Breadfruit Battles Mosquitoes

Clusters of male flowers of the breadfruit plant, known as inflorescences, are prized in certain regions of the world: When these plant parts are dried and burned, the smoke can ward off flying insects, especially mosquitoes. Researchers have now elucidated the chemicals in breadfruit inflorescences responsible for keeping biting bugs at bay (J. Agric. Food Chem., DOI: 10.1021/jf300101w). Furthermore, they’ve shown that the breadfruit-based compounds are more effective at deterring Aedes aegypti mosquitoes than the popular insect repellent N,N-diethyl-m-toluamide, otherwise known as DEET. Researchers led by A. Maxwell P. Jones of the University of British Columbia, Kelowna, studied a hydrodistillate of breadfruit male inflorescences and found that certain fractions worked well in preventing mosquitoes from biting. From these fractions they identified capric acid, undecanoic acid, and lauric acid as the active mosquito-deterring compounds. Each of these fatty acids proved more effective than DEET against the mosquitoes when applied in equimolar concentrations. The researchers believe the compounds could provide an alternative to DEET-based repellents.