Life

CBD From Hemp Seen Effective On Insects Resistant To Pesticides

Harvard

A groundbreaking study has recently highlighted hemp leaf extract, specifically its CBD-rich composition, as an effective agent in killing yellow fever mosquito larvae. Among these larvae is a strain of mosquito that has developed significant resistance to traditional insecticides, making the discovery all the more compelling. This research underscores the versatile potential of hemp products, presenting an entirely new application for CBD, a compound already renowned for its medicinal properties. The study suggests that using hemp extract as an insecticide could save millions of lives by addressing the mosquito population responsible for spreading deadly diseases like malaria, dengue, and yellow fever.

“Mosquitoes are one of the deadliest animals in the world, mainly because as adults they serve as vectors of disease,” said Erick Martinez Rodriguez, lead author of the study and a graduate student in entomology at Ohio State University. “It’s very important to be able to control these pests at an early stage when they are at their most vulnerable.”

In the fight against insecticide resistance, hemp extract offers a promising solution. Much like bacteria that adapt to survive antibiotics, mosquitoes have developed a resistance to many conventional insecticides due to years of heavy exposure. As these resistant strains grow, so does the difficulty of controlling mosquito populations, especially in regions most affected by mosquito-borne diseases. By targeting the larvae, researchers aim to control mosquito populations before they reach adulthood, a stage when they are mobile and challenging to contain.

Rodriguez’s interest in natural alternatives for pest control was inspired by previous research conducted at Ohio State. Earlier studies had shown that the bark of a plant native to Madagascar served as a natural mosquito repellent and insecticide. Building on this concept, Rodriguez sought to investigate hemp as another natural source, believing its unique properties could make it a viable alternative to synthetic insecticides. The potential to deploy such natural, plant-based insecticides in areas heavily impacted by disease-carrying mosquitoes could transform public health in these regions.

To carry out the experiment, Rodriguez and his team prepared the hemp leaf extract by first drying and pulverizing the leaves into a fine powder. They then soaked the powder in methanol for several weeks to reach the required CBD concentration. After removing the methanol, the researchers were left with a concentrated CBD-rich extract that was ready to be tested on the mosquito larvae. This extract was combined with the larvae’s food, providing a way to observe its effects under controlled conditions.

The results were remarkable: hemp extract proved equally toxic to both insecticide-resistant and non-resistant mosquito larvae. The lethal impact of the CBD-rich hemp extract was surprising due to the relatively small amount needed to kill the larvae. According to Rodriguez, the concentration required to achieve 50% mortality was on par with other natural extracts previously tested in their laboratory, demonstrating that CBD could hold significant insecticidal power. “If you compare the amount of hemp extract needed to kill 50% of the population to other synthetic conventional insecticides, it is on the high side, but when you compare it side-by-side to other natural extracts we have tested in our lab, only a relatively low amount is required to produce high mortality values in larvae,” he noted.

While CBD in higher concentrations led to complete mortality among the mosquito larvae, lower doses resulted in varying levels of mortality over time, allowing researchers to observe the compound’s potential as a controlled pest management solution. Cannabidiol, or CBD, is one of many active compounds found in hemp plants, a type of Cannabis sativa that contains little to no THC, the psychoactive compound associated with cannabis. As such, CBD has earned attention for its wide range of applications, from medicinal uses to pet care products, and now as an insecticide.

This finding brings about an intriguing question regarding CBD’s effect on other organisms, particularly insects beneficial to ecosystems, like honeybees and butterflies. Researchers are cautious about the broader ecological impact, and further studies are likely needed to determine whether the extract’s toxic effects are selective enough to spare desirable insects while targeting mosquitoes. “CBD is a compound that appears to be safe for people and our companion animals to ingest,” said Peter Piermarini, a co-author of the study. “It’ll be interesting to learn more about how CBD interacts with various proteins in mammals and insects to understand why it’s safe for people but not insects.”

CBD’s potential for mosquito control represents a significant breakthrough in entomology and public health. The limitations of conventional insecticides, which often pose health risks to humans and animals while leaving toxic residues in the environment, have driven the search for safer alternatives. Hemp-based insecticides could present a sustainable and environmentally friendly option. Given the health crisis posed by mosquito-borne diseases worldwide, especially in developing regions, this discovery could have life-saving implications. It represents a step forward in the quest to develop efficient and eco-friendly pest control solutions.

Future research will focus on how best to apply CBD in real-world settings to manage mosquito populations without unintended consequences for other species. For now, this study serves as a promising example of how exploring natural compounds can yield innovative solutions to pressing global health issues. The versatile nature of hemp products continues to surprise, and the potential of CBD as an insecticide highlights yet another way this plant can contribute to human well-being.