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Flowers and insect visitors of Calanthe izuinsularis. (a) Photoscotosia lucicolens; (b) Odontopera arida melanchonica; (c) Noctuidae sp.; (d) Geometridae sp.; (e) Trichoplusia intermixta; (f) Diarsia deparca; (g) Paliga minnehaha; (h) Serrodes campanus; (i) Lasioglossum apristum; (j) Lasioglossum occidens; (k) Lasioglossum occidens. The pollinaria indicated by white arrows can be seen attached to the bee's mesothorax.
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Calanthe izuinsularis is a rare, beautiful and fragrant orchid endemic to the Izu archipelago. Although it is known that mainland populations of closely related Calanthe species are pollinated by medium- to large-sized bees, it is likely that C. izuinsularis has been forced to alter its floral biology to attract alternative pollinators, as large-si...
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... intensive nighttime observation covering 89 hours of time-lapse photography detected no nocturnal moth visitors to the flowers of C. discolor, even in the sympatric population of the present investigation (Suetsugu et al. unpublished data). However, although most of the nocturnal moths exhibited typical pollinator behaviour, inserting their proboscises into the spur of the C. izuinsularis flowers, no images of moths with C. izuinsularis pollinaria attached to their proboscises were captured (Figure 1). In some cases this might be have been expected, as moth species such as Paliga minnehaha (Crambidae) are too small to carry the C. izuinsularis pollinaria. ...
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... nocturnal moths were the most frequent visitors, there were also a significant number of hymenopteran visitors, and in terms of the number of times visited (8/38), they are the second-most frequent functional group of C. izuinsularis floral visitors. All of the bee species observed visiting the flowers of C. izuinsularis exhibited typical pollinator behaviour, crawling deep into the chamber formed between the column and labellum to forage for nectar (Figure 1). Although the smaller bees (Lasioglossum (Evylaeus) sp.) were unable to carry pollinaria, the sweat bee Lasioglossum occidens was observed with pollinaria attached to its thorax (Figure 1). ...
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... of the bee species observed visiting the flowers of C. izuinsularis exhibited typical pollinator behaviour, crawling deep into the chamber formed between the column and labellum to forage for nectar (Figure 1). Although the smaller bees (Lasioglossum (Evylaeus) sp.) were unable to carry pollinaria, the sweat bee Lasioglossum occidens was observed with pollinaria attached to its thorax (Figure 1). Consecutive before and after photographs indicated the bee had not been carrying any pollinaria when it arrived at the flower, and thus indicated that the attached pollinaria were truly derived from C. izuinsularis, even though it cannot be absolutely certain how the pollinaria became attached to its mesothorax. ...
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... been found on the islands of Kohzu, Nii and Hachijo, as well as the hybrids of C. izuinsularis and C. aristulifera found on Mikura Island, the site of the current study (Cribb and Bailes 2001). Indeed, a previous study of a sympatric C. aristulifera population at the current study site found that C. aristulifera was also pollinated by L. occidens (Suetsugu et al. Forthcoming 2016). Given that C. aristulifera and C. discolor are rarely visited by nocturnal moths (Suhara 1993;Sugiura 2013;Suetsugu and Fukushima 2014), the weight of evidence suggests that pollination by hymenopteran floral visitors is the most likely mechanism of hybridisation between C. izuinsularis, C. discolor and C. ...
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... pollinaria can only be transferred when the bee crawls deep into the spur and the anthers make contact with the mesothorax. It is also likely that this alternative mechanism of pollination in both C. izuinsularis and C. aristulifera arose on Mikura Island by convergent evolution in response to the lack of bumblebees and other relatively large bees, such as the genus Eucera (Fukasawa and Miyano 2010). ...
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Floral biology and pollination mechanisms of Cymbidium aloifolium an epiphytic orchid were investigated in Tripura, India. The flowering period of C . aloifolium lasted for approximately 4 months from the late spring to the summer, with raceme inflorescence where flowers open acropetally. The flower longevity strictly depends on pollination, 3 to 5...
Citations
... In addition to the above observations, I opportunistically collected flower visitors of J. osense during this study. I also attempted to photograph flower visitors using time-lapse photography (Suetsugu et al. 2017). Digital cameras (WG-30 and WG-70, RICHO, Tokyo, Japan) were mounted on tripodsGorillapod (Gorillapod, Joby, San Francisco, USA) and placed in front of the inflorescences of J. osense to photograph flower visitors. ...
Petrosaviales is an early diverging monocot order that includes only two genera with distinct nutritional modes, namely the autotrophic Japonolirion and mycoheterotrophic Petrosavia . A rare serpentine plant endemic to Japan, Japonolirion osense is the only species of this genus. Although Petrosavia species are known to produce seeds by autonomous self‐pollination, the mating system and flower visitors of J . osense remain unknown. In this study, the pollination biology of J . osense was investigated on a serpentine slope in northern Hokkaido, Japan. Pollination experiments suggested that J . osense predominantly depends on cross‐pollination by insect pollinators for seed production. Ants and dipterans were the main flower visitors to this species. This study showed that the two genera in Petrosaviales with distinct nutritional modes also have contrasting mating systems, which provides insights into the evolution of pollination biology in this early diverging monocot order.
... Calanthe species are evergreen or deciduous terrestrial herbs with thick roots, small oval pseudobulbs, and large corrugated leaves . The flowers of Calanthe species are usually bright-colored, with an empty spur, and are often pollinated by bees (Sugiura, 2013;Ren et al., 2014;Sakata et al., 2014;Suetsugu et al., 2017), although butterflies and hoverflies (Ren et al., 2014) were also recorded as effective pollinators for a few Calanthe species. China is one of the diversity centers for both Habenaria and Calanthe, with high proportion of endemism. ...
... There is an urgent need to protect Calanthe species accounting for their deceptive pollination system. Without containing rewarding nectar in their spurs, Calanthe populations usually threatened from pollinator limitation and extremely low levels of fruit sets (Sugiura, 2013;Ren et al., 2014;Sakata et al., 2014;Suetsugu et al., 2017;Luo et al., 2020; Fig. S8). Non-rewarding orchids are poorer competitors for pollinator visitation than rewarding orchids in plant communities (Pellissier et al., 2010). ...
Climate change has impacted the distribution and abundance of numerous plant and animal species during the last century. Orchidaceae is one of the largest yet most threatened families of flowering plants. However, how the geographical distribution of orchids will respond to climate change is largely unknown. Habenaria and Calanthe are among the largest terrestrial orchid genera in China and around the world. In this paper, we modeled the potential distribution of eight Habenaria species and ten Calanthe species in China under the near-current period (1970–2000) and the future period (2081–2100) to test the following two hypotheses: 1) narrow-ranged species are more vulnerable to climate change than wide-ranged species; 2) niche overlap between species is positively correlated with their phylogenetic relatedness. Our results showed that most Habenaria species will expand their ranges, although the climatic space at the southern edge will be lost for most Habenaria species. In contrast, most Calanthe species will shrink their ranges dramatically. Contrasting range changes between Habenaria and Calanthe species may be explained by their differences in climate-adaptive traits such as underground storage organs and evergreen/deciduous habits. Habenaria species are predicted to generally shift northwards and to higher elevations in the future, while Calanthe species are predicted to shift westwards and to higher elevations. The mean niche overlap among Calanthe species was higher than that of Habenaria species. No significant relationship between niche overlap and phylogenetic distance was detected for both Habenaria and Calanthe species. Species range changes in the future was also not correlated with their near current range sizes for both Habenaria and Calanthe. The results of this study suggest that the current conservation status of both Habenaria and Calanthe species should be adjusted. Our study highlights the importance of considering climate-adaptive traits in understanding the responses of orchid taxa to future climate change.
... Camera monitoring has a big potential in supplementing human observations in the field as it is time-efficient and at the same time accumulates valuable ecological data (Bjerge et al., 2023;Hofmeester et al., 2020). Recently, insects visiting mushrooms on the forest floor have been monitored by the use of time-lapse cameras (Schmid et al., 2019) and similar techniques have also been used to observe insects visiting flowers (Alison et al., 2022;Bjerge et al., 2023;Suetsugu et al., 2017). In this study, we use time-lapse cameras to better understand the importance of fungal fruit bodies for forest invertebrates. ...
Fungi and invertebrates comprise a major part of biodiversity in dead wood ecosystems and invertebrates depend on fungi to utilise the dead wood resource. Many invertebrates also visit the long‐lived fruit bodies of wood‐decay fungi to feed on spores, the hymenium or other invertebrates. However, as traditional sampling methods are labour‐intensive, we know little of these interactions.
In this study, we use time‐lapse cameras to monitor invertebrates visiting the hymenium of a common wood‐decay fungus, Fomitopsis pinicola , and explain their activity in terms of temporal variation, temperature and presence of Gyrophaena boleti , a highly abundant fungivorous beetle living primarily in fruit bodies of F. pinicola .
The most common invertebrates on F. pinicola fruit bodies were Coleoptera, Araneae, Diptera, Gastropoda and Chilopoda. The invertebrate activity exhibited strong temporal variation with higher abundance during night and, for Coleoptera, earlier in the season. We discuss how this might correlate with the sporulation period of F. pinicola . The presence of G. boleti had a positive impact on the predatory Lordithon lunulatus and Ipidia binotata , and a negative impact on the fungivorous Thymalus limbatus and Peltis ferruginea . Chilopoda and L. lunulatus were ephemeral visitors, while the fungivorous Coleoptera and Araneae stayed the longest.
We estimated the invertebrates' visitation frequency and duration, which would be time‐consuming to obtain with traditional methods. We offer improvements to our method and urge future research on invertebrate–fungus interactions to quantify invertebrate visits to fungal fruit bodies.
... Photographs and videos can keep recording for longer time without getting tired and can be reviewed repeatedly in order to record precise data of each flower visitation event. Successive observations using these devices have helped identify effective pollinator taxa [31][32][33] or changes in pollinators' activity with the time of day 21,22,34,35 . By using several cameras, they can also observe the patterns of pollinator visitation among several www.nature.com/scientificreports/ ...
... Another problem with the application of our system to other plant species is that pollinator detection rates may be dropped in flowers with complex spatial structure 74 or for mass tiny insect pollinators. For those species, multiple cameras from different angles may be required for each target flower 33 . Methods for pollinator species identification must also be improved. ...
Understanding of pollination systems is an important topic for evolutionary ecology, food production, and biodiversity conservation. However, it is difficult to grasp the whole picture of an individual system, because the activity of pollinators fluctuates depending on the flowering period and time of day. In order to reveal effective pollinator taxa and timing of visitation to the reproductive success of plants under the complex biological interactions and fluctuating abiotic factors, we developed an automatic system to take photographs at 5-s intervals to get near-complete flower visitation by pollinators during the entire flowering period of selected flowers of Nelumbo nucifera and track the reproductive success of the same flowers until fruiting. Bee visits during the early morning hours of 05:00–07:59 on the second day of flowering under optimal temperatures with no rainfall or strong winds contributed strongly to seed set, with possible indirect negative effects by predators of the pollinators. Our results indicate the availability of periodic and consecutive photography system in clarifying the plant-pollinator interaction and its consequence to reproductive success of the plant. Further development is required to build a monitoring system to collect higher-resolution time-lapse images and automatically identify visiting insect species in the natural environment.
... There is also substantial evidence that some calanthe species are pollinated by bees (Sugiura, 2013;Ren et al., 2014;Sakata et al., 2014;Suetsugu and Fukushima, 2014;Suetsugu et al., 2016Suetsugu et al., , 2017. For example, calanthe striata is exclusively pollinated by the carpenter bee, Xylocopa appendiculata circumvolans (Sugiura, 2013). ...
... Our study showed that the bee E. nipponensis is a potential pollinator of calanthe discolor × c. striata. It can be assumed that Eucera visits to calanthe discolor × c. striata are rare, as we observed only a single visitation during our study; however, even rare pollination events can contribute to hybridization events in nature (Cozzolino et al., 2006;Suetsugu et al., 2017). Interestingly, Suetsugu and Fukushima (2014) reported that E. nipponensis is the main polli-nator of calanthe discolor; this study was conducted in a different population, but these results in combination with the results of the present study strongly suggest that the hybrid and parental species share pollinators. ...
... Seven species have been reported to be autogamous (Suetsugu & Fukushima 2014). It has also been reported that medium-to-large bees, such as Xylocopa, Eucera, Bombus, and Apis could pollinate Calanthe (Sugiura 2013;Sakata et al. 2014;Suetsugu & Fukushima 2014;Suetsugu et al. 2016Suetsugu et al. , 2017. Furthermore, it was reported that the pollinator of Calanthe argenteostriata was Pieris rapae, in the national orchid conservation center of China (Zhang et al. 2010). ...
Flowers have developed different strategies to attract pollinators through visual or olfactory signals. Most flowers offer pollinators a reward (e.g. nectar and pollen) for the pollination service. However, one-third of Orchidaceae have been shown not to provide a reward. Calanthe are terrestrial orchids distributed throughout China, Nepal, Japan and tropical Asia. Despite its high diversity, the pollination biology of Calanthe remains largely unknown, even though it is an important aspect of plant conservation. In the study, through field surveying, there were three Hesperiidae butterflies pollinating two species of Calanthe and the pollination behavior differed between the two species of Calanthe, which might lead to different fruit setting rates. There was no nectar in the flowers of the two species, indicating deceptive pollination. Using a glass cylinder experiment, it was deduced that the two species of Calanthe were most likely to attract pollinators by generalized food deception. Interestingly, Hesperiidae butterflies were traditionally thought to be nectar thieves and generally do not transmit pollinia. However, our findings showed that, in this case, the thieves were deceived by the plants and pollinated them for free.
... Calanthe discolor, which is widely distributed throughout the islands of Japan, including the Izu Islands (from Izuoshima Island to Hachijojima Island), is pollinated by medium-sized bees (Suetsugu & Fukushima, 2014). On the other hand, C. izu-insularis, endemic to Kozushima and Mikurajima Islands in the Izu Islands (Cribb & Bailes, 2001;Yukawa, 2015) is still somewhat dependent on bee pollination, although C. izu-insularis has also changed its floral coloration and scent to facilitate moth pollination because most floral visitors to this species were moths (Suetsugu et al., 2017). In addition, individuals hypothesized to have been derived from natural hybridization between C. discolor and C. izuinsularis have also been found in the Izu Islands (Cribb & Bailes, 2001). ...
... Owing to its use as an ornamental plant and the consequent excessive collection, its population size on the Izu Islands has declined to several hundred; thus, this species is classified as 'endangered' in the Japanese Red List (Ministry of the Environment, Japan, 2018). Although the predominant floral visitors to this species are nocturnal moths, pollination by the small bee species Lasioglossum occidens has been reported (Suetsugu et al., 2017). ...
... The results of PCA of flower morphology supported the grouping and detection of hybridization based on microsatellite markers developed by Nakahama et al. (2018) (Fig. 5). The reduced number of keels on the mid-lobe of the lip and long spur and dorsal sepal length, the pale coloration and the strong, fragrant scent might represent adaptations of C. izu-insularis for moth pollinators (Giménez-Benavides, Escudero & Iriondo, 2007;Suetsugu et al., 2017). On oceanic islands where social bee species are not distributed, flower traits evolve to adapt to pollination by other insects, such as species of Lepidoptera or Diptera (Mizusawa et al., 2014;Shrestha et al., 2016). ...
Natural hybridization often occurs between insular and widespread species, and investigating these hybridization patterns is important in improving our understanding of the evolution of insular plant species. To this end, we studied the floral morphology and genetic structure of the widespread species Calanthe discolor, the insular closely related species C. izu-insularis and their putative natural hybrids on Honshu Island (mainland) and the Izu Islands (oceanic islands), Japan, using microsatellite markers. Natural hybridization probably occurred on all the investigated Izu Islands in Japan, although C. izu-insularis was morphologically and genetically different from C. discolor. Bumblebees and other relatively large bees are not distributed in the Izu Islands and therefore natural hybridization would have occurred via pollination by relatively small solitary bees that are pollinators of both Calanthe spp. We also showed that in the islands more remote from the mainland, the proportions of insular C. izu-insularis increased and the floral morphologies of both species changed. The results suggested that insular C. izu-insularis evolved on the Izu Islands and the widespread C. discolor adapted to the poor pollinator fauna on oceanic islands.
... Modern photographic equipment can, to a certain extent, be automated allowing for capturing of relatively infrequent events such as pollination. For example, a waterproof camera with a timer was used in the habitat of the Calanthe izuinsularis orchid to capture the identity and behaviour of that species' pollinator [3]. It would have been difficult or impossible for the authors to take those photographs without potentially disturbing the pollinating insects. ...
... Since agar is soft, the specimen can be partially submerged to allow for a sharper focus of surface features. 3. For determining the actual size of a specimen and for future reference, a small scale bar should be placed close to the specimen and photographed together. ...
Photography is a good way to capture and communicate scientific information. Knowledge of some key principles of photography may greatly improve the results achieved. Examples of the setup of photographic equipment and photographs are included as a guide to the reader.
... These two species sympatrically grow in the Izu Islands (Cribb and Bailes, 2001;Suetsugu et al., 2016). In addition, they are pollinated by the same bee species, Lasioglossum occidens (Suetsugu et al., 2016(Suetsugu et al., , 2017. Although the morphological difference between C. izu-insularis and the hybridized individuals is unclear, the application of molecular techniques should make it possible to distinguish them. ...
Microsatellite markers were developed for the endangered orchid Calanthe izu-insularis (Orchidaceae). This species is unique to the Izu Islands in Japan. Unfortunately, its population size has decreased because of excessive collection for horticultural purposes. In addition, although natural hybridization between C. izu-insularis and C. discolor var. discolor has been reported, morphological differences between C. izu-insularis and the hybridized individuals remain unclear. Using next-generation sequencing, 11 polymorphic microsatellite markers were developed. All developed markers could amplify C. aristulifera and nine markers could amplify C. d. var. discolor, two other orchid species that are also endangered in Japan. The number of alleles and expected heterozygosity at each locus were 1-6 (mean, 2.35) and 0.00-0.79 (mean, 0.30), respectively. These microsatellite markers will help conservation geneticists in their investigation of the proportion of pure C. izu-insularis individuals in the Izu Islands.
Calanthe amamiana is a terrestrial orchid that thrives on the shady forest floors of broad‐leaved forests on Amami Island, central Ryukyus, Japan. Here, I report on the floral and pollination biology of this critically endangered orchid based on a 7‐year study conducted in the species' natural habitats. As the nectarless flowers are probably self‐compatible but are unable to autonomously self‐pollinate, they need to attract pollen vectors by deceit for pollination. To advertise themselves, the flowering inflorescences, which comprise a few to dozens of flowers, use whitish floral colors that are comparatively conspicuous against the shaded background. The exclusive pollinator was the long‐horned bee Eucera okinawae , which nests in soils of the forest floor, although bee abundance varied considerably among study years. Natural fruit‐set ratios were generally low but showed interannual variation. The annual fruit‐set ratios were positively correlated with annual bee abundance, thereby suggesting that under natural conditions, the orchid is pollinator‐limited. Given that C . amamiana is dependent exclusively on E . okinawae for pollination and is also probably pollinator‐limited, conservation plans for this orchid should take into consideration the welfare of long‐horned bees. In particular, as nectariferous flowers were unavailable within broad‐leaved forests, to satisfy the foraging requirements of long‐horned bees, conservation managers should be cognizant of conservation values of flowering plants distributed in sun‐lit sites near orchid habitats, and manage those in an appropriate manner.
