Could cannabis-derived terpenes offer a natural and environmentally-friendly way of managing pests?
That’s what a team of researchers from Italy have suggested based on the finding of a new study published in ScienceDirect.
The study was looking to test the theory that the cannabis plant “has evolved as a natural weapon against phytophagous insects”. It does this by secreting important secondary metabolites such as cannabinoids and volatile terpenes.
Terpenes are a part of a plant’s essential oil and are responsible for the distinctive smell of plants such as cannabis. Along with cannabinoids such as THC and CBD, terpenes are produced in the trichomes of cannabis plants, which are the small hairs that cover the plant’s flowers and leaves.
In order to test the effectiveness of cannabis terpenes on various common pests, the scientists used steam-distillation to extract the essential oil from a variety of industrial hemp flowers (Felina 32).
The essential oil – which primarily consisted of terpenes (E)-caryophyllene (45.4%), myrcene (25.0%) and α-pinene (17.9%) – was tested on mosquitoes, the peach-potato aphid, the common house fly and the tobacco cutworm, all of which are common agricultural pests.
The oil was also tested on ladybirds and earthworms. Two invertebrates that are beneficial to plants.
Results from insecticidal tests found terpene-rich hemp oil to be extremely effective at killing the aphids and mosquito larvae, with a strike rate of 100% for both species. It also killed 80% of the house flies, 66% of the tobacco cutworms, and 33% of the adult mosquitoes.
Curiously, the essential oil was also found to be non-toxic to the beneficial ladybugs and earthworms.
The scientists said their results shed light on the possible use of hemp essential oil “as a source of environmental-friendly botanical insecticides”. They suggest it could be valuable in pest management and organic agriculture, particularly to manage aphid and housefly populations.
Therapeutic value of terpenes
Terpenes have also been found to have health benefits for humans. Mycrene, for example – which has a spicy and herbal aroma and is also plentiful in mango, eucalyptus and lemongrass – has been shown to reduce pain and inflammation.
By affecting the permeability of cell membranes, mycrene can also increase or diminish the effects of other terpenes and cannabinoids. This is why consuming a mango before using cannabis can enhance and lengthen the experience. by allowing more cannabinoids to be absorbed by the brain.
Hemp and CBD
Hemp is a variety of cannabis that has low levels of THC – the cannabinoid that gets you high – and is legal to grow under licence in the UK and most countries.
It has traditionally been grown for manufacturing purposes, hence the term ‘industrial hemp’.
Hemp essential oil can also contain viable levels of CBD, a cannabinoid that has vast therapeutic value and is currently on its way to becoming one of the most popular health supplements in the world.