Cannabis Extracts Show Promise Against Mosquitoes

A systematic review of laboratory studies suggests that Cannabis sativa may have insecticidal activity against several medically important insects—including mosquitoes and cat fleas. But the evidence is still too limited and inconsistent to support cannabis-based products as an established vector-control tool. Published in 2024 in the Revista da Faculdade de Ciências Médicas de Sorocaba, the review examined experimental research on cannabis preparations tested against insects at different stages of development. The researchers identified effects involving five species: the mosquitoes Aedes albopictus, Anopheles stephensi, Anopheles gambiae, and Culex quinquefasciatus, as well as the flea Ctenocephalides felis felis. The studies evaluated several cannabis-based formulations, including essential oils, plant extracts, and an essential-oil nanoemulsion. Reported effects included mortality during the egg, larval, pupal, and adult stages. Some experiments also examined reproductive outcomes, such as fertility, fecundity, birth rates, and the emergence of adult insects. Larvae were the most frequently studied life stage, appearing in all of the experiments included in the review. That focus is relevant to mosquito control because eliminating larvae before they mature can reduce the number of disease-carrying adults. However, the researchers cautioned that the available studies were too few and too different from one another to establish which cannabis formulation works best, at what concentration, or against which species. The review included only eight experimental studies focused on medically important insects. Most species were represented by a single study, while Culex quinquefasciatus accounted for the largest share of the evidence. The experiments also varied in the cannabis plant material used, extraction methods, chemical composition, exposure conditions, and outcome measurements. Those differences make direct comparisons difficult and limit the strength of any overall conclusion. A separate 2024 laboratory study provides additional evidence relevant to mosquito control. In that work, researchers tested hemp leaf extracts against susceptible and pyrethroid-resistant strains of Aedes aegypti. The extracts killed larvae from both strains within 48 hours, and the researchers identified cannabidiol, or CBD, as the primary compound associated with the observed toxicity. The results point to a possible avenue for developing larvicides that work differently from commonly used pyrethroid insecticides—but they do not demonstrate that a cannabis-derived product is ready for field use. Mosquitoes such as Aedes, Anopheles, and Culex species can transmit pathogens responsible for diseases including dengue, Zika, yellow fever, malaria, and West Nile fever. The Centers for Disease Control and Prevention’s overview of vector-borne diseases describes mosquitoes, ticks, and fleas as vectors that can spread disease-causing germs through bites. The review’s findings therefore represent a research lead rather than a public-health solution. Laboratory toxicity does not necessarily translate into effectiveness outdoors, where sunlight, rain, water chemistry, temperature, and insect behavior can alter performance. Researchers would also need to assess effects on fish, aquatic invertebrates, pollinators, beneficial insects, and other non-target organisms, as well as the stability, cost, and safety of any proposed formulation. The authors emphasized that major knowledge gaps remain, particularly concerning reproductive effects and the differences between formulations and insect species. Standardized experiments with clearly characterized cannabis extracts, larger numbers of vector species, and field-based testing will be needed before the plant’s role in integrated mosquito-management programs can be determined. For now, the evidence supports describing cannabis and hemp compounds as promising candidates for further insecticide research—not as proven replacements for existing vector-control measures.