Naturalistae 28: 15-17 (Feb. 2024)© 2024 by Okayama University of Science, PDF downloadable at http://www1.ous.ac.jp/garden/

Short Report

Attraction of both male and female Protaetia orientalis(Cetoniinae, Scarabaeidae) to Luisia teres (Orchidaceae)
in Kagoshima, southern Kyushu, Japan
Hiroyuki TAKASAKI1*, Koji NAKAMINE2 & Atsuko NAKAMINE3
Abstract: The pollination vectors of the Luisia teres orchid were studied in situations where thecupreous chafer Protaetia pryeri, the sole known pollinator, is scarce. Observations were made on
a transplanted orchid in Okayama, southwestern Honshu, Japan, and two wild sites in Kagoshima,southern Kyushu. Another chafer, P. orientalis, visited the orchid at all observation sites, which indicates its probable role as a pollinator. Both male and female chafers were attracted to the orchid.

I. Introduction
The natural range of Luisia teres (Thunb.)
Blume (Orchidaceae) extends from southern
China to northern Vietnam and temperate East
Asia (POWO 2023). In Japan, this orchid species is distributed in southern Kinki of Honshu,Shikoku, Kyushu and further south through theRyukyu Islands (Ono et al. 1997), and listed as
Near Threatened (NT) in the Red List 2020 (Ministry of the Environment, Japan 2020). Tetsu &Suetsugu (2015) provided the first report on its
pollinators based on observations of a living plantbrought from Kagoshima Prefecture, Kyushu, toSanda City in Hyogo Prefecture, southwestern
Honshu.
Tetsu & Suetsugu (2015) reported Protaetia
brevitarsis (Cetoniinae, Scarabaeidae) as a pollinator of L. teres. They also mentioned two scarabbeetles (Scarabaeidae), Anomala albopilosa(known as the green chafer or white-haired leafchafer, Rutelinae) and Rhomborrhina japonica(drone beetle, Cetoniinae) as possible pollinators.
Anomala albopilosa was observed visiting theorchid, feeding on the petals and carrying pollinia on its frons. Rhomborrhina japonica wascaptured in the neighborhood and tested on theorchid flower to be attracted to it. However, Tetsu
and Suetsugu (2015) sexed none of the beetles.
In Okinawa Prefecture of the Ryukyu Islands,
adult P. pryeri pryeri (cupreous polished chafer)
was observed flying toward, hovering around,and landing on L. teres during its flowering season (Araki et al. 2016). The detailed study of thechafer and the orchid revealed all of the chafers
attracted to the orchid were males, while bothmales and females were caught when banana
traps were placed nearby. Cotton balls soakedin the orchid flower extract and placed on fern
leaves attracted many adult male P. pryeri. Later,
Wakamura et al. (2020) showed that the flower
extract contained the same substance as the sex
pheromone emitted by the female P. pryeri.
However, the pollinator chafer P. pryeri isa rare species in Kyushu, Shikoku, and Kinki(Wakayama Prefecture), although its distribution barely reaches southern Kyushu and recent
collection records have been accumulated (e.g.,Nakamine 2023). The present study attempted
to solve this mystery, i.e. how this orchid is pollinated in Kyushu, Shikoku, and Kinki, where P.
pryeri is rare.
II. Materials and Methods
In late April 2023, a living plant of Luisia teresthat had fallen to the ground under a Cinnamomum
camphora in Kagoshima City, southern Kyushu
was collected. It must have fallen due to heavy
rain or strong wind. The plant was tied to a branchof Quercus phillyraeoides planted in Okayama
City, southwestern Honshu for observation ofthe visitors. Following the sightings of visiting
chafers in Okayama in July 2023, probablepollinators were searched on natural growths ofL. teres on C. camphora at two sites (north andsouth) in Kagoshima City on weekends in thesame month.

1.

Department of Zoology, Faculty of Science, Okayama University of Science, 1-1 Ridai-cho, Kita-ku, Okayama-shi, Okayama, 700-0005, Japan. 岡
山理科大学理学部動物学科，〒700-0005 岡山県岡山市北区理大町1-1.
2.
Kagoshima Prefectural Sendai Senior High School, 6-3 Goryo-shimo-cho, Satsuma-Sendai-shi, Kagoshima, 895-0061, Japan. 鹿児島県立川内高等学校，〒895-0061 鹿児島県薩摩川内市御陵下町6-3.
3.
Kagoshima Prefectural Museum, 1-1 Shiroyama-cho, Kagoshima-shi, Kagoshima, 892-0853, Japan. 鹿児島県立博物館，〒892-0853 鹿児島県鹿児島市城山町1-1.
*Correspondence: Hiroyuki TAKASAKI, E-mail: takasaki@zool.ous.ac.jp- 15 -TAKASAKI, NAKAMINE & NAKAMINE

Fig. 1. Protaetia orientalis on Luisia teres on a camphor tree. Photo byA. Nakamine, July 23, 2023.

III. Results
In Okayama City, on July 10, the Luisia terestied to Quercus phillyraeoides was flowering. On
July 12, a male Rhomborrhina japonica came toa flower and was caught. On July 13, a beetle
probably Protaetia orientalis visited a flower, but
it was sensitive and flew away before capture. On
July 14, at 13:25, a male P. orientalis visited theorchid and was caught. On July 16, after 10:00,
three P. orientalis were observed on the orchid.
Two of them soon flew away, but the remaining
one, which failed in its flight, fell to the groundand turned out to be a female. Although P. brevitarsis
was found in large numbers together with P.
orientalis and R. japonnica on a sap-flowing Q.
variabilis about 1 km of the site, P. brevitarsis
was not observed on the orchid. In addition, ants
(Lasius japonicus) were observed visiting theorchid’s flowers, although they were unlikely topollinate without carrying pollinia.
In Kagoshima City, on July 17, a female P.
orientalis was caught on L. teres growing on
Cinnamomum camphora at the south site (byK.N.). On July 23, both sites in Kagoshima City
were checked, and a P. orientalis on L. teres (Fig.
1) was observed at the north site (by A.N.). It had
pollinia attached to its frons (Fig. 2).
At least the plant of L. teres transplanted inFig. 2. Pollinia of Luisia teres attached to the frons of the chafer. Photoby A. Nakamine, July 23, 2023.

Okayama City (Fig. 3) bore swollen fruits wheninspected after attracting the chafers.
IV. Discussion
The present observations suggest that bothmale and female Protaetia orientalis are attracted
to the orchid Luisia teres. These beetles likely act
as pollinators for the orchid. Tetsu & Suetsugu(2015) identified one of the pollinators for thisorchid was P. brevitarsis, with a metallic green
ground color. However, its color shown in thephotograph is different from the metallic browncolor, typical of P. brevitarsis. Protaetia orientalis,whose ground color is a metallic green, may havebeen misidentified as P. brevitarsis. Nevertheless,both are congeneric with P. pryeri.
Although Arakaki et al. (2016) and Wakamura
et al. (2020) concluded that the orchid attractant
is a chemical mimic of the sex pheromone offemale P. pryeri, Tetsu & Suetsugu (2015) andthe present observations suggest that L. tereslures a wide range of male and female cetoniine
beetles that pollinate the orchid. Incidentally,Arakaki et al. (2016) added the attraction of amale P. ishigakia by the orchid. If the female
sex pheromone theory of Arakaki et al. (2016)
and Wakamura et al. (2020) is correct, the rangeof chafer species attracted by the pheromone- 16 -Attraction of both male and female Protaetia orientalis to Lusia teres in Kagoshima

Fig. 3. Swollen fruit of Luisia teres after attracting the chafers inOkayama. Photo by H. Takasaki, July 16, 2023.

needs to be expanded. In addition, both males
and females of sap-feeding cetoniine chafers areattracted to the scent of L. teres, which does notnecessarily function as a female sex pheromone
alone. The attractant pheromone, if synthesized
and artificially modified, could be used as a pestcontrol bait as some cetoniine chafers, including
P. pryeri, are agricultural pests.
Acknowledgements
We thank Y. Aosaki, K. Kanai, N. Kumagai,and K. Matsuhira of the Kagoshima Entomological Society for providing information on theflowering of Luisia teres in Kagoshima. I. Kurokiof Okayama University of Science (OUS) kindly
identified the ant species. K. Takumi of OUS
helped the authors to obtain a reference paper.
References
Arakaki, N., Yasuda, K., Kanayama, S., Jitsuno, S., Oike,
M. & Wakamura, S. (2016) Attraction of males of

the cupreous polished chafer Protaetia pryeri pryeri(Coleoptera: Scarabaeidae) for pollination by an epiphytic orchid Luisia teres (Asparagales: Orchidaceae).
Applied Entomology and Zoology 51: 241-246.
Ministry of the Environment, Japan (2020) Red List 2020.
https://www.env.go.jp/content/900515981.pdf (Accessed 5 December 2023).
Nakamine, K. (2023) Protaetia pryeri collected in Kagoshima and Satsuma-Sendai Cities. Satsuma 171:182 (in Japanese).
Ono, M., Ohba, H., Murata, J., & Nishida, M. (eds.)(1997) Revised Makino’s Illustrated Flora in Colour.
Hokuryukan, Tokyo (in Japanese).
POWO (2023) Plants of the World Online. Facilitatedby the Royal Botanic Gardens, Kew. Published on
http://www.plantsoftheworldonline.org/ (Accessed 5December 2023).
Tetsu, S. & Suetsugu, K. (2015) Floral visitors of Luisia
teres (Orchidaceae). Journal of Japanese Botany 90:
359-363 (in Japanese).
Wakamura, S., Arakaki, N., Moriyama, D., Kanayama, S.,Oike, M., Kimura, A., Wajima, S., Ono, H. & Yasui,
H. (2020) Does the orchid Luisia teres attract its malechafer pollinators (Scarabaeidae: Protaetia pryeripryeri) by sexual deception? Chemoecology 30: 49-57.
高崎浩幸・中峯浩司・中峯敦子：鹿児島市おけるシロテンハナムグリ（Protaetia orientalis ）雌雄のLuisiateres（ラン科）への誘引
要約
ボウラン（Luisia teres）
について，これまでに確認されている唯一の送粉者であるリュウキュウツヤハナムグリ（Protaetia pryeri）が稀である場合の送粉者を調査した．本研究の結果では，移植した岡山市および自生地の鹿児島市２ヵ所において同属のシロテンハナムグリ（P.
orientalis）がこのランに誘引された．しかもオスもメスも誘引され，このランの受粉媒介者である可能性が高い．

- 17 -(Accepted 7 December 2023)