For medicine hunters, bugs mark the spot. Research by a joint team of scientists from the Smithsonian Tropical Research Institute (STRI) in Panama, McGill University and the University of Toronto has shown that the vivid colours of certain poisonous insects, which causes predators to avoid them, is also a relatively reliable indicator of medicinal compounds located in their host plants.

For their research, the scientists sought out 10 plants already known to contain compounds active against diseases such as breast cancer and malaria, and 10 known to be medicinally inactive. Colourful insects (mostly bright red and yellow) were found on nine of 10 medicinal plants and only four non-medicinal plants. Furthermore, nearly four times as many colourful insects appeared on each medicinally active plant than on non-medicinal plants. Plain-coloured insects displayed no discernible preference between the two plant test groups.

“These findings are incredibly exciting and important,” says Todd Capson, director of the project for STRI. “The results of this study could have direct and positive impacts on the future of medical treatment for many diseases around the world.”

Indeed, the team’s discovery is undoubtedly exciting for bio-prospecting organizations, but the findings are also a compelling argument against deforestation around the world. “Intact ecosystems are what allow this type of facilitated search to take place,” says Capson. “If you can say that we would have not found this plant unless we’d used this insect, that creates an incentive to conserve insect species as well as plant species.”

Jim MacInnis