*3.2.1.2 Is it honey from acacia trees?*

The eDNA analyses were conducted on 14 honey products purchased at high-end supermarkets in Tokyo. None of the products sold as single-flower honey/monofloral was actually from a single source. The DNA of false acacia was detected in all of the seven well-known acacia brands, but it was dominant in only four of them and the second-dominant following other plants in the other three products. In some of those sold as honey from a single source such as astragalus, ilex, amur cork, buckwheat, or manuka, these nominal source plants were not the dominant sources, or their DNA was not detected at all. None of the products analyzed was actually from a single source. Since honeybees visit various flowers, this is not surprising.

Acacia single-flower honey is much sought after in Japan, and it is traded at a high price. Among the seven acacia monofloral/single-flower honey products, however, acacia was found to be a dominant source for honey only in four of them, and the other three products contained honey only from false acacia as its seconddominant source. A product sold as monofloral honey may actually have been from several source plants/multifloral honey. Astragalus honey made in Tokyo is from

#### **Figure 3.**

*An example of analysis results of honey we produce. More than 20 kinds of plants were confirmed. With the exception of* Prunus maximowiczii*,* Wisteria floribunda, *and* Trifolium repens*, most species are not famous as honey source plants. Based on data from IDEA Consultants, Inc.*

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*Application of Environmental DNA: Honey Bee behavior and Ecosystems for Sustainable…*

three sources, while 18 source plants were detected in another astragalus honey made in Fukuoka. Some of the honey brands tested had plants containing toxic

Verifying the quality of high value-added honey is important for the development of a healthy beekeeping industry. Thus, DNA analysis can be a powerful tool to identify origins. If the list on the label contains a plant species that does not grow in the local area or does not contain the DNA that should be detectable as a species

We analyzed 14 honeys purchased at a luxury supermarket (**Table 1**). More than

half of the products contained plant DNA on the label, but some products were not detected at all. Manuka DNA was not detected in the Manuka honey analyzed this time. Manuka honey may have been shipped after aging for several years after harvest, so it is possible that DNA degraded during this aging period. DNA is generally unstable and fragile. Since it breaks down over time, there is a possibility that the labeled honey source cannot be detected by DNA analysis, even if it is correct. However, this sample remains suspicious because it has confirmed several plant DNAs normally growing in New Zealand. Following the accusation that their Manuka honey was fake, New Zealand authority has mandated DNA analysis for

With eDNA analysis, we can better understand the flora of the areas around the hives. This method could only identify plant DNAs that were visited by bees. Furthermore, this method may not show a correlation between the amount of DNA and the volume of existing plants. Despite these disadvantages, honey eDNA

Bees are much better at finding flowers than humans. Occasionally, plant species that humans are incapable of identifying may be found in the DNA of honey. In the honey produced near Mt. Fuji, the DNA of several types of plants which were not identified in and around the production area were detected. One of them, *Gaultheria pyroloides,* distributes in the alpine area of Mt. Fuji, which was more than 8 km away in terms of horizontal distance and 1500 m in vertical distance from the beehives. This simple result provides two possibilities that this plant grows at low attitudes or the bees fly over a distance of more than 8 km. It is a new scientific discovery in any case.

It is typically thought that honeybees mainly use grassland plants. This may be because we usually observe only house flowers near the ground. The honey made by our bees contains a lot of woody plants, and we can also see such examples in previous studies showing that woody plants are more prominent as nectar plants

on the product label, it may be misrepresenting the honey and its origin.

**3.3 eDNA analyses can open the door for new scientific findings**

analysis is a effective tool to verify the general trends of honey origins.

*3.3.1 Discovering the flora and phenology in surrounding areas*

*DOI: http://dx.doi.org/10.5772/intechopen.92717*

*3.2.1.3 eDNA would reveal the authenticity of honey*

alkaloid as their source plants.

their Manuka honey since 2018 [49].

*3.3.2 Honeybees are experts at flower hunting*

*3.3.3 Importance of woody plants as a source for honey*

than previously thought [50].

three sources, while 18 source plants were detected in another astragalus honey made in Fukuoka. Some of the honey brands tested had plants containing toxic alkaloid as their source plants.
