Newly released government files indicate that the administration of former British Prime Minister Margaret Thatcher considered a clandestine operation to combat cocaine production by introducing a species of moth capable of destroying coca plants.
The plan, conceptualized during the height of Britain's efforts in the war on drugs, would have involved breeding thousands of moths at the Porton Down facility in Wiltshire. These insects would then have been air-dropped from helicopters over coca fields in Peru, the primary source of the raw ingredient for cocaine.
Government papers declassified by the National Archives show that Thatcher's government allocated approximately £100,000 to explore the feasibility of this biological warfare approach. The initiative aimed to disrupt the supply of cocaine reaching Britain, classified as a Class A drug.
Central to the proposal was Eloria noyesi, a moth species whose larvae have a diet that exclusively consumes coca leaves. Crucially, the moth could process these chemicals without adverse effects, making it a potential biological agent.
Officials noted that a natural infestation of Eloria noyesi had previously devastated approximately 2,000 hectares of illegal coca cultivation near Tarapoto, Peru, between 1987 and 1988. This event led to estimated losses exceeding $37 million for drug traffickers and prompted Peruvian authorities to seek British expertise in developing a mass-rearing program.
Documents from 1989 reveal that military scientists were tasked with investigating methods for large-scale breeding of the moths. Foreign Office briefings suggested that the proposal was inspired by the natural infestation's success. Margaret Thatcher reportedly found the idea "sufficiently interesting to merit being pursued."
However, the plan encountered significant obstacles. By the end of 1989, the Home Office reportedly concluded that while the scheme might be technically achievable, its impact on cocaine production would likely be temporary. Concerns were also raised about potential environmental consequences.
Furthermore, ministers expressed apprehension that a leak about the operation could jeopardize its success and potentially endanger individuals involved. Consequently, the plan to deploy weaponized moths against drug cartels never advanced beyond the conceptual stage.