Written by Kerre Ann Willsher, PhD
Nepetalactone, a chemical in Catnip (nepeta cataria), a species of mint, has been found to be a very effective mosquito repellant (American Chemical Society. & ScienceDaily, 2001; Le Page, 2021). This is good news as some species of mosquito are developing resistance to DEET which is the most widely used repellant worldwide. Insect repellant is an important adjunct to current tools such as insecticide-treated bed nets in the prevention of Malaria. However, the research in eastern Indonesia on Catnip to prevent malaria was non-conclusive (Ipa et al., 2020). Catnip has a similar smell to mint and would be more acceptable than other insecticides.
However, Nepetalactone is difficult and expensive to extract from Catnip plants. Martin et al at Concordia University added eight genes to a yeast strain creating a chemical pathway to making large quantities of Nepetalactone (Le Page, 2021). Nonetheless, there is still work to be done as the process also produces a chemical that is harmful to the yeast. Martin et al maintain that this problem is easily solved and are in discussions with insecticide companies (Le Page, 2021).
The author has two cats who just love having catnip spray on their scratching posts. This must be a reason that mosquitos are rarely a problem in her house. But what to do to avoid attracting cats when wearing Catnip repellent outdoors no-one seems to know!!!!
American Chemical Society., & ScienceDaily. (2001). Catnip Repels Mosquitoes More Effectively Than DEET. Retrieved from https://www.sciencedaily.com/releases/2001/08/010828075659.htm
Ipa, M., Widawati, M., Laksono, A. D., Krusini, I., & Dhewantara, P. W. (2020). Variation of preventive practices and its association with malaria infection in eastern Indonesia: Findings from community-based survey. PLoS Med. doi:10.1371/journal.pone.0232909
Le Page, M. (2021, September 25, 2021). Catnip chemical from yeast could be mosquito beater. New Scientist, p. 14.