Did you know that plants sometimes use essential oil constituents as chemical weapons?
You have probably heard about photosensitizers – chemicals that cause cell death when activated by ultraviolet light. But you may not know why plants create these compounds, some of which are found in essential oils.
Plants use them as an ingenious form of pest control. Once an insect consumes a photosensitizing chemical (as part of a leaf or fruit meal) it penetrates into the tissues of the insect.
All it takes is for that fly or bug to take a stroll in the sunlight. The photosensitizing agents are then activated by ultraviolet light, causing cell death and subsequently, the death of that hungry insect.
And so, while we humans do our best to avoid photosensitizing compounds in essential oils by, for example, removing fouranocoumarins from Bergamot oil, photoinsecticides can be a greener way to keep pests away. Once activated by sunlight, they decompose and leave no toxic trail.