Solving the mystery of a centuries-old plague

Edward O. Wilson identified two different ant species in investigating the mystery of centuries-old plagues, a tropical fire ant in the early 1500s and an introduced African ant in the late 1700s. Both ant plagues came with widespread crop destruction that Wilson blames on the arrival of sap-sucking insects that are tended by the ants in exchange for a sweet honeydew secretion. “This was the first recorded environmental crisis of the New World,” Wilson said. “The problem with invasive species has been as old as the appearance of the first invasive species to the New World — the Europeans. That first invasive species [Europeans] became tormented by the second [ants].” Wilson, Pellegrino University Professor Emeritus, said he became interested in accounts of the plague ants during research on West Indian ant species that he began in the 1980s. As he became more familiar with the ant fauna of the area, particularly in the late 1990s and early 2000s, Wilson began to comb through historical material looking for clues to the plague ants’ identity. Wilson uncovered several historical accounts of the two plagues, which occurred on several Caribbean islands from 1518 to 1519 and from 1760 to 1770. Settlers of the time assumed that the crop destruction came from the ants but Wilson doesn’t believe that was the case. A second insect, unnoticed among the swarming ants, destroyed the crops.