American beautyberry proven effective against mosquitos and ticks

Posted on September 25, 2009 by Nancy Houser

An Agricultural Research Service (ARS) scientist, Charles Cantrell, had been told by his grandfather that the fresh, crushed leaves of the American beautyberry (Callicarpa Americana) always helped him keep biting insects away from his drafts animals—the horses and mules. This bit of wisdom passed onto the scientist is possibly going to be the next breakthrough against things like mosquitoes and possibly ticks.

Last year, the isolated compounds from the American beautyberry plant were studied in the ARS Natural Products Utilization Research Unit in Oxford, Miss, now led by the grandfather’s grandson. It was found that two of the beautyberry compounds—callicarpenal and intermedeol—not only repelled the mosquitoes but also the blacklegged ticks (a principal carrier of bacteria in humans that cause Lyme disease).

The study done with the DEET commercial repellent was found to repel more than 95% of the tick nymphs. When the American beautyberry compound callicarpenal was studied, it repelled 100% of the blacklegged ticks for three hours after it was applied, and 53% for four hours.

Another study done by Cantrell and the entomologist Jerome Klun of ARS’s Chemicals Affecting Insect Behavior Research Unit in Beltsville, Maryland, and Oxford plant physiologist Stephen Duke, had isolated some compounds from the plants—noticeably Callicarpenal, which was to be studied in the anti-mosquito work.

Prior to this study, ARS had developed the repellant SS220 which was as effective as DEET, considered the number one commercial insect repellent in the world and developed by both ARS and the U .S. Army. The study done of callicarpenal was conducted against the mosquito species Aedes aegypti (the yellow-fever mosquito) and the Anopheles stephensi (a mosquito known to spread malaria in Asia).