Summaryobjective To assess the cost-effectiveness (CE) of annual targeted larviciding campaigns from 2001 to 2005 against the dengue vector Aedes aegypti in two urban areas of Cambodia with a population of 2.9 million people.methods The intervention under analysis consisted of annual larviciding campaigns targeting medium to large water storage containers in households and other premises. The CE compared the intervention against the hypothetical alternative of no intervention. The CE was calculated as the ratio of disability adjusted life years (DALYs) saved to the net cost of the intervention (in 2005 US dollars) by year. A sensitivity analysis explored the range of study parameters.results The intervention reduced the number of dengue cases and deaths by 53%. It averted an annual average of 2980 dengue hospitalizations, 11 921 dengue ambulatory cases and 23 dengue deaths, resulting in a saving of 997 DALYs per year.

Surveys were conducted of adult and immature mosquitoes in an area undergoing oil palm development in north Sarawak. Point prevalence data from 2 sites were collected annually, coinciding with annual phases of forest clearing, burning/cultivation, and maintenance. Major habitat perturbation during the forest/clearing transition shifted the major mosquito faunal equilibrium in terms of species composition, relative density and occurrence. Analyses of variance showed that the mean numbers of 4 species of Anopheles decreased significantly after forest clearing. Relative densities of immature stages decreased after forest clearing, but A. letifer and Culex tritaeniorhynchus remained relatively unchanged after the second year. Comparisons with the pre-development forest stage showed that the reductions in person-biting rates, adult survival and combined entomological inoculation rates (EIR) of A. donaldi and A. letifer decreased the risk of malaria transmission by 90% over the 4 years period. Concomitant reductions in EIR and annual malaria incidence were also correlated. This study highlighted the 'law of unintended consequences', since 2 contrasting effects were observed: reduction of malaria vectors but concomitant increase of dengue vectors.

North American spiny lizards (Sceloporus) include approximately 80 morphologically and ecologically diverse species (Wiens & Reeder 1997). Yarrow's spiny lizard, a member of the large-bodied S. torquatus group, exhibits considerable genetic and chromatic variation (Wiens et al. 1999). In the northernmost extent of its range in southern Arizona and New Mexico, S. jarrovii inhabits an archipelago of montane 'sky-islands' surrounded by arid lowlands, providing an ideal situation for studies of population differentiation. This species has also become a model system for studies of mating systems, population biology, and demography (e.g. Ballinger 1979; Middendorf 1984); therefore, highly variable molecular markers will be valuable tools for studies of population biology and differentiation in this species.

Studies on larval population densities and adult emergence rates of the Brugian filariasis vectors Mansonia bonneae Edwards and Ma. dives Schiner were conducted in freshwater swamp forest bordering the Sadong River, Serian District, Sarawak, East Malaysia, during 1984-85. Three species of aquatic host-plants in the Family Araceae were identified as supporting immature stages of the Ma. bonneae/dives complex. Proportions of positive plants were 4.7%, 6.5% and 3.4% with 6.4 +/- 2.6, 7.3 +/- 2.8 and 10.1 +/- 1.1 larvae per positive plant, respectively, for the plant species Homalomena cordata Schott, H. rostrata Griffiths and Hydrostemma motleyi (Hook. f.) Mabberley. These data indicate no significant preferences between the three types of host-plant. Detailed monitoring of the host-plant H. cordata revealed no significant monthly fluctuations in larval density per plant nor the proportion of positive plants. 11.6% of larvae were Ma. dives and 88.4% were Ma. bonneae. Mean daily yields of Ma. bonneae/dives adults per square metre of H. cordata vegetated water surface were 0.45 males plus 0.57 females during the wet season (December-February) compared with 0.2 males plus 0.31 females during the dry season (June-August). Thus output of adults per plant was approximately halved, and suitable breeding areas were further reduced, during the dry season. By extrapolation from these rates, a crude mean estimate for productivity of Ma. bonneae/dives females is 1.6 million per hectare per annum in swamp forest habitats vegetated with any of the host-plants studied.