Mosquitoes pose a serious threat to the economy, health status, and biosecurity of countries around the world. Mosquitoes kill an average of 700,000 people per year. The global expansion of air, sea, and land transport networks has greatly enhanced the spread of mosquitoes internationally. In the Pacific, the number of mosquito-borne diseases occurring has been on the rise in recent years, possibly as a result of human-mediated dispersal of larvae and adult mosquitoes. The Kingdom of Tonga has had numerous outbreaks of dengue fever and chikungunya virus in recent years. Previous research has catalogued species occurrences and distributions throughout Tonga. However, it is unknown whether new species have arrived in Tonga, and if distribution of previously found species has changed since the last comprehensive survey in 2006. Present research aims to update the literature by conducting a mosquito survey at 84 sites across the four islands of Tongatapu, Pangaimotu, ‘Oneata, and ‘Eua to record the distribution and occurrence of mosquito larvae. Nine mosquito species were collected: Aedes aegypti Linnaeus, A. albopictus Skuse, A. tongae Edwards, A. horrescens Edwards, A. vexans nocturnus Theobold, Culex annulirostris Skuse, C. albinervis Edwards, C. quinquefasciatus Say and C. sitiens Wiedemann. The collection of A. albopictus is the second time that this species has been recorded in Tonga. Moreover, the spatial extent of this species throughout Tonga was far greater than previously recorded. A major outcome of this survey has been the creation of an identification key for the mosquito larvae species of Tonga. This key should increase the accuracy of positive mosquito larvae identifications in Tonga. Mosquitoes were more frequently collected in artificial (e.g., used car tyres, fuel drums, containers) than natural (e.g., pools, ponds, tree holes) habitats. Car tyres, water containers, fuel drums, fridges, washing machines, and ponds were the most common habitats in which mosquito larvae were found. Aedes aegypti, A. albopictus, and C. quinquefasciatus were the three most common mosquito species collected, whereas A. tongae, A. horrescens, A. vexans nocturnus, C. annulirostris, C. sitiens, and C. albinervis were less frequently found. Multiple logistic regression analyses indicated that habitat volume had a significant positive effect on the presence of A. albopictus and A. tongae, whereas conductivity had a significant positive effect on the presence of C. annulirostris. Additionally, the volume by temperature interaction was a significant predictor of species presence for A. aegypti, A. albopictus, and C. annulirostris (as habitat volume increases, the effect of temperature went from neutral to negative). This suggests that larger, cooler habitats favour colonisation by these species. The number of artificial habitats (particularly used car tyres) present may have significantly increased since previous studies. Management should therefore focus on implementing community-run mosquito projects aimed at reducing the number of artificial habitats capable of being colonised by mosquito larvae. Covering, tipping out water, and infilling these habitats with soil to prevent mosquito oviposition is a pragmatic and straightforward mosquito control solution. This should immensely reduce the abundance of mosquitoes and may prevent disease outbreak in Tonga.

National accounting and national accounts concepts have very strong links to business accounting and business accounts concepts, and economic theory. The current trend in national accounting work is to carry out the task based on a framework which functions as an integrated general purpose statistical information system. The principal constraints to this approach are data availability which is a function of the standard and serviceability of the country's national statistical system, and general conventional accounting principles. It is submitted that one of the important properties that a system of national accounts should possess is inherent flexibility in order to allow such a system to respond sensitively to developments in economic theory and specialized needs/demands. Even though the development of certain national accounting principles can be traced back to the seventeenth century, national accounting generally is a twentieth century invention, with the development of the SNA as a very major breakthrough. One of the SNA's most valuable contributions is its provision of a consistent and comprehensive framework in terms of national accounting concepts, definitions and principles. The application of the conventional national accounting principles to Tonga and other developing countries has been confronted with many conceptual and statistical problems. The existence of imperfect national price systems in developing countries has led many critics to question the validity of national income estimates for such countries. It has been submitted that such imperfection of national price systems has been essentially a function of constraints on commodity and factor movements. It is argued however that many such restrictions cannot be applied with significant force to the case of Tonga and that there exists great validity and usefulness in making national income estimation. Non-market portion of total production in the economy of Tonga is significant. Its estimation for national accounting purposes is faced with the conceptual problems of setting appropriate boundary of production and imputation. The recommendations of the SNA with regard to the former are endorsed for national accounting practice in Tonga with special attention to transactions such as the unilateral provisions of free and/or partially paid services by Tongans to government and church authorities. Due to the predominantly agricultural character of the Tongan economy and the existence of a partial subsistence sector, certain conceptual problems arising from the need to make clear distinctions between production and consumption, and saving and investment in accordance with the Keynesian framework are bound to prevail with regard to national accounting in the Kingdom. There are also the problems associated with any attempt to distinguish the various factor shares of national income. Recommendations and comments concerning possible means of minimizing these problems or perhaps putting such, problems into some balanced perspective, are presented. Statistical problems faced with national accounting work in Tonga are generally associated with the inadequacy and unreliability of basic national accounting statistics, and the shortage of appropriate material and human resources. While most of the statistical problems can be substantially alleviated by more liberal direction of resources to the process of data collection and national income estimation, some of the statistical problems like the conceptual problems would persist in Tonga as long as the general standard of the Kingdom's national statistical system is low and the general state of under-development prevails. A close scrutiny of the general performance and structure of the Tongan economy, current and anticipated future needs/demands for various national accounting statistical series, and current and anticipated future status of data availability, suggests that a system of national accounts for Tonga which could bring out the important economic characteristics and inter-relationships of important sectors in the economy would be considered as very desirable. With the increasing complexity of the Kingdom's economy and associated increasing diversity of needs/demands for appropriate statistical series, it is felt that a system of national accounts which offers greater disaggregation of important aggregates and which views the production sector at some component levels such as "Agricultural", "Non-Agricultural, Non-Financial" and "Financial" production sub-sectors even though it is a diversion from the general recommendations of the SNA, would merit a high level of serviceability. A system of national accounts which is essentially based on a system of sector accounts with the incorporation of the above stated partitioning of the production sector is therefore proposed for Tonga. The proposed system also consists of sets of supplementary tables and aggregative accounts which aim at providing essential supplementary information via the adoption of different classification systems or appropriate aggregations of information exhibited in the sector accounts. Issues concerning suggested future expansion of the proposed system to include appropriate input-output matrices and flow of funds tables and the need for a proper development and application of an appropriate social accounting matrix (SAM) for Tonga are also discussed. The proposed system of national accounts for Tonga is relatively comprehensive and possesses inherent flexibility which is a reflection of its primary inheritance from the SNA. Even though it might take some time before the proposed design can be implemented in full, its relative comprehensiveness would automatically serve a lot of useful purposes e.g. its explicit facilitation of attention to gaps in the existing data series. The implementation of the proposed system is regarded as a feasible long term project for the Tonga national statistical agency. The extent to which it can be implemented in the very near future given Government's acceptance, would depend heavily on the priority level the Tonga Government attaches or would attach to the task of developing and improving the Kingdom's national accounting system.