Does Callicarpa Beautyberry Repel Insects Such As Mosquitoes, Ticks Or Fire Ants?

Mosquitoes are a big problem in many places and ticks are becoming an even bigger concern. Fire ants are more localized but they can be a real problem in the garden. Both folklore and modern day experiences suggest a remedy for these pests based on callicarpa, the beautyberry. Some people plant it in the garden to reduce insect numbers. Others prepare various concoctions to spread on clothing or skin to keep pests off and some just rub the leaves on their skin for a similar effect. One person even reported that she eats the berries and never gets bit!

What does the science say?

Meet Callicarpa – The Beautyberry

Beautyberry is an attractive shrub that makes thousands of tiny pink flowers in summer. These are followed by clusters of highly ornamental bright, purple berries (white berry cultivars exist). The berries persist into fall if they don’t get eaten by birds or mammals and although they look poisonous they are edible and can be used to make jelly, wine or tea.

There are a few species but the most common are Callicarpa americana, the American beautyberry and Callicarpa japonica the Japanese beautyberry. Callicarpa bodinieri is a native of China and Callicarpa dichotoma is an Asian species, both of which are common garden plants in Europe and North America.

Beautyberry Folklore

Beautyberry leaves have been used as a bug repellent by indigenous people in North America. They were simply rubbed on the skin to provide protection. Early 20th-century farmers placed crushed leaves under the harness of horses and mules for the same reason.

American Indians made beautyberry tea to treat illnesses.

Beautyberry Internet Claims

Here are some claims that I found on the internet.

“Many experienced outdoor enthusiasts and survival experts use the leaves of the beautyberry shrub as an insect repellent instead of commercial sprays containing DEET”. I really doubt that. No one is going to go into the woods hoping to find a plant they can use for bugs. We all carry DEET or an equivalent product.

“My daughter eats the berries and she doesn’t get bit by anything”. I found zero evidence that the berries repel insects or that the berries contain insect repelling chemicals. All of the scientific studies used leaves.

I make a spray from the leaves that definitely works for mosquitoes, but not so much for ticks”.  Some claim it works for mosquitoes, others that it works for ticks. The fundamental problem with such claims is that unless they are accompanied with a recipe for making the mixture, they tells us very little about what works and what does not work.

Here is a recipe from Prepper Gardens:

• 1 cup of crushed beautyberry leaves,
• 4 ounces of rubbing alcohol,
• 2 drops of desired body wash or spray (personal choice),
• Personal size spray bottle,

An important ingredient here is the alcohol which is probably better at extracting organic compounds than water, however it is not the solvent used in research and so we have no idea how effective this mixture is.

Many internet recipes use water or boiling water and they are even less likely to be effective than one based on alcohol.

Some Beautyberry Chemistry

Three compounds, callicarpenal, intermedeol and spathulenol, have been extracted from Callicarpa by the USA Department of Agriculture and have been shown to have some insect repelling properties.

These compounds are plant terpenoids which is a class of important plant metabolites. Other terpenoids you might be familiar with include the scent of eucalyptus, the flavors of cinnamon, cloves, and ginger, the yellow color in sunflowers, the red color in tomatoes and the cannabinoids found in cannabis.

In general, most terpenoids are insoluble in water but are soluble in ethanol, chloroform and diethyl ether.

Plants vs Tea vs Pure Chemicals

You can use callicarpa in three general ways to try and repel insects. You can grow the plant in the garden. You can use parts of the plant to make various teas and infusions – for simplicity I’ll call all of these teas. Or you can use pure chemicals. This last option is not available to gardeners but it is the one normally used in research.

A big problem with the internet is that these three options are mixed up and considered to be the same thing which leads to all kinds of incorrect conclusions.

A good example is the citronella plant that is used to ward off mosquitoes. By the way, the plant sold by most nurseries is NOT the citronella plant – another myth I debunk in Citronella Plant – Does it Really Keep Mosquitoes Away. Citronella, as a pure extracted chemical does repel mosquitoes. Growing the plant in the garden does nothing to repel mosquitoes. In fact mosquitoes seem to like sitting on its leaves.

I found this article heading about beautyberry:  “The American beautyberry has been found to repel mosquitoes and other biting insects, according to a 12-month study by the U.S. Department of Agriculture.” That sounds very convincing. There is even a link to the study to make it sound even more convincing, but you have to read the study to really understand things. The study tested pure chemicals – not plants. The heading is a lie that implies plants repel insects – they don’t! Not only that but “other biting insects”, except for a few cases, have not been tested.

Laboratories have extracted pure callicarpenal and intermedeol from callicarpa and they have shown they repel some insects. Gardeners then jump to the conclusion that teas and plants also work. That may or may not be the case, but unless research has shown these other options to also work, we should assume they don’t work, or work poorly.

Why? Because growing plants may not give off the insect repelling chemicals, or if they do, they may be given off in very small amounts that have no effect on insects.

Home made teas may also not work because they use water to try and extract the active ingredients. This is why scientists usually extract such chemicals in alcohol or other organic solvents.

Let’s see what science really says.

Does Beautyberry Repel Ticks?

There are many types of ticks and it is clear from research that not all ticks react the same way. Blacklegged ticks (Ixodes scapularis) are the principal carrier of bacteria that cause Lyme disease in humans. The lone star tick (Amblyomma americanum) transmits a disease known as ehrlichioses. These are the two types of ticks that were studied in the following.

Relatively pure extracted compounds from callicarpa were tested by applying each compound on cloth strips wrapped around a person’s index finger. Ticks were then placed on the fingertip. Dose amounts were similar to commercial DEET products that are known to repel ticks. Callicarpenal repelled 100% of the blacklegged ticks after 3 hours, but only 53% after 4 hours. Intermedeol repelled only 73% after 3 hours.

In comparison, only intermedeol showed limited repellency of the lone star tick, at the same dose. At nine times the dose callicarpenal and intermedeol had a repellency of 20 and 40% respectively. Most discussions of this work on the internet ignore this second finding and report that “callicarpenal is effective against ticks”.

Here are some recommendations for reducing tick populations that work.

Does Beautyberry Repel Mosquitoes?

A biting assay for mosquitoes showed that callicarpenal was 21% less effective than DEET but significantly more effective than a control (ethanol).

Another study found that “spathulenol, intermedeol, and callicarpenal showed significant repellent activity against the mosquito species A. aegypti and Anopheles stephensi”.

Does Beautyberry Repel Fire Ants?

Callicarpenal and intermedeol have been tested for two different species of imported fire ants, Solenopsis invicta and Solenopsis richteri as well as a hybrid of the two. Both compounds showed significant repellency at a 50 ppm dose. Intermedeol was more effective than callicarpenal.

Toxicity Of Callicarpa