These Scientists Want to Unleash an Army of Caterpillars to Destroy Cocaine Crops

Colombian scientists say the insect could replace cocaine-killing herbicides.

cocaine tussock moth
Gonzalo Andrade

A small moth could become the newest weapon in Colombia’s war on drugs. The caterpillars of Eloria noyesi, also known as the cocaine tussock moth (or el gringo, by the locals) love to snack on the leaves of the coca plant. And a group of scientists think they perhaps could unleash the little caterpillars as an attack cocaine crops without resorting to dangerous herbicides.

Last week, Colombian president Juan Manuel Santos announced that the country would stop using a controversial herbicide, glyphosate, to destroy cocaine crops, writes Manuel Rueda for Fusion. Critics have claimed the chemical can cause all kinds of health problems, such as miscarriages, skin problems and cancer; in fact, the World Health Organization reclassified glyphosate-based herbicides as a possible carcinogen back in March.

Without the herbicide, the Colombian government is looking for new (and cheaper) ways to destroy cocaine crops without harming people in the area. The rebel groups that produce cocaine often employ armed guards to protect the coca crops, making manual eradication dangerous work. But a group of scientists has argued for years that the cocaine tussock moth could be an alternative method for wiping out the drug lords’ main source of income.

Eloria Noyesi only lays its eggs on coca leaves,” Carlos Alberto Gomez, president of the privately-funded National Network of Botanical Gardens tells Rueda. “Its instincts allow it to find coca plants wherever they are.”

The plan would go something like this: raise thousands of the tiny, beige moths in a lab, pack them into boxes and release them in the jungles where the guerrilla fighters produce their cocaine. According to Gomez, the moths will head straight for the coca fields, lay thousands of eggs and annihilate the coca once their caterpillars hatch.

However, there's a lot of work to be done before the plan could be viable, writes Rueda, the most important being to make sure to get the right species of moth. According to Gonzalo Andrade, a biology professor and butterfly researcher at Bogota’s National University, only one or two of the five species of coca that grows in Colombia can be processed into cocaine. “If the moth turns out to eat other coca species, I wouldn’t be so sure about deploying it because it could destroy [legal] coca crops used by indigenous communities for traditional purposes," Andrade tells Rueda.

This idea isn't exactly popular. The plan drew fire from environmental groups off the bat. While the moths are native to the region, Ricardo Vargas, director of the environmental group Andean Action, said that dropping a huge population of moths into the area could throw the local ecosystem out of whack. "With a plan like this, the chance for ecological mischief is very high and very dangerous," Vargas told the Associated Press in 2005. 

Unleashing a hoard of caterpillars on the plants could also simply mean that cociane growers will turn to a hoard of insecticides to kill them, which could have other health drawbacks as well. 

When it was first proposed in 2005, officials in the Colombian government said the proposal was an interesting alternative to spraying herbicides from above. In the meantime, the argument over whether to use glyphosate herbicides continues. Some officials from the Colombian and United States governments, which provides financial backing for the spraying, argue that cocaine is a greater health risk than the herbicides. But now that the Colombian government is reassessing the herbicide’s risks, it might be the cocaine tussock moth’s time to shine.

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