AN ASSESSMENT OF BIODIVERSITY IN THE REKAWA, USSANGODA AND KALAMETIYA INLAND COASTAL ECOSYSTEMS IN SOUTHERN SRI LANKA

The survey was carried out to document the status of inland biodiversity in the Rekawa,Ussangoda and Kalametiya area along the Southern coastal zone of Sri Lanka. Thesurvey extended from October 2002 - March 2003 (6 months). A reconnaissance surveyof the inland areas was conducted, prior to the regular field sampling, in order to selectrepresentative sampling sites within the Ruk area. Eight sites were selected for regularfield sampling at fortnightly intervals, and the plants and animals of the area weresurveyed in a scientific manner, using appropriate sampling techniques.The survey area harbours a variety of natural and man-made vegetationlhabitat types,including both terrestrial and wetland systems. A total of 287 plant species belonging to222 genera under 94 families were documented from the above inland vegetationlhabitattypes of the Ruk area. Several sub types of Mangroves, based mainly on floristics, couldbe found in the RUK area. These include the Lumnitzera dominated stands (Rekawa),Ceriops dominated stands (Rekawa), Avicennia dominated stands (Rekawa), Mixedstands (Rekawa, Kahanda), Excoecaria dominated stands (between Lunawa andKalametiya) and Sonneratia dominated stands (Kalametiya, Malpeththawa). It isinteresting to note that some mangrove stands are represented by only a single species.A total of 328 species of vertebrates were recorded from the RUK area, of which 14species (4%) are endemic, while 27 species (8%) are nationally threatened. Thevertebrates include 52 species of fish, 17 species of amphibians, 49 species of reptiles,184 species of birds, and 26 species of mammals. The invertebrates include 72 species ofcolorful butterflies, 25 spec.es of terrestrial molluscs an": 9 species of aquatic molluscs.Three beach stretches that are important turtle nesting sites, eleven birding hotspots andthree bird roosting sites were identified within the RUK area.The study area has been identified for major development initiatives, under the SouthernDevelopment Programme of the Government of Sri Lanka. Therefore, the relevantconservation agencies should take steps to ensure that, biodiversity conservation concernsare adequately addressed in specific developmental activities planned for the area.

Eliminating Malaria Vectors.

Malaria vectors which predominantly feed indoors upon humans have been locally eliminated from several settings with insecticide treated nets (ITNs), indoor residual spraying or larval source management. Recent dramatic declines of An. gambiae in east Africa with imperfect ITN coverage suggest mosquito populations can rapidly collapse when forced below realistically achievable, non-zero thresholds of density and supporting resource availability. Here we explain why insecticide-based mosquito elimination strategies are feasible, desirable and can be extended to a wider variety of species by expanding the vector control arsenal to cover a broader spectrum of the resources they need to survive. The greatest advantage of eliminating mosquitoes, rather than merely controlling them, is that this precludes local selection for behavioural or physiological resistance traits. The greatest challenges are therefore to achieve high biological coverage of targeted resources rapidly enough to prevent local emergence of resistance and to then continually exclude, monitor for and respond to re-invasion from external populations

Population genetic structure of Aedes polynesiensis in the Society Islands of French Polynesia: implications for control using a Wolbachia-based autocidal strategy

Abstract Background Aedes polynesiensis is the primary vector of Wuchereria bancrofti in the South Pacific and an important vector of dengue virus. An improved understanding of the mosquito population genetics is needed for insight into the population dynamics and dispersal, which can aid in understanding the epidemiology of disease transmission and control of the vector. In light of the potential release of a Wolbachia infected strain for vector control, our objectives were to investigate the microgeographical and temporal population genetic structure of A. polynesiensis within the Society Islands of French Polynesia, and to compare the genetic background of a laboratory strain intended for release into its population of origin. Methods A panel of eight microsatellite loci were used to genotype A. polynesiensis samples collected in French Polynesia from 2005-2008 and introgressed A. polynesiensis and Aedes riversi laboratory strains. Examination of genetic differentiation was performed using F-statistics, STRUCTURE, and an AMOVA. BAYESASS was used to estimate direction and rates of mosquito movement. Results FST values, AMOVA, and STRUCTURE analyses suggest low levels of intra-island differentiation from multiple collection sites on Tahiti, Raiatea, and Maupiti. Significant pair-wise FST values translate to relatively minor levels of inter-island genetic differentiation between more isolated islands and little differentiation between islands with greater commercial traffic (i.e., Tahiti, Raiatea, and Moorea). STRUCTURE analyses also indicate two population groups across the Society Islands, and the genetic makeup of Wolbachia infected strains intended for release is similar to that of wild-type populations from its island of origin, and unlike that of A. riversi. Conclusions The observed panmictic population on Tahiti, Raiatea, and Moorea is consistent with hypothesized gene flow occurring between islands that have relatively high levels of air and maritime traffic, compared to that of the more isolated Maupiti and Tahaa. Gene flow and potential mosquito movement is discussed in relation to trials of applied autocidal strategies.</p

The dominant Anopheles vectors of human malaria in the Asia-Pacific region: occurrence data, distribution maps and bionomic précis

<p>Abstract</p> <p>Background</p> <p>The final article in a series of three publications examining the global distribution of 41 dominant vector species (DVS) of malaria is presented here. The first publication examined the DVS from the Americas, with the second covering those species present in Africa, Europe and the Middle East. Here we discuss the 19 DVS of the Asian-Pacific region. This region experiences a high diversity of vector species, many occurring sympatrically, which, combined with the occurrence of a high number of species complexes and suspected species complexes, and behavioural plasticity of many of these major vectors, adds a level of entomological complexity not comparable elsewhere globally. To try and untangle the intricacy of the vectors of this region and to increase the effectiveness of vector control interventions, an understanding of the contemporary distribution of each species, combined with a synthesis of the current knowledge of their behaviour and ecology is needed.</p> <p>Results</p> <p>Expert opinion (EO) range maps, created with the most up-to-date expert knowledge of each DVS distribution, were combined with a contemporary database of occurrence data and a suite of open access, environmental and climatic variables. Using the Boosted Regression Tree (BRT) modelling method, distribution maps of each DVS were produced. The occurrence data were abstracted from the formal, published literature, plus other relevant sources, resulting in the collation of DVS occurrence at 10116 locations across 31 countries, of which 8853 were successfully geo-referenced and 7430 were resolved to spatial areas that could be included in the BRT model. A detailed summary of the information on the bionomics of each species and species complex is also presented.</p> <p>Conclusions</p> <p>This article concludes a project aimed to establish the contemporary global distribution of the DVS of malaria. The three articles produced are intended as a detailed reference for scientists continuing research into the aspects of taxonomy, biology and ecology relevant to species-specific vector control. This research is particularly relevant to help unravel the complicated taxonomic status, ecology and epidemiology of the vectors of the Asia-Pacific region. All the occurrence data, predictive maps and EO-shape files generated during the production of these publications will be made available in the public domain. We hope that this will encourage data sharing to improve future iterations of the distribution maps.</p