The extinction of mosquitoes from this island, an oft-proclaimed wish of park visitors who expose too much skin and reveal a faith in inhumanity, is likely to be a fool's errand. Those species that harbour virulent pathogens enjoy the connivance of half-witting hosts: skyrise gardeners plagued by poor routines, ill-maintained roofs and sites of stagnant waterbodies, and further resist eradication by plunging into new recombinant pathways and aerial reservoirs. The country has been declared malaria-free since 1982, but in 2009, a rash of outbreaks in three localised clusters – Sembawang, Mandai-Sungei Kadut and Jurong Island – aroused concerns that Plasmodium vivax might once again threaten the population. The putative vector, Anopheles sinensis females that were the predominant anophelines in two of the sites, proved to be blanks, and the episode remains an epidemiological mystery.
Other, more prominent, enemies of public health have also turned out to be moving targets, agents of microscopic terror that float beyond established norms and rise to new heights. Once thought to roam no more than 50-100 metres from its breeding sites, Aedes aegypti has shown the ability to disperse over a distance of more than 300 metres. Females have also demonstrated the will to reach every floor of a 21-storey apartment block after release at the 12th level. Possibly an adaptive response to the systematic elimination of handy breeding sites, this trait is perhaps why conventional tactics against outbreaks of dengue fever such as the focal spraying of insecticides have been largely measures of insignificance.
Along with these discouraging trends, the avowed foes of meagre bloodsuckers are likely to be further sapped by the finding that at least 137 species of mosquitoes have found a home in Singapore. Only seven (Aedes aegypti, Ae albopictus, Culex quinquefasciatus, C. tritaeniorhynchus, C. gelidus, Anopheles maculatus and An sundaicus) are recognised villains, vampires who thirst from dusk to dawn and infect their victims with the seeds of dengue, yellow fever, malaria, chikungunya, elephantiasis and Japanese Encephalitis. The vast majority, however, sampled from the island's wilder parts or collected by boys in green who served as bait, appear to be insects restricted to forested swamps, mangroves and the marching grounds of armed men, and are likely to be mere nuisances than mortal threats. Still, that is probably cold comfort for those who remain bugged and bothered by the heralds of unwelcome buzz, the hapless prey of thirsty hordes who skim over solid air and skirt clumsy swings to deliver short, sharp stabs of desire on soft, sweaty skin.