Cannabis extract against mosquito larvae
Cannabis extract results in 100% destruction of pesticide-resistant mosquito larvae
New research aimed at tackling global insecticide resistance has found that an extract from the cannabis plant, typically used to treat various health conditions, is highly effective in killing mosquito larvae.
Mosquitoes and insecticide resistance: a global threat and possible solutions
Mosquitoes affect millions of lives as they are carriers of malaria, dengue fever, the Zika virus, and other serious diseases. In recent decades, insecticides have proven effective in many parts of the world, but mosquitoes are increasingly developing resistance to various insecticides, posing a significant public health challenge.
What exactly is insecticide resistance, and how does it develop?
Insecticide resistance develops when a mosquito population undergoes genetic changes that allow them to withstand chemical agents that previously killed them. This is an evolutionary process similar to antibiotic resistance observed in humans today.
Mosquitoes have short lifespans and reproduce quickly, which enables rapid adaptation to their environment. If the same insecticide is used repeatedly in a particular area, genetic resistance to that chemical emerges. Mosquitoes that survive the poisoning pass on their resistance to their offspring, and over time, an increasing proportion of the population becomes resistant.
The global situation
According to reports from the World Health Organization (WHO), a growing proportion of mosquito populations are becoming resistant to insecticides, especially in areas where chemicals are heavily used to prevent diseases. In Africa, where malaria is a severe public health issue, malaria-transmitting mosquitoes are highly resistant to pyrethroid-based insecticides, which are also used to treat mosquito nets. Similar trends are observed in parts of Asia and South America.
Why is insecticide resistance dangerous?
Reduced effectiveness of insecticides poses a serious problem in controlling disease outbreaks. When spraying is ineffective, controlling the spread of diseases becomes more difficult. This is especially critical in the fight against malaria, which claims over 400,000 lives annually, mostly affecting children.
Mosquito insecticide resistance presents a considerable challenge to the world, but advances in science and technology offer hope for effective solutions. Integrated approaches and new technologies can help reduce disease transmission and maintain the public health gains achieved over past decades.
According to the latest research, cannabis extract and the CBD it contains could play a key role in this fight
CBD, or cannabidiol, is a natural component of the cannabis plant. Known for its calming effects, it is increasingly popular for pain relief, anxiety reduction, inflammation control, and treating sleep disorders. CBD Oils, capsules, and creams are widely used because many experience improvements in various health issues without the side effects commonly associated with conventional treatments. While CBD is popular as a natural therapeutic option, surprisingly, new research highlights a completely different potential application.
A study published in the Insects journal found that cannabis extract kills mosquito larvae from two different strains of the yellow fever mosquito within 48 hours, including one strain resistant to insecticides.
To test the toxic effect of cannabis on mosquito larvae, the team ground air-dried cannabis leaves into a fine powder and soaked it in methanol for several weeks. The methanol was then removed to yield a crude extract, which was finally mixed into the larvae's food.
The extract used was potent enough to be equally toxic to mosquito larvae of both strains. What was surprising," said lead researcher Martinez Rodriguez, "is how small an amount was needed to achieve such lethal effects."
"When we compare the amount of cannabis extract needed to kill the population to that required for traditional synthetic insecticides, this study ranks at the top. Even compared to other natural extracts, only a relatively small quantity is needed to reach a high mortality rate," said Martinez Rodriguez.
Benefits of cannabis and future research directions
Although it is still unclear exactly how the extract biologically affects mosquito larvae, the research results indicate that CBD was the primary active ingredient in the cannabis extract, successfully bypassing larvae resistance to other insecticides.
One advantage of cannabis is that it can be cultivated sustainably compared to other plant alternatives, meaning cannabis-based insecticides could be produced relatively cheaply.
According to Peter Piermarini, co-author of the study and professor at the Ohio State University Department of Entomology, while this discovery bodes well for developing future natural mosquito control products, further research is needed to assess the safety of cannabis and CBD for honeybees and other pollinators, which scientists do not want to harm or disrupt.
"CBD is a compound safe for humans and most animals," said Piermarini. "It will be interesting to learn more about how CBD interacts with various insect proteins to understand why it is safe for humans but toxic to mosquito larvae."
Reference: Erick J. Martínez Rodríguez, P. Larry Phelan, Luis Canas, Nuris Acosta, Harinantenaina L. Rakotondraibe and Peter M. Piermarini29: “Larvicidal effects of hemp extracts and cannabidiol against the yellow fever mosquito Aedes aegypti”
