the best studied and most tractable genetic system among monocots. The development of biotechnology has led to a great increase in our knowledge of maize genetics and understanding of the structure and behaviour of maize genomes. Conventional breeding practices can now be complemented by a number of new and powerful techniques. Some of these often referred to as molecular methods, enable scientists to see the layout of the entire genome of any organism and to select plants with preferred characteristics by "reading" at the molecular level, saving precious time and resources. DNA markers have provided valuable tools in various analyses ranging from phylogenetic analysis to the positional cloning of genes. Application of molecular markers for genetic studies of maize include: assessment of genetic variability and characterization of germ plasm, identification and fingerprinting of genotypes, estimation of genetic distance, detection of monogamic and quantitative trait loci, marker assisted selection, identification of sequence of useful candidate genes, etc. The development of high-density molecular maps which has been facilitated by PCR-based markers, have made the mapping and tagging of almost any trait possible and serve as bases for marker assisted selection. Sequencing of maize genomes would help to elucidate gene function, gene regulation and their expression. Modern biotechnology also includes an array of tools for introducing or deieting a particular gene or genes to produce plants with novel traits. Development of informatics and biotechnology are resulted in bioinformatic as well as in expansion of microarrey technique. Modern biotechnologies could complement and improve the efficiency of traditional selection and breeding techniques to enhance agricultural productivity.

  7. ["Breeding for distress" in fowl].

    Science.gov (United States)

    Bartels, T

    1995-03-01

    During the last hundred years the fancying and breeding of exhibition poultry became very popular as free time activity. Certain breeding standards were set, and the aim of actual breeding endeavours is to meet these standards through selective breeding. Not only were serious defects established as standard qualities (e.g. domestic ducks with feather crests, rumplessness, and ear-tufts in the domestic fowl), but certain distinctive marks were changed into excessive formations (e.g. pigeon breeds with large, cauliflower-like wattles, or enlarged crops and severe behaviour changes). Accurate analysis of such breeding efforts shows that these breeds are to be called defective and abnormal in the sense of section 11b of the German protection of animals legislation. Whether an increased embryonic mortality, especially during the hatching period, constitutes a condemnable state of cruelty against is recently being discussed. Criticised are also standard features which handicap, in varying degrees, certain functional systems of the natural behaviour patterns. Section 11b of the German protection of animal legislation in its present wording is definitely no sufficient mean to control the contemporary excess in breeding of domestic animals.

  8. Towards a risk map of malaria for Sri Lanka: the importance of house location relative to vector breeding sites

    DEFF Research Database (Denmark)

    Van Der Hoek, Wim; Konradsen, Flemming; Amerasinghe, Priyanie H

    2003-01-01

    BACKGROUND: In Sri Lanka, the major malaria vector Anopheles culicifacies breeds in pools formed in streams and river beds and it is likely that people living close to such breeding sites are at higher risk of malaria than people living further away. This study was done to quantify the importance...... Sri Lanka, malaria cases were compared with community controls for distance from house to breeding sites and a number of other variables, including type of housing construction and use of anti-mosquito measures. The presence of An. culicifacies in bedrooms was determined by indoor insecticide spray...... adult An. culicifacies in the bedrooms. Poor housing construction was an independent risk factor for malaria. CONCLUSIONS: Risk maps of malaria in Sri Lanka can be based on the location of houses relative to streams and rivers that are potential breeding sites for the malaria vector An. culicifacies...

  9. Breeding Ecology of Birds -22 ...

    Indian Academy of Sciences (India)

    local timber or energy demands. ... grounds for mosquitoes and thus a source of malaria, and from the viewpoint of administrators and land .... level off. The Economics of Solitary and Colonial Nesting. So far we have learnt that different patterns of nesting behaviour are likely to evolve according to the type of resource ...

  10. ROOT VEGETABLES, BREEDING TRENDS, RESULTS

    Directory of Open Access Journals (Sweden)

    M. I. Fedorova

    2017-01-01

    Full Text Available The main advantage of root vegetables is their unique specificity and high economic importance. The benefits and medicinal properties of root vegetables being highly demanded by the market requirements to the commodity are highlighted in the article. The main directions of breeding program for root vegetable crops, including species of Apiaceae family with carrot, parsnips; Chenopodioideae family with red beet; Brassicaceae family with radish, Daikon, Raphanus sativus L. var. lobo Sazonova & Stank, turnip and rutabaga. Initial breeding accessions of carrot, red beet, radish, Daikon, Raphanus sativus L. var. lobo Sazonova & Stank, turnip and rutabaga have been selected out to be used for breeding program for heterosis. The mf and ms breeding lines were developed, and with the use of them the new gene pool was created. Variety supporting breeding program and methods were also proposed. 

  11. A qualitative study of community perception and acceptance of biological larviciding for malaria mosquito control in rural Burkina Faso.

    Science.gov (United States)

    Dambach, Peter; Jorge, Margarida Mendes; Traoré, Issouf; Phalkey, Revati; Sawadogo, Hélène; Zabré, Pascal; Kagoné, Moubassira; Sié, Ali; Sauerborn, Rainer; Becker, Norbert; Beiersmann, Claudia

    2018-03-23

    Vector and malaria parasite's rising resistance against pyrethroid-impregnated bed nets and antimalarial drugs highlight the need for additional control measures. Larviciding against malaria vectors is experiencing a renaissance with the availability of environmentally friendly and target species-specific larvicides. In this study, we analyse the perception and acceptability of spraying surface water collections with the biological larvicide Bacillus thuringiensis israelensis in a single health district in Burkina Faso. A total of 12 focus group discussions and 12 key informant interviews were performed in 10 rural villages provided with coverage of various larvicide treatments (all breeding sites treated, the most productive breeding sites treated, and untreated control). Respondents' knowledge about the major risk factors for malaria transmission was generally good. Most interviewees stated they performed personal protective measures against vector mosquitoes including the use of bed nets and sometimes mosquito coils and traditional repellents. The acceptance of larviciding in and around the villages was high and the majority of respondents reported a relief in mosquito nuisance and malarial episodes. There was high interest in the project and demand for future continuation. This study showed that larviciding interventions received positive resonance from the population. People showed a willingness to be involved and financially support the program. The positive environment with high acceptance for larviciding programs would facilitate routine implementation. An essential factor for the future success of such programs would be inclusion in regional or national malaria control guidelines.

  12. [Malaria indices, larval ecology and trophic activity of Anopheles mosquitoes in Djohong (Adamaoua, Cameroon) in the rainy season].

    Science.gov (United States)

    Raccurt, C P; Bourianne, C; Lambert, M T; Tribouley, J; Mandji, O; Amadou, A; Bouloumie, J; Ripert, C

    1993-01-01

    In Djohong in the wet season the prevalence of malaria is 17.5% for Plasmodium falciparum and 1.1% for Plasmodium malariae. In children 2 to 9 years of age the plasmodic index is 38.6% (mesoendemicity) for the children of the peasants and 9.4% for those belonging to other socioeconomical groups. In infants less than 12 months old, the plasmodic index is 9.3%, this relatively high rate corresponding to the high transmission period of the rainy season. Anopheles gambiae is the mosquito species most often found in the area (2/3 of the mosquitoes caught in the houses). The breeding sites in he surrounding of the houses are rainwater holes linked to human activity. At a larger distance from the houses, in the valley, the breeding sites are water holes borrowed for the retting of cassava tubercle or natural rock pools found in the basaltic shores of the Mbere river. The trophic activity of Anopheles gambiae and Anopheles funestus is high between 0 and 4 hours a.m. In October the mean number of anopheline mosquitoes bites per night per inhabitant is 33 inside the houses and 7 outside.

  13. Anopheles plumbeus (Diptera: Culicidae) in Germany: updated geographic distribution and public health impact of a nuisance and vector mosquito.

    Science.gov (United States)

    Heym, Eva C; Kampen, Helge; Fahle, Marcus; Hohenbrink, Tobias L; Schäfer, Mandy; Scheuch, Dorothee E; Walther, Doreen

    2017-01-01

    The aim of this study was to map the current spatial distribution of Anopheles plumbeus in Germany, a potential vector of malaria parasites and West Nile virus. Reports of mass occurrence and nuisance connected with artificial breeding site usage by this species were analysed. Distribution data were collected from 2011 to 2014 mainly through trapping and submissions of adult mosquito specimens to a citizen science project. In the framework of the latter, additional information was gathered on recent nuisance incidents caused by An. plumbeus, including a longitudinal analysis of mosquito occurrence and the impact of management measures at a nuisance site in south-western Germany. Based on the most comprehensive set of collection data obtained during the last decades, An. plumbeus is shown to be widely distributed over Germany. The data also indicate a continuing extension of the breeding site repertoire of the species from natural to artificial habitats that facilitate mass development. Increasing incidents of persistent nuisance suggest that this mosquito species is rarely diagnosed correctly and managed adequately. As An. plumbeus is both a serious nuisance pest and a potential vector species, awareness of this species and the public health problems linked to it should be raised among pest managers and public health personnel. © 2016 John Wiley & Sons Ltd.

  14. MosqTent: An individual portable protective double-chamber mosquito trap for anthropophilic mosquitoes.

    Science.gov (United States)

    Lima, José Bento Pereira; Galardo, Allan Kardec Ribeiro; Bastos, Leonardo Soares; Lima, Arthur Weiss da Silva; Rosa-Freitas, Maria Goreti

    2017-03-01

    Here, we describe the development of the MosqTent, an innovative double-chamber mosquito trap in which a human being attracts mosquitoes while is protected from being bitten within the inner chamber of the trap, while mosquitoes are lured to enter an outer chamber where they are trapped. The MosqTent previously collected an average of 3,000 anophelines/man-hour compared to 240 anophelines/man-hour for the human landing catch (HLC), thereby providing high numbers of human host-seeking mosquitoes while protecting the collector from mosquito bites. The MosqTent performed well by collecting a high number of specimens of Anopheles marajoara, a local vector and anthropophilic mosquito species present in high density, but not so well in collecting An. darlingi, an anthropophilic mosquito species considered the main vector in Brazil but is present in low-density conditions in the area. The HLC showed a higher efficiency in collecting An. darlingi in these low-density conditions. The MosqTent is light (<1 kg), portable (comes as a bag with two handles), flexible (can be used with other attractants), adaptable (can be deployed in a variety of environmental settings and weather conditions), and it can be used in the intra-, peri-, and in the extradomicile. Also, the MosqTent collected similar portions of parous females and anthropophilic mosquito species and collects specimens suitable for downstream analysis. Further developments may include testing for other fabric colors, different mesh sizes and dimensions for other hematophagous insects and conditions, additional chemical mosquito attractants, and even the replacement of the human attractant in favor of other attractants. MosqTent modifications that would allow the trap to be applied as a vector control tool with killing action could also be explored.

  15. MosqTent: An individual portable protective double-chamber mosquito trap for anthropophilic mosquitoes.

    Directory of Open Access Journals (Sweden)

    José Bento Pereira Lima

    2017-03-01

    Full Text Available Here, we describe the development of the MosqTent, an innovative double-chamber mosquito trap in which a human being attracts mosquitoes while is protected from being bitten within the inner chamber of the trap, while mosquitoes are lured to enter an outer chamber where they are trapped. The MosqTent previously collected an average of 3,000 anophelines/man-hour compared to 240 anophelines/man-hour for the human landing catch (HLC, thereby providing high numbers of human host-seeking mosquitoes while protecting the collector from mosquito bites. The MosqTent performed well by collecting a high number of specimens of Anopheles marajoara, a local vector and anthropophilic mosquito species present in high density, but not so well in collecting An. darlingi, an anthropophilic mosquito species considered the main vector in Brazil but is present in low-density conditions in the area. The HLC showed a higher efficiency in collecting An. darlingi in these low-density conditions. The MosqTent is light (<1 kg, portable (comes as a bag with two handles, flexible (can be used with other attractants, adaptable (can be deployed in a variety of environmental settings and weather conditions, and it can be used in the intra-, peri-, and in the extradomicile. Also, the MosqTent collected similar portions of parous females and anthropophilic mosquito species and collects specimens suitable for downstream analysis. Further developments may include testing for other fabric colors, different mesh sizes and dimensions for other hematophagous insects and conditions, additional chemical mosquito attractants, and even the replacement of the human attractant in favor of other attractants. MosqTent modifications that would allow the trap to be applied as a vector control tool with killing action could also be explored.

  16. Evaluation of botanicals as repellents against mosquitoes.

    Science.gov (United States)

    Das, N G; Baruah, I; Talukdar, P K; Das, S C

    2003-01-01

    Repellent properties of three plant extracts--essential oil (steam distillate) of Zanthoxylum limonella (fruits), Citrus aurantifolia (leaf) and petroleum ether extract of Z. limonella (fruits) were evaluated as repellent against Aedes (S.) albopictus mosquitoes in mustard (Dhara) and coconut (Parachute) oil base under laboratory conditions. Three concentrations--10, 20 and 30% of the repellents were evaluated. Repellents in mustard oil afforded longer protection time against the bites of Aedes (S.) albopictus mosquitoes than those in coconut oil. At 30% concentration, 296-304 min protection time was achieved by the test repellents in mustard oil base while repellents in coconut oil exhibited 223.5-245 min protection time at the same concentration. Oil of Z. limonella gave the highest protection time against the bites of Aedes (S.) albopictus mosquitoes at all the concentrations than other herbal repellents tested both in mustard and coconut oil.

  17. New State Records of Mosquitoes for Colorado.

    Science.gov (United States)

    Rose, Dominic A; Kondratieff, B C; Weissmann, M J

    2015-06-01

    The 1967 treatment of the Mosquitoes of Colorado by Harmston and Lawson and subsequent publications have recorded 46 culicid species from Colorado. As part of a study to create an updated synopsis of the mosquitoes of Colorado, adult trapping at numerous localities was conducted in Colorado during the summers of 2013 and 2014. This review also included an examination of mosquito specimens in various relevant museum collections. Aedes (Ochlerotatus) niphadopsis and Ae. (Och.) spencerii spencerii were collected during the 2013 and 2014 field seasons. Records for Ae. (Och.) canadensis canadensis, Ae. (Stegomyia) aegypti, and Uranotaenia (Pseudoficalbia) anhydor syntheta were obtained from examination of museum specimens. These species constitute new state records for Colorado, with 51 species now known from the state.

  18. Human to mosquito transmission of dengue viruses

    Directory of Open Access Journals (Sweden)

    Lauren B Carrington

    2014-06-01

    Full Text Available The successful transmission of dengue virus from a human host to a mosquito vector requires a complex set of factors to align. It is becoming increasingly important to improve our understanding of the parameters that shape the human to mosquito component of the transmission cycle so that vaccines and therapeutic anti-virals can be fully evaluated and epidemiological models refined. Here we describe these factors, and discuss the biological and environmental impacts and demographic changes that are influencing these dynamics. Specifically, we examine features of the human infection required for the mosquito to acquire the virus via natural blood feeding, as well as the biological and environmental factors that influence a mosquito’s susceptibility to infection, up to the point that they are capable of transmitting the virus to a new host.

  19. Anopheline (Diptera:Culicidae) breeding in a traditional tank-based village ecosystem in north central Sri Lanka

    DEFF Research Database (Denmark)

    Amerasinghe, F P; Konradsen, F; Fonseka, K T

    1997-01-01

    A 13-mo survey of immature anopheline mosquitoes breeding in surface water habitats was done at Mahameegaswewa village within the Huruluwewa watershed in north central Sri Lanka as part of a multidisciplinary study on malaria epidemiology. The watershed is representative of the ancient small tank....... A clear progression in breeding habitat use from stream bed to tank bed and drainage area pools was seen in An. culicifacies during the premonsoon period. Environmental management measures to reduce or modify these habitats could potentially decrease malaria. transmission....

  20. Mosquito infection responses to developing filarial worms.

    Directory of Open Access Journals (Sweden)

    Sara M Erickson

    2009-10-01

    Full Text Available Human lymphatic filariasis is a mosquito-vectored disease caused by the nematode parasites Wuchereria bancrofti, Brugia malayi and Brugia timori. These are relatively large roundworms that can cause considerable damage in compatible mosquito vectors. In order to assess how mosquitoes respond to infection in compatible mosquito-filarial worm associations, microarray analysis was used to evaluate transcriptome changes in Aedes aegypti at various times during B. malayi development. Changes in transcript abundance in response to the different stages of B. malayi infection were diverse. At the early stages of midgut and thoracic muscle cell penetration, a greater number of genes were repressed compared to those that were induced (20 vs. 8. The non-feeding, intracellular first-stage larvae elicited few differences, with 4 transcripts showing an increased and 9 a decreased abundance relative to controls. Several cecropin transcripts increased in abundance after parasites molted to second-stage larvae. However, the greatest number of transcripts changed in abundance after larvae molted to third-stage larvae and migrated to the head and proboscis (120 induced, 38 repressed, including a large number of putative, immunity-related genes (approximately 13% of genes with predicted functions. To test whether the innate immune system of mosquitoes was capable of modulating permissiveness to the parasite, we activated the Toll and Imd pathway controlled rel family transcription factors Rel1 and Rel2 (by RNA interference knockdown of the pathway's negative regulators Cactus and Caspar during the early stages of infection with B. malayi. The activation of either of these immune signaling pathways, or knockdown of the Toll pathway, did not affect B. malayi in Ae. aegypti. The possibility of LF parasites evading mosquito immune responses during successful development is discussed.

  1. Filarial worms reduce Plasmodium infectivity in mosquitoes.

    Directory of Open Access Journals (Sweden)

    Matthew T Aliota

    2011-02-01

    Full Text Available Co-occurrence of malaria and filarial worm parasites has been reported, but little is known about the interaction between filarial worm and malaria parasites with the same Anopheles vector. Herein, we present data evaluating the interaction between Wuchereria bancrofti and Anopheles punctulatus in Papua New Guinea (PNG. Our field studies in PNG demonstrated that An. punctulatus utilizes the melanization immune response as a natural mechanism of filarial worm resistance against invading W. bancrofti microfilariae. We then conducted laboratory studies utilizing the mosquitoes Armigeres subalbatus and Aedes aegypti and the parasites Brugia malayi, Brugia pahangi, Dirofilaria immitis, and Plasmodium gallinaceum to evaluate the hypothesis that immune activation and/or development by filarial worms negatively impact Plasmodium development in co-infected mosquitoes. Ar. subalbatus used in this study are natural vectors of P. gallinaceum and B. pahangi and they are naturally refractory to B. malayi (melanization-based refractoriness.Mosquitoes were dissected and Plasmodium development was analyzed six days after blood feeding on either P. gallinaceum alone or after taking a bloodmeal containing both P. gallinaceum and B. malayi or a bloodmeal containing both P. gallinaceum and B. pahangi. There was a significant reduction in the prevalence and mean intensity of Plasmodium infections in two species of mosquito that had dual infections as compared to those mosquitoes that were infected with Plasmodium alone, and was independent of whether the mosquito had a melanization immune response to the filarial worm or not. However, there was no reduction in Plasmodium development when filarial worms were present in the bloodmeal (D. immitis but midgut penetration was absent, suggesting that factors associated with penetration of the midgut by filarial worms likely are responsible for the observed reduction in malaria parasite infections.These results could have an

  2. Genetic Control of Mosquitoes: population suppression strategies

    Directory of Open Access Journals (Sweden)

    André Barretto Bruno Wilke

    2012-10-01

    Full Text Available Over the last two decades, morbidity and mortality from malaria and dengue fever among other pathogens are an increasing Public Health problem. The increase in the geographic distribution of vectors is accompanied by the emergence of viruses and diseases in new areas. There are insufficient specific therapeutic drugs available and there are no reliable vaccines for malaria or dengue, although some progress has been achieved, there is still a long way between its development and actual field use. Most mosquito control measures have failed to achieve their goals, mostly because of the mosquito's great reproductive capacity and genomic flexibility. Chemical control is increasingly restricted due to potential human toxicity, mortality in no target organisms, insecticide resistance, and other environmental impacts. Other strategies for mosquito control are desperately needed. The Sterile Insect Technique (SIT is a species-specific and environmentally benign method for insect population suppression, it is based on mass rearing, radiation mediated sterilization, and release of a large number of male insects. Releasing of Insects carrying a dominant lethal gene (RIDL offers a solution to many of the drawbacks of traditional SIT that have limited its application in mosquitoes while maintaining its environmentally friendly and species-specific utility. The self-limiting nature of sterile mosquitoes tends to make the issues related to field use of these somewhat less challenging than for self-spreading systems characteristic of population replacement strategies. They also are closer to field use, so might be appropriate to consider first. The prospect of genetic control methods against mosquito vectored human diseases is rapidly becoming a reality, many decisions will need to be made on a national, regional and international level regarding the biosafety, social, cultural and ethical aspects of the use and deployment of these vector control methods.

  3. Historical applications of induced sterilisation in field populations of mosquitoes

    NARCIS (Netherlands)

    Dame, David A.; Curtis, Christopher F.; Benedict, Mark Q.; Robinson, Alan S.; Knols, Bart G. J.

    2009-01-01

    Research on sterile mosquito technology from 1955 to the 1980s provided a substantial body of knowledge on propagation and release of sterile mosquitoes. Radiation sterilisation and chemosterilisation have been used effectively to induce dominant lethality and thereby sterilise important mosquito

  4. Rift Valley fever potential mosquito vectors and their infection status ...

    African Journals Online (AJOL)

    Background: Rift Valley fever (RVF) is a mosquito-borne viral zoonotic disease. Rift Valley fever virus (RVFV) has been isolated from more than 40 species of mosquitoes from eight genera. This study was conducted to determine the abundance of potential mosquito vectors and their RVFV infection status in Ngorongoro ...

  5. Evaluating the effects of mosquito control adulticides on honey bees

    Science.gov (United States)

    While mosquito control adulticides can be effective in rapidly reducing mosquito populations during times of high arbovirus transmission, the impacts of these control measures on pollinators has been of recent interest. The purpose of our study was to evaluate mosquito and honey bee mortality using ...

  6. Plasmodium ookinetes coopt mammalian plasminogen to invade the mosquito midgut

    DEFF Research Database (Denmark)

    Ghosh, Anil K; Coppens, Isabelle; Gårdsvoll, Henrik

    2011-01-01

    Ookinete invasion of the mosquito midgut is an essential step for the development of the malaria parasite in the mosquito. Invasion involves recognition between a presumed mosquito midgut receptor and an ookinete ligand. Here, we show that enolase lines the ookinete surface. An antienolase antibo...

  7. Modelling the dynamics of Chikungunya in human and mosquito ...

    African Journals Online (AJOL)

    In this paper, we developed and qualitatively analyzed a model for the transmission dynamics of chikungunya virus in a human a nd mosquito populations. The chikungunya virus is transmitted by Aedes mosquitoes usually Aedes albopictus mosquito and it is of big threat to global public health. Rigorous analysis of the ...

  8. Agricultural chemicals: life changer for mosquito vectors in agricultural landscapes?

    OpenAIRE

    Kibuthu, Tabitha W.; Njenga, Sammy M.; Mbugua, Amos K.; Muturi, Ephantus J.

    2016-01-01

    Background Although many mosquito species develop within agricultural landscapes where they are potentially exposed to agricultural chemicals (fertilizers and pesticides), the effects of these chemicals on mosquito biology remain poorly understood. This study investigated the effects of sublethal concentrations of four agricultural chemicals on the life history traits of Anopheles arabiensis and Culex quinquefasciatus mosquitoes. Methods Field and laboratory experiments were conducted to exam...

  9. Can transgenic mosquitoes afford the fitness cost?

    Science.gov (United States)

    Lambrechts, Louis; Koella, Jacob C; Boëte, Christophe

    2008-01-01

    In a recent study, SM1-transgenic Anopheles stephensi, which are resistant partially to Plasmodium berghei, had higher fitness than non-transgenic mosquitoes when they were maintained on Plasmodium-infected blood. This result should be interpreted cautiously with respect to malaria control using transgenic mosquitoes because, despite the evolutionary advantage conferred by the transgene, a concomitant cost prevents it from invading the entire population. Indeed, for the spread of a resistance transgene in a natural situation, the transgene's fitness cost and the efficacy of the gene drive will be more crucial than any evolutionary advantage.

  10. Mutation breeding in chickpea

    International Nuclear Information System (INIS)

    2009-01-01

    Chickpea is an important food legume in Turkey. Turkey is one of the most important gene centers in the world for legumes. The most widely known characteristic of chickpea is that it is an important vegetable protein source used in human and animal nutrition. However, the dry grains of chickpea, has 2-3 times more protein than our traditional food of wheat. In addition, cheakpea is also energy source because of its high carbohydrate content. It is very rich in some vitamin and mineral basis. In the plant breeding, mutation induction has become an effective way of supplementing existing germplasm and improving cultivars. Many successful examples of mutation induction have proved that mutation breeding is an effective and important approach to food legume improvement. The induced mutation technique in chickpea has proved successful and good results have been attained. Realizing the potential of induced mutations, a mutation breeding programme was initiated at the Nuclear Agriculture Section of the Saraykoey Nuclear Research and Training Center in 1994. The purpose of the study was to obtain high yielding chickpea mutants with large seeds, good cooking quality and high protein content. Beside this some characters such as higher adaptation ability, tolerant to cold and drought, increased machinery harvest type, higher yield, resistant to diseases especially to antracnose and pest were investigated too. Parents varieties were ILC-482, AK-7114 and AKCIN-91 (9 % seed moisture content and germination percentage 98 %) in these experiments. The irradiation doses were 0 (control), 50, 100, 150, 200, 250, 300, 350, 400, 500 ve 600 Gy for greenhouse experiments and 0 (control), 50, 100, 150, 200, 250, 300, 350 ve 400 Gy for field experiments, respectively. One thousand seeds for per treatment were sown in the field for the M 1 . At maturity, 3500 single plants were harvested and 20 seeds were taken from each M 1 plant and planted in the following season. During plant growth

  11. Urbanization is a main driver for the larval ecology of Aedes mosquitoes in arbovirus-endemic settings in south-eastern Côte d'Ivoire

    Science.gov (United States)

    Koudou, Benjamin G.; Müller, Pie; Malone, David; Tano, Yao; Utzinger, Jürg

    2017-01-01

    Background Failure in detecting naturally occurring breeding sites of Aedes mosquitoes can bias the conclusions drawn from field studies, and hence, negatively affect intervention outcomes. We characterized the habitats of immature Aedes mosquitoes and explored species dynamics along a rural-to-urban gradient in a West Africa setting where yellow fever and dengue co-exist. Methodology Between January 2013 and October 2014, we collected immature Aedes mosquitoes in water containers in rural, suburban, and urban areas of south-eastern Côte d’Ivoire, using standardized sampling procedures. Immature mosquitoes were reared in the laboratory and adult specimens identified at species level. Principal findings We collected 6,159, 14,347, and 22,974 Aedes mosquitoes belonging to 17, 8, and 3 different species in rural, suburban, and urban environments, respectively. Ae. aegypti was the predominant species throughout, with a particularly high abundance in urban areas (99.374%). Eleven Aedes larval species not previously sampled in similar settings of Côte d’Ivoire were identified: Ae. albopictus, Ae. angustus, Ae. apicoargenteus, Ae. argenteopunctatus, Ae. haworthi, Ae. lilii, Ae. longipalpis, Ae. opok, Ae. palpalis, Ae. stokesi, and Ae. unilineatus. Aedes breeding site positivity was associated with study area, container type, shade, detritus, water turbidity, geographic location, season, and the presence of predators. We found proportionally more positive breeding sites in urban (2,136/3,374, 63.3%), compared to suburban (1,428/3,069, 46.5%) and rural areas (738/2,423, 30.5%). In the urban setting, the predominant breeding sites were industrial containers (e.g., tires and discarded containers). In suburban areas, containers made of traditional materials (e.g., clay pots) were most frequently encountered. In rural areas, natural containers (e.g., tree holes and bamboos) were common and represented 22.1% (163/738) of all Aedes-positive containers, hosting 18.7% of the

  12. Urbanization is a main driver for the larval ecology of Aedes mosquitoes in arbovirus-endemic settings in south-eastern Côte d'Ivoire.

    Directory of Open Access Journals (Sweden)

    Julien B Z Zahouli

    2017-07-01

    Full Text Available Failure in detecting naturally occurring breeding sites of Aedes mosquitoes can bias the conclusions drawn from field studies, and hence, negatively affect intervention outcomes. We characterized the habitats of immature Aedes mosquitoes and explored species dynamics along a rural-to-urban gradient in a West Africa setting where yellow fever and dengue co-exist.Between January 2013 and October 2014, we collected immature Aedes mosquitoes in water containers in rural, suburban, and urban areas of south-eastern Côte d'Ivoire, using standardized sampling procedures. Immature mosquitoes were reared in the laboratory and adult specimens identified at species level.We collected 6,159, 14,347, and 22,974 Aedes mosquitoes belonging to 17, 8, and 3 different species in rural, suburban, and urban environments, respectively. Ae. aegypti was the predominant species throughout, with a particularly high abundance in urban areas (99.374%. Eleven Aedes larval species not previously sampled in similar settings of Côte d'Ivoire were identified: Ae. albopictus, Ae. angustus, Ae. apicoargenteus, Ae. argenteopunctatus, Ae. haworthi, Ae. lilii, Ae. longipalpis, Ae. opok, Ae. palpalis, Ae. stokesi, and Ae. unilineatus. Aedes breeding site positivity was associated with study area, container type, shade, detritus, water turbidity, geographic location, season, and the presence of predators. We found proportionally more positive breeding sites in urban (2,136/3,374, 63.3%, compared to suburban (1,428/3,069, 46.5% and rural areas (738/2,423, 30.5%. In the urban setting, the predominant breeding sites were industrial containers (e.g., tires and discarded containers. In suburban areas, containers made of traditional materials (e.g., clay pots were most frequently encountered. In rural areas, natural containers (e.g., tree holes and bamboos were common and represented 22.1% (163/738 of all Aedes-positive containers, hosting 18.7% of the Aedes fauna. The predatory mosquito

  13. Urbanization is a main driver for the larval ecology of Aedes mosquitoes in arbovirus-endemic settings in south-eastern Côte d'Ivoire.

    Science.gov (United States)

    Zahouli, Julien B Z; Koudou, Benjamin G; Müller, Pie; Malone, David; Tano, Yao; Utzinger, Jürg

    2017-07-01

    Failure in detecting naturally occurring breeding sites of Aedes mosquitoes can bias the conclusions drawn from field studies, and hence, negatively affect intervention outcomes. We characterized the habitats of immature Aedes mosquitoes and explored species dynamics along a rural-to-urban gradient in a West Africa setting where yellow fever and dengue co-exist. Between January 2013 and October 2014, we collected immature Aedes mosquitoes in water containers in rural, suburban, and urban areas of south-eastern Côte d'Ivoire, using standardized sampling procedures. Immature mosquitoes were reared in the laboratory and adult specimens identified at species level. We collected 6,159, 14,347, and 22,974 Aedes mosquitoes belonging to 17, 8, and 3 different species in rural, suburban, and urban environments, respectively. Ae. aegypti was the predominant species throughout, with a particularly high abundance in urban areas (99.374%). Eleven Aedes larval species not previously sampled in similar settings of Côte d'Ivoire were identified: Ae. albopictus, Ae. angustus, Ae. apicoargenteus, Ae. argenteopunctatus, Ae. haworthi, Ae. lilii, Ae. longipalpis, Ae. opok, Ae. palpalis, Ae. stokesi, and Ae. unilineatus. Aedes breeding site positivity was associated with study area, container type, shade, detritus, water turbidity, geographic location, season, and the presence of predators. We found proportionally more positive breeding sites in urban (2,136/3,374, 63.3%), compared to suburban (1,428/3,069, 46.5%) and rural areas (738/2,423, 30.5%). In the urban setting, the predominant breeding sites were industrial containers (e.g., tires and discarded containers). In suburban areas, containers made of traditional materials (e.g., clay pots) were most frequently encountered. In rural areas, natural containers (e.g., tree holes and bamboos) were common and represented 22.1% (163/738) of all Aedes-positive containers, hosting 18.7% of the Aedes fauna. The predatory mosquito species

  14. SPECIES COMPOSITION OF MALARIAL MOSQUITOES KHARKIV REGION. NATURAL FACTORS OF MALARIA TRANSMISSION

    Directory of Open Access Journals (Sweden)

    Gazzawi - Rogozinа L. V.

    2015-05-01

    Full Text Available Introduction. This article describes the species composition of the dominant Anopheles mosquitoes in the Kharkiv region, the season of their possible effective infection, as well as ongoing anti-malaria activities . Key words: malaria , mosquitoes, p . Anopheles, epidemiology, census, hydraulic events. Material & methods. The analysis of entomological and meteorological situation in Ukraine and in the Kharkiv region according to data of the Ukrainian Center of control and monitoring of diseases of the Ministry of Health of Ukraine and Kharkiv regional laboratory center. Collection of material (imaginal and larval was carried out on the territory of natural and artificial water bodies of Kharkiv region in the period 2013 - 2014. When collecting the material used conventional accounting methods mosquito populations. On the territory of the region under study, we have found 30 species of mosquitoes three genera: Anopheles, Culex, Aedes. Results & discussion. Epidemiological role of each species of mosquitoes depends on several conditions. Dangerous vector species can only be found in large numbers, a significant percentage of individuals in a population that feeds on the blood of man, having a sufficiently long season activity and a sufficient number of females surviving to age possible maturation of sporozoites in their body. In Ukraine, the major carriers - Anopheles maculipennis, An. m. messeae, An. m. atroparvus, An. claviger, An. plumbeus, An. hyrcanus. Mosquito species registered in the territory of the Kharkiv region are susceptible to currently known types of human malaria parasites . Moreover, the dominant species in terms of urban landscapes are An.maculipennis and An.messeae . These species possess all the qualities necessary to be considered dangerous malaria vector control. They are well infected with the three main types of human parasites. In the study area , in terms of urban landscapes, gonoaktivnye females occurs within 3

  15. Safflower: genetics and breeding

    International Nuclear Information System (INIS)

    Knowles, P.F.

    1982-01-01

    A review of genetic studies related to the breeding of improved cultivars of safflower (Carthamus tinctorius L.) indicated that it was possible to modify the following over a wide range: duration of the rosette stage, stem length, branching habit, degree of spininess, head number, head size, flower morphology, mating system, seed size, hull thickness and thereby oil and protein contents, and fatty acid composition of the oil. Safflower breeders have concentrated most of their efforts on identifying and evaluating the great range of variability in cultivated safflower and its closely related wild species, and not on exploring means to increase variability. Limited experiments with gamma rays and ethyl methanesulphonate indicated that additional variability could be induced. Mutagenic agents should be used to obtain the following: resistance to foliar diseases where resistant germplasm is not available, increased levels of resistance to Phytophthora root rot, resistance to dodder and orobanche, resistance to insect pests, earlier maturity, and additional modifications in the fatty acid composition of the oil. (author)

  16. Mutation breeding in chickpea

    International Nuclear Information System (INIS)

    Sagel, Z.; Tutluer, M. I.; Peskircioglu, H.; Kantoglu, Y.; Kunter, B.

    2009-01-01

    Chickpea is an important food legume in Turkey. Turkey is one of the most important gene centers in the world for legumes. Realizing the potential of induced mutations, a mutation breeding programme was initiated at the Nuclear Agriculture Section of the Saraykoy Nuclear Research and Training Center in 1994. The purpose of the study was to obtain high yielding chickpea mutants with large seeds, good cooking quality and high protein content. Beside this some characters such as higher adaptation ability, tolerant to cold and drought, increased machinery harvest type, higher yield, resistant to diseases especially to antracnose and pest were investigated too. Parent varieties were ILC-482, AK-7114 and AKCIN-91 had been used in these experiments. The irradiation doses were 0 (control), 50, 100, 150, 200, 250, 300, 350 and 400 Gy for field experiments, respectively. As a result of these experiments, two promising mutant lines were chosen and given to the Seed Registration and Certification Center for official registration These two promising mutants were tested at five different locations of Turkey, in 2004 and 2005 years. After 2 years of registration experiments one of outstanding mutants was officially released as mutant chickpea variety under the name TAEK-SAGEL, in 2006. Some basic characteristics of this mutant are; earliness (95-100 day), high yield capacity (180-220 kg/da), high seed protein (22-25 %), first pot height (20-25 cm), 100 seeds weight (42-48 g), cooking time (35-40 min) and resistance to Ascochyta blight.

  17. RosBREED: Enabling marker-assisted breeding in Rosaceae

    NARCIS (Netherlands)

    Iezzoni, A.F.; Weebadde, C.; Luby, J.; Yue, C.; Weg, van de W.E.; Fazio, G.; Main, D.; Peace, C.P.; Bassil, N.V.; McFerson, J.

    2010-01-01

    Genomics research has not yet been translated into routine practical application in breeding Rosaceae fruit crops (peach, apple, strawberry, cherry, apricot, pear, raspberry, etc.). Through dedicated efforts of many researchers worldwide, a wealth of genomics resources has accumulated, including EST

  18. Protection Ability Comparison of Several Mosquito Repellent Lotion Incorporated with Essential Oils of Mosquito Repellent Plants

    Directory of Open Access Journals (Sweden)

    Pramono Putro Utomo

    2014-12-01

    Full Text Available Most mosquito repellent lotions available on the market today contain the active ingredient diethyltoluamide (DEET which is very harmful to the skin. Natural mosquito repellent research using various essential oils (geranium oil, lemon oil, citronella oil and lavender oil as the active ingredient and the addition of aloe vera gel as a moisturizer has been done on a laboratory scale. The purpose of this study was to compare the protection ability of the mosquito repellent plants in Indonesia. The results showed that geranium oil, lemongrass oil, lavender oil and lemon oil could act as mosquito repellent. Best lotion formula all containing 15% essential oils have the effectiveness above 50% until the sixth hour were geranium oil, citronella oil and lavender oil while lemon oil only giving effectiveness above 50% until the second hour.

  19. Palm bract breeding sites and their exploitation by Toxorhynchites (Lynchiella) haemorrhoidalis haemorrhoidalis (Diptera: Culicidae) in an upland forest of the central Amazon.

    Science.gov (United States)

    Hutchings, R S

    1994-03-01

    Considering the potential importance of Toxorhynchites (Lynchiella) haemorrhoidalis haemorrhoidalis (F.) as a biological control agent of other mosquitoes, this species was studied in an upland forest of the Central Amazon. Palm bracts, the natural breeding sites, were sampled monthly in two different study areas for a period of 1 yr to detect the presence of immature stages and to determine their capacity to recolonize new or empty bracts. The ability of these breeding sites (bracts) to retain water was greater on a plateau where there is less humidity than in a valley. The availability of breeding sites may be related to the number of existing palms and the low precipitation. Tx. h. haemorrhoidalis is multivoltine, and the greatest abundance of larvae occurred in natural breeding sites in the valley. The population fluctuations of the larvae of this species may be influenced by the availability of natural breeding sites and by low precipitation which occurs during the dry season.

  20. Cómo controlar los mosquitos en interiores (Controlling Mosquitoes Indoors)

    Centers for Disease Control (CDC) Podcasts

    2016-08-23

    Los mosquitos pueden portar virus como el del Nilo Occidental o del Zika. En este podcast, Don Francisco le muestra a sus vecinos formas en las que pueden reducir el número de mosquitos dentro de su casa.  Created: 8/23/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 8/23/2016.

  1. First report of the oriental mosquito Aedes albopictus on the West African island of Bioko, Equatorial Guinea.

    Science.gov (United States)

    Toto, J-C; Abaga, S; Carnevale, P; Simard, F

    2003-09-01

    The invasive oriental mosquito Aedes (Stegomyia) albopictus (Skuse) (Diptera: Culicidae) was detected on Bioko Island for the first time in November 2001. It was found to be well established breeding in artificial containers at Planta, near Malabo, the capital of Equatorial Guinea. Associated species of mosquito larvae were Aedes aegypti (L.), Ae. africanus (Theobald), Culex near decens Theobald, Cx. duttoni Theobald, Cx. quinquefasciatus Say, Cx. tigripes De Grandpré & De Charmoy, Eretmapodites quinquevittatus Theobald and Mansonia africana (Theobald). This is the third tropical African country to be invaded by Ae. albopictus, which has recently spread to many parts of the Americas and Europe--with vector competence for dengue, yellow fever and other arboviruses. In the Afrotropical environment, it will be interesting to monitor the ecological balance and/or displacement between introduced Ae. albopictus and indigenous Ae. aegpyti (domestic, peri-domestic and sylvatic populations).

  2. A global assembly of adult female mosquito mark-release-recapture data to inform the control of mosquito-borne pathogens

    NARCIS (Netherlands)

    Guerra, C.A.; Reiner Jr, R.C.; Perkins, T.A.; Lindsay, S.W.; Midega, J.T.; Brady, O.J.; Barker, C.M.; Reisen, W.K.; Harrington, L.C.; Takken, W.; Kitron, U.; Lloyd, A.L.; Hay, S.I.; Scott, T.W.; Smith, D.L.

    2014-01-01

    Background Pathogen transmission by mosquitos is known to be highly sensitive to mosquito bionomic parameters. Mosquito mark-release-recapture (MMRR) experiments are a standard method for estimating such parameters including dispersal, population size and density, survival, blood feeding frequency

  3. Cultured skin microbiota attracts malaria mosquitoes

    NARCIS (Netherlands)

    Verhulst, N.O.; Beijleveld, H.; Knols, B.G.J.; Takken, W.; Schraa, G.; Bouwmeester, H.J.; Smallegange, R.C.

    2009-01-01

    Background - Host-seeking of the African malaria mosquito, Anopheles gambiae sensu stricto, is guided by human odours. The precise nature of the odours, and the composition of attractive blends of volatiles, remains largely unknown. Skin microbiota plays an important role in the production of human

  4. Cultured skin microbiota attracts malaria mosquitoes

    NARCIS (Netherlands)

    Verhulst, Niels O.; Beijleveld, Hans; Knols, Bart Gj; Takken, Willem; Schraa, Gosse; Bouwmeester, Harro J.; Smallegange, Renate C.

    2009-01-01

    Host-seeking of the African malaria mosquito, Anopheles gambiae sensu stricto, is guided by human odours. The precise nature of the odours, and the composition of attractive blends of volatiles, remains largely unknown. Skin microbiota plays an important role in the production of human body odours.

  5. Cultured skin microbiota attracts malaria mosquitoes

    NARCIS (Netherlands)

    Verhulst, N.O.; Beijleveld, H.; Knols, B.G.J.; Takken, W.; Schraa, G.; Bouwmeester, H.J.; Smallegange, R.C.

    2009-01-01

    Background: Host-seeking of the African malaria mosquito, Anopheles gambiae sensu stricto, is guided by human odours. The precise nature of the odours, and the composition of attractive blends of volatiles, remains largely unknown. Skin microbiota plays an important role in the production of human

  6. Musings on Sketches, Artists, and Mosquito Nets

    Centers for Disease Control (CDC) Podcasts

    2014-09-23

    Byron Breedlove reads his essay Musings on Sketches, Artists, and Mosquito Nets about the art of James Whistler and the transmission of vector borne diseases.  Created: 9/23/2014 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 10/20/2014.

  7. Malaria mosquitoes attracted by fatal fungus.

    Directory of Open Access Journals (Sweden)

    Justin George

    Full Text Available Insect-killing fungi such as Beauveria bassiana are being evaluated as possible active ingredients for use in novel biopesticides against mosquito vectors that transmit malaria. Fungal pathogens infect through contact and so applications of spores to surfaces such as walls, nets, or other resting sites provide possible routes to infect mosquitoes in and around domestic dwellings. However, some insects can detect and actively avoid fungal spores to reduce infection risk. If true for mosquitoes, such behavior could render the biopesticide approach ineffective. Here we find that the spores of B. bassiana are highly attractive to females of Anopheles stephensi, a major anopheline mosquito vector of human malaria in Asia. We further find that An. stephensi females are preferentially attracted to dead and dying caterpillars infected with B. bassiana, landing on them and subsequently becoming infected with the fungus. Females are also preferentially attracted to cloth sprayed with oil-formulated B. bassiana spores, with 95% of the attracted females becoming infected after a one-minute visit on the cloth. This is the first report of an insect being attracted to a lethal fungal pathogen. The exact mechanisms involved in this behavior remain unclear. Nonetheless, our results indicate that biopesticidal formulations comprising B. bassiana spores will be conducive to attraction and on-source visitation by malaria vectors.

  8. Influence of trap construction on mosquito capture

    Czech Academy of Sciences Publication Activity Database

    Šebesta, Oldřich; Peško, Juraj; Gelbič, Ivan

    2012-01-01

    Roč. 6, č. 2 (2012), s. 209-215 ISSN 1934-7391 R&D Projects: GA MŠk 2B08003 Institutional research plan: CEZ:AV0Z50070508 Institutional support: RVO:68081766 ; RVO:60077344 Keywords : CDC miniature light traps * baited lard-can traps * mosquitoes Subject RIV: EG - Zoology

  9. Water management for controlling the breeding of Anopheles mosquitoes in rice irrigation schemes in Kenya

    DEFF Research Database (Denmark)

    Mutero, C M; Blank, H; Konradsen, F

    2000-01-01

    collected in the experimental plots were identified as being An. arabiensis. By far the highest numbers of An. arabiensis 1st instar larvae were found in the intermittently irrigated subplots, indicating that the water regime provided the most attractive environment for egg laying. However, the ratio...... between the 4th and 1st instar larvae in the subplots was only 0.08, indicating very low survival rates. In contrast, the 4th/1st instar ratio for subplots with other water management regimes ranged between 0.27 and 0.68, suggesting a correspondingly higher survival than observed with intermittent...... differences among subplots with different water regimes. The average yield per hectare ranged from 4.8-5.3 metric tonnes. The average daily water percolation/seepage rate was 3.6 mm and did not significantly differ among different water management regimes. Further research is necessary to, among other things...

  10. Mutation breeding newsletter. No. 18

    International Nuclear Information System (INIS)

    1981-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  11. Tricolored Blackbird - Breeding [ds20

    Data.gov (United States)

    California Natural Resource Agency — These data come from observations of breeding tricolored blackbirds throughout their range in California. NAD27 coordinates are given in the data for each record....

  12. Mutation breeding newsletter. No. 6

    International Nuclear Information System (INIS)

    1975-08-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  13. Mutation breeding newsletter. No. 2

    International Nuclear Information System (INIS)

    1973-02-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  14. Mutation breeding newsletter. No. 5

    International Nuclear Information System (INIS)

    1975-02-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  15. Mutation breeding newsletter. No. 32

    International Nuclear Information System (INIS)

    1988-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  16. Mutation breeding newsletter. No. 9

    International Nuclear Information System (INIS)

    1977-01-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  17. Mutation breeding newsletter. No. 8

    International Nuclear Information System (INIS)

    1976-09-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  18. Mutation breeding newsletter. No. 10

    International Nuclear Information System (INIS)

    1977-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  19. Mutation breeding newsletter. No. 7

    International Nuclear Information System (INIS)

    1976-01-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  20. Bee Queen Breeding Methods - Review

    Directory of Open Access Journals (Sweden)

    Silvia Patruica

    2016-05-01

    Full Text Available The biological potential of a bee family is mainly generated by the biological value of the queen. Whether we grow queens widely or just for our own apiaries, we must consider the acquisition of high-quality biological material, and also the creation of optimal feeding and caring conditions, in order to obtain high genetic value queens. Queen breeding technology starts with the setting of hoeing families, nurse families, drone-breeding families – necessary for the pairing of young queens, and also of the families which will provide the bees used to populate the nuclei where the next queens will hatch. The complex of requirements for the breeding of good, high-production queens is sometimes hard to met, under the application of artificial methods. The selection of breeding method must rely on all these requirements and on the beekeeper’s level of training.

  1. Mutation breeding newsletter. No. 36

    International Nuclear Information System (INIS)

    1990-07-01

    This issue of the Newsletter presents abstracts and short communications of research results on radiation and chemical induced mutation breeding projects. Positive traits such as disease resistance and increased productivity are highlighted

  2. Mutation breeding newsletter. No. 33

    International Nuclear Information System (INIS)

    1989-01-01

    This issue of the newsletter reports a number of research news and research abstracts on application of radiation induced mutation techniques to increase mutagenesis and mutation frequency in plant breeding projects

  3. Mutation breeding newsletter. No. 16

    International Nuclear Information System (INIS)

    1980-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  4. Mutation Breeding Newsletter. No. 37

    International Nuclear Information System (INIS)

    1991-01-01

    This newsletter contains a brief account of FAO/IAEA meetings held in 1990 on plant breeding involving the use of induced mutations. It also features a list of commercially available plant cultivars produced by such techniques. Refs and tabs

  5. Mutation breeding newsletter. No. 3

    International Nuclear Information System (INIS)

    1974-01-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  6. Mutation breeding newsletter. No. 4

    International Nuclear Information System (INIS)

    1974-08-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  7. Mutation breeding newsletter. No. 19

    International Nuclear Information System (INIS)

    1982-01-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  8. Mutation breeding newsletter. No. 1

    International Nuclear Information System (INIS)

    1972-05-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  9. Tricolored Blackbird - Breeding [ds20

    Data.gov (United States)

    California Department of Resources — These data come from observations of breeding tricolored blackbirds throughout their range in California. NAD27 coordinates are given in the data for each record....

  10. Mutation breeding newsletter. No. 24

    International Nuclear Information System (INIS)

    1984-07-01

    This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  11. Mutation breeding newsletter. No. 31

    International Nuclear Information System (INIS)

    1988-03-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  12. Mutation breeding newsletter. No. 30

    International Nuclear Information System (INIS)

    1987-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  13. Mutation breeding newsletter. No. 23

    International Nuclear Information System (INIS)

    1983-01-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  14. Mutation breeding newsletter. No. 34

    International Nuclear Information System (INIS)

    1989-07-01

    This issue of the Newsletter presents abstracts and short communications of research results on radiation and chemical induced mutation breeding projects. Positive traits such as disease resistance and increased productivity are highlighted

  15. Mutation breeding newsletter. No. 13

    International Nuclear Information System (INIS)

    1979-02-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  16. Mutation breeding newsletter. No. 17

    International Nuclear Information System (INIS)

    1981-03-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  17. Mutation breeding newsletter. No. 28

    International Nuclear Information System (INIS)

    1986-09-01

    This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  18. Mutation breeding newsletter. No. 27

    International Nuclear Information System (INIS)

    1986-02-01

    This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  19. Mutation breeding newsletter. No. 11

    International Nuclear Information System (INIS)

    1978-02-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  20. Mutation breeding newsletter. No. 20

    International Nuclear Information System (INIS)

    1982-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  1. Mutation breeding newsletter. No. 15

    International Nuclear Information System (INIS)

    1980-02-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  2. Mutation breeding newsletter. No. 12

    International Nuclear Information System (INIS)

    1978-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  3. Mutation breeding newsletter. No. 29

    International Nuclear Information System (INIS)

    1987-02-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  4. Mutation breeding newsletter. No. 26

    International Nuclear Information System (INIS)

    1985-10-01

    This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  5. Mutation breeding newsletter. No. 22

    International Nuclear Information System (INIS)

    1983-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  6. Mutation breeding newsletter. No. 25

    International Nuclear Information System (INIS)

    1985-01-01

    This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  7. Mutation breeding newsletter. No. 14

    International Nuclear Information System (INIS)

    1979-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  8. Spatial distribution & physicochemical characterization of the breeding habitats of Aedes aegypti in & around Kolkata, West Bengal, India.

    Science.gov (United States)

    Chatterjee, Soumendranath; Chakraborty, Arunima; Sinha, Shuvra Kanti

    2015-12-01

    Dengue infection is endemic in several areas and the dengue virus is transmitted by Aedes mosquitoes. Thus, it becomes important to understand the breeding ecology of dengue vector and characterize the physicochemical parameters of its breeding habitat. The objective of this study was to analyze the physicochemical parameters of the breeding habitat of the dengue vector and to find out the nutrient composition of the habitat in and around Kolkata, West Bengal. In addition, a geographic information system (GIS) was used to map the disease prone areas for its effective management and prevention. Water samples were collected from various breeding habitats of Aedes mosquitoes of Kolkata and adjoining areas and were analysed for various physicochemical properties like acidity, alkalinity, hardness, electrical conductivity, total dissolved solids, concentration of chloride (Cl - ), sodium (Na + ), potassium (K + ), fluoride (F - ) in relation to larval prevalence. Parameters like water pH, total dissolved solids, total hardness, electrical conductivity, concentration of chloride, sodium and potassium were seen to vary throughout the year. Certain parameters were found to be dependent on container type, like concentration of fluoride. Significant positive correlations were seen between per dip larval density and total dissolved solids (TDS) and electrical conductivity. Water pH, electrical conductivity, total dissolved solids were seen to play a major role in the ovipositional preferences. Container type did not seem to affect TDS. Tyres had the highest TDS in most of the cases. Nutrient composition like sodium concentration was mostly found in the coconut shells, potassium concentration also showed the same. Thus, container type and various parameters and nutrients play a major role in determining where a gravid female mosquito will lay its eggs. It was observed that by altering various chemical and physical properties of breeding habitats it was possible to control the

  9. Comparison between diflubenzuron and a Bacillus thuringiensis israelensis- and Lysinibacillus sphaericus-based formulation for the control of mosquito larvae in urban catch basins in Switzerland.

    Science.gov (United States)

    Guidi, Valeria; Lüthy, Peter; Tonolla, Mauro

    2013-06-01

    A field test was conducted to evaluate a commercial biolarvicide based on Bacillus thuringiensis var. israelensis and Lysinibacillus sphaericus to control mosquitoes breeding in catch basins in southern Switzerland. The efficacy and residual activity of the microbial mosquito larvicide applied at the recommended rate of 10 g per catch basin was compared to the currently used larvicide diflubenzuron. Both products provided a very good control activity (> 97% of reduction) of late instars (3rd and 4th instars) and pupae for 4 wk. However, only the microbial formulation controlled immature stages during the whole period of the trial, with > 98% of larval reduction. A single application of the microbial larvicide applied at 10 g per catch basin significantly reduced the number of immature mosquitoes for at least 70 days. The quantity of rainfall in the 48-h period before each sampling and the water temperature did not influence the efficacy of the treatments. Under the environmental conditions encountered in southern Switzerland, the larvicide tested may be a valid alternative to diflubenzuron to control mosquitoes in urban catch basins. The long-lasting control by the microbial larvicide further reduces the number of treatments required to keep the population of mosquitoes at low levels.

  10. First record of the invasive mosquito species Aedes (Stegomyia albopictus (Diptera: Culicidae on the southernmost Mediterranean islands of Italy and Europe

    Directory of Open Access Journals (Sweden)

    Marco Di Luca

    2017-11-01

    Full Text Available Abstract Background Aedes albopictus, a known worldwide vector of several mosquito-borne disease pathogens including dengue, chikungunya and Zika viruses, was introduced into Europe in the late 1970s through global trade. First recorded in northern Italy in 1990, this mosquito species has rapidly spread throughout the country, where it was responsible for an outbreak of chikungunya in 2007 that affected more than 200 people. As part of the VectorNet project, which is aimed at improving preparedness and responsiveness for animal and human vector-borne diseases in Europe, a mosquito targeted study was carried out on the three southernmost Italian islands. The objective was to verify the current European southern distribution limits of Ae. albopictus and the potential occurrence of other invasive mosquito species, in the light of the introduction of high risk for vector-borne disease pathogens into Europe via migration flows. Results In the summer 2015, six surveys for container-breeding mosquitoes were carried out by setting up a network of oviposition traps and BG Sentinel traps in selected areas on the islands of Pantelleria, Lampedusa and Linosa. Aedes albopictus was found on all three islands under investigation. The consequences on public health with regard to the presence of this mosquito vector and the migrant people entering the country from Africa and the Middle East are also discussed here. Conclusions The detection of the Asian tiger mosquito on these islands, which represent the last European strip of land facing Africa, has important implications for public health policy and should prompt the national authorities to implement tailored surveillance activities and reinforce plans for preparedness strategies in such contexts.

  11. Species composition and habitat characterization of mosquito (Diptera: Culicidae) larvae in semi-urban areas of Dhaka, Bangladesh

    Science.gov (United States)

    Bashar, Kabirul; Rahman, Md. Sayfur; Nodi, Ila Jahan; Howlader, Abdul Jabber

    2016-01-01

    Mosquito larvae are purely aquatic and develop in water bodies, the type of which is more or less specific to each species. Therefore, a study was carried out to identify the habitat characters of different mosquito species along with their species composition in semi-urban area of Dhaka in Bangladesh during the month of May and June 2012. A total of 6088 mosquito larvae belonging to 12 species (Aedes aegypti, Aedes albopictus, Anopheles barbirostris, Anopheles peditaeniatus, Anopheles vagus, Culex gelidus, Culex hutchinsoni, Culex quinquefasciatus, Culex tritaeniorhynchus, Mansonia annulifera, Mansonia uniformis, and Toxorhynchites splendens) under 5 genera were collected from 14 different types of habitats. Culex quinquefsciatus was the dominant (21.7/500 ml) species followed by Cx. tritaeniorhynchus (10.53/500 ml). Dissolved oxygen and chlorophyll a were the preeminent predictors for the abundance of all collected mosquito larvae except Ae. aegypti. Water temperature was positively associated with the breeding of An. vagus (r = 0.421, p = <0.001), An. barbirostris (r = 0.489, p = <0.001) and An. peditaeniatus (r = 0.375, p = <0.001). Water depth, distance from nearest house, emergent plant coverage, and alkalinity were found as the basis of larval abundance. Every Culex species and Tx. splendens (r = 0.359, p = 0.001) were found positively associated with chemical oxygen demand, while Mn. annulifera showed negative association (r = −0.115, p = 0.0297). This study also highlighted that various physicochemical factors affect the presence or abundance of mosquito larvae. PMID:27241953

  12. Species composition and habitat characterization of mosquito (Diptera: Culicidae) larvae in semi-urban areas of Dhaka, Bangladesh.

    Science.gov (United States)

    Bashar, Kabirul; Rahman, Md Sayfur; Nodi, Ila Jahan; Howlader, Abdul Jabber

    2016-03-01

    Mosquito larvae are purely aquatic and develop in water bodies, the type of which is more or less specific to each species. Therefore, a study was carried out to identify the habitat characters of different mosquito species along with their species composition in semi-urban area of Dhaka in Bangladesh during the month of May and June 2012. A total of 6088 mosquito larvae belonging to 12 species (Aedes aegypti, Aedes albopictus, Anopheles barbirostris, Anopheles peditaeniatus, Anopheles vagus, Culex gelidus, Culex hutchinsoni, Culex quinquefasciatus, Culex tritaeniorhynchus, Mansonia annulifera, Mansonia uniformis, and Toxorhynchites splendens) under 5 genera were collected from 14 different types of habitats. Culex quinquefsciatus was the dominant (21.7/500 ml) species followed by Cx. tritaeniorhynchus (10.53/500 ml). Dissolved oxygen and chlorophyll a were the preeminent predictors for the abundance of all collected mosquito larvae except Ae. aegypti. Water temperature was positively associated with the breeding of An. vagus (r = 0.421, p = <0.001), An. barbirostris (r = 0.489, p = <0.001) and An. peditaeniatus (r = 0.375, p = <0.001). Water depth, distance from nearest house, emergent plant coverage, and alkalinity were found as the basis of larval abundance. Every Culex species and Tx. splendens (r = 0.359, p = 0.001) were found positively associated with chemical oxygen demand, while Mn. annulifera showed negative association (r = -0.115, p = 0.0297). This study also highlighted that various physicochemical factors affect the presence or abundance of mosquito larvae.

  13. Mosquito population regulation and larval source management in heterogeneous environments.

    Directory of Open Access Journals (Sweden)

    David L Smith

    Full Text Available An important question for mosquito population dynamics, mosquito-borne pathogen transmission and vector control is how mosquito populations are regulated. Here we develop simple models with heterogeneity in egg laying patterns and in the responses of larval populations to crowding in aquatic habitats. We use the models to evaluate how such heterogeneity affects mosquito population regulation and the effects of larval source management (LSM. We revisit the notion of a carrying capacity and show how heterogeneity changes our understanding of density dependence and the outcome of LSM. Crowding in and productivity of aquatic habitats is highly uneven unless egg-laying distributions are fine-tuned to match the distribution of habitats' carrying capacities. LSM reduces mosquito population density linearly with coverage if adult mosquitoes avoid laying eggs in treated habitats, but quadratically if eggs are laid in treated habitats and the effort is therefore wasted (i.e., treating 50% of habitat reduces mosquito density by approximately 75%. Unsurprisingly, targeting (i.e. treating a subset of the most productive pools gives much larger reductions for similar coverage, but with poor targeting, increasing coverage could increase adult mosquito population densities if eggs are laid in higher capacity habitats. Our analysis suggests that, in some contexts, LSM models that accounts for heterogeneity in production of adult mosquitoes provide theoretical support for pursuing mosquito-borne disease prevention through strategic and repeated application of modern larvicides.

  14. Paratransgenesis: a promising new strategy for mosquito vector control.

    Science.gov (United States)

    Wilke, André Barretto Bruno; Marrelli, Mauro Toledo

    2015-06-24

    The three main mosquito genera, Anopheles, Aedes and Culex, transmit respectively malaria, dengue and lymphatic filariasis. Current mosquito control strategies have proved unsuccessful, and there still is a substantial number of morbidity and mortality from these diseases. Genetic control methods have now arisen as promising alternative strategies, based on two approaches: the replacement of a vector population by disease-refractory mosquitoes and the release of mosquitoes carrying a lethal gene to suppress target populations. However, substantial hurdles and limitations need to be overcome if these methods are to be used successfully, the most significant being that a transgenic mosquito strain is required for every target species, making genetically modified mosquito strategies inviable when there are multiple vector mosquitoes in the same area. Genetically modified bacteria capable of colonizing a wide range of mosquito species may be a solution to this problem and another option for the control of these diseases. In the paratransgenic approach, symbiotic bacteria are genetically modified and reintroduced in mosquitoes, where they express effector molecules. For this approach to be used in practice, however, requires a better understanding of mosquito microbiota and that symbiotic bacteria and effector molecules be identified. Paratransgenesis could prove very useful in mosquito species that are inherently difficult to transform or in sibling species complexes. In this approach, a genetic modified bacteria can act by: (a) causing pathogenic effects in the host; (b) interfering with the host's reproduction; (c) reducing the vector's competence; and (d) interfering with oogenesis and embryogenesis. It is a much more flexible and adaptable approach than the use of genetically modified mosquitoes because effector molecules and symbiotic bacteria can be replaced if they do not achieve the desired result. Paratransgenesis may therefore become an important integrated

  15. Managing mainland salt marshes for breeding birds

    OpenAIRE

    Maier, Martin

    2014-01-01

    The Wadden Sea region is one of the most important breeding areas in Western Europe for coastal breeding bird species. It is expected that management of salt marshes is important for successful conservation of breeding bird populations but the impact of management on the habitat quality for breeding birds is still not fully understood. In this study the effects of management on the three crucial habitat characteristics for breeding birds were studied on mainland salt marshes: effects of manag...

  16. Evolution, plant breeding and biodiversity

    Directory of Open Access Journals (Sweden)

    Salvatore Ceccarelli

    2011-11-01

    Full Text Available This paper deals with changes in biodiversity during the course of evolution, plant domestication and plant breeding. It shows than man has had a strong influence on the progressive decrease of biodiversity, unconscious at first and deliberate in modern times. The decrease in biodiversity in the agricultures of the North causes a severe threat to food security and is in contrasts with the conservation of biodiversity which is part of the culture of several populations in the South. The concluding section of the paper shows that man could have guided evolution in a different way and shows an example of participatory plant breeding, a type of breeding which is done in collaboration with farmers and is based on selection for specific adaptation. Even though participatory plant breeding has been practiced for only about 20 years and by relatively few groups, the effects on both biodiversity and crop production are impressive. Eventually the paper shows how participatory plant breeding can be developed into ‘evolutionary plant breeding’ to cope in a dynamic way with climate changes.

  17. Additional records of vector mosquito diversity collected from Al Khor district of North-eastern Qatar

    Directory of Open Access Journals (Sweden)

    Mahmoud Mohammed Kardousha

    2015-10-01

    Full Text Available Objective: To survey mosquito diversity in the north-eastern area, which includes the most important gas industrial city in Qatar, and to investigate the potential mosquitoes for transmitting diseases. Methods: A study was performed from September 2009 until June 2011 in Al-Khor district of North-eastern Qatar. Five localities were selected for larval collection: Al Khor City (the main city, Al Dhakira, Ras Laffan (gas industrial city, Simsimah and Al Ghuwariyah. The survey was carried out by using different sampling methods and covering all expected natural breeding sites. The larvae were collected, preserved and transferred to the laboratory for identification. Results: Our findings revealed that 10 species of mosquito larvae had been detected from the area and five of them were new records in Qatar. The species encountered were: Ochlerotatus caspius (Pallas 1771, Anopheles stephensi (Liston 1901, Culex quinquefasciatus (Say 1823 (Cx. quinquefasciatus, Culex pipiens biotype molestus (Forskal 1775 (Cx. pipiens, Culex univittatus (Theobald 1901, Culex pusillus (Macquart 1850, Culex tritaeniorhynchus (Giles 1901 (Cx. tritaeniorhynchus, Culex laticinctus (Edwards 1913, Culex sitiens (Weidmann 1828 and Culex perexiguus (Theobald 1901. The new recorded species were Cx. quinquefasciatus, Cx. tritaeniorhynchus, Culex laticinctus, Culex sitiens and Culex perexiguus. The most prevalent type was Cx. pipiens molestus (31.29% and followed by Culex pusillus and Cx. quinquefasciatus which have relatively similar prevalence of 18.72% and 18.52% respectively. Anopheles stephensi was an established vector for malaria. Cx. pipiens molestus and Cx. quinquefasciatus were vectors of West Nile virus and filariasis. Cx. tritaeniorhynchus was established as a vector of Rift Valley virus and Culex univittatus was the main vector of Sindbis virus. Conclusions: The north-eastern area of Qatar harbors is the most important industrial city in the country, which has

  18. Evaluation of botanicals as repellents against mosquitoes

    OpenAIRE

    N.G. Das, I. Baruah, P.K. Talukdar & S.C. Das

    2003-01-01

    Repellent properties of three plant extracts—essential oil (steam distillate) of Zanthoxylumlimonella (fruits), Citrus aurantifolia (leaf) and petroleum ether extract of Z. limonella (fruits)were evaluated as repellent against Aedes (S.) albopictus mosquitoes in mustard (Dhara) and coconut(Parachute) oil base under laboratory conditions. Three concentrations—10, 20 and 30% of therepellents were evaluated. Repellents in mustard oil afforded longer protection time against thebites of Aedes (S.)...

  19. Fate of blood meal iron in mosquitos

    OpenAIRE

    Zhou, Guoli; Kohlhepp, Pete; Geiser, Dawn; Frasquillo, Maria del Carmen; Vazquez-Moreno, Luz; Winzerling, Joy J.

    2007-01-01

    Iron is an essential element of living cells and organisms as a component of numerous metabolic pathways. Hemoglobin and ferric-transferrin in vertebrate host blood are the two major iron sources for female mosquitoes. We used inductively coupled plasma mass spectrometry (ICP-MS) and radioisotope-labeling to quantify the fate of iron supplied from hemoglobin or as transferrin in Aedes aegypti. At the end of the first gonotrophic cycloe, ~87% of the ingested total meal heme iron was excreted, ...

  20. Mosquito age and avian malaria infection

    OpenAIRE

    Pigeault, Romain; Nicot, Antoine; Gandon, Sylvain; Rivero, Ana

    2015-01-01

    Background The immune system of many insects wanes dramatically with age, leading to the general prediction that older insects should be more susceptible to infection than their younger counterparts. This prediction is however challenged by numerous studies showing that older insects are more resistant to a range of pathogens. The effect of age on susceptibility to infections is particularly relevant for mosquitoes given their role as vectors of malaria and other diseases. Despite this, the e...

  1. Optimal control strategy of malaria vector using genetically modified mosquitoes.

    Science.gov (United States)

    Rafikov, M; Bevilacqua, L; Wyse, A P P

    2009-06-07

    The development of transgenic mosquitoes that are resistant to diseases may provide a new and effective weapon of diseases control. Such an approach relies on transgenic mosquitoes being able to survive and compete with wild-type populations. These transgenic mosquitoes carry a specific code that inhibits the plasmodium evolution in its organism. It is said that this characteristic is hereditary and consequently the disease fades away after some time. Once transgenic mosquitoes are released, interactions between the two populations and inter-specific mating between the two types of mosquitoes take place. We present a mathematical model that considers the generation overlapping and variable environment factors. Based on this continuous model, the malaria vector control is formulated and solved as an optimal control problem, indicating how genetically modified mosquitoes should be introduced in the environment. Numerical simulations show the effectiveness of the proposed control.

  2. Manipulating insulin signaling to enhance mosquito reproduction

    Directory of Open Access Journals (Sweden)

    Rasgon Jason L

    2009-08-01

    Full Text Available Abstract Backgrond In the mosquito Aedes aegypti the insulin/insulin growth factor I signaling (IIS cascade is a key regulator of many physiological processes, including reproduction. Two important reproductive events, steroidogenesis in the ovary and yolk synthesis in the fat body, are regulated by the IIS cascade in mosquitoes. The signaling molecule phosphatase and tensin homolog (PTEN is a key inhibitor of the IIS cascade that helps modulate the activity of the IIS cascade. In Ae. aegypti, six unique splice variants of AaegPTEN were previously identified, but the role of these splice variants, particularly AaegPTEN3 and 6, were unknown. Results Knockdown of AaegPTEN or its specific splice variant AaegPTEN6 (the splice variant thought to regulate reproduction in the ovary and fat body using RNAi led to a 15–63% increase in egg production with no adverse effects on egg viability during the first reproductive cycle. Knockdown of AaegPTEN3, expressed predominantly in the head, had no effect on reproduction. We also characterized the protein expression patterns of these two splice variants during development and in various tissues during a reproductive cycle. Conclusion Previous studies in a range of organisms, including Drosophila melanogaster and Caenorhabditis elegans, have demonstrated that disruption of the IIS cascade leads to decreased reproduction or sterility. In this study we demonstrate that knockdown of the IIS inhibitor PTEN can actually increase reproduction in the mosquito, at least during the first reproductive cycle.

  3. Physico-Chemical Characteristics of Culex pipiens sensu lato and Culex torrentium (Diptera: Culicidae) Breeding Sites in Germany.

    Science.gov (United States)

    Lühken, Renke; Steinke, Sonja; Leggewie, Mayke; Tannich, Egbert; Krüger, Andreas; Becker, Stefanie; Kiel, Ellen

    2015-09-01

    Culex pipiens sensu lato (L.) and Culex torrentium Martini, 1925 are two widely distributed mosquito species in Europe. Due to difficulties in morphological discrimination, the current knowledge on differences in the breeding ecology is fragmentary. Therefore, this study evaluated the relation between the presence-absence of both species at various types of breeding habitats in response to physico-chemical parameters, using a recently developed molecular assay that allows reliable species-specific typing of larvae and pupae. The results revealed that the two species often occur in sympatry at the studied breeding sites, and there were no substantial differences concerning presence-absence of the two species with regard to the various environmental parameters investigated. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. Emperor penguins breeding on iceshelves.

    Science.gov (United States)

    Fretwell, Peter T; Trathan, Phil N; Wienecke, Barbara; Kooyman, Gerald L

    2014-01-01

    We describe a new breeding behaviour discovered in emperor penguins; utilizing satellite and aerial-survey observations four emperor penguin breeding colonies have been recorded as existing on ice-shelves. Emperors have previously been considered as a sea-ice obligate species, with 44 of the 46 colonies located on sea-ice (the other two small colonies are on land). Of the colonies found on ice-shelves, two are newly discovered, and these have been recorded on shelves every season that they have been observed, the other two have been recorded both on ice-shelves and sea-ice in different breeding seasons. We conduct two analyses; the first using synthetic aperture radar data to assess why the largest of the four colonies, for which we have most data, locates sometimes on the shelf and sometimes on the sea-ice, and find that in years where the sea-ice forms late, the colony relocates onto the ice-shelf. The second analysis uses a number of environmental variables to test the habitat marginality of all emperor penguin breeding sites. We find that three of the four colonies reported in this study are in the most northerly, warmest conditions where sea-ice is often sub-optimal. The emperor penguin's reliance on sea-ice as a breeding platform coupled with recent concerns over changed sea-ice patterns consequent on regional warming, has led to their designation as "near threatened" in the IUCN red list. Current climate models predict that future loss of sea-ice around the Antarctic coastline will negatively impact emperor numbers; recent estimates suggest a halving of the population by 2052. The discovery of this new breeding behaviour at marginal sites could mitigate some of the consequences of sea-ice loss; potential benefits and whether these are permanent or temporary need to be considered and understood before further attempts are made to predict the population trajectory of this iconic species.

  5. The effect of water physical quality and water level changes on the occurrence and density of larvae of Anopheles mosquitoes around the shoreline of the Koka reservoir, Central Ethiopia

    Science.gov (United States)

    Teklu, B. M.; Tekie, H.; McCartney, M.; Kibret, S.

    2010-08-01

    Entomological studies to determine the effect of the physical characteristics of larval breeding water bodies and reservoir water level changes on the occurrence of Anopheles mosquito larvae and on the spatial and temporal formation of larval breeding habitats were conducted in two villages at Koka reservoir between August and December 2007. Of the two study villages, Ejersa is in close proximity to the reservoir, and Kuma is 5 km away from it. Data on the type, number and physical characteristics of Anopheles larval breeding habitat, species composition and densities of anopheles mosquitoes in and around the study villages were investigated and recorded. Meteorological and reservoir water level data were compared with availability of Anopheles larval breeding sites and densities. Entomological data from the weekly larval collections showed that Anopheles pharoensis Theobald, Anopheles gambiae s.l. Giles, Anopheles coustani Laveran and Anopheles squamosus Theobald were breeding in the study area. The mean larval density of A. gambiae s.l. in this study was higher in slightly turbid and shallow aquatic habitats than in turbid and relatively deep aquatic habitats (F=16.97, plevels and the number of positive breeding habitats at Ejersa during the sampling period (r=0.605, pphysical characteristics such as water temperature, turbidity, depth and vegetation cover play an important role in the species composition, total Anopheles larval count, and the density of Anopheles mosquitoes in the vicinity. The proliferation of suitable breeding habitats around the reservoir villages is strongly associated with reservoir water level changes. This is particularly important for A. pharoensis and A. arabiensis which are important vectors of malaria in the area. Further investigation on the species diversity, physical and chemical habitat characteristics and impact of water holding capacity of the soil need to be done to generate detailed baseline data which will serve as a basis

  6. Variation in Aedes aegypti Mosquito Competence for Zika Virus Transmission

    OpenAIRE

    Roundy, Christopher M.; Azar, Sasha R.; Rossi, Shannan L.; Huang, Jing H.; Leal, Grace; Yun, Ruimei; Fernandez-Salas, Ildefonso; Vitek, Christopher J.; Paploski, Igor A.D.; Kitron, Uriel; Ribeiro, Guilherme S.; Hanley, Kathryn A.; Weaver, Scott C.; Vasilakis, Nikos

    2017-01-01

    To test whether Zika virus has adapted for more efficient transmission by Aedes aegypti mosquitoes, leading to recent urban outbreaks, we fed mosquitoes from Brazil, the Dominican Republic, and the United States artificial blood meals containing 1 of 3 Zika virus strains (Senegal, Cambodia, Mexico) and monitored infection, dissemination, and virus in saliva. Contrary to our hypothesis, Cambodia and Mexica strains were less infectious than the Senegal strain. Only mosquitoes from the Dominican...

  7. Biocontrol of larval mosquitoes by Acilius sulcatus (Coleoptera: Dytiscidae)

    OpenAIRE

    Chandra, Goutam; Mandal, Samir K; Ghosh, Arup K; Das, Dipanwita; Banerjee, Siddhartha S; Chakraborty, Sumanta

    2008-01-01

    Abstract Background Problems associated with resistant mosquitoes and the effects on non-target species by chemicals, evoke a reason to find alternative methods to control mosquitoes, like the use of natural predators. In this regard, aquatic coleopterans have been explored less compared to other insect predators. In the present study, an evaluation of the role of the larvae of Acilius sulcatus Linnaeus 1758 (Coleoptera: Dytiscidae) as predator of mosquito immatures was made in the laboratory...

  8. Rapid Detection of Arthropod-Borne Pathogens in Mosquitoes

    Science.gov (United States)

    1997-06-01

    in ELISA testing. A cone-shaped plastic pestle is attached to a Dremel drill and the mosquito is homogenized. At a laboratory, each Eppendorf tube is...understanding of the current practice for obtaining mosquitoes for testing. We recieved a plastic eppendorf tube and a plastic pestle used to homogenize...circumsporozoite antigen in Anopheline Mosquitoes collected in Southern Thailand . Lee, M., B. A. Harrison, G. E. Lewis, Jr. Am J. Trop Med Hyg 42(4), 1990

  9. Differential utilization of blood meal amino acids in mosquitoes

    OpenAIRE

    Miesfeld, Roger

    2009-01-01

    Guoli Zhou, Roger MiesfeldDepartment of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, USAAbstract: Amino acids in the mosquito blood meal have two forms, protein-bound and plasma-free amino acids. To determine if the metabolic fate and flux of these two forms of blood meal amino acids are distinct, we fed mosquitoes eight [14C]-labeled amino acids, seven of which are essential for mosquitoes (leucine, valine, isoleucine, phenylalanine, lysine, arginine, histidine), and one th...

  10. Preliminary evaluation of mosquito larvicidal efficacy of plant extracts

    OpenAIRE

    N.G. Das, D. Goswami & B. Rabha

    2007-01-01

    Mosquitoes are the most important single group ofinsects in terms of public health importance, whichtransmit a number of diseases, such as malaria, filariasis,dengue, Japanese encephalitis, etc. causing millionsof deaths every year. Repeated use of syntheticinsecticides for mosquito control has disrupted naturalbiological control systems and led to resurgencesin mosquito populations. It has also resulted in thedevelopment of resistance1, undesirable effects onnon-target organisms and fostered...

  11. Sport horses : breeding specialist from a single breeding programme?

    NARCIS (Netherlands)

    Rovere, G.A.

    2016-01-01

    Summary The general goal of this thesis was to provide information useful for the breeding programme of the Royal Dutch Warmblood Studbook (KWPN) in relation with the ongoing specialisation of the population. Data provided by KWPN consisted of records from studbook-first inspection,

  12. Development of breeding objectives for beef cattle breeding ...

    African Journals Online (AJOL)

    Mnr J F Kluyts

    production and marketing system, identification of sources of income and expense in commercial herds, determination of ..... decreasing marginal returns with an increase in the scale of the enterprise and thus, if operating at an optimum, the farm could ..... Training and Accreditation School Handbook. Anim. Genet. Breed.

  13. Development of breeding objectives for beef cattle breeding ...

    African Journals Online (AJOL)

    ... traits influencing income and expense, derivation of economic values, choice of selection criteria, and estimation of phenotypic and genetic parameters. The modelling methods to derive economic weights can be divided into simulation, dynamic programming and profit functions. Keywords: Beef cattle, Breeding objectives ...

  14. Breed base representation in dairy animals of 5 breeds

    Science.gov (United States)

    Inheritance of DNA from different dairy breeds can be determined by genotyping, just as individual ancestors such as parents, grandparents, or even great grandparents can be identified correctly in a high percentage of the cases by genotyping even if not reported or reported incorrectly in pedigrees...

  15. The immune strategies of mosquito Aedes aegypti against microbial infection.

    Science.gov (United States)

    Wang, Yan-Hong; Chang, Meng-Meng; Wang, Xue-Li; Zheng, Ai-Hua; Zou, Zhen

    2018-06-01

    Yellow fever mosquito Aedes aegypti transmits many devastating arthropod-borne viruses (arboviruses), such as dengue virus, yellow fever virus, Chikungunya virus, and Zika virus, which cause great concern to human health. Mosquito control is an effective method to block the spread of infectious diseases. Ae. aegypti uses its innate immune system to fight against arboviruses, parasites, and fungi. In this review, we briefly summarize the recent findings in the immune response of Ae. aegypti against arboviral and entomopathogenic infections. This review enriches our understanding of the mosquito immune system and provides evidence to support the development of novel mosquito control strategies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Vector competence of Anopheles and Culex mosquitoes for Zika virus

    Directory of Open Access Journals (Sweden)

    Brittany L. Dodson

    2017-03-01

    Full Text Available Zika virus is a newly emergent mosquito-borne flavivirus that has caused recent large outbreaks in the new world, leading to dramatic increases in serious disease pathology including Guillain-Barre syndrome, newborn microcephaly, and infant brain damage. Although Aedes mosquitoes are thought to be the primary mosquito species driving infection, the virus has been isolated from dozens of mosquito species, including Culex and Anopheles species, and we lack a thorough understanding of which mosquito species to target for vector control. We exposed Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes to blood meals supplemented with two Zika virus strains. Mosquito bodies, legs, and saliva were collected five, seven, and 14 days post blood meal and tested for infectious virus by plaque assay. Regardless of titer, virus strain, or timepoint, Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes were refractory to Zika virus infection. We conclude that Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes likely do not contribute significantly to Zika virus transmission to humans. However, future studies should continue to explore the potential for other novel potential vectors to transmit the virus.

  17. DsRed2 transient expression in Culex quinquefasciatus mosquitoes

    Directory of Open Access Journals (Sweden)

    Andre Barretto Bruno Wilke

    2013-06-01

    Full Text Available Culex quinquefasciatus mosquitoes have been successfully genetically modified only once, despite the efforts of several laboratories to transform and establish a stable strain. We have developed a transient gene expression method, in Culex, that delivers plasmid DNA directly to the mosquito haemolymph and additional tissues. We were able to express DsRed2 fluorescent protein in adult Cx. quinquefasciatus mosquitoes by injecting plasmids directly into their thorax. The expression of DsRed2 in adult Cx. quinquefasciatus mosquitoes is an important stepping stone to genetic transformation and the potential use of new control strategies and genetic interactions.

  18. Low persistence of Bacillus thuringiensis serovar israelensis spores in four mosquito biotopes of a salt marsh in southern France.

    Science.gov (United States)

    Hajaij, Myriam; Carron, Alexandre; Deleuze, Julien; Gaven, Bruno; Setier-Rio, Marie-Laure; Vigo, Gerard; Thiéry, Isabelle; Nielsen-LeRoux, Christina; Lagneau, Christophe

    2005-11-01

    We studied the persistence of Bacillus thuringiensis serovar israelensis (Bti) in a typical breeding site of the mosquito Ochlerotatus caspius in a particularly sensitive salt marsh ecosystem following two Bti-based larvicidal applications (Vectobac 12AS, 1.95 L/ha). The treated area was composed of four larval biotopes that differed in terms of the most representative plant species (Sarcocornia fruticosa, Bolboschoenus maritimus, Phragmites australis, and Juncus maritimus) and the physical and chemical characteristics of the soil. We sampled water, soil, and plants at various times before and after the applications (from spring to autumn, 2001) and quantified the spores of B. thuringiensis (Bt) and Bacillus species. The B. cereus group accounted for between 0% and 20% of all Bacillus spp. before application depending on the larval biotope. No Bti were found before application. The variation in the quantity of bacilli during the mosquito breeding season depended more on the larval biotope than on the season or the larvicidal application. More bacilli were found in soil (10(4)-10(6) spores/g) than on plant samples (10(2)-10(4) spores/g). The abundance in water (10(5) to 10(7) spores/L) appeared to be correlated to the water level of the breeding site. The number of Bti spores increased just after application, after declining; no spores were detected in soil or water 3 months after application. However, low numbers of Bti spores were present on foliage from three of the four studied plant strata. In conclusion, the larvicidal application has very little impact on Bacillus spp. flora after one breeding season (two applications).

  19. Long lasting persistence of Bacillus thuringiensis Subsp. israelensis (Bti in mosquito natural habitats.

    Directory of Open Access Journals (Sweden)

    Mathieu Tilquin

    Full Text Available BACKGROUND: The detrimental effects of chemical insecticides on the environment and human health have lead to the call for biological alternatives. Today, one of the most promising solutions is the use of spray formulations based on Bacillus thuringiensis subsp. israelensis (Bti in insect control programs. As a result, the amounts of Bti spread in the environment are expected to increase worldwide, whilst the common belief that commercial Bti is easily cleared from the ecosystem has not yet been clearly established. METHODOLOGY/MAIN FINDINGS: In this study, we aimed to determine the nature and origin of the high toxicity toward mosquito larvae found in decaying leaf litter collected in several natural mosquito breeding sites in the Rhône-Alpes region. From the toxic fraction of the leaf litter, we isolated B. cereus-like bacteria that were further characterized as B. thuringiensis subsp. israelensis using PCR amplification of specific toxin genes. Immunological analysis of these Bti strains showed that they belong to the H14 group. We finally used amplified length polymorphism (AFLP markers to show that the strains isolated from the leaf litter were closely related to those present in the commercial insecticide used for field application, and differed from natural worldwide genotypes. CONCLUSIONS/SIGNIFICANCE: Our results raise the issue of the persistence, potential proliferation and environmental accumulation of human-spread Bti in natural mosquito habitats. Such Bti environmental persistence may lengthen the exposure time of insects to this bio-insecticide, thereby increasing the risk of resistance acquisition in target insects, and of a negative impact on non-target insects.

  20. Surveillance should be strengthened to improve epidemiological understandings of mosquito-borne Barmah Forest virus infection

    Directory of Open Access Journals (Sweden)

    David Durrheim

    2012-08-01

    Full Text Available Introduction: Barmah Forest virus (BFV is a mosquito-borne virus causing epidemic polyarthritis in Australia. This study used case follow-up of cases from the surveillance system to demonstrate that routinely collected BFV notification data were an unreliable indicator of the true location of exposure.Methods: BFV notifications from June 2001 to May 2011 were extracted from the New South Wales (NSW Notifiable Conditions Information Management System to study case distribution. Disease cluster analysis was performed using spatial scan statistics. Exposure history data were collected from cases notified in 2010 and 2011 to accurately determine travel to high-risk areas.Results: Cluster analysis using address data identified an area of increased BFV disease incidence in the mid-north coast of NSW contiguous with estuarine wetlands. When travel to this area was investigated, 96.7% (29/30 cases reported having visited coastal regions within four weeks of developing symptoms.Discussion: Along the central NSW coastline, extensive wetlands occur in close proximity to populated areas. These wetlands provide ideal breeding habitats for a range of mosquito species implicated in the transmission of BFV. This is the first study to fully assess case exposure with findings suggesting that sporadic cases of BFV in people living further away from the coast do not reflect alternative exposure sites but are likely to result from travel to coastal regions. Spatial analysis by case address alone may lead to inaccurate understandings of the true distribution of arboviral diseases. Subsequently, this information has important implications for the collection of mosquito-borne disease surveillance information and public health response strategies.

  1. Landscape movements of Anopheles gambiae malaria vector mosquitoes in rural Gambia.

    Directory of Open Access Journals (Sweden)

    Christopher J Thomas

    Full Text Available BACKGROUND: For malaria control in Africa it is crucial to characterise the dispersal of its most efficient vector, Anopheles gambiae, in order to target interventions and assess their impact spatially. Our study is, we believe, the first to present a statistical model of dispersal probability against distance from breeding habitat to human settlements for this important disease vector. METHODS/PRINCIPAL FINDINGS: We undertook post-hoc analyses of mosquito catches made in The Gambia to derive statistical dispersal functions for An. gambiae sensu lato collected in 48 villages at varying distances to alluvial larval habitat along the River Gambia. The proportion dispersing declined exponentially with distance, and we estimated that 90% of movements were within 1.7 km. Although a 'heavy-tailed' distribution is considered biologically more plausible due to active dispersal by mosquitoes seeking blood meals, there was no statistical basis for choosing it over a negative exponential distribution. Using a simple random walk model with daily survival and movements previously recorded in Burkina Faso, we were able to reproduce the dispersal probabilities observed in The Gambia. CONCLUSIONS/SIGNIFICANCE: Our results provide an important quantification of the probability of An. gambiae s.l. dispersal in a rural African setting typical of many parts of the continent. However, dispersal will be landscape specific and in order to generalise to other spatial configurations of habitat and hosts it will be necessary to produce tractable models of mosquito movements for operational use. We show that simple random walk models have potential. Consequently, there is a pressing need for new empirical studies of An. gambiae survival and movements in different settings to drive this development.

  2. Rose breeding: past, present, prospects

    NARCIS (Netherlands)

    Vries, de D.P.; Dubois, L.A.M.

    1996-01-01

    In this review the PAST, PRESENT and PROSPECT will be considered as three separate periods in the history of the breeding and development of rose cultivars. The recurring theme is the genetic variation. This theme was chosen because there is justified doubt as to sufficient genetic variation

  3. Induced mutations in sesame breeding

    International Nuclear Information System (INIS)

    Ashri, A.

    2001-01-01

    The scope of induced mutations in sesame (Sesamum indicum L.) breeding is reviewed. So far in Egypt, India, Iraq, Rep. of Korea, and Sri Lanka, 14 officially released varieties have been developed through induced mutations: 12 directly and 2 through cross breeding (one using the 'dt45' induced mutant from Israel). For another variety released in China there are no details. The induced mutations approach was adopted primarily in order to obtain genetic variability that was not available in the germplasm collection. The mutagens commonly applied have been gamma rays, EMS and sodium azide. Sesame seeds can withstand high mutagen doses, and there are genotypic differences in sensitivity between varieties. The mutants induced in the above named countries and others include better yield, improved seed retention, determinate habit, modified plant architecture and size, more uniform and shorter maturation period, earliness, resistance to diseases, genic male sterility, seed coat color, higher oil content and modified fatty acids composition. Some of the induced mutants have already given rise to improved varieties, the breeding value of other mutants is now being assessed and still others can serve as useful markers in genetic studies and breeding programmes. (author)

  4. Decreased toxicity of Bacillus thuringiensis subsp. israelensis to mosquito larvae after contact with leaf litter.

    Science.gov (United States)

    Tetreau, Guillaume; Stalinski, Renaud; Kersusan, Dylann; Veyrenc, Sylvie; David, Jean-Philippe; Reynaud, Stéphane; Després, Laurence

    2012-08-01

    Bacillus thuringiensis subsp. israelensis is a bacterium producing crystals containing Cry and Cyt proteins, which are toxic for mosquito larvae. Nothing is known about the interaction between crystal toxins and decaying leaf litter, which is a major component of several mosquito breeding sites and represents an important food source. In the present work, we investigated the behavior of B. thuringiensis subsp. israelensis toxic crystals sprayed on leaf litter. In the presence of leaf litter, a 60% decrease in the amount of Cyt toxin detectable by immunology (enzyme-linked immunosorbent assays [ELISAs]) was observed, while the respective proportions of Cry toxins were not affected. The toxicity of Cry toxins toward Aedes aegypti larvae was not affected by leaf litter, while the synergistic effect of Cyt toxins on all B. thuringiensis subsp. israelensis Cry toxins was decreased by about 20% when mixed with leaf litter. The toxicity of two commercial B. thuringiensis subsp. israelensis strains (VectoBac WG and VectoBac 12AS) and a laboratory-produced B. thuringiensis subsp. israelensis strain decreased by about 70% when mixed with leaf litter. Taken together, these results suggest that Cyt toxins interact with leaf litter, resulting in a decreased toxicity of B. thuringiensis subsp. israelensis in litter-rich environments and thereby dramatically reducing the efficiency of mosquitocidal treatments.

  5. Molecular data reveal a cryptic species within the Culex pipiens mosquito complex.

    Science.gov (United States)

    Dumas, E; Atyame, C M; Malcolm, C A; Le Goff, G; Unal, S; Makoundou, P; Pasteur, N; Weill, M; Duron, O

    2016-12-01

    The Culex pipiens mosquito complex is a group of evolutionarily closely related species including C. pipiens and Culex quinquefasciatus, both infected by the cytoplasmically inherited Wolbachia symbiont. A Wolbachia-uninfected population of C. pipiens was however described in South Africa and was recently proposed to represent a cryptic species. In this study, we reconsidered the existence of this species by undertaking an extensive screening for the presence of Wolbachia-uninfected C. pipiens specimens and by characterizing their genetic relatedness with known members of the complex. We first report on the presence of Wolbachia-uninfected specimens in several breeding sites. We next confirm that these uninfected specimens unambiguously belong to the C. pipiens complex. Remarkably, all uninfected specimens harbour mitochondrial haplotypes that are either novel or identical to those previously found in South Africa. In all cases, these mitochondrial haplotypes are closely related, but different, to those found in other C. pipiens complex members known to be infected by Wolbachia. Altogether, these results corroborate the presence of a widespread cryptic species within the C. pipiens species complex. The potential role of this cryptic C. pipiens species in the transmission of pathogens remains however to be determined. The designation 'Culex juppi nov. sp.' is proposed for this mosquito species. © 2016 The Royal Entomological Society.

  6. Decreased Toxicity of Bacillus thuringiensis subsp. israelensis to Mosquito Larvae after Contact with Leaf Litter

    Science.gov (United States)

    Stalinski, Renaud; Kersusan, Dylann; Veyrenc, Sylvie; David, Jean-Philippe; Reynaud, Stéphane; Després, Laurence

    2012-01-01

    Bacillus thuringiensis subsp. israelensis is a bacterium producing crystals containing Cry and Cyt proteins, which are toxic for mosquito larvae. Nothing is known about the interaction between crystal toxins and decaying leaf litter, which is a major component of several mosquito breeding sites and represents an important food source. In the present work, we investigated the behavior of B. thuringiensis subsp. israelensis toxic crystals sprayed on leaf litter. In the presence of leaf litter, a 60% decrease in the amount of Cyt toxin detectable by immunology (enzyme-linked immunosorbent assays [ELISAs]) was observed, while the respective proportions of Cry toxins were not affected. The toxicity of Cry toxins toward Aedes aegypti larvae was not affected by leaf litter, while the synergistic effect of Cyt toxins on all B. thuringiensis subsp. israelensis Cry toxins was decreased by about 20% when mixed with leaf litter. The toxicity of two commercial B. thuringiensis subsp. israelensis strains (VectoBac WG and VectoBac 12AS) and a laboratory-produced B. thuringiensis subsp. israelensis strain decreased by about 70% when mixed with leaf litter. Taken together, these results suggest that Cyt toxins interact with leaf litter, resulting in a decreased toxicity of B. thuringiensis subsp. israelensis in litter-rich environments and thereby dramatically reducing the efficiency of mosquitocidal treatments. PMID:22610426

  7. Effects of intraspecific larval competition on adult longevity in the mosquitoes Aedes aegypti and Aedes albopictus.

    Science.gov (United States)

    Reiskind, M H; Lounibos, L P

    2009-03-01

    Larval competition is common in container-breeding mosquitoes. The impact of competition on larval growth has been thoroughly examined and findings that larval competition can lead to density-dependent effects on adult body size have been documented. The effects of larval competition on adult longevity have been less well explored. The effects of intraspecific larval densities on the longevity of adults maintained under relatively harsh environmental conditions were tested in the laboratory by measuring the longevity of adult Aedes aegypti (L.) and Aedes albopictus (Skuse) (Diptera: Culicidae) that had been reared under a range of larval densities and subsequently maintained in high- or low-humidity regimes (85% or 35% relative humidity [RH], respectively) as adults. We found significant negative effects of competition on adult longevity in Ae. aegypti, but not in Ae. albopictus. Multivariate analysis of variance suggested that the negative effect of the larval environment on the longevity of Ae. aegypti adults was most strongly associated with increased development time and decreased wing length as adults. Understanding how larval competition affects adult longevity under a range of environmental conditions is important in establishing the relationship between models of mosquito population regulation and epidemiological models of vector-borne disease transmission.

  8. Anopheles (Anopheles) petragnani Del Vecchio 1939-a new mosquito species for Germany.

    Science.gov (United States)

    Becker, Norbert; Pfitzner, Wolf Peter; Czajka, Christina; Kaiser, Achim; Weitzel, Thomas

    2016-07-01

    The so far known species of the Anopheles Claviger Complex, Anopheles claviger s.s. and Anopheles petragnani, can only be distinguished by partial overlapping characteristics of immature stages and by nucleotide sequence variation of the genomic ribosomal DNA (rDNA) internal transcribed spacer 2 (ITS2) region. The known distribution of An. petragnani is so far restricted to the western Mediterranean region, whereas An. claviger s.s. occurs across most of Europe, up to the Middle East and North Africa. In our study, we investigated the larval mosquito fauna in rock pools of the Murg valley (Black Forest, Germany) once a month from April to December 2015.Among other species, larvae belonging to the Anopheles Claviger Complex were found. The fourth instar larvae were morphologically identified by chaetotaxy of the head and abdomen. The results were confirmed by a multiplex PCR and additional sequencing of the amplificates.Of the 1289 collected larvae from the rock pools, seven belonged to the Anopheles Claviger Complex. Five individuals were determined morphologically as An. petragnani and two as An. claviger s.s. The associated mosquito fauna comprised of Aedes japonicus japonicus (548 individuals), Culex pipiens s.l. and Culex torrentium (493 individuals) and Culex hortensis (241 individuals).This is the first record of An. petragnani north of the Alps. Further studies will reveal whether this is an isolated population of An. petragnani and if the investigated rock pool breeding sites represent typical habitats of this species in temperate regions in Central Europe.

  9. Mosquito diversity in Keeriparai and Mundanthurai hill ranges of the Western Ghats, southern India

    Directory of Open Access Journals (Sweden)

    A. Munirathinam

    2015-07-01

    Full Text Available After a gap of 25 years the Centre for Research in Medical Entomology (CRME surveyed the mosquito biodiversity in the tail-end hill ranges of the Western Ghats, viz., Kanyakumari (Keeriparai and Tirunelveli districts (Kalakkad-Mundanthurai Tiger Reserve (KMTR and Courtallam of Tamil Nadu between July 2010 and June 2013.  The altitude of the hills ranged from 100–950 m covered by evergreen forests.  A major emphasis was given to collect the immature stages of mosquitoes, from various breeding habitats, viz., slow flowing streams, spring pool, rocky pool, leaf axils, latex cup, tree hole, bamboo stumps, etc.  Altogether 4602 immature individuals were collected, reared individually to be identified at the adult stage.  A total of 3583 specimens belonging to 50 species classified under 21 genera and 18 subgenera were recorded.  The major vector species found in these hill ranges were Stegomyia aegypti, S. albopicta (Dengue and Chikungunya, Culex bitaeniorhynchus, C. tritaeniorhynchus (Japanese encephalitis, Downsiomyia nivea (diurnally subperiodic filariasis and Anopheles mirans (Simian malaria vectors were recorded. 

  10. Impacts of the creation, expansion and management of English wetlands on mosquito presence and abundance - developing strategies for future disease mitigation.

    Science.gov (United States)

    Medlock, Jolyon M; Vaux, Alexander G C

    2015-03-03

    The incidence of mosquito-borne diseases is increasing in Europe, partly due to the incursion of a number of invasive species known to be vectors of dengue and chikungunya viruses, but also due to the involvement of native species in the transmission of West Nile virus and malaria. For some of these pathogens, there is a risk of the re-emergence of vector-borne diseases that were once widespread in Europe, but declined partly due to large-scale land-drainage projects. Some mosquito species exploit container habitats as breeding sites in urban areas; an adaptation to human-made micro-habitats resulting from increased urbanisation. However, many species thrive in natural wetland ecosystems. Owing to the impacts of climate change there is an urgent need for environmental adaptation, such as the creation of new wetlands to mitigate coastal and inland flooding. In some cases, these initiatives can be coupled with environmental change strategies to protect a range of endangered flora and fauna species by enhancing and extending wetland landscapes, which may by driven by European legislation, particularly in urban areas. This paper reviews field studies conducted in England to assess the impact of newly created wetlands on mosquito colonisation in a) coastal, b) urban and c) arable reversion habitats. It also considers the impact of wetland management on mosquito populations and explores the implications of various water and vegetation management options on the range of British mosquito species. Understanding the impact of wetland creation and management strategies on mosquito prevalence and the potential risk of increasing the levels of nuisance or disease vector species will be crucial in informing health and well-being risk assessments, guiding targeted control, and anticipating the social effects of extreme weather and climate change. Although new wetlands will certainly extend aquatic habitats for mosquitoes, not all species will become a major nuisance or a vector

  11. Brazilian mosquito (Diptera: Culicidae fauna: I. Anopheles species from Porto Velho, Rondônia state, western Amazon, Brazil

    Directory of Open Access Journals (Sweden)

    Sirlei Antunes Morais

    2012-12-01

    Full Text Available This study contributes to knowledge of Anopheles species, including vectors of Plasmodium from the western Brazilian Amazon in Porto Velho, Rondônia State. The sampling area has undergone substantial environmental changes as a consequence of agricultural and hydroelectric projects, which have caused intensive deforestation and favored habitats for some mosquito species. The purpose of this study was to diagnose the occurrence of anopheline species from collections in three locations along an electric-power transmission line. Each locality was sampled three times from 2010 to 2011. The principal adult mosquitoes captured in Shannon trap were Anopheles darlingi, An. triannulatus, An. nuneztovari l.s., An.gilesi and An. costai. In addition, larvae were collected in ground breeding sites for Anopheles braziliensis, An. triannulatus, An. darlingi, An. deaneorum, An. marajoara, An. peryassui, An. nuneztovari l.s. and An. oswaldoi-konderi. Anopheles darlingi was the most common mosquito in the region. We discuss Culicidae systematics, fauna distribution, and aspects of malaria in altered habitats of the western Amazon.

  12. Brazilian mosquito (Diptera: Culicidae) fauna: I. Anopheles species from Porto Velho, Rondônia state, western Amazon, Brazil.

    Science.gov (United States)

    Morais, Sirlei Antunes; Urbinatti, Paulo Roberto; Sallum, Maria Anice Mureb; Kuniy, Adriana Akemi; Moresco, Gilberto Gilmar; Fernandes, Aristides; Nagaki, Sandra Sayuri; Natal, Delsio

    2012-12-01

    This study contributes to knowledge of Anopheles species, including vectors of Plasmodium from the western Brazilian Amazon in Porto Velho, Rondônia State. The sampling area has undergone substantial environmental changes as a consequence of agricultural and hydroelectric projects, which have caused intensive deforestation and favored habitats for some mosquito species. The purpose of this study was to diagnose the occurrence of anopheline species from collections in three locations along an electric-power transmission line. Each locality was sampled three times from 2010 to 2011. The principal adult mosquitoes captured in Shannon trap were Anopheles darlingi, An. triannulatus, An. nuneztovari l.s., An.gilesi and An. costai. In addition, larvae were collected in ground breeding sites for Anopheles braziliensis, An. triannulatus, An. darlingi, An. deaneorum, An. marajoara, An. peryassui, An. nuneztovari l.s. and An. oswaldoi-konderi. Anopheles darlingi was the most common mosquito in the region. We discuss Culicidae systematics, fauna distribution, and aspects of malaria in altered habitats of the western Amazon.

  13. [The recurring necessity of mosquito surveillance and research].

    Science.gov (United States)

    Kampen, Helge; Werner, Doreen

    2015-10-01

    Hematophagous arthropods and the diseases associated with them represent a growing threat to human and animal health in Europe. After the eradication of endemic malaria from Europe in the middle of the last century, there has been a resurgence of mosquitoes as significant vectors of disease agents under the influence of continuing globalisation, as exotic species and mosquito-borne pathogens are being introduced with increasing frequency. At present, southern Europe is particularly affected by disease outbreaks and cases, but invasive mosquito species, including efficient vectors, have also emerged in Germany. While there is considerable knowledge on the vector potential of many tropical and subtropical mosquito species, corresponding data on the indigenous mosquito species are scarce. Exceptions are the Anopheles species, which were already vectors of malaria parasites in historic Europe. It must be assumed, however, that many further indigenous species are able to transmit pathogens under certain conditions and will by all means gain vector competence under a scenario of climate warming. Thus, the permanent surveillance of mosquitoes and mosquito-borne disease agents is paramount for the purposes of conducting risk analyses and modelling, in addition to research work addressing the conditions of the spread of vectors and pathogens and of pathogen transmission. Only ample data can facilitate taking appropriate prophylactic action and designing control strategies. International health organizations have realised this and started to promote data collection on mosquitoes and mosquito-borne diseases in the EU. At a national levels, authorities are more reluctant, although, similar to other fields of health, it has been shown for mosquito-borne diseases that preventive measures are more cost-saving than disease case management and the coverage of follow-up costs. The present article is intended to illustrate the necessity of the re-intensification of mosquito

  14. Conservation priorities for Ethiopian sheep breeds combining threat status, breed merits and contributions to genetic diversity

    Directory of Open Access Journals (Sweden)

    Windig Jack J

    2008-07-01

    Full Text Available Abstract Prioritizing livestock breeds for conservation needs to incorporate both genetic and non-genetic aspects important for the survival of the breeds. Here, we apply a maximum-utility-strategy to prioritize 14 traditional Ethiopian sheep breeds based on their threat status, contributions to farmer livelihoods (current breed merits and contributions to genetic diversity. Contributions of the breeds to genetic diversity were quantified using Eding's marker-estimated kinship approaches. Non-genetic aspects included threats (e.g. low population size, low preferences by farmers and current merits (economic, ecological and cultural merits. Threat analysis identified eight of the 14 breeds as threatened. Analysis of current merits showed that sub-alpine and arid-lowland breeds contribute most to farmer livelihoods in comparison to other breeds. The highest contribution to the genetic diversity conserved was from the Simien breed. Simien showed high between-breed (low between-breed kinship = 0.04 as well as high within-breed diversity (low within-breed kinship = 0.09 and high HE = 0.73 and allelic richness = 6.83. We combined the results on threat status, current breed merits and contributions to genetic diversity to produce a ranking of the 14 breeds for conservation purposes. Our results balance the trade-offs between conserving breeds as insurance against future uncertainties and current sustainable utilization. The ranking of breeds provides a basis for conservation strategies for Ethiopian sheep and contributes to a regional or global conservation plan.

  15. Ecological problems in horse-breeding

    Directory of Open Access Journals (Sweden)

    Y. V. Zachinyaew

    2005-05-01

    Full Text Available In the article is represented general information devoted to environmental problems in the horse- breeding. The concept of development of ecological explorations in the horse-breeding is considered as well.

  16. Breeding for behavioural change in farm animails

    DEFF Research Database (Denmark)

    Sandøe, Peter; D'eath, RB; Lawrence, AB

    2009-01-01

    In farm animal breeding, behavioural traits are rarely included in selection programmes despite their potential to improve animal production and welfare. Breeding goals have been broadened beyond production traits in most farm animal species to include health and functional traits...

  17. Breeding for behavioural change in farm animals

    DEFF Research Database (Denmark)

    D'Eath, R.B.; Conington, J.; Lawrence, A.B.

    2010-01-01

    In farm animal breeding, behavioural traits are rarely included in selection programmes despite their potential to improve animal production and welfare. Breeding goals have been broadened beyond production traits in most farm animal species to include health and functional traits...

  18. Cedrol, a malaria mosquito oviposition attractant is produced by fungi isolated from rhizomes of the grass Cyperus rotundus.

    Science.gov (United States)

    Eneh, Lynda K; Saijo, Hiromi; Borg-Karlson, Anna-Karin; Lindh, Jenny M; Rajarao, Gunaratna Kuttuva

    2016-09-17

    Cedrol, a sesquiterpene alcohol, is the first identified oviposition attractant for African malaria vectors. Finding the natural source of this compound might help to elucidate why Anopheles gambiae and Anopheles arabiensis prefer to lay eggs in habitats containing it. Previous studies suggest that cedrol may be a fungal metabolite and the essential oil of grass rhizomes have been described to contain a high amount of different sesquiterpenes. Rhizomes of the grass Cyperus rotundus were collected in a natural malaria mosquito breeding site. Two fungi were isolated from an aqueous infusion with these rhizomes. They were identified as Fusarium falciforme and a species in the Fusarium fujikuroi species complex. Volatile compounds were collected from the headspace above fungal cultures on Tenax traps which were analysed by gas chromatography-mass spectrometry (GCMS). Cedrol and a cedrol isomer were detected in the headspace above the F. fujikuroi culture, while only cedrol was detected above the F. falciforme culture. Cedrol an oviposition attractant for African malaria vectors is produced by two fungi species isolated from grass rhizomes collected from a natural mosquito breeding site.

  19. Plant breeding and genetics newsletter. No. 2

    International Nuclear Information System (INIS)

    1998-12-01

    This is the second issue of the Plant Breeding and Genetics Newsletter. The Newsletter will inform you about current activities of the FAO/IAEA sub-programme on plant breeding and genetics which is implemented by the Plant Breeding and Genetics Section of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture (Vienna) in close collaboration with the Plant Breeding Unit of the FAO/IAEA Agriculture and Biotechnology Laboratory (Seibersdorf)

  20. Plant breeding and genetics newsletter. No. 1

    International Nuclear Information System (INIS)

    1998-05-01

    This is the first issue of the Plant Breeding and Genetics Newsletter. The Newsletter will inform you about current activities of the FAO/IAEA sub-programme on plant breeding and genetics which is implemented by the Plant Breeding and Genetics Section of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture (Vienna) in close collaboration with the Plant Breeding Unit of the FAO/IAEA Agriculture and Biotechnology Laboratory (Seibersdorf)

  1. Genomics-assisted breeding in fruit trees

    OpenAIRE

    Iwata, Hiroyoshi; Minamikawa, Mai F.; Kajiya-Kanegae, Hiromi; Ishimori, Motoyuki; Hayashi, Takeshi

    2016-01-01

    Recent advancements in genomic analysis technologies have opened up new avenues to promote the efficiency of plant breeding. Novel genomics-based approaches for plant breeding and genetics research, such as genome-wide association studies (GWAS) and genomic selection (GS), are useful, especially in fruit tree breeding. The breeding of fruit trees is hindered by their long generation time, large plant size, long juvenile phase, and the necessity to wait for the physiological maturity of the pl...

  2. Breeding sites of Phlebotomus sergenti, the sand fly vector of cutaneous leishmaniasis in the Judean Desert.

    Science.gov (United States)

    Moncaz, Aviad; Faiman, Roy; Kirstein, Oscar; Warburg, Alon

    2012-01-01

    Phlebotomine sand flies transmit Leishmania, phlebo-viruses and Bartonella to humans. A prominent gap in our knowledge of sand fly biology remains the ecology of their immature stages. Sand flies, unlike mosquitoes do not breed in water and only small numbers of larvae have been recovered from diverse habitats that provide stable temperatures, high humidity and decaying organic matter. We describe studies designed to identify and characterize sand fly breeding habitats in a Judean Desert focus of cutaneous leishmaniasis. To detect breeding habitats we constructed emergence traps comprising sand fly-proof netting covering defined areas or cave openings. Large size horizontal sticky traps within the confined spaces were used to trap the sand flies. Newly eclosed male sand flies were identified based on their un-rotated genitalia. Cumulative results show that Phlebotomus sergenti the vector of Leishmania tropica rests and breeds inside caves that are also home to rock hyraxes (the reservoir hosts of L. tropica) and several rodent species. Emerging sand flies were also trapped outside covered caves, probably arriving from other caves or from smaller, concealed cracks in the rocky ledges close by. Man-made support walls constructed with large boulders were also identified as breeding habitats for Ph. sergenti albeit less important than caves. Soil samples obtained from caves and burrows were rich in organic matter and salt content. In this study we developed and put into practice a generalized experimental scheme for identifying sand fly breeding habitats and for assessing the quantities of flies that emerge from them. An improved understanding of sand fly larval ecology should facilitate the implementation of effective control strategies of sand fly vectors of Leishmania.

  3. Breeding sites of Phlebotomus sergenti, the sand fly vector of cutaneous leishmaniasis in the Judean Desert.

    Directory of Open Access Journals (Sweden)

    Aviad Moncaz

    Full Text Available Phlebotomine sand flies transmit Leishmania, phlebo-viruses and Bartonella to humans. A prominent gap in our knowledge of sand fly biology remains the ecology of their immature stages. Sand flies, unlike mosquitoes do not breed in water and only small numbers of larvae have been recovered from diverse habitats that provide stable temperatures, high humidity and decaying organic matter. We describe studies designed to identify and characterize sand fly breeding habitats in a Judean Desert focus of cutaneous leishmaniasis. To detect breeding habitats we constructed emergence traps comprising sand fly-proof netting covering defined areas or cave openings. Large size horizontal sticky traps within the confined spaces were used to trap the sand flies. Newly eclosed male sand flies were identified based on their un-rotated genitalia. Cumulative results show that Phlebotomus sergenti the vector of Leishmania tropica rests and breeds inside caves that are also home to rock hyraxes (the reservoir hosts of L. tropica and several rodent species. Emerging sand flies were also trapped outside covered caves, probably arriving from other caves or from smaller, concealed cracks in the rocky ledges close by. Man-made support walls constructed with large boulders were also identified as breeding habitats for Ph. sergenti albeit less important than caves. Soil samples obtained from caves and burrows were rich in organic matter and salt content. In this study we developed and put into practice a generalized experimental scheme for identifying sand fly breeding habitats and for assessing the quantities of flies that emerge from them. An improved understanding of sand fly larval ecology should facilitate the implementation of effective control strategies of sand fly vectors of Leishmania.

  4. Ecological aspects for application of genetically modified mosquitoes

    NARCIS (Netherlands)

    Takken, W.; Scott, T.W.; Rogers, R.J.

    2003-01-01

    The idea of using genetically modified mosquitoes (GMM) to reduce vector-borne diseases is founded on the notion that genetic constructs that will render mosquitoes incapable of pathogen transmission can be driven into vector populations. Conceptually, this is an exciting and novel approach to

  5. Biological control agent for mosquito larvae: Review on the killifish ...

    African Journals Online (AJOL)

    Jane

    2011-08-15

    Aug 15, 2011 ... Biological control of mosquito larvae by using fish has shown many advantages over ... number of malaria cases in India that has been reduced from 75 million to 150,000 and deaths from 750,000 to ... aquatic weeds and G. affinis on the mosquito larvae. In addition to that G. affinis has some adverse effects ...

  6. Relative abundance of mosquito species in Katsina Metropolis ...

    African Journals Online (AJOL)

    A study was conducted on the relative abundance of mosquito species, around selected areas of Katsina metropolis, Katsina State, Nigeria during the months of January, February, April and June 2010. Mosquitoes were collected from five sampling sites: Kofar Durbi, Kofar Kaura, Kofar Marusa, GRA and Layout. These were ...

  7. Statistical Survey of Mosquito Vectors in the Vicinity of Waldhuni ...

    African Journals Online (AJOL)

    Mosquitoes are one of the most medically significant vectors, and they transmit parasites and pathogens, which have major impact on the human population. The vector borne diseases caused by mosquitoes, such as dengue, malaria, yellow fever, chickungunya and filariasis, the major health problems in India.

  8. Insecticide susceptibility status of human biting mosquitoes in ...

    African Journals Online (AJOL)

    This situation presents a challenge to chemicals that are currently used to control mosquitoes in sub-Saharan African. Furthermore, there is limited ... Results: Mosquito species tested were Anopheles gambiae s.l., An. funestus, Aedes aegypti, and Culex quinquefasciatus species. Real-time PCR have showed that the main ...

  9. Environmental statistical modelling of mosquito vectors at different geographical scales

    NARCIS (Netherlands)

    Cianci, D.

    2015-01-01

    Vector-borne diseases are infections transmitted by the bite of infected arthropod vectors, such as mosquitoes, ticks, fleas, midges and flies. Vector-borne diseases pose an increasingly wider threat to global public health, both in terms of people affected and their geographical spread. Mosquitoes

  10. Advances in insect physiology. Progress in mosquito research

    Science.gov (United States)

    This book review briefly summarizes the most interesting topics/chapters from the book: "Advances in Insect Physiology: Progress in mosquito Research". The book is an excellent overview of the recent advances in mosquito biology. This volume encompasses 13 chapters from 32 contributing authors who ...

  11. Mosquitoes as vectors of human disease in South Africa | Jupp ...

    African Journals Online (AJOL)

    While malaria is the most important mosquito-borne disease in South Africa, there are also several mosquito-borne viruses that also cause human disease. The most significant are chikungunya, West Nile, Sindbis and Rift Valley fever viruses. In this review these are compared with malaria, mainly in regard to their ecology ...

  12. Mosquito fauna of a tropical museum and zoological garden complex

    African Journals Online (AJOL)

    The mosquito fauna of Museum and Zoological Garden Complex (JZC), a major tourist attraction inJos Metropolis of Nigeria, was studied The choice of the complex was out of public health curiosity. A total of 627 mosquitoes comprising 4 genera, Aedes, Culex, Coquilletidia and Eretmapodites, and9 species were caught n ...

  13. Analysis of a malaria model with mosquito-dependent transmission ...

    Indian Academy of Sciences (India)

    parasites in their blood stream and can pass the infection to mosquitoes. After sometime they lose their immunity and return to the susceptible class. Humans leave the population through emigration from one class to the other or by natural death. The mosquito population N2 is divided into two classes: susceptible X2 and ...

  14. Crowdsourcing for large-scale mosquito (Diptera: Culicidae) sampling

    Science.gov (United States)

    Sampling a cosmopolitan mosquito (Diptera: Culicidae) species throughout its range is logistically challenging and extremely resource intensive. Mosquito control programmes and regional networks operate at the local level and often conduct sampling activities across much of North America. A method f...

  15. Genetic characterization of Zanskari breed of horse

    Indian Academy of Sciences (India)

    However, poor management of these animals has led to dilution of their characteristic features to some ex- ... animals of Zanskari breed from its breeding tract in Jammu and Kashmir state. About 10 ml of blood per ..... variation of Polish endangered Bilgoraj horses and two common horse breeds in microsatellite loci. J. Appl.

  16. Selective breeding in organic dairy production

    NARCIS (Netherlands)

    Nauta, W.J.

    2009-01-01

    Organic dairy farming started to take off in the early 1990s, when the European Union laid down organic standards for animal production. Until now, however, only incidental steps have been taken towards organic breeding and organic farmers mainly use breeding stock from conventional breeding

  17. Population structure of ice-breeding seals.

    Science.gov (United States)

    Davis, Corey S; Stirling, Ian; Strobeck, Curtis; Coltman, David W

    2008-07-01

    The development of population genetic structure in ice-breeding seal species is likely to be shaped by a combination of breeding habitat and life-history characteristics. Species that return to breed on predictable fast-ice locations are more likely to exhibit natal fidelity than pack-ice-breeding species, which in turn facilitates the development of genetic differentiation between subpopulations. Other aspects of life history such as geographically distinct vocalizations, female gregariousness, and the potential for polygynous breeding may also facilitate population structure. Based on these factors, we predicted that fast-ice-breeding seal species (the Weddell and ringed seal) would show elevated genetic differentiation compared to pack-ice-breeding species (the leopard, Ross, crabeater and bearded seals). We tested this prediction using microsatellite analysis to examine population structure of these six ice-breeding species. Our results did not support this prediction. While none of the Antarctic pack-ice species showed statistically significant population structure, the bearded seal of the Arctic pack ice showed strong differentiation between subpopulations. Again in contrast, the fast-ice-breeding Weddell seal of the Antarctic showed clear evidence for genetic differentiation while the ringed seal, breeding in similar habitat in the Arctic, did not. These results suggest that the development of population structure in ice-breeding phocid seals is a more complex outcome of the interplay of phylogenetic and ecological factors than can be predicted on the basis of breeding substrate and life-history characteristics.

  18. Field evaluation of herbal mosquito repellents.

    Science.gov (United States)

    Das, N G; Nath, D R; Baruah, I; Talukdar, P K; Das, S C

    1999-12-01

    Repellent properties of Zanthoxylum armatum DC. Syn. Z. alatum Roxb. (Timur), Curcuma aromatica (Jungli haldi) and Azadirachta indica (Neem) oils were evaluated against mosquitoes in mustard (Brassica sp.) and coconut (Cocos sp.) oil base and compared with synthetic repellent. Dimethyl phthalate (DMP) as standard. Timur and jungli haldi afforded better protection in the both the base at all the concentrations. Tepellents in mustard oil gave longer protection time than those in coconut oil. At 0.57 mg/cm2 concentration timur oil gave significantly higher protection both in mustard (445 min) as well as coconut oil (404 min) than the other repellents and DMP.

  19. Does polyandrous impede mosquito control by autocidal?

    Directory of Open Access Journals (Sweden)

    K.Jayaprakash

    2014-03-01

    Full Text Available Vector mosquito control by releasing genetically altered males has been attempted under the presumption that the females are monandrous. The present observation was through the sex–linked inheritance pattern of eye-colour and the estimation of polyandrous in in-vitro mating. A small proportion (18.2% of the female Anopheles stephensi population exhibited polyandrous on examination of 850 F1 adults when two types of males (white and black eyed where allowed to mate with homozygous white eyed females. The above results were discussed with relation to the consequences of the polyandrous trait in sterile insect technique, genetic control programmes.

  20. Extractos del diario de un mosquito moderno

    Directory of Open Access Journals (Sweden)

    Jesse B. Leslie

    1943-01-01

    que desempeñamos en la guerra con España. Matamos más soldados y produjimos más enfermedades, penalidades y devastación en el ejército que las mismas balas. No cabe duda de que nuestra reputación como combatientes es internacional y digna de la primera página de los diarios. ¿ En honor de quién y por qué creen ustedes que se bautizaron los botes y las flotas "Mosquito"?

  1. Emperor penguins breeding on iceshelves.

    Directory of Open Access Journals (Sweden)

    Peter T Fretwell

    Full Text Available We describe a new breeding behaviour discovered in emperor penguins; utilizing satellite and aerial-survey observations four emperor penguin breeding colonies have been recorded as existing on ice-shelves. Emperors have previously been considered as a sea-ice obligate species, with 44 of the 46 colonies located on sea-ice (the other two small colonies are on land. Of the colonies found on ice-shelves, two are newly discovered, and these have been recorded on shelves every season that they have been observed, the other two have been recorded both on ice-shelves and sea-ice in different breeding seasons. We conduct two analyses; the first using synthetic aperture radar data to assess why the largest of the four colonies, for which we have most data, locates sometimes on the shelf and sometimes on the sea-ice, and find that in years where the sea-ice forms late, the colony relocates onto the ice-shelf. The second analysis uses a number of environmental variables to test the habitat marginality of all emperor penguin breeding sites. We find that three of the four colonies reported in this study are in the most northerly, warmest conditions where sea-ice is often sub-optimal. The emperor penguin's reliance on sea-ice as a breeding platform coupled with recent concerns over changed sea-ice patterns consequent on regional warming, has led to their designation as "near threatened" in the IUCN red list. Current climate models predict that future loss of sea-ice around the Antarctic coastline will negatively impact emperor numbers; recent estimates suggest a halving of the population by 2052. The discovery of this new breeding behaviour at marginal sites could mitigate some of the consequences of sea-ice loss; potential benefits and whether these are permanent or temporary need to be considered and understood before further attempts are made to predict the population trajectory of this iconic species.

  2. A simple language to script and simulate breeding schemes: the breeding scheme language

    Science.gov (United States)

    It is difficult for plant breeders to determine an optimal breeding strategy given that the problem involves many factors, such as target trait genetic architecture and breeding resource availability. There are many possible breeding schemes for each breeding program. Although simulation study may b...

  3. High efficiency germ-line transformation of mosquitoes.

    Science.gov (United States)

    Lobo, Neil F; Clayton, John R; Fraser, Malcolm J; Kafatos, Fotis C; Collins, Frank H

    2006-01-01

    The ability to manipulate the mosquito genome through germ-line transformation provides us with a powerful tool for investigating gene structure and function. It is also a valuable method for the development of novel approaches to combating the spread of mosquito-vectored diseases. To date, germ-line transformation has been demonstrated in several mosquito species. Transgenes are introduced into pre-blastocyst mosquito embryos using microinjection techniques that take a few hours, and progeny are screened for the presence of a marker gene. The microinjection protocol presented here can be applied to most mosquitoes and contains several improvements over other published methods that increase the survival of injected embryos and, therefore, the number of transformants. Transgenic lines can be established in approximately 1 month using this technique.

  4. Variation in Aedes aegypti Mosquito Competence for Zika Virus Transmission.

    Science.gov (United States)

    Roundy, Christopher M; Azar, Sasha R; Rossi, Shannan L; Huang, Jing H; Leal, Grace; Yun, Ruimei; Fernandez-Salas, Ildefonso; Vitek, Christopher J; Paploski, Igor A D; Kitron, Uriel; Ribeiro, Guilherme S; Hanley, Kathryn A; Weaver, Scott C; Vasilakis, Nikos

    2017-04-01

    To test whether Zika virus has adapted for more efficient transmission by Aedes aegypti mosquitoes, leading to recent urban outbreaks, we fed mosquitoes from Brazil, the Dominican Republic, and the United States artificial blood meals containing 1 of 3 Zika virus strains (Senegal, Cambodia, Mexico) and monitored infection, dissemination, and virus in saliva. Contrary to our hypothesis, Cambodia and Mexica strains were less infectious than the Senegal strain. Only mosquitoes from the Dominican Republic transmitted the Cambodia and Mexica strains. However, blood meals from viremic mice were more infectious than artificial blood meals of comparable doses; the Cambodia strain was not transmitted by mosquitoes from Brazil after artificial blood meals, whereas 61% transmission occurred after a murine blood meal (saliva titers up to 4 log 10 infectious units/collection). Although regional origins of vector populations and virus strain influence transmission efficiency, Ae. aegypti mosquitoes appear to be competent vectors of Zika virus in several regions of the Americas.

  5. Mosquito Vectors and the Globalization of Plasmodium falciparum Malaria.

    Science.gov (United States)

    Molina-Cruz, Alvaro; Zilversmit, Martine M; Neafsey, Daniel E; Hartl, Daniel L; Barillas-Mury, Carolina

    2016-11-23

    Plasmodium falciparum malaria remains a devastating public health problem. Recent discoveries have shed light on the origin and evolution of Plasmodium parasites and their interactions with their vertebrate and mosquito hosts. P. falciparum malaria originated in Africa from a single horizontal transfer between an infected gorilla and a human, and became global as the result of human migration. Today, P. falciparum malaria is transmitted worldwide by more than 70 different anopheline mosquito species. Recent studies indicate that the mosquito immune system can be a barrier to malaria transmission and that the P. falciparum Pfs47 gene allows the parasite to evade mosquito immune detection. Here, we review the origin and globalization of P. falciparum and integrate this history with analysis of the biology, evolution, and dispersal of the main mosquito vectors. This new perspective broadens our understanding of P. falciparum population structure and the dispersal of important parasite genetic traits.

  6. Citizen Science as a Tool for Mosquito Control.

    Science.gov (United States)

    Jordan, Rebecca C; Sorensen, Amanda E; Ladeau, Shannon

    2017-09-01

    In this paper, we share our findings from a 2-year citizen science program called Mosquito Stoppers. This pest-oriented citizen science project is part of a larger coupled natural-human systems project seeking to understand the fundamental drivers of mosquito population density and spatial variability in potential exposure to mosquito-borne pathogens in a matrix of human construction, urban renewal, and individual behaviors. Focusing on residents in West Baltimore, participants were recruited through neighborhood workshops and festivals. Citizen scientists participated in yard surveys of potential mosquito habitat and in evaluating mosquito nuisance. We found that citizen scientists, with minimal education and training, were able to accurately collect data that reflect trends found in a comparable researcher-generated database.

  7. Community Movement in Applying Mosquito Net on House Ventilations: An Initial Support for Green Architecture to Decrease Dengue Disease in Bandung Indonesia

    Science.gov (United States)

    Rinawan, F. R.; Dewi, I. P. P.; Haifa, G. Z.; Suharno, K. D.; Oktavinus, K.; Lyn, P. S.

    2017-10-01

    Green architecture still has risk to dengue disease when trees cover house roofs’ gutter. This study was aimed to continue a geographical information system (GIS) and remote sensing (RS) study on roofs factor association with dengue disease by initiating community movement in applyingmosquito net on house ventilations to cut the disease transmission and mosquito breeding sites inside house. Our methods was an operational research in which improvement of interventions, policies and regulations towards dengue disease prevention is our intended endpoint. Several steps were conducted such as: (1) research problems formulation from GIS-RS analysis from previous phase research in Bandung city, (2) informal and formal approach to community leaders and primary healthcare centre (Puskesmas), (3) Video education and focus group discussion (FGD), (4) initial application of mosquito nets on house in communities; and (5) advocacy to Mayor of Bandung city (was on progress).Our study resulted several supports: one of sub-city leaders (Camat) in the city, village leaders (Lurah), and sub-village leaders (Ketua RW) of 5 villages (kelurahan), one kelurahan which mainly comprised formal settlements needed more efforts, which was experts on dengue disease from university to directly explain the mosquito nets application to its community. Informal leaders in all kelurahan’s community suggested only mothers movement was not enough, thus, youths in community was mentioned to help the community movement on the mosquito nets application.

  8. Schools as Potential Risk Sites for Vector-Borne Disease Transmission: Mosquito Vectors in Rural Schools in Two Municipalities in Colombia.

    Science.gov (United States)

    Olano, Víctor Alberto; Matiz, María Inés; Lenhart, Audrey; Cabezas, Laura; Vargas, Sandra Lucía; Jaramillo, Juan Felipe; Sarmiento, Diana; Alexander, Neal; Stenström, Thor Axel; Overgaard, Hans J

    2015-09-01

    Dengue and other vector-borne diseases are of great public health importance in Colombia. Vector surveillance and control activities are often focused at the household level. Little is known about the importance of nonhousehold sites, including schools, in maintaining vector-borne disease transmission. The objectives of this paper were to determine the mosquito species composition in rural schools in 2 municipalities in Colombia and to assess the potential risk of vector-borne disease transmission in school settings. Entomological surveys were carried out in rural schools during the dry and rainy seasons of 2011. A total of 12 mosquito species were found: Aedes aegypti, Anopheles pseudopunctipennis, Culex coronator, Cx. quinquefasciatus, and Limatus durhamii in both immature and adult forms; Ae. fluviatilis, Cx. nigripalpus, Cx. corniger, and Psorophora ferox in immature forms only; and Ae. angustivittatus, Haemagogus equinus, and Trichoprosopon lampropus in adult forms only. The most common mosquito species was Cx. quinquefasciatus. Classrooms contained the greatest abundance of adult female Ae. aegypti and Cx. quinquefasciatus. The most common Ae. aegypti breeding sites were containers classified as "others" (e.g., cans), followed by containers used for water storage. A high level of Ae. aegypti infestation was found during the wet season. Our results suggest that rural schools are potentially important foci for the transmission of dengue and other mosquito-borne diseases. We propose that public health programs should be implemented in rural schools to prevent vector-borne diseases.

  9. Current trends in plant breeding

    International Nuclear Information System (INIS)

    Jalani, B.S.; Rajanaidu, N.

    2000-01-01

    The current world population is 6 billion and it is likely to reach 7 billion in 2010 and 8 billion 2025. Sufficient food must be produced for the ever increasing human population. The available suitable land for intensive agriculture is limited. We have to produce more food from less land, pesticide, labour and water resources. Hence, increase in crop productivity are essential to feed the world in the next century. Plant breeding provides the avenue to increase the food production to feed the growing world population. Development of a cultivar involves (I) Construction of a genetic model (II) creating a gene pool (III) selection among plants and (IV) testing the selected genotypes for adaptation to the biotic and abiotic environments (Frey, 1999). This paper discusses the trends in plant breeding using the oil palm as a model. It covers (i) genetic resources (ii) physiological traits (III) exploitation of genotype x environment interaction (IV) oil palm clones, and (v) biotechnology application. (Author)

  10. Breeding quinoa (Chenopodium quinoa Willd.)

    DEFF Research Database (Denmark)

    Zurita-Silva, Andrés; Fuentes, Francisco; Zamora, Pablo

    2014-01-01

    Quinoa (Chenopodium quinoa Willd.) originated in the Andean region of South America; this species is associated with exceptional grain nutritional quality and is highly valued for its ability to tolerate abiotic stresses. However, its introduction outside the Andes has yet to take off on a large...... scale. In the Andes, quinoa has until recently been marginally grown by small-scale Andean farmers, leading to minor interest in the crop from urban consumers and the industry. Quinoa breeding programs were not initiated until the 1960s in the Andes, and elsewhere from the 1970s onwards. New molecular...... tools available for the existing quinoa breeding programs, which are critically examined in this review, will enable us to tackle the limitations of allotetraploidy and genetic specificities. The recent progress, together with the declaration of "The International Year of the Quinoa" by the Food...

  11. Assortative mating and fragmentation within dog breeds

    Directory of Open Access Journals (Sweden)

    Hailer Frank

    2008-01-01

    Full Text Available Abstract Background There are around 400 internationally recognized dog breeds in the world today, with a remarkable diversity in size, shape, color and behavior. Breeds are considered to be uniform groups with similar physical characteristics, shaped by selection rooted in human preferences. This has led to a large genetic difference between breeds and a large extent of linkage disequilibrium within breeds. These characteristics are important for association mapping of candidate genes for diseases and therefore make dogs ideal models for gene mapping of human disorders. However, genetic uniformity within breeds may not always be the case. We studied patterns of genetic diversity within 164 poodles and compared it to 133 dogs from eight other breeds. Results Our analyses revealed strong population structure within poodles, with differences among some poodle groups as pronounced as those among other well-recognized breeds. Pedigree analysis going three generations back in time confirmed that subgroups within poodles result from assortative mating imposed by breed standards as well as breeder preferences. Matings have not taken place at random or within traditionally identified size classes in poodles. Instead, a novel set of five poodle groups was identified, defined by combinations of size and color, which is not officially recognized by the kennel clubs. Patterns of genetic diversity in other breeds suggest that assortative mating leading to fragmentation may be a common feature within many dog breeds. Conclusion The genetic structure observed in poodles is the result of local mating patterns, implying that breed fragmentation may be different in different countries. Such pronounced structuring within dog breeds can increase the power of association mapping studies, but also represents a serious problem if ignored. In dog breeding, individuals are selected on the basis of morphology, behaviour, working or show purposes, as well as geographic

  12. Effect of deforestation and land use changes on mosquito productivity and development in western Kenya highlands: Implication for malaria Risk

    Directory of Open Access Journals (Sweden)

    Eliningaya Kweka

    2016-10-01

    Full Text Available Background: African highlands were known to be free of malaria for the past fifty years. However, the ever growing human population in the highlands of Africa have led to the deforestation and land coverage changes to create space for more land for cultivation, grazing and house construction materials needs. This has lead to creation of suitable breeding habitats which are in open places. Decrease of canopy and forest cover has led to increased temperature both in outdoors and indoors in deforested areas. This increased temperature has resulted in shortening of developmental stages of aquatic stages of mosquitoes and sporogony development in adult mosquitoes. Method: Assessment of the effects of deforestation and land coverage changes (decrease which leads to temperature changes and subsequently increases survivorship of adults and sporogony development in adult mosquitoes body was gathered from previous data collected from 2003 to 2012 using different analysis techniques. Habitats productivity, species dynamics and abundance, mosquitoes feeding rates and sporogony development are presented in relation to temperature changes.Results: The effects of temperature rise due to land cover changes in highlands of western Kenya on larval developmental rates, adult sporogony developments and malaria risk in human population were derived. Vector species dynamics and abundance in relation to land use changes have been found to change with time.Conclusion: This study found that, land cover changes is a key driver for the temperature rise in African highlands and increases the rate of malaria vectors Anopheles gambiae s.s , An. funestus and An. arabiensis colonising the highlands. It has also significantly enhanced sporogony development rate and adult vector survival and therefore the risk of malaria transmission in the highlands.

  13. Microsporidia parásitos de larvas de mosquito de la Costa Pacífica del Chocó

    Directory of Open Access Journals (Sweden)

    Zuluaga Juan S.

    1993-12-01

    Full Text Available Two genera of Microsporidia were found infecting mosquito larvae in three localities on the Pacific coast of Choco. Vavraia sp. (Microsporida: Pleistophoridae was found in larvae of Wyeomyia circumcincta, W. simmsi and Anopheles albimanus collected from plants of the Bromeliacea family in Arusí y Joví. Amblyospora sp. (Microsporida: Amblyosporidae was found parasitizingAedes angustivittatuslarvae COllectedfrom a terrestrial breeding pond in the locality of Nuqur. Morphology of the spores of the two parasites under light microscopy is described, as well as preliminary data on host range when exposed to laboratory rearad Aedes aegypti, Culex quinquefasciatus and Anopheles albimanus. Their rola in mosquito control is discussed.Se reportan dos géneros de microsporidia que parasitan larvas de mosquitos en criaderos naturales de tres localidades en la costa Pacffica Chocoana. Vavraia sp. (Microsporida: Pleistophoridae parásita larvas de Wyeomyia circumcincta, de Wyeomya simmsi y de Anopheles neivai, recolectadas en las rosetas de especies de la familia Bromeliaceae en las localidades de Arusí y Joví. Amblyospora sp. (Microsporida: Amblyosporidae parásita larvas deAedes angustivittatusde criaderos terrestres semipermanentes en la localidad de Nuquí. Se describe la morfología de estos dos microsporidia al microscopio óptico. Estudios preliminares de infección en larvas de Aedes aegypti, Culex quinquefasciatus yAnopheles albimanus, criadas en laboratorio, indican que Vavraia sp. infecta las tres especies, con preferencia a Culex quinquefasciatus. Las larvas expuestas a esporas de Amblyospora sp. no presentaron infección. Se discute el posible papel de estos dos géneros en el control de las poblaciones de mosquitos.

  14. How does competition among wild type mosquitoes influence the performance of Aedes aegypti and dissemination of Wolbachia pipientis?

    Directory of Open Access Journals (Sweden)

    Suellen de Oliveira

    2017-10-01

    Full Text Available Wolbachia has been deployed in several countries to reduce transmission of dengue, Zika and chikungunya viruses. During releases, Wolbachia-infected females are likely to lay their eggs in local available breeding sites, which might already be colonized by local Aedes sp. mosquitoes. Therefore, there is an urgent need to estimate the deleterious effects of intra and interspecific larval competition on mosquito life history traits, especially on the duration of larval development time, larval mortality and adult size.Three different mosquito populations were used: Ae. aegypti infected with Wolbachia (wMelBr strain, wild Ae. aegypti and wild Ae. albopictus. A total of 21 treatments explored intra and interspecific larval competition with varying larval densities, species proportions and food levels. Each treatment had eight replicates with two distinct food levels: 0.25 or 0.50 g of Chitosan and fallen avocado leaves. Overall, overcrowding reduced fitness correlates of the three populations. Ae. albopictus larvae presented lower larval mortality, shorter development time to adult and smaller wing sizes than Ae. aegypti. The presence of Wolbachia had a slight positive effect on larval biology, since infected individuals had higher survivorship than uninfected Ae. aegypti larvae.In all treatments, Ae. albopictus outperformed both wild Ae. aegypti and the Wolbachia-infected group in larval competition, irrespective of larval density and the amount of food resources. The major force that can slow down Wolbachia invasion is the population density of wild mosquitoes. Given that Ae. aegypti currently dominates in Rio, in comparison with Ae. albopictus frequency, additional attention must be given to the population density of Ae. aegypti during releases to increase the likelihood of Wolbachia invasion.

  15. Novel acetylcholinesterase target site for malaria mosquito control.

    Directory of Open Access Journals (Sweden)

    Yuan-Ping Pang

    2006-12-01

    Full Text Available Current anticholinesterase pesticides were developed during World War II and are toxic to mammals because they target a catalytic serine residue of acetylcholinesterases (AChEs in insects and in mammals. A sequence analysis of AChEs from 73 species and a three-dimensional model of a malaria-carrying mosquito (Anopheles gambiae AChE (AgAChE reported here show that C286 and R339 of AgAChE are conserved at the opening of the active site of AChEs in 17 invertebrate and four insect species, respectively. Both residues are absent in the active site of AChEs of human, monkey, dog, cat, cattle, rabbit, rat, and mouse. The 17 invertebrates include house mosquito, Japanese encephalitis mosquito, African malaria mosquito, German cockroach, Florida lancelet, rice leaf beetle, African bollworm, beet armyworm, codling moth, diamondback moth, domestic silkworm, honey bee, oat or wheat aphid, the greenbug, melon or cotton aphid, green peach aphid, and English grain aphid. The four insects are house mosquito, Japanese encephalitis mosquito, African malaria mosquito, and German cockroach. The discovery of the two invertebrate-specific residues enables the development of effective and safer pesticides that target the residues present only in mosquito AChEs rather than the ubiquitous serine residue, thus potentially offering an effective control of mosquito-borne malaria. Anti-AgAChE pesticides can be designed to interact with R339 and subsequently covalently bond to C286. Such pesticides would be toxic to mosquitoes but not to mammals.

  16. Mutation breeding newsletter. No. 41

    International Nuclear Information System (INIS)

    1994-07-01

    This newsletter contains short descriptions of research methods for the use of radiation to induce mutations and facilitate plant breeding. This method is used to develop species of plants that can survive in harsh climates and thus provide a food supply for humans and animals. Some of the mutants discussed include a salt tolerant barley, a disease resistant shrub, a cold tolerant chickpea, a highly productive Canavalia virosa and productive tomato. Refs, figs and tabs

  17. Mutation breeding newsletter. No. 38

    International Nuclear Information System (INIS)

    1991-12-01

    This issue contains a number of contributions from readers describing experiments in plant breeding (the individual items are indexed separately) and a report on the 30th Gamma-Field Symposium held in Tsukuba, Japan in July 1991. Also included is a list of officially released mutant varieties of seed-propagated crops taken from the FAO/IAEA database of mutant varieties. It is planned to organize a database on available crop plant mutant variety germplasm collections. Refs, figs and tabs

  18. Genomic selection in plant breeding.

    Science.gov (United States)

    Newell, Mark A; Jannink, Jean-Luc

    2014-01-01

    Genomic selection (GS) is a method to predict the genetic value of selection candidates based on the genomic estimated breeding value (GEBV) predicted from high-density markers positioned throughout the genome. Unlike marker-assisted selection, the GEBV is based on all markers including both minor and major marker effects. Thus, the GEBV may capture more of the genetic variation for the particular trait under selection.

  19. fat-tailed sheep breeds

    African Journals Online (AJOL)

    Barresi-e asar-e sen va Jens barehay-e zel- e mazanderan bar tavan-e parvari va khosusiat-e lasheh (Study of age and sex effects on growth performance and carcass characteristics of Mazanderan Zel sheep breed) pajuhesh va sazandegi 37, 97-. 99 (in Persian). McClinton, O.W. & Carson, A.F., 2000. Growth and carcass ...

  20. SOYBEAN - MOLECULAR ASPECTS OF BREEDING

    Directory of Open Access Journals (Sweden)

    Aleksandra Sudarić

    2012-12-01

    Full Text Available The book Soybean: Molecular Aspects of Breeding focuses recent progress in our understanding of the genetics and molecular biology of soybean. This book is divided into four parts and contains 22 chapters. Part I, Molecular Biology and Biotechnology focuses advances in molecular biology and laboratory procedures that have been developed recently to manipulate DNA. Part II, Breeding for abiotic stress covers proteomics approaches form as a powerful tool for investigating the molecular mechanisms of the plant responses to various types of abiotic stresses. Part III, Breeding for biotic stress addresses issues related to application of molecular based strategies in order to increase soybean resistance to various biotic factors. Part IV, Recent Technology reviews recent technologies into the realm of soybean monitoring, processing and product use. While the information accumulated in this book is of primary interest for plant breeders, valuable insights are also offered to agronomists, molecular biologists, physiologists, plant pathologists, food scientists and students. The book is a result of efforts made by many experts from different countries (USA, Japan, Croatia, Serbia, China, Canada, Malawi, Iran, Hong Kong, Brasil, Mexico.

  1. Charge Breeding of Radioactive Ions

    CERN Document Server

    Wenander, F J C

    2013-01-01

    Charge breeding is a technique to increase the charge state of ions, in many cases radioactive ions. The singly charged radioactive ions, produced in an isotope separator on-line facility, and extracted with a low kinetic energy of some tens of keV, are injected into a charge breeder, where the charge state is increased to Q. The transformed ions are either directed towards a dedicated experiment requiring highly charged ions, or post-accelerated to higher beam energies. In this paper the physics processes involved in the production of highly charged ions will be introduced, and the injection and extraction beam parameters of the charge breeder defined. A description of the three main charge-breeding methods is given, namely: electron stripping in gas jet or foil; external ion injection into an electron-beam ion source/trap (EBIS/T); and external ion injection into an electron cyclotron resonance ion source (ECRIS). In addition, some preparatory devices for charge breeding and practical beam delivery aspects ...

  2. Habitat productivity and pyrethroid susceptibility status of Aedes aegypti mosquitoes in Dar es Salaam, Tanzania.

    Science.gov (United States)

    Mathias, Leah; Baraka, Vito; Philbert, Anitha; Innocent, Ester; Francis, Filbert; Nkwengulila, Gamba; Kweka, Eliningaya J

    2017-06-09

    Aedes aegypti (Diptera: Culicidae) is the main vector of the dengue virus globally. Dengue vector control is mainly based on reducing the vector population through interventions, which target potential breeding sites. However, in Tanzania, little is known about this vector's habitat productivity and insecticide susceptibility status to support evidence-based implementation of control measures. The present study aimed at assessing the productivity and susceptibility status of A. aegypti mosquitoes to pyrethroid-based insecticides in Dar es Salaam, Tanzania. An entomological assessment was conducted between January and July 2015 in six randomly selected wards in Dar es Salaam, Tanzania. Habitat productivity was determined by the number of female adult A. aegypti mosquitoes emerged per square metre. The susceptibility status of adult A. aegypti females after exposure to 0.05% deltamethrin, 0.75% permethrin and 0.05% lambda-cyhalothrin was evaluated using the standard WHO protocols. Mortality rates were recorded after 24 h exposure and the knockdown effect was recorded at the time points of 10, 15, 20, 30, 40, 50 and 60 min to calculate the median knockdown times (KDT 50 and KDT 95 ). The results suggest that disposed tyres had the highest productivity, while water storage tanks had the lowest productivity among the breeding habitats Of A. aegypti mosquitoes. All sites demonstrated reduced susceptibility to deltamethrin (0.05%) within 24 h post exposure, with mortalities ranging from 86.3 ± 1.9 (mean ± SD) to 96.8 ± 0.9 (mean ± SD). The lowest and highest susceptibilities were recorded in Mikocheni and Sinza wards, respectively. Similarly, all sites demonstrated reduced susceptibility permethrin (0.75%) ranging from 83.1 ± 2.1% (mean ± SD) to 96.2 ± 0.9% (mean ± SD), in Kipawa and Sinza, respectively. Relatively low mortality rates were observed in relation to lambda-cyhalothrin (0.05%) at all sites, ranging from 83.1 ± 0

  3. Semen quality of Italian local pig breeds

    Directory of Open Access Journals (Sweden)

    G. Gandini

    2010-01-01

    Full Text Available From 1996 to 1999 a conservation programme was carried out within the framework of EC contract “European gene banking project for the pig genetic resources” (Ollivier et al., 2001 in the Italian local pig breeds. The aims of the program included the primary characterization of the breeds, i.e. information on the organization in charge of the breed, breeding population numbers, breed description and qualifications, and field trials on productive and reproductive performances. In this context the “Semen Bank of Italian local pig breeds” was built. A total of 30,835 straws of four Italian local pig breeds (Cinta Senese, Casertana, Mora Romagnola and Nero Siciliano, collected from 42 sires, have been stored. In this work semen quality traits, lipid composition and freezability of the four Italian local pig breeds are reported.

  4. Tracing {sup 13}C reveals the below ground connection between trees and fungi

    Energy Technology Data Exchange (ETDEWEB)

    Siegwolf, R.T.W.; Steinmann, K.; Saurer, M.; Koerner, Ch.

    2003-03-01

    Freshly assimilated atmospheric CO{sub 2} is transferred as sugars from the leaves into the whole organism. Since mycorrhiza fungi and tree roots are in an intensive symbiosis, the fungi provide important information about the tree internal carbon distribution. (author)

  5. Hot Cell Liners Category of Transuranic Waste Stored Below Ground within Area G

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Robert Wesley [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hargis, Kenneth Marshall [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-09-01

    A large wildfire called the Las Conchas Fire burned large areas near Los Alamos National Laboratory (LANL) in 2011 and heightened public concern and news media attention over transuranic (TRU) waste stored at LANL’s Technical Area 54 (TA-54) Area G waste management facility. The removal of TRU waste from Area G had been placed at a lower priority in budget decisions for environmental cleanup at LANL because TRU waste removal is not included in the March 2005 Compliance Order on Consent (Reference 1) that is the primary regulatory driver for environmental cleanup at LANL. The Consent Order is an agreement between LANL and the New Mexico Environment Department (NMED) that contains specific requirements and schedules for cleaning up historical contamination at the LANL site. After the Las Conchas Fire, discussions were held by the U.S. Department of Energy (DOE) with the NMED on accelerating TRU waste removal from LANL and disposing it at the Waste Isolation Pilot Plant (WIPP). This report summarizes available information on the origin, configuration, and composition of the waste containers within the Hot Cell Liners category; their physical and radiological characteristics; the results of the radioassays; and the justification to reclassify the five containers as LLW rather than TRU waste.

  6. Disentangling above- and below-ground competition between lianas and trees in a tropical forest

    NARCIS (Netherlands)

    Schnitzer, S.A.; Kuzee, M.E.; Bongers, F.J.J.M.

    2005-01-01

    1 Light is thought to be the most limiting resource in tropical forests, and thus aboveground competition is commonly accepted as the mechanism that structures these communities. In many tropical forests, trees compete not only with other trees, but also with lianas, which compete aggressively for

  7. Equivalence in the strength of deer herbivory on above and below ground communities

    DEFF Research Database (Denmark)

    Lessard, Jean-Philippe; Reynolds, W. Nicholas; Bunn, Windy A.

    2012-01-01

    that herbivory would alter the composition and diversity of communities, but the strength of the effects of herbivory would weaken from plants, to leaf-litter invertebrates, and to belowground microarthropod communities. First, we found that herbivory negatively impacted plant seedling and sapling abundance...... and performance, reduced the abundance of ants and the taxonomic richness of arthropods in the litter layer and reduced the richness of soil microarthropod communities. Second, in contrast to our hypothesis, the magnitude of effect size did not vary among trophic levels, indicating that effects of deer herbivory...... cascade from plants to the leaf-litter and soil arthropod communities with equal strength. While much recent research has focused on how specific traits of plants may mediate the effects of herbivory on associated species, our results suggest that indirect effects of herbivory might influence many...

  8. Completing below-ground carbon budgets for pastures, recovering forests, and mature forests of Amazonia

    Science.gov (United States)

    Davidson, Eric A.; Nepstad, Daniel C.; Trumbore, Susan E.

    1995-01-01

    This progress report covers the following efforts initiated for the year: year-round monthly soil CO2 flux measurements were started in both primary and secondary forests and in managed and degraded pastures; root sorting and weighing has begun and all four ecosystems at Paragominas have been analyzed through samples; regional modeling of soil water dynamics and minimum rooting depth has been done and the RADAMBRASIL soils database has been digitized and a 20 year record of the precipitation for the region has been produced, along with a hydrological ('bucket-tipping') model that will run within a GIS framework; prototype tension lysimeters have been designed and installed in soil pits to begin assessing the importance of DOC as a source of organic matter in deep soils; and many publications, listed in this document, have resulted from this year's research. Two of the papers published are included with this annual report document.

  9. Effect of fertilization on below-ground plant mass of submontane Polygono-Cirsietum meadow

    Czech Academy of Sciences Publication Activity Database

    Holub, Petr; Tůma, I.; Fiala, Karel

    2013-01-01

    Roč. 6, č. 1 (2013), s. 33-42 ISSN 1803-2451 R&D Projects: GA ČR(CZ) GA526/06/0556; GA MZe QJ1220007; GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:67179843 ; RVO:67985939 Keywords : biomass partitioning * grassland * fertilization * primary productivity Subject RIV: EH - Ecology, Behaviour; EF - Botanics (BU-J)

  10. Above- and below-ground effects of plant diversity depend on species origin

    DEFF Research Database (Denmark)

    Kuebbing, Sara E.; Classen, Aimee Taylor; Sanders, Nate

    2015-01-01

    Although many plant communities are invaded by multiple nonnative species, we have limited information on how a species' origin affects ecosystem function. We tested how differences in species richness and origin affect productivity and seedling establishment. We created phylogenetically paired......-interaction models to describe how species' interactions influenced diversity-productivity relationships. Communities with more species had higher total biomass than did monoculture communities, but native and nonnative communities diverged in root : shoot ratios and the mechanism responsible for increased...

  11. Information indices as a tool for quantifying development of below-ground terrestrial ecosystems

    NARCIS (Netherlands)

    Holtkamp, R.; Tobor-Kaplon, M.A.

    2007-01-01

    Information indices from ecosystem network analysis (ENA) describe the size and organization of an ecosystem and are claimed to quantify ecosystem development [Ulanowicz, R.E., 1986, Growth and Development, Springler-Verslag, New York, 203 pp.]. To date, these indices were not used to describe a

  12. Alternations of Structure and Functional Activity of Below Ground Microbial Communities at Elevated Atmospheric Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    He, Zhili; Xu, Meiying; Deng, Ye; Kang, Sanghoon; Wu, Liyou; Van Nostrand, Joy D.; Hobbie, Sarah E.; Reich, Peter B.; Zhou, Jizhong

    2010-05-17

    The global atmospheric concentration of CO2 has increased by more than 30percent since the industrial revolution. Although the stimulating effects of elevated CO2 (eCO2) on plant growth and primary productivity have been well studied, its influences on belowground microbial communities are poorly understood and controversial. In this study, we showed a significant change in the structure and functional potential of soil microbial communities at eCO2 in a grassland ecosystem, the BioCON (Biodiversity, CO2 and Nitrogen) experimental site (http://www.biocon.umn.edu/) using a comprehensive functional gene array, GeoChip 3.0, which contains about 28,0000 probes and covers approximately 57,000 gene variants from 292 functional gene families involved in carbon, nitrogen, phosphorus and sulfur cycles as well as other functional processes. GeoChip data indicated that the functional structure of microbial communities was markedly different between ambient CO2 (aCO2) and eCO2 by detrended correspondence analysis (DCA) of all 5001 detected functional gene probes although no significant differences were detected in the overall microbial diversity. A further analysis of 1503 detected functional genes involved in C, N, P, and S cycles showed that a considerable portion (39percent) of them were only detected under either aCO2 (14percent) or eCO2 (25percent), indicating that the functional characteristics of the microbial community were significantly altered by eCO2. Also, for those shared genes (61percent) detected, some significantly (p<0.05) changed their abundance at eCO2. Especially, genes involved in labile C degradation, such as amyA, egl, and ara for starch, cellulose, and hemicelluloses, respectively, C fixation (e.g., rbcL, pcc/acc), N fixation (nifH), and phosphorus utilization (ppx) were significantly increased under eCO2, while those involved in decomposing recalcitrant C, such as glx, lip, and mnp for lignin degradation remained unchanged. This study provides insights into our understanding of belowground microbial communities and their feedbacks to terrestrial ecosystems at eCO2.

  13. Non-invasive monitoring of below ground cassava storage root bulking by ground penetrating radar technology

    Science.gov (United States)

    Ruiz Vera, U. M.; Larson, T. H.; Mwakanyamale, K. E.; Grennan, A. K.; Souza, A. P.; Ort, D. R.; Balikian, R. J.

    2017-12-01

    Agriculture needs a new technological revolution to be able to meet the food demands, to overcome weather and natural hazards events, and to monitor better crop productivity. Advanced technologies used in other fields have recently been applied in agriculture. Thus, imagine instrumentation has been applied to phenotype above-ground biomass and predict yield. However, the capability to monitor belowground biomass is still limited. There are some existing technologies available, for example the ground penetrating radar (GPR) which has been used widely in the area of geology and civil engineering to detect different kind of formations under the ground without the disruption of the soil. GPR technology has been used also to monitor tree roots but as yet not crop roots. Some limitation are that the GPR cannot discern roots smaller than 2 cm in diameter, but it make it feasible for application in tuber crops like Cassava since harvest diameter is greater than 4 cm. The objective of this research is to test the availability to use GPR technology to monitor the growth of cassava roots by testing this technique in the greenhouse and in the field. So far, results from the greenhouse suggest that GPR can detect mature roots of cassava and this data could be used to predict biomass.

  14. Dosimetry of Rn-222 in the air in environments located above and below ground level

    International Nuclear Information System (INIS)

    Cazula, Camila Dias

    2015-01-01

    Exposure of the general population to ionizing radiation comes mainly from natural sources. The main contribution is due to inhalation of radon (Rn-222), a gas that occurs naturally (UNSCEAR, 2000). The Rn-222 concentration in the environment is controlled by factors such as soil permeability and water content, the weather variability, materials used in the foundation and the usual positive pressure differential between the soil and the internal environment. Studies indicate that the concentration of radon shows a wide variation in the basement, ground floor and upper floors of buildings. The objective of this study is to determine radon levels in basements, ground floor and floors above ground level, at a university in the city of Sao Paulo and in one residential building in the city of Peruibe. Rn-222 measurements were performed using the method with nuclear track of solid state detectors (CR-39). The studied environments present Rn-222 concentration well below the values recommended by the International Commission on Radiological Protection, published in the 2009 document, of 300 Bq/m 3 for homes and 1000 Bq/m 3 for the workplace. In the residential building, the concentration of Ra-266, Th-232 and K-40 in the materials used in the building construction was also analyzed, by gamma spectrometry. The effective total dose for the resident due to external exposure was 0.8 mSv y -1 , lower than the annual dose limit for the general public of 1 mSv y -1 . (author)

  15. Testing the growth rate hypothesis in vascular plants with above- and below-ground biomass.

    Directory of Open Access Journals (Sweden)

    Qiang Yu

    Full Text Available The growth rate hypothesis (GRH proposes that higher growth rate (the rate of change in biomass per unit biomass, μ is associated with higher P concentration and lower C:P and N:P ratios. However, the applicability of the GRH to vascular plants is not well-studied and few studies have been done on belowground biomass. Here we showed that, for aboveground, belowground and total biomass of three study species, μ was positively correlated with N:C under N limitation and positively correlated with P:C under P limitation. However, the N:P ratio was a unimodal function of μ, increasing for small values of μ, reaching a maximum, and then decreasing. The range of variations in μ was positively correlated with variation in C:N:P stoichiometry. Furthermore, μ and C:N:P ranges for aboveground biomass were negatively correlated with those for belowground. Our results confirm the well-known association of growth rate with tissue concentration of the limiting nutrient and provide empirical support for recent theoretical formulations.

  16. EPN Chemical ecology and new techniques for below ground sampling and analyses of volatile semiochemicals

    Science.gov (United States)

    It is well established that herbivory induced plant volatiles (HIPVs) attract natural enemies of the herbivores. Utilizing this plant response has become a fundamental part of above ground IPM programs. We now know that also roots can release HIPVs and that these compounds attract beneficial organis...

  17. Links between plant litter chemistry, species diversity, and below-ground ecosystem function

    OpenAIRE

    Meier, Courtney L.; Bowman, William D.

    2008-01-01

    Decomposition is a critical source of plant nutrients, and drives the largest flux of terrestrial C to the atmosphere. Decomposing soil organic matter typically contains litter from multiple plant species, yet we lack a mechanistic understanding of how species diversity influences decomposition processes. Here, we show that soil C and N cycling during decomposition are controlled by the composition and diversity of chemical compounds within plant litter mixtures, rather than by simple metrics...

  18. and below-ground biomass partitioning in two arid-zone dwarf shrubs

    African Journals Online (AJOL)

    ground fractions could be influenced by plant adaptations to herbivory. The response of potted Indigofera spinosa and I. cliffordiana to heavy and moderate top defoliations, compared to non-defoliated controls, was investigated. Relative growth ...

  19. 33 Shafts Category of Transuranic Waste Stored Below Ground within Area G

    Energy Technology Data Exchange (ETDEWEB)

    Hargis, Kenneth Marshall [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Monk, Thomas H [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-22

    This report compiles information to support the evaluation of alternatives and analysis of regulatory paths forward for the 33 shafts. The historical information includes a form completed by waste generators for each waste package (Reference 6) that included a waste description, estimates of Pu-239 and uranium-235 (U-235) based on an accounting technique, and calculations of mixed fission products (MFP) based on radiation measurements. A 1979 letter and questionnaire (Reference 7) provides information on waste packaging of hot cell waste and the configuration of disposal shafts as storage in the 33 Shafts was initiated. Tables of data by waste package were developed during a review of historical documents that was performed in 2005 (Reference 8). Radiological data was coupled with material-type data to estimate the initial isotopic content of each waste package and an Oak Ridge National Laboratory computer code was used to calculate 2009 decay levels. Other sources of information include a waste disposal logbook for the 33 shafts (Reference 9), reports that summarize remote-handled waste generated at the CMR facility (Reference 10) and placement of waste in the 33 shafts (Reference 11), a report on decommissioning of the LAMPRE reactor (Reference 12), interviews with an employee and manager involved in placing waste in the 33 shafts (References 13 and 14), an interview with a long-time LANL employee involved in waste operations (Reference 15), a 2002 plan for disposition of remote-handled TRU waste (Reference 16), and photographs obtained during field surveys of several shafts in 2007. The WIPP Central Characterization Project (CCP) completed an Acceptable Knowledge (AK) summary report for 16 canisters of remote-handled waste from the CMR Facility that contains information relevant to the 33 Shafts on hot-cell operations and timeline (Reference 17).

  20. Picturing Adoption of Below-Ground Biodiversity Technologies among Smallholder Farmers around Mabira Forest, Uganda

    Directory of Open Access Journals (Sweden)

    Isabirye, BE.

    2010-01-01

    Full Text Available Faced with a multitude of soil and water amendment technologies, farmers have the task of choosing the technologies to adopt for ensuring subsistence and income sustainability. In 2008, a study to characterize the farmers was conducted around Mabira Forest, to assess the adoption of soil technologies fostering Belowground Biodiversity (BGBD. Eighty-four households (38 participating and 46 non-participants from four villages were randomly selected and interviewed. Results showed that the adoption pattern was significantly driven by farm size, labor, household size, age and wealth status of the house. Also important were farm location, gender of household head, primary occupation, soil and water conservation technologies training, land tenure, and social capital. For the few current adopters, there was a perceived increase in labor demand but overall productivity was higher, partly resulting from increased crop productivity due to soil fertility enhancement and soil structure modification. It is therefore concluded that, around Mabira forest, BGBD technologies will be adopted by farming households with sufficient land, labor and social capital.

  1. Larval habitats and biodiversity of anopheline mosquitoes (Diptera: Culicidae) in a malarious area of southern Iran.

    Science.gov (United States)

    Hanafi-Bojd, A A; Vatandoost, H; Oshaghi, M A; Charrahy, Z; Haghdoost, A A; Sedaghat, M M; Abedi, F; Soltani, M; Raeisi, A

    2012-06-01

    Malaria is the most important mosquito-borne disease in Iran. It is endemic in south to southeastern part of the country. Knowledge about bio-ecology of vectors will support authorities for appropriate management of the disease. Bashagard district is one of the main endemic areas for malaria in south of Iran. This study was conducted to determine anopheline fauna, diversity and affinity in the area, characterization of larval habitats, and mapping their potential distribution across the district. The potential aquatic habitats for Anopheles larvae were extracted from Indian Remote Sensing Satellite (IRS) image and digital elevation model of the area using GIS. Surface water bodies were sampled monthly during 2009–10 for anopheline larvae, while characteristics of their physical environment were recorded and water samples were analyzed. A total of 4511 Anopheles larvae were found during the year with the lowest and highest frequencies in February and April, respectively. Dominant species was Anopheles culicifacies. The Shanon diversity index ranged from 0.570–0.829 at fixed collection sites, while the affinity index was significant among some vector species. Riversides and riverbeds were the main breeding places which provided sandy, rocky, and clay beds for different species. The potential breeding places as well as distribution of collected species were mapped. Knowledge about ecology of malaria vectors provides information to health sector for effective control programs.

  2. Laboratory and Field Evaluation of SS220 and Deet Against Mosquitoes in Queensland, Australia

    Science.gov (United States)

    2009-01-01

    methylpiperindinyl-3-cyclohexen-1-carboxamide] against mosquitoes in Queensland, Australia , were conducted. In the laboratory, both compounds provided...carboxa- mide], mosquito repellents, Culex annulirostris, Australia INTRODUCTION The use of personal protection measures, particularly the application...Queensland, Australia . MATERIALS AND METHODS Test mosquitoes Female mosquitoes used in the laboratory evaluation study were Ae. aegypti (Townsville

  3. Encontro de Aedes (Stegomyia albopictus (Skuse em Bromeliaceae na periferia de São Paulo, SP, Brasil The Aedes (Stegomyia albopictus (Skuse breeding in Bromeliaceae on the outskirts of an urban area of Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Delsio Natal

    1997-10-01

    Full Text Available Foram coletadas larvas de Aedes albopictus em uma planta da família Bromeliaceae, na periferia da cidade de São Paulo, SP, Brasil. Esse encontro abre perspectivas de estudo para avaliação do potencial desse vegetal como criadouro desse mosquito no País.Larvae of Aedes albopictus from a plant of the Bromeliaceae family on the outskirts of S. Paulo, SP, Brazil, were collected. This occurrence sheds new light on the attempt to determine the potential of this plants as a breeding site for this mosquito in Brazil.

  4. Mosquito repellent activity of volatile oils from selected aromatic plants.

    Science.gov (United States)

    Lalthazuali; Mathew, Nisha

    2017-02-01

    Essential oils from fresh leaves of four aromatic plants viz., Ocimum sanctum, Mentha piperita, Eucalyptus globulus and Plectranthus amboinicus were extracted by hydrodistillation. The test solutions were prepared as 20% essential oil in ethanol and positive control as 20% DEET in ethanol. Essential oil blend was prepared as 5% concentration. Nulliparous, 3-5-day-old female adult Aedes aegypti mosquitoes were used for repellency screening as per ICMR protocol. The study showed that the repellency of 20% essential oil of O. sanctum, M. piperita and P. amboinicus were comparable with that of the standard DEET (20%) as no mosquito landing on the test was observed up to 6 h. The E. globulus oil exhibited mosquito repellency only upto 1½ h. Considerable mosquito landing and feeding was displayed in negative control. In the case of the oil blend, no landing of mosquitoes was seen up to 6 h as that of positive control. The results showed that the essential oil blend from O. sanctum, M. piperita, E. globulus and P. amboinicus could repel Ae. aegypti mosquitoes or prevent from feeding as in the case of DEET even at a lower concentration of 5%. This study demonstrates the potential of essential oils from O. sanctum, M. piperita, E. globulus and P. amboinicus and their blend as mosquito repellents against Ae. aegypti, the vector of dengue, chikungunya and yellow fever.

  5. Effects of rainfall on Culex mosquito population dynamics.

    Science.gov (United States)

    Valdez, L D; Sibona, G J; Diaz, L A; Contigiani, M S; Condat, C A

    2017-05-21

    The dynamics of a mosquito population depends heavily on climatic variables such as temperature and precipitation. Since climate change models predict that global warming will impact on the frequency and intensity of rainfall, it is important to understand how these variables affect the mosquito populations. We present a model of the dynamics of a Culex quinquefasciatus mosquito population that incorporates the effect of rainfall and use it to study the influence of the number of rainy days and the mean monthly precipitation on the maximum yearly abundance of mosquitoes M max . Additionally, using a fracturing process, we investigate the influence of the variability in daily rainfall on M max . We find that, given a constant value of monthly precipitation, there is an optimum number of rainy days for which M max is a maximum. On the other hand, we show that increasing daily rainfall variability reduces the dependence of M max on the number of rainy days, leading also to a higher abundance of mosquitoes for the case of low mean monthly precipitation. Finally, we explore the effect of the rainfall in the months preceding the wettest season, and we obtain that a regimen with high precipitations throughout the year and a higher variability tends to advance slightly the time at which the peak mosquito abundance occurs, but could significantly change the total mosquito abundance in a year. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Towards the genetic manipulation of mosquito disease vectors

    International Nuclear Information System (INIS)

    Crampton, J.M.; Lycett, G.J.; Warren, A.

    1998-01-01

    Our research is aimed at developing the technologies necessary to undertake the genetic manipulation of insect vector genomes. In the longer term, we wish to explore the potential that this technology may have for developing novel strategies for the control of vector-borne diseases. The focus of our current research has been to: i) identify and characterise endogenous transposable elements in the genomes of mosquito vectors -research has focussed on identifying both Class I and Class 11 elements and determining their structure and distribution within mosquito genomes; ii) develop and use transfection systems for mosquito cells in culture as a test bed for transformation vectors and promoters - transfection techniques, vector constructs and different promoters driving reporter genes have been utilised to optimise the transformation of both Aedes aegypti and Anopheles gambiae cells in culture; iii) identify putative promoter sequences which are induced in the female mosquito midgut when it takes a blood meal - the Anopheles gambiae trypsin gene locus has been cloned and sequenced and the intergenic regions assessed for their ability to induce reporter gene expression in mosquito gut cells. The progress we have made in each of these areas will be described and discussed in the context of our longer term aim which is to introduce genes coding for antiparasitic agents into mosquito genomes in such a way that they are expressed in the mosquito midgut and disrupt transmission of the malaria parasite. (author)

  7. EPA-Registered Repellents for Mosquitoes Transmitting Emerging Viral Disease.

    Science.gov (United States)

    Patel, Radha V; Shaeer, Kristy M; Patel, Pooja; Garmaza, Aleksey; Wiangkham, Kornwalee; Franks, Rachel B; Pane, Olivia; Carris, Nicholas W

    2016-12-01

    In many parts of the United States, mosquitoes were previously nuisance pests. However, they now represent a potential threat in the spread of viral diseases. The Aedes aegypti, Aedes albopictus, and Culex species mosquitoes are endemic to the United States and together may transmit a variety of viral diseases of growing concern, including West Nile virus, chikungunya, dengue fever, and Zika virus. The Centers for Disease Control and Prevention and the Environmental Protection Agency (EPA) recommend N,N-diethyl-meta-toluamide (DEET) as a first-line mosquito repellent, but for patients refusing to use DEET or other conventional repellents, guidance is limited to any EPA-registered product. Therefore, we conducted a systematic review of the literature to identify which EPA-registered personal mosquito repellent provides the best protection from A. aegypti, A. albopictus, and Culex spp. mosquitoes. We abstracted data from 62 published reports of EPA-registered mosquito repellents. The conventional repellent picaridin has the strongest data to support its use as a second-line agent, while IR3535 and oil of lemon eucalyptus are reasonably effective natural products. Citronella, catnip, and 2-undecanone offer limited protection or have limited data. These results can be used by pharmacists and other health care professionals to advise patients on the selection of an EPA-registered mosquito repellent. Regardless of the repellent chosen, it is vital for patients to follow all instructions/precautions in the product labeling to ensure safe and effective use. © 2016 Pharmacotherapy Publications, Inc.

  8. Biocontrol of larval mosquitoes by Acilius sulcatus (Coleoptera: Dytiscidae

    Directory of Open Access Journals (Sweden)

    Banerjee Siddhartha S

    2008-10-01

    Full Text Available Abstract Background Problems associated with resistant mosquitoes and the effects on non-target species by chemicals, evoke a reason to find alternative methods to control mosquitoes, like the use of natural predators. In this regard, aquatic coleopterans have been explored less compared to other insect predators. In the present study, an evaluation of the role of the larvae of Acilius sulcatus Linnaeus 1758 (Coleoptera: Dytiscidae as predator of mosquito immatures was made in the laboratory. Its efficacy under field condition was also determined to emphasize its potential as bio-control agent of mosquitoes. Methods In the laboratory, the predation potential of the larvae of A. sulcatus was assessed using the larvae of Culex quinquefasciatus Say 1823 (Diptera: Culicidae as prey at varying predator and prey densities and available space. Under field conditions, the effectiveness of the larvae of A. sulcatus was evaluated through augmentative release in ten cemented tanks hosting immatures of different mosquito species at varying density. The dip density changes in the mosquito immatures were used as indicator for the effectiveness of A. sulcatus larvae. Results A single larva of A. sulcatus consumed on an average 34 IV instar larvae of Cx. quinquefasciatus in a 24 h period. It was observed that feeding rate of A. sulcatus did not differ between the light-on (6 a.m. – 6 p.m., and dark (6 p.m. – 6 a.m. phases, but decreased with the volume of water i.e., space availability. The prey consumption of the larvae of A. sulcatus differed significantly (P A. sulcatus larvae, while with the withdrawal, a significant increase (p A. sulcatus in regulating mosquito immatures. In the control tanks, mean larval density did not differ (p > 0.05 throughout the study period. Conclusion the larvae of the dytiscid beetle A. sulcatus proved to be an efficient predator of mosquito immatures and may be useful in biocontrol of medically important mosquitoes.

  9. Biocontrol of larval mosquitoes by Acilius sulcatus (Coleoptera: Dytiscidae).

    Science.gov (United States)

    Chandra, Goutam; Mandal, Samir K; Ghosh, Arup K; Das, Dipanwita; Banerjee, Siddhartha S; Chakraborty, Sumanta

    2008-10-15

    Problems associated with resistant mosquitoes and the effects on non-target species by chemicals, evoke a reason to find alternative methods to control mosquitoes, like the use of natural predators. In this regard, aquatic coleopterans have been explored less compared to other insect predators. In the present study, an evaluation of the role of the larvae of Acilius sulcatus Linnaeus 1758 (Coleoptera: Dytiscidae) as predator of mosquito immatures was made in the laboratory. Its efficacy under field condition was also determined to emphasize its potential as bio-control agent of mosquitoes. In the laboratory, the predation potential of the larvae of A. sulcatus was assessed using the larvae of Culex quinquefasciatus Say 1823 (Diptera: Culicidae) as prey at varying predator and prey densities and available space. Under field conditions, the effectiveness of the larvae of A. sulcatus was evaluated through augmentative release in ten cemented tanks hosting immatures of different mosquito species at varying density. The dip density changes in the mosquito immatures were used as indicator for the effectiveness of A. sulcatus larvae. A single larva of A. sulcatus consumed on an average 34 IV instar larvae of Cx. quinquefasciatus in a 24 h period. It was observed that feeding rate of A. sulcatus did not differ between the light-on (6 a.m. - 6 p.m.), and dark (6 p.m. - 6 a.m.) phases, but decreased with the volume of water i.e., space availability. The prey consumption of the larvae of A. sulcatus differed significantly (P sulcatus larvae, while with the withdrawal, a significant increase (p sulcatus in regulating mosquito immatures. In the control tanks, mean larval density did not differ (p > 0.05) throughout the study period. the larvae of the dytiscid beetle A. sulcatus proved to be an efficient predator of mosquito immatures and may be useful in biocontrol of medically important mosquitoes.

  10. Current status of genome editing in vector mosquitoes: A review.

    Science.gov (United States)

    Reegan, Appadurai Daniel; Ceasar, Stanislaus Antony; Paulraj, Michael Gabriel; Ignacimuthu, Savarimuthu; Al-Dhabi, Naif Abdullah

    2017-01-16

    Mosquitoes pose a major threat to human health as they spread many deadly diseases like malaria, dengue, chikungunya, filariasis, Japanese encephalitis and Zika. Identification and use of novel molecular tools are essential to combat the spread of vector borne diseases. Genome editing tools have been used for the precise alterations of the gene of interest for producing the desirable trait in mosquitoes. Deletion of functional genes or insertion of toxic genes in vector mosquitoes will produce either knock-out or knock-in mutants that will check the spread of vector-borne diseases. Presently, three types of genome editing tools viz., zinc finger nuclease (ZFN), transcription activator-like effector nucleases (TALEN) and clustered regulatory interspaced short palindromic repeats (CRISPR) and CRISPR associated protein 9 (Cas9) are widely used for the editing of the genomes of diverse organisms. These tools are also applied in vector mosquitoes to control the spread of vector-borne diseases. A few studies have been carried out on genome editing to control the diseases spread by vector mosquitoes and more studies need to be performed with the utilization of more recently invented tools like CRISPR/Cas9 to combat the spread of deadly diseases by vector mosquitoes. The high specificity and flexibility of CRISPR/Cas9 system may offer possibilities for novel genome editing for the control of important diseases spread by vector mosquitoes. In this review, we present the current status of genome editing research on vector mosquitoes and also discuss the future applications of vector mosquito genome editing to control the spread of vectorborne diseases.

  11. Breeds in danger of extintion and biodiversity

    Directory of Open Access Journals (Sweden)

    A. Blasco

    2008-07-01

    Full Text Available Some arguments currently used to support breed conservation are examined. The central point is that we cannot conserve all breeds because we do not have financial resources enough to keep everything (mainly in developing countries and in many cases we do not have special reasons to conserve breeds. A breed is a human product and it should not be confused with specie. A breed can be generated or transformed. We can create synthetic breeds with the best characteristics of several breeds. Selection is not exhausting genetic variability (there are several experiments showing that, and genetic variability within breeds is large. We need reasons to keep breeds in danger in extinction. A breed is a tool, and we can decide to keep it when it is useful because it is specially adapted to some environments (although in this case it should not be in danger of extinction, it can be useful in crossbreeding to shorten the way of obtaining response to selection, or it has some extreme values for traits that may be useful in the future (in this case we have to define clearly which traits and how we expect the future to be. We can add cultural reasons when we have money enough to spend in culture.

  12. Characteristics of and factors associated with dengue vector breeding sites in the City of Colombo, Sri Lanka.

    Science.gov (United States)

    Louis, Valérie R; Montenegro Quiñonez, Carlos Alberto; Kusumawathie, Pad; Palihawadana, Paba; Janaki, Sakoo; Tozan, Yesim; Wijemuni, Ruwan; Wilder-Smith, Annelies; Tissera, Hasitha A

    2016-03-01

    Dengue has emerged as a major public health problem in Sri Lanka. Vector control at community level is a frequent and widespread strategy for dengue control. The aim of the study was to assess Aedes mosquito breeding sites and the prevention practices of community members in a heavily urbanized part of Colombo. A cross-sectional entomological survey was conducted from April to June 2013 in 1469 premises located in a subdistrict of the City of Colombo. Types of breeding sites and, where found, their infestation with larvae or pupae were recorded. Furthermore, a questionnaire was administered to the occupants of these premises to record current practices of dengue vector control. The surveyed premises consisted of 1341 residential premises and 110 non-residential premises (11 schools, 99 work or public sites), 5 open lands, and 13 non-specified. In these 1469 premises, 15447 potential breeding sites suitable to host larvae of pupae were found; of these sites18.0% contained water. Among the 2775 potential breeding sites that contained water, 452 (16.3%) were positive for larvae and/or pupae. Schools were associated with the proportionally highest number of breeding sites; 85 out of 133 (63.9%) breeding sites were positive for larvae and/or pupae in schools compared with 338 out of 2288 (14.8%) in residential premises. The odds ratio (OR) for schools and work or public sites for being infested with larvae and/or pupae was 2.77 (95% CI 1.58, 4.86), when compared to residential premises. Occupants of 80.8% of the residential premises, 54.5% of the schools and 67.7% of the work or public sites reported using preventive measures. The main prevention practices were coverage of containers and elimination of mosquito breeding places. Occupants of residential premises were much more likely to practice preventive measures than were those of non-residential premises (OR 2.23; 1.49, 3.36). Schools and working sites were associated with the highest numbers of breeding sites and

  13. Mosquito Records from Mexico: The Mosquitoes (Diptera: Culicidae) of Tamaulipas State.

    Science.gov (United States)

    Ortega-Morales, Aldo I; Zavortink, Thomas J; Huerta-Jiménez, Herón; Sánchez-Rámos, Francisco J; Valdés-Perezgasga, Ma Teresa; Reyes-Villanueva, Filiberto; Siller-Rodríguez, Quetzaly K; Fernandez-Salas, Ildefonso

    2015-03-01

    To document the diversity and distribution of mosquito species inhabiting the Mexican state of Tamaulipas, collection trips were conducted to all physiographic regions (Grand Northamerican Plains, Coastal Plain of North Gulf, and Sierra Madre Oriental) and subregions across the state. Additionally, we re-examined mosquito specimens in two Mexican entomological collections: the Collection of Insects and Mites of Medical Importance and the Collection of Arthropods of Medical Importance. In total, 3,931 specimens were collected. These represent the two Culicidae subfamilies Anophelinae and Culicinae, 10 tribes, 17 genera, 27 subgenera, 80 named species, and 2 undescribed species. Of these, 3 tribes, 6 genera, 7 subgenera, and 20 species are new records for the mosquito fauna of Tamaulipas. Fourteen species recorded in the historical records were not found in collections made for this study. Taxonomic notes, new distribution limits, and comments about the medical importance of some of the species collected are reported. © The Author 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  14. Annotated checklist of the mosquitoes of the Republic of Moldova.

    Science.gov (United States)

    Sulesco, Tatiana M; Toderas, Ion K; Toderas, Lidia G

    2013-06-01

    The mosquito fauna of the Republic of Moldova is poorly known. In an effort to understand the Culicidae fauna better, mosquito collections have been conducted between early April and middle November from 2008 to 2012. A total of 10,923 larval specimens and 8,246 adults were collected from 20 regions of Moldova. Altogether 36 species have been recorded during the recent study, bringing the total Moldovan mosquito fauna to 40 species in 9 genera and 11 subgenera. New state records include the following 7 species: Anopheles pseudopictus, An. melanoon, Aedes geminus, Culex torrentium, Culiseta longiareolata, Coquillettidia buxtoni, and Uranotaenia unguiculata.

  15. Breeding schemes in reindeer husbandry

    Directory of Open Access Journals (Sweden)

    Lars Rönnegård

    2003-04-01

    Full Text Available The objective of the paper was to investigate annual genetic gain from selection (G, and the influence of selection on the inbreeding effective population size (Ne, for different possible breeding schemes within a reindeer herding district. The breeding schemes were analysed for different proportions of the population within a herding district included in the selection programme. Two different breeding schemes were analysed: an open nucleus scheme where males mix and mate between owner flocks, and a closed nucleus scheme where the males in non-selected owner flocks are culled to maximise G in the whole population. The theory of expected long-term genetic contributions was used and maternal effects were included in the analyses. Realistic parameter values were used for the population, modelled with 5000 reindeer in the population and a sex ratio of 14 adult females per male. The standard deviation of calf weights was 4.1 kg. Four different situations were explored and the results showed: 1. When the population was randomly culled, Ne equalled 2400. 2. When the whole population was selected on calf weights, Ne equalled 1700 and the total annual genetic gain (direct + maternal in calf weight was 0.42 kg. 3. For the open nucleus scheme, G increased monotonically from 0 to 0.42 kg as the proportion of the population included in the selection programme increased from 0 to 1.0, and Ne decreased correspondingly from 2400 to 1700. 4. In the closed nucleus scheme the lowest value of Ne was 1300. For a given proportion of the population included in the selection programme, the difference in G between a closed nucleus scheme and an open one was up to 0.13 kg. We conclude that for mass selection based on calf weights in herding districts with 2000 animals or more, there are no risks of inbreeding effects caused by selection.

  16. Behaviors and Numerical Simulations of Malaria Dynamic Models with Transgenic Mosquitoes

    OpenAIRE

    Liu, Xiongwei; Xu, Junjun; Wang, Xiao; Cheng, Lizhi

    2013-01-01

    The release of transgenic mosquitoes to interact with wild ones is a promising method for controlling malaria. How to effectively release transgenic mosquitoes to prevent malaria is always a concern for researchers. This paper investigates two methods of releasing transgenic mosquitoes and proposes two epidemic models involving malaria patients, anopheles, wild mosquitoes, and transgenic mosquitoes based on system of continuous differential equations. A basic reproduction number ${\\mathbf{R}}...

  17. Can urban planning reduce the risks of mosquito-borne disease?

    OpenAIRE

    Webb, Cameron; Russell, Richard C.

    2015-01-01

    Mosquito-borne disease impacts many communities in Australia on an annual basis. While increasing urbanisation is bringing the community closer to productive mosquito habitats, environmental management of local wetlands is often in conflict with effective mosquito control strategies and abundant mosquito populations increase the risks of disease caused by Ross River virus and Barmah Forest virus. Wetland conservation projects are increasing the availability of productive mosquito habitat whil...

  18. Congruence between selection on breeding values and farmers' selection criteria in sheep breeding under conventional nucleus breeding schemes.

    Science.gov (United States)

    Gizaw, S; Getachew, T; Tibbo, M; Haile, A; Dessie, T

    2011-05-01

    Designing breeding schemes suitable for smallholder livestock production systems in developing regions has hitherto been a challenge. The suggested schemes either do not address farmers' breeding goals (centralized station-based nucleus schemes) or yield slow genetic progress (village-based schemes). A new breeding scheme that integrates the merits of previously suggested schemes has been designed for Menz sheep improvement in Ethiopia. It involves selection based on breeding values in nucleus flocks to produce elite rams, a one-time only provision of improved rams to villagers and a follow-up village-based selection to sustain genetic progress in village flocks. Here, we assessed whether conventional selection of breeding rams based on breeding values for production traits, which is the practice in station-based nucleus flocks, meets farmers' breeding objectives. We also elicited determinants of farmers' ram choice. Low but significant correlations were found between rankings of rams based on farmers' selection criteria, estimated breeding values (EBV) and body weight (BW). Appearance traits (such as color and horn) and meat production traits (BW and linear size traits) significantly determined farmers' breeding ram choice. The results imply that conventional selection criteria based solely on EBV for production traits do not address farmers' trait preferences fully, but only partially. Thus, a two-stage selection procedure involving selection on breeding values in nucleus centers followed by farmers' selection among top- ranking candidate rams is recommended. This approach accommodates farmers' preferences and speeds up genetic progress in village-based selection. The Menz sheep scheme could be applied elsewhere with similar situations to transform conventional station-based nucleus breeding activities into participatory breeding programs.

  19. Breeding for Grass Seed Yield

    DEFF Research Database (Denmark)

    Boelt, Birte; Studer, Bruno

    2010-01-01

    Seed yield is a trait of major interest for many fodder and amenity grass species and has received increasing attention since seed multiplication is economically relevant for novel grass cultivars to compete in the commercial market. Although seed yield is a complex trait and affected...... important aspects and components affecting the seed yield potential and the agronomic and environmental aspects affecting the utilization and realization of the seed yield potential. Finally, it discusses the potential of plant breeding to sustainably improve total seed yield in fodder and amenity grasses....

  20. Field evaluation of CDC and Mosquito Magnet X traps baited with dry ice, CO2 sachet, and octenol against mosquitoes.

    Science.gov (United States)

    Xue, Rui-De; Doyle, Melissa A; Kline, Daniel L

    2008-06-01

    The Centers for Disease Control and Prevention (CDC) light traps and Mosquito Magnet X (MMX) traps baited with dry ice, octenol, and a new formulation (granular) of carbon dioxide (CO2) were evaluated against adult mosquitoes in the field. The results showed that the MMX traps (68.6%) baited with dry ice collected more mosquitoes compared to the CDC light traps (32.4%) only. The CDC traps baited with dry ice (64%) collected significantly more mosquitoes than traps baited with CO2 sachets (11%) or octenol (23%). The MMX traps baited with dry ice (85.5%) collected significantly more mosquitoes than traps baited with CO2 sachets (6.5%) or octenol (9%). The CDC traps baited with the formulations of normal and slow release CO2 sachets collected more mosquitoes than the formulation of fast release sachets. The CDC traps baited with fresh sachets and 24-h-exposed sachets collected significantly more mosquitoes than the traps baited with 48-h- and 72-h-exposed sachets.

  1. Modelling the Active Hearing Process in Mosquitoes

    Science.gov (United States)

    Avitabile, Daniele; Homer, Martin; Jackson, Joe; Robert, Daniel; Champneys, Alan

    2011-11-01

    A simple microscopic mechanistic model is described of the active amplification within the Johnston's organ of the mosquito species Toxorhynchites brevipalpis. The model is based on the description of the antenna as a forced-damped oscillator coupled to a set of active threads (ensembles of scolopidia) that provide an impulsive force when they twitch. This twitching is in turn controlled by channels that are opened and closed if the antennal oscillation reaches a critical amplitude. The model matches both qualitatively and quantitatively with recent experiments. New results are presented using mathematical homogenization techniques to derive a mesoscopic model as a simple oscillator with nonlinear force and damping characteristics. It is shown how the results from this new model closely resemble those from the microscopic model as the number of threads approach physiologically correct values.

  2. Mutation Breeding for Crop Improvement

    International Nuclear Information System (INIS)

    Rajbir, S. Sangwan

    2017-01-01

    Chromosomes contain genes responsible of different traits of any organism. Induced mutation using chemical mutagens and radiation to modify molecular structure of plants played a major role in the development of high genetic variability and help develop new superior crop varieties. The Mutation Breeding is applicable to all plants and has generated lot of agronomically interesting mutants, both in vegetatively and seed propagated plants. The technique is easy but long and challenging to detect, isolate and characterize the mutant and gene. A specific dose of irradiation has to be used to obtain desired mutants. However, with modern molecular technique, the gene responsible for mutation can be identified. The CRISPR-Cas9 allows the removal of a specific gene which is responsible of unwanted trait and replacing it with a gene which induces a desired trait. There have been more than 2700 officially released mutant varieties from 170 different plant species in more than 60 countries throughout the world and A more participatory approach, involving all stakeholders in plant breeding, is needed to ensure that it is demand/farmers driven.

  3. Breeding of speciality maize for industrial purposes

    OpenAIRE

    Pajić Zorica; Radosavljević Milica; Filipović Milomir; Todorović Goran; Srdić Jelena; Pavlov Milovan

    2010-01-01

    The breeding programme on speciality maize with specific traits was established at the Maize Research Institute, Zemun Polje, several decades ago. The initial material was collected, new methods applying to breeding of speciality maize, i.e. popping maize, sweet maize and white-seeded maize, were introduced. The aim was to enhance and improve variability of the initial material for breeding these three types of maize. Then, inbred lines of good combining abilities were developed and used as c...

  4. Use of induced mutations in soybean breeding

    International Nuclear Information System (INIS)

    Zakri, A.H.; Jalani, B.S.; Ng, K.F.

    1981-01-01

    Artificial induction of mutation in plants is carried out using #betta#-irradiation and ethyl metanesulphonate (EMS) to expand the genetic variability of locally-grown soybean. This aspect of mutation breeding complements of conventional breeding approach undertaken by the Joint Malaysia Soybean Breeding Project group. Recovery of agronomically-important mutants such as earliness, lateness, bigger seed size and improved plant architecture were recorded. The significance of these findings is discussed. (author)

  5. Mosquitos Culicidae como vetores emergentes de infecções Culicidae mosquitoes as emerging vectors of diseases

    Directory of Open Access Journals (Sweden)

    Oswaldo Paulo Forattini

    1998-12-01

    Full Text Available Apresenta-se sucinta revisão do relacionamento entre as chamadas infecções emergentes e o conceito de vetores emergentes. Estes são entendidos não apenas no que concerne aos que são descritos como tais, de forma nova, mas também aqueles com acentuadas mudanças de comportamento. Os fatores específicos que propiciam esse fenômeno identificam-se à poderosa influência humana sobre o ambiente. Assim, aquele construído pelo homem e conhecido como antrópico representa a função de pressão seletiva que induz as populações vetoras a se adaptarem às novas circunstâncias. Nelas inclui-se fatores ecológicos ambientais, ou demográficos, que incrementam o contato com os novos comportamentos vetoriais. Relata-se o encontro de criadouros anômalos de mosquitos Culicidae nas Américas. A interpretação desses encontros é feita visando à vigilância epidemiológica. O significado dessa emergência ou reemergência pode se traduzir no aparecimento de problemas epidemiológicos. Sugere-se que, em sendo assim, a vigilância epidemiológica deva ser feita em grau global.A review is presented of the relationships between the so-called emerging infectious diseases and what may be defined as emerging vectors. These include not only those that have recently appeared but also those that present remarkable behavioral changes. Specific factors leading to that emergence can be associated with the powerful human influence on the environment. So the man-made, i.e. anthropic environment, exercises a selective pressure inducing vector populations to adapt to new circumstances. These may arise from ecological, environmental, or demographic factors that increase contact with the new vector. With this in mind, data on anomalous Culicidae breeding places in the Americas are reported. An interpretation of these findings is offered in the light of epidemiological surveillance. The question is whether vector emergence or re-emergence may constitute an

  6. Breeding sites of Aedes albopictus in Jesús Menéndez municipality

    Directory of Open Access Journals (Sweden)

    Marco Antonio Cruz Cruz

    2015-10-01

    Full Text Available Introduction: aedes albopictus is a vector mosquito of dengue, yellow fever, chikungunya virus, and other arboviruses that has been increasing its spread in Jesús Menéndez municipality, Las Tunas, during the last years.Objectives: to identify the breeding sites of the Aedes albopictus in Jesús Menéndez municipality.Methods: the houses were entirely inspected between January and December, 2014, in work cycles of 44 days according to planning. During the inspections all the available probable tanks for Aedes albopictus were checked and treated by the personnel in charge of the integrated management of vectors. In each visit all the water containers were checked, looking for larvae of this species. Samples were taken from each kind of container where there were larvae.Results: presence of Aedes albopictus was identified in 11 of the Popular Councils mainly in the three urban areas during the whole year. It was observed that the breeding places are diverse; the artificial tanks were the ones that prevailed.Conclusions: the variety of breeding places used by the Aedes albopictus was demonstrated in Jesús Menéndez municipality during every month of the year.

  7. Microinjection of A. aegypti Embryos to Obtain Transgenic Mosquitoes

    OpenAIRE

    Jasinskiene, Nijole; Juhn, Jennifer; James, Anthony A.

    2007-01-01

    In this video, Nijole Jasinskiene demonstrates the methodology employed to generate transgenic Aedes aegypti mosquitoes, which are vectors for dengue fever. The techniques for correctly preparing microinjection needles, dessicating embryos, and performing microinjection are demonstrated.

  8. Microinjection of A. aegypti embryos to obtain transgenic mosquitoes.

    Science.gov (United States)

    Jasinskiene, Nijole; Juhn, Jennifer; James, Anthony A

    2007-01-01

    In this video, Nijole Jasinskiene demonstrates the methodology employed to generate transgenic Aedes aegypti mosquitoes, which are vectors for dengue fever. The techniques for correctly preparing microinjection needles, desiccating embryos, and performing microinjection are demonstrated.

  9. Dirofilaria repens microfilariae in Aedes vexans mosquitoes in Slovakia

    Czech Academy of Sciences Publication Activity Database

    Bocková, E.; Rudolf, Ivo; Kočišová, A.; Betášová, Lenka; Venclíková, Kristýna; Mendel, Jan; Hubálek, Zdeněk

    2013-01-01

    Roč. 112, č. 10 (2013), s. 3465-3470 ISSN 0932-0113 Institutional support: RVO:68081766 Keywords : Dirofilaria * mosquitoes * Aedes vexans Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.327, year: 2013

  10. Cacipacore virus as an emergent mosquito-borne Flavivirus

    Directory of Open Access Journals (Sweden)

    Mario Luis Garcia de Figueiredo

    Full Text Available Abstract INTRODUCTION: Cacipacore virus (CPCV, a possible bird-associated flavivirus, has yet to be detected in mosquitoes. Our purpose is examining CPCV in mosquitoes from the Amazon region of Brazil. METHODS: Approximately 3,253 Culicidae (grouped into 264 pools were collected from the Amazon region during 2002-2006 and analyzed using a Flavivirus genus-specific reverse transcription- polymerase chain reaction followed by nested polymerase chain reaction assay and by nucleotide sequencing of amplicons. RESULTS: Nucleotide sequences from five mosquito samples showed high similarity to the those of CPCV originally isolated in the Amazon region. CONCLUSIONS: This is the first report of CPCV-infected mosquitoes which has implications on the arbovirus maintenance in nature and transmission to man.

  11. Aerial Application of Malathion: Information for Mosquito Control Professionals

    Science.gov (United States)

    EPA recently completed the malathion draft human health risk assessment for all uses. This letter to mosquito control professionals provides modifications to application directions that can reduce malathion deposition while maintaining effectiveness.

  12. Biodiversity of mosquitoes in Manipur State and their medical significance.

    Science.gov (United States)

    Dutta, P; Khan, S A; Khan, A M; Sharma, C K; Mahanta, J

    2005-07-01

    Entomological studies conducted during monsoon and post-monsoon season in Manipur State revealed the presence of fifty-five species of mosquitoes under ten genera. Out of the seventeen Anopheles species recorded, Anopheles aconitus, An. dirus and An. nivipes were recorded for the first time from the state. The present study has confirmed the existence of An. dirus, the major malaria vector in the Northeast from a selected area of the state. Among Culicines, four species viz., Aedes nigrostriatus, Malaya genurostris, Aediomyia catasticta and Toxorhynchites splendens which were not reported earlier from this state have been recorded in the present study. With the addition of these seven species of mosquitoes to the earlier record of mosquitoes so far reported from Manipur, the mosquito fauna swells up to one hundred and eleven including the major vectors of malaria of the Northeast and the potential vectors of Japanese encephalitis and dengue virus transmission in India.

  13. Stress Hormones Bring Birds, Pathogens and Mosquitoes Together.

    Science.gov (United States)

    Dhondt, André A; Dobson, Andrew P

    2017-05-01

    Do stress hormones, such as corticosterone, enhance bird susceptibility to mosquitoes in ways that enhance rates of co-infection? Does this then enhance pathogen emergence? Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Biological Control of Mosquito Vectors: Past, Present, and Future

    Directory of Open Access Journals (Sweden)

    Giovanni Benelli

    2016-10-01

    Full Text Available Mosquitoes represent the major arthropod vectors of human disease worldwide transmitting malaria, lymphatic filariasis, and arboviruses such as dengue virus and Zika virus. Unfortunately, no treatment (in the form of vaccines or drugs is available for most of these diseases andvectorcontrolisstillthemainformofprevention. Thelimitationsoftraditionalinsecticide-based strategies, particularly the development of insecticide resistance, have resulted in significant efforts to develop alternative eco-friendly methods. Biocontrol strategies aim to be sustainable and target a range of different mosquito species to reduce the current reliance on insecticide-based mosquito control. In thisreview, weoutline non-insecticide basedstrategiesthat havebeenimplemented orare currently being tested. We also highlight the use of mosquito behavioural knowledge that can be exploited for control strategies.

  15. Risk of Disease from Mosquito and Tick Bites

    Science.gov (United States)

    Insect repellents help reduce the risk of mosquito and tick bites, which can transmit diseases including West Nile Virus, malaria, encephalitis, yellow fever, dengue fever, chikungunya virus, Lyme disease, Rocky Mountain spotted fever, and ehrlichiosis.

  16. Fungal infection counters insecticide resistance in African malaria mosquitoes

    NARCIS (Netherlands)

    Farenhorst, Marit; Mouatcho, Joel C.; Kikankie, Christophe K.; Brooke, Basil D.; Hunt, Richard H.; Thomas, Matthew B.; Koekemoer, Lizette L.; Knols, Bart G. J.; Coetzee, Maureen

    2009-01-01

    The evolution of insecticide resistance in mosquitoes is threatening the effectiveness and sustainability of malaria control programs in various parts of the world. Through their unique mode of action, entomopathogenic fungi provide promising alternatives to chemical control. However, potential

  17. Polymer nanoparticles containing essential oils: new options for mosquito control.

    Science.gov (United States)

    Werdin González, Jorge Omar; Jesser, Emiliano Nicolás; Yeguerman, Cristhian Alan; Ferrero, Adriana Alicia; Fernández Band, Beatriz

    2017-07-01

    Mosquitoes (Diptera: Culicidae) are vectors of important parasites and pathogens causing death, poverty and social disability worldwide. The overuse of synthetic insecticides to control mosquito vectors lead to resistance, adverse environmental effects and high operational costs. Therefore, the development of eco-friendly control tools is an important public health challenge. In this study, two different essential oils (EO) (geranium, Geranium maculatum, and bergamot, Citrus bergamia) loaded polymeric nanoparticle (PN) were elaborated using polyethylene glycol (PEG) and chitosan (Qx) as the polymeric matrix/coating. In addition, the mosquito larvicidal acute and residual activity of the PN was evaluated on Culex pipiens pipiens. The physicochemical characterization of PN revealed that PEG-PN had sizes nanoparticles containing essential oil are a promising source of eco-friendly mosquito larvicidal products.

  18. Novel Viruses Isolated from Mosquitoes in Pantanal, Brazil.

    Science.gov (United States)

    Pauvolid-Corrêa, Alex; Solberg, Owen; Couto-Lima, Dinair; Nogueira, Rita Maria; Langevin, Stanley; Komar, Nicholas

    2016-11-03

    Genomic sequences are described from five novel viruses and divergent strains of Brejeira and Guaico Culex viruses from mosquitoes collected in Pantanal, Brazil, in 2010. Copyright © 2016 Pauvolid-Corrêa et al.

  19. Prospects for Hybrid Breeding in Bioenergy Grasses

    DEFF Research Database (Denmark)

    Aguirre, Andrea Arias; Studer, Bruno; Frei, Ursula

    2012-01-01

    , we address crucial topics to implement hybrid breeding, such as the availability and development of heterotic groups, as well as biological mechanisms for hybridization control such as self-incompatibility (SI) and male sterility (MS). Finally, we present potential hybrid breeding schemes based on SI...... of different hybrid breeding schemes to optimally exploit heterosis for biomass yield in perennial ryegrass (Lolium perenne L.) and switchgrass (Panicum virgatum), two perennial model grass species for bioenergy production. Starting with a careful evaluation of current population and synthetic breeding methods...

  20. Guidelines for success in mutation breeding

    International Nuclear Information System (INIS)

    Joshua, D.C.

    2000-01-01

    There is renewed interest to induce mutations and to use them in plant breeding for crop improvement. But, often the projects on mutation breeding remain incomplete without achieving the desired specific objectives. A thorough knowledge of the various aspects of this technology is imperative to benefit from these experiments. With this in view, the essential basic information regarding mutagens, their mode of action, mutagenic treatment, sample size, handling the M 1 and M 2 generations, screening the mutants and their use in basic and applied fields are dealt with in this paper. This is meant to help those who are entering this field of plant breeding without previous experience in mutation breeding. (author)