Cannabinoids, naturally occurring compounds found in hemp plants, may have evolved to deter pests from chewing on them, according to Cornell University research that showed higher cannabinoid concentrations in hemp leaves led to proportionately less damage from insect larvae. The study opens the door for potentially developing pesticides from cannabinoid extracts, though such uses would be limited to non-edible plants, given the pharmacological properties of the compounds, which include CBD, THC and their precursor CBG.

In the decades since scientists first identified cannabinoids, research has focused on their medicinal and intoxicating effects, but it's never been clear why these plants evolved cannabinoids in the first place. Researchers have hypothesized that cannabinoids may protect plants from ultraviolet light, pathogens and herbivores. It has been speculated that they are defensive compounds, because they primarily accumulate in female flowers to protect seeds, which is a fairly common concept in plants.

The study gives us insight into how cannabinoids function in natural systems and can help us develop new THC-compliant hemp cultivars that maintain these natural built-in defenses against herbivores. The potential use of cannabinoids as a pesticide is an exciting area for future research, but there will certainly be regulatory barriers due to pharmacological activity of the compounds, and more studies are needed to understand what pests cannabinoids will be effective against.