Short Communication |
Corresponding author: Suganthi Appalasamy ( suganthi.a@umk.edu.my ) Academic editor: Christopher K. Starr
© 2022 Nivaarani Arumugam, Nor Syahaiza Ahmad Zamri, Jayaraj Vijaya Kumaran, Maryana Mohamad Nor, Sreeramanan Subramaniam, Suganthi Appalasamy.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Arumugam N, Zamri NSA, Kumaran JV, Nor MM, Subramaniam S, Appalasamy S (2022) First report on pollinating behavior of the small carpenter bee Ceratina ridleyi Cockerell (Hymenoptera, Apidae) in Globba leucantha var. bicolor Holttum (Zingiberaceae). Journal of Hymenoptera Research 90: 173-183. https://doi.org/10.3897/jhr.90.79930
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Small carpenter bees of the genus Ceratina are widespread, but little-studied as pollinators despite their presence in various pollinator assemblages. This study documents the importance of Ceratina ridleyi as a pollinator of the small-flowered Malaysian ginger Globba leucantha var. bicolor. Species of Zingiberaceae are defined by peculiar floral morphologies (e.g staminodes and a single functional anther) but are rarely studied for their insect pollinators. Surprisingly, C. ridleyi was revealed as the single pollinator of Globba leucantha’s showy flowers even though the presence of Apis sp., Trigona sp., and Amegilla sp. were observed in the study site. This small carpenter bee collects both pollen and nectar from the ginger flower. Pollen grains were observed attached to its scopal hairs and hairs on the ventral thorax and ventral abdomen. The bee contacts the flower’s sole stigma only during foraging for pollen, where the stigma contacts pollen accumulated on hairs of the bee’s ventral thorax and ventral abdomen. This study represents the first pollination report of a Ceratina pollinating a species of Zingiberaceae, and only the second report of any Ceratina pollinating a flower with complex morphology.
lioceratina, limestone forest, pollinator, wild ginger, xylocopinae
Bees are the well-known insect pollinator, especially in global crop pollination (
Very few studies evaluate the pollination value of Ceratina bees. One study reported them to contribute to the overall seed set of Heterotheca (Asteraceae) although they were relatively inefficient (
The family Zingiberaceae (common name: gingers) from the order Zingiberales is largely confined to Southeast Asia and one of the families less studied for plant-pollinator interaction. Ginger plants have hermaphrodite flowers with a single anther and are often bright in color (
This study was conducted in the limestone forest of Gua Setir (5°39.92'N, 101°55.48'E) at Jeli, Kelantan, Malaysia, in October 2020 and October 2021, as shown in Fig.
Globba leucantha var. bicolor is a slender herb, generally distributed in a shady forest, specifically in a damp and humid microhabitat. The plant was identified based on characters described in
Morphometry of 38 freshly picked flowers was measured using a digital vernier caliper (MITUTOYO, Japan). Measurement procedures were done in the field between 08:30h to 09:30h. Anther length (LL), anther width (AW), lip length (LL), lip width (LW), flower length (FL), flower width (FW), front opening length (FOW), and lateral opening width (LOW) were measured for each flower (Fig.
Floral morphometry and morphology of ginger Globba leucantha a AL: Anther length, AW: Anther width, LL: Lip length, LW: Lip width, FW: Flower width b FL: Flower length, FOL: Front opening length, LOW: Lateral opening width c morphology of G. leucantha in lateral view d habit of G. leucantha.
Three individual plants of G. leucantha were observed by two people for three days each to identify the presence of pollinators through the direct observation method (
Pollen grains were collected from flowers and hind leg of the pollinator. Collected pollen grains were stained using Safranin (R&M Chemicals, UK) and observed under a compound light microscope attached to an image analyzer (LEICA, Germany). The structure of pollen grains was compared to verify the pollen grains were from the same floral species.
An individual plant of Globba leucantha var. bicolor forms a single terminal inflorescence that produces one to ten flowers per day for a few months. A matured bud slowly opens at 01:00 h and fully bloom around 02:15 h. Anthesis occurs for less than a day (around 02:15 h – 20:00 h). Filament begins to roll around 20:00 h, indicating the beginning of the withering process. The floral completely withered around 23:40 h. Morphometry analysis for 38 flowers is shown in Table
Floral morphometry analysis for ginger Globba leucantha from Gua Setir, Malaysia. x̄ = mean; SD = standard deviation.
Floral Structures | x̄ ± SD | Range |
---|---|---|
Anther length, LL (mm) | 3.31 ± 0.18 | 3.16–3.59 |
Anther width, AW (mm) | 2.11 ± 0.03 | 2.06–2.14 |
Lip length, LL (mm) | 10.65 ± 0.19 | 10.44–10.93 |
Lip width, LW (mm) | 3.18 ± 0.23 | 2.96–3.43 |
Flower length, FL (mm) | 21.92 ± 1.79 | 16.07–25.28 |
Flower width, FW (mm) | 5.46 ± 1.31 | 2.88–7.70 |
Front opening length, FOL (mm) | 20.62 ± 1.91 | 15.26–24.27 |
Lateral opening width, LOW (mm) | 13.25 ± 2.47 | 8.68–19.87 |
A small carpenter bee, Ceratina ridleyi Cockerell, 1910 was identified as the single pollinator of G. leucantha var. bicolor (Fig.
The small carpenter bee, C. ridleyi visited the flowers from 08:00 h to 15:00 h (Fig.
Contacts between C. ridleyi and G. leucantha involves several body parts. Anther and lip were two standard positions on the flower occupied by the bee (Fig.
Small carpenter bee, Ceratina ridleyi (♀) collecting pollen in ginger flower, Globba leucantha a scopa in hind leg (red arrow) covered with pollen grains, direct contact of stigma (yellow arrow) and abdomen b hairs in the ventral body part (red arrows) and hind leg (yellow arrow) covered with pollen grains c observation of pollen grains on hind femur under a stereomicroscope (2 × magnification).
This study reveals that Ceratina ridleyi, a small carpenter bee is the single pollinator of Globba leucantha var. bicolor in the study area. Blue-banded bees, carpenter bees, halictid bees, honey bees, and stingless bees are among those previously recorded pollinating ginger flowers (
Globba leucantha shows a high degree of specificity in pollination, similar in G. aurantiaca, Indonesia (
Open habitats are the general preference of Ceratina (
Direct contact between C. ridleyi and G. leucantha results in successful pollination. Brief plant-pollinator interactions were observed, lasting three to 15 sec, mainly involving the collection of pollen (anther) and nectar (lip). The bee primarily touched either anther or lip and was never observed to walk about on the flower. Pollen grains of G. leucantha var. bicolor are white and medium in size, range within 25–50µm based on pollen grains size category by
The ginger flower morphology and morphometry facilitates pollinating activity by the small carpenter bee as shown in the Table
Ceratina ridleyi is the specific pollinator of Globba leucantha var. bicolor at our study site in Malaysia. This is the first report documenting the plant-pollinator interaction between this ginger plant and a bee. We also discuss the floral phenology of G. leucantha. Information provided in this report is a pioneer and essential data for future pollination studies of ginger and behavior study of C. ridleyi.
This study was supported by the Ministry of Higher Education (MOHE) Malaysia through Fundamental Research Grant Scheme (FRGS/1/2019/STG03/UMK/02/3) and Universiti Malaysia Kelantan through UMK Rising Star 2021 Grant (R/STA/A0800/01350A/007/2021/00937) and Yayasan Muhibah Tan Sri Fng Ah Seng Innovation Fund 2021 (R/TSF/A0800/01350A/006/2021/00906). The authors also would like to thank the Faculty of Earth Science, Universiti Malaysia Kelantan for facilities support, and Jeli District Council (Ref.: MDJ. 383 Jld.2) for giving permission to conduct research at Gua Setir, Kelantan. A special thanks to Associate Professor Dr. John S. Ascher from the Department of Biological Sciences, National University of Singapore, and Mr. Zestin Soh from Zestin Soh Photography, Singapore for the bee’s scientific name argument in the bees & wasps of Singapore group.