I love Callicarpas (aka beautyberries), blousy, deciduous shrubs with distinctive purple berries in late summer and fall. I’ve just now learned that there is even more to love about them. Some compounds in the plants have been shown to repel two species of mosquitoes:
In bite deterrent studies, spathulenol, intermedeol and callicarpenal showed significant repellent activity against A. aegypti and Anopheles stephensi.
Here’s an article from 2006 (why am I just hearing about this?) describing the results of the science. And here’s the published paper with details of the experiments and the resulting data. Two species of Callicarpa, C. americana and C. japonica were tested and both showed repellent qualities. The research began after a botanist in Mississippi mentioned a tradition of using leaves of the plant to repel biting insects.
“My grandfather would cut branches with the leaves still on them and crush the leaves, then he and his brothers would stick the branches between the harness and the horse to keep deerflies, horseflies and mosquitoes away,” said Charles T. Bryson, an ARS botanist in Stoneville, Miss. “I was a small child, maybe 7 or 8 years old, when he told me about the plant the first time. For almost 40 years, I’ve grabbed a handful of leaves, crushed them and rubbed them on my skin with the same results.”
It sounds to me that it’s worth a try as described above. Don’t count on it to be available as a repellent yet, but grow a plant or two and grab some leaves. My mother is quickly attacked by mosquitoes in her yard and I’ll be telling her to try this. A couple of these shrubs grow in her yard. I’ll try to remember to report back in the summer on the results of this non-scientific study.
C. americana (American beautyberry) and C. dichotoma (Purple beautyberry) are two of the most commonly grown species in our area. C. japonica (Japanese beautyberry) is not as available and is said to have less showy fruit, or at least less persistent fruits.
Purple beautyberry tends to be a bit more refined. There are are a few nice cultivars in the trade, including some with white berries. Here’s a purple one that’s often seen:
Welch’s Pink is a nice cultivar of American beautyberry:
The small flowers on these plants aren’t as noticeable as the berries, but are a nice summer accent until the big show later. Birds don’t seem to like the berries so they last into fall when they kind of disappear. Be sure to cut a few branches for interesting flower arrangements.
Let me know if you find that they help ward off mosquitoes.