But the minimus was easily wiped out by insecticides like DDT. This was because, as a Nepali entomologist once told me, minimus acted ‘like a king’. It had refined tastes. Unlike other mosquitos, it preferred not animal but human blood, and after feasting sought out comfortable accommodations — resting inside houses, not outside. DDT was easiest to spray on walls inside houses, exactly where minimus liked to hang out.
During the 1950s and 1960s, the World Health Organisation and United States led a global campaign to wipe out malaria in scores of countries around the world, including Nepal. Many of these efforts fell far short of the goal, mostly because the mosquito carriers proved hard to eliminate or they developed resistance to insecticides and medicines.
In Nepal, however, despite manpower shortages and a daunting geography, eliminating the Anopheles minimus proved relatively easy. Although never reaching complete eradication, Nepal’s program proved far more successful than most.
The near complete removal of malaria in a country whose history had been moulded by the disease brought dramatic changes: vast movements of people from the hill ridges to valley floors and to the Tarai, as well as movement north from the plains. There was large-scale deforestation and habitat loss, and tumultuous social and political reconfigurations. Almost everyone was affected, but especially the Tharu, one of Nepal’s largest ethnic groups, who lived primarily in or near the forest belt.
These changes would probably never have come, at least not in exactly the same form, had the Anopheles minimus possessed slightly different habits. Indeed, if it had not liked resting exactly where DDT was sprayed, malaria might still be a dominant force in Nepali life.
This little non-human actor deserves a big place in Nepal’s history books alongside the much better known political movers and shakers.
Tom Robertson is an environmental historian and Executive Director of Fulbright Nepal. A longer version of this article will appear in this month’s Journal of American History.
Learning from Malaria, Bjørn Lomborg
The return of the parasites, Hemlata Rai