Cats, ducks and ants were humanity's first pest controllers, long before DDT
Egyptians were setting cats loose in grain stores around 3000 BC, and Chinese farmers placed colonies of weaver ants in citrus orchards to eat beetles and caterpillars. Pest control is as old as farming itself. After a century dominated by chemicals, some of those ancient living allies are back in favour.
Early methods were blunt: burn or plough under the weeds, kill the larger animals competing for crops. Crop rotation, mixed planting and breeding resistant varieties also go back a long way. Europeans had domesticated ferrets as mousers by 1500 BC, and mongooses were probably brought into Egyptian homes to deal with rats and snakes. Cave art suggests Chinese farmers used ducks in rice paddies to eat pests thousands of years ago.
Chemistry arrived early too. Sumerians dusted crops with sulphur compounds around 2500 BC. The modern era, though, was kicked off by the Colorado potato beetle sweeping across the United States. Farmers eventually turned to arsenic-based sprays, and when the feared mass poisoning of consumers never came, insecticides won broad acceptance. Industrial farming, plant-derived insecticides such as pyrethrum, and in the 20th century synthetic compounds like DDT made chemical control dominant.
Living allies never entirely disappeared. In 1762 a mynah bird was shipped to Mauritius to eat locusts, and in the 1880s Californian citrus growers deployed ladybirds against scale insects. Cheap, effective DDT halted such experiments, until by the 1960s pests were evolving resistance and environmental damage was mounting. Biological control then enjoyed a revival, either by releasing lab-bred natural enemies or by boosting local ones. A common modern example puts a bacterium that kills mosquito larvae into water sources.
Simple mechanics still matter. Repeatedly working freshly ploughed grassland exposes wireworms, the larvae of click beetles, to hungry birds. Rotating crops starves pests of their host plants and has cut early-season Colorado potato beetle outbreaks by as much as 95 percent. Chemicals remain the main tool, but they are increasingly one part of an integrated strategy.
Source: Pest control
