The most dramatic conquest by mosquitoes came when old diseases encountered a new continent. When Columbus arrived in the New World, the mosquitoes there were pesky but carried no diseases. (Winegard chalks this up to different farming practices here: far less cultivation and disruption of natural ecosystems, and less direct contact with animals through husbandry. Syphilis was perhaps the only disease to ride the Columbian Exchange eastward.) But the blood of the new arrivals, and the mosquitoes that crossed with their ships, changed everything. Just twenty-two years after Columbus stepped onto Hispaniola, a census revealed that the local Taino population had dropped from between five and eight million people to just twenty-six thousand. Along with smallpox and influenza, mosquito-borne diseases led, by Winegard’s estimate, to the deaths of ninety-five million indigenous inhabitants of the Americas, from a pre-contact population of about a hundred million.
To the colonizers, who spread more slowly than the diseases they brought, these were largely invisible deaths, which helped create the pernicious myth of an empty continent and a Manifest Destiny to fill it. A rare account from a marooned Spanish sailor who made his way from Florida to Mexico City in 1536 described seeing native people “so bitten by mosquitoes that you would think they had the disease of Saint Lazarus the Leper. . . . It made us extremely sad to see how fertile the land was, and very beautiful, and very full of springs and rivers, and to see every place deserted and burned villages, and the people so thin and ill.” By the seventeenth century, the losses were so great that a French explorer considered them a justification for racism: “It appears visibly that God wishes that they yield their place to new peoples.” As the recent arrivals cleared land for their own purposes, they also created fresh habitats for mosquitoes, allowing their populations to skyrocket.