Research Article |
Corresponding author: Renzo Perissinotto ( renzo.perissinotto@mandela.ac.za ) Academic editor: Andrey Frolov
© 2021 Renzo Perissinotto, Lynette Clennell.
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:
Perissinotto R, Clennell L (2021) Census of the fruit and flower chafers (Coleoptera, Scarabaeidae, Cetoniinae) of the Macau SAR, China. ZooKeys 1026: 17-43. https://doi.org/10.3897/zookeys.1026.60036
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The coleopteran fauna of the Macau SAR in southern China has historically received only limited attention and no updated information has been published since the last substantial works produced in the 1990s. An annotated and illustrated review of the fruit and flower chafers (Scarabaeidae, Cetoniinae) of this region is here presented, in order to provide an account of the current status of the taxonomic diversity and ecology of this important insect group. Eleven species were observed in the SAR during an intense investigation undertaken during the period 2017–2020, with six of these representing new records for Macau and two for the broader region of the Pearl River Delta, also known as the Greater Bay Area. Although this census leads to a substantial increase in the number of species known for the area, it also highlights the threats that the recent escalation in urban development and land-use transformation are posing to a number of species which seem unable to maintain a sustainable population in the region, mainly due to habitat destruction.
Cetoniini, new records, Palearctic Region, Schizorhinini, Taenioderini
Fruit and flower chafers are good indicators of environmental health status and are increasingly used in environmental assessment and planning studies (e.g.,
Unlike in the other Chinese SAR in the same region, Hong Kong, in Macau there has been relatively little research undertaken in the past on its insect fauna, with only a handful of publications produced on the subject to date. Among these, to our knowledge only three have reported records of occurrence of Cetoniinae, namely
This under-reporting is further compounded by issues of outdated or incorrect identifications. The main purpose of this work is, therefore, to provide a modern census of the cetoniine beetles of the Macau SAR, based on extended and frequent field surveys, comprehensive observation gathering methods and updated identification approaches using local and global expertise. To our knowledge, along with a similar study undertaken recently by
Macau is characterised by a subtropical climate and what remains of its natural terrestrial plant assemblages includes five vegetation types, namely coniferous forest, coniferous and broad-leaved mixed forest, evergreen broad-leaved forest, evergreen and deciduous broad-leaved mixed forest and shrub (
The Macau Special Administrative Region (SAR) of China consists of the Macau Peninsula, linked directly to the mainland province of Guangdong, and one larger island resulting from the merger of the two previous islands of Taipa and Coloane through the land reclaimed area of Cotai (Fig.
Map of the Macau SAR showing its various components including the Peninsula, the islands of Taipa and Coloane as well as the reclaimed lands of Cotai, the International Airport and the Hong Kong – Zhuhai – Macau Bridge Port (adapted from: https://www.britannica.com; used with permission).
The Macau SAR is a very prosperous region, reportedly enjoying one of the highest per capita incomes in the world, but is also among the most densely populated areas on the planet. Remarkably, despite its extraordinary population pressure and developmental momentum, some areas of its original, natural landscape still remain, although they are often encroached upon by alien vegetation (
Cetoniine observations were undertaken on an opportunistic basis from Sep 2017 and virtually on a daily basis during the two-year period Oct 2018–Oct 2020. This generally involved non-manipulative methods, with photographs taken in situ as much as possible. Fruit-baited traps were deployed during the summer of 2019 in urban marginal areas, with the main purpose of attempting to run a mark-recapture exercise and estimate the numerical abundance for the various species. Unfortunately, too few specimens and species were found to enter the traps and therefore the attempt was abandoned thereafter. Traps were made using a standard 1 L bottle with the neck cut-off and inverted inside the bottle in order to create a funnel-like entrance that would allow beetles to enter, but not re-exit (
Occasionally, mature adults ready to emerge were excavated from decomposing tree trunks still in their cocoons, or obtained after rearing third instar larvae collected in the wild, under laboratory controlled-conditions. In the latter case, larvae were kept in plastic containers of 1 L capacity, containing the natural wood material found in situ. Water was sprayed on the soil surface at regular intervals of ca. 1–2 weeks until pupation. Voucher specimens for reference and identification verification purposes were usually selected from specimens found already dead in the field. These are currently housed in the Macau Anglican College, Taipa (MACT) or in the reference collection of Stanislav Jákl, Prague (SJCP) for further investigation. Other specimens for analysis were accessed from the historical Easton Collection currently housed in the Library of the University of Macau (UMEC). Preserved specimens were analysed in detail for the typical diagnostic characters of each species, including aedeagal parameres. Observations and data records were also obtained from the citizen science platform iNaturalist (www.inaturalist.org), after direct verification with each individual observer. The following literature references were used to extract historical information records:
Photographs of specimen dorsal and lateral views were generally taken in situ as far as practical, using a Nikon CoolPix S9700 digital camera with macro setting. Where this was not possible in the field, specimens were photographed, sexed and measured under controlled conditions and released immediately afterwards. On rare occasions, visual disturbances were removed from the photographs using Microsoft Word 2010 (Picture Tools), in order to increase clarity and resolution of the images. Specimen total length (TL) and maximum width (MW) were measured using a Vernier calliper, from the anterior margin of the clypeus to the apex of the pygidium and at the widest point of the elytra, respectively.
In this work, all the species recorded during the census in the Macau SAR are illustrated with photos of live specimens in their natural or reconstructed setting, highlighting their key dorsal and, where possible, lateral characters. For a comprehensive list of currently recognised synonyms, the reader is referred to the latest revision of the Palearctic Coleoptera by
Examples of remaining pockets of subtropical evergreen forest in Macau A Colina da Guia (Macau Peninsula) B Colina da Barra (Macau Peninsula) C Taipa Pequena (Taipa) D Taipa Grande (Taipa) E Alto de Coloane (Coloane) F Monte de Ká-Hó (Coloane). Photographs: A Shutterstock.com C JTM.co.mo B, D–F Lynette Clennell.
Cetonia versicolor Fabricius, 1775.
Cetonia bealiae Gory & Percheron, 1833: 282.
Within the Palearctic Region, G. bealiae is known from the Chinese provinces of Fujian, Guangdong, Hebei, Hubei, Jiangxi, Zhejiang and the Hong Kong SAR (
1♂: Coloane Village, 29 Jun 2019, in fruit-baited trap, R Perissinotto & L Clennell (MACT).
Taipa Pequena, 4 Mar 2019, on flowers of Ligustrum sinense, R Perissinotto; Coloane, Hác-Sá, 4 Apr 2019, on flowers of L. sinense, R Perissinotto & L Clennell; ibidem 11 Apr 2020, R Perissinotto & L Clennell.
In Macau, this species varies in size between 12.5 and 15 mm in TL and between 7 and 9 mm in MW. Colour forms range from black to olive green background, with testaceous to reddish green pronotum and ochreous to testaceous mid-elytral bands. The white maculation on the general surface appears to be consistent. During 2019, one individual was retrieved inside a fruit-baited trap, while four others were observed feeding on flowers of Ligustrum sinense. In 2020, only one specimen was observed while feeding on flowers of L. sinense. In Macau, this species appears to have its peak of adult activity between early spring and early summer, while no specimens have been recorded in late summer, autumn, or winter. In nearby Hong Kong, this species has been recorded feeding on flowers of Viburnum odoratissimum and Lonicera sp. between March and May (
Cetonia jucunda Faldermann, 1835: 386.
Mainly a Palearctic species, recorded from the Chinese provinces and municipalities of Beijing, Chongqing, Fujian, Gansu, Guizhou, Guangxi, Hainan, Hebei, Heilongjiang, Hubei, Jiangsu, Jiangxi, Liaoning, Nei Mongol, Sichuan, Shanghai, Shandong, Shanxi, Yunnan, Zhejiang and the Hong Kong SAR (
1♂, 1♀: Coloane, Hác-Sá, 8 Apr 2020, on flowers of Ligustrum sinense, R Perissinotto (MACT).
No locality and date, 14 mm (in
A rare species in Macau, despite its widespread distribution and common occurrence in the surrounding regions, such as the Hong Kong SAR (
Cetonia horsfieldii Hope, 1831.
Cetonia horsfieldii Hope, 1831: 25.
Known in the Palearctic Region from the Himalayan countries of Nepal, Bhutan, and the Sikkim Province of India, as well as the Chinese provinces of Guizhou, Jiangxi, Yunnan, and the island of Taiwan (
1♂: Taipa Monument, 27 Sep 2018, dead on path, R Perissinotto (MACT); 1♀: Coloane Village, 28 Aug 2019, on flowers of Zanthoxylum avicennae, R Perissinotto & L Clennell (MACT).
Macau, Guia Hill, 25 Oct 2017, R Perissinotto & L Clennell; Taipa Pequena, 4 May 2018, R Perissinotto & L Clennell; ibidem 11 Oct 2018, R Perissinotto & L Clennell; Macau Peninsula, 22 Dec 2019, Angus Chan (pers. comm.); Coloane, Hác-Sá, 7 Apr 2020, on flowers of Ligustrum sinense, R Perissinotto & L Clennell.
This species appears to be a new record for the broader region, having also been observed for the first time in Hong Kong only in April 2018 (
Cetonia modesta Fabricius, 1792
Glycyphaniola nicobarica laotica Mikšić, 1968: 48.
According to Jákl (in
1♀: Taipa Central, October 2017, Jeff Lei (MACT); 1♂: Barra Hill, 5 May 2018, dead on roadside, L Clennell (MACT); 1♂: Taipa Pequena, 26 Sep 2018, on flowers of Rhus chinensis by roadside, R Perissinotto & L Clennell (MACT); 1♀: Coloane Village , 13 Mar 2019, on flowers of Bidens sp., R Perissinotto (SJCP); 1♂: ibidem 13 Apr 2019, R Perissinotto (SJCP).
Taipa Pequena, 26 Oct 2017, on flowers of Rhus chinensis, R Perissinotto & L Clennell; ibidem 2 Mar 2020; Coloane Village , 2 Jul 2019, on flowers of Bidens sp., R Perissinotto & L Clennell; ibidem, 29 Sep 2018, R Perissinotto & L Clennell; Coloane, Ká-Hó, 7 Oct 2018, R Perissinotto & L Clennell; Macau, Guia Hill, 14 Mar 2020, on flowers of Ligustrum sinense, R Perissinotto & L Clennell; St. Francis Xavier’s Parish, Macau [Coloane], 7 Jul 2019 13:04, Kit Chang (https://www.inaturalist.org/observations/28360614); ibidem 12 Apr 2020 13:29, L Clennell (https://www.inaturalist.org/observations/55132359); ibidem 27 Sep 2020 14:59, L Clennell (https://www.inaturalist.org/observations/60940151); ibidem 30 Sep 2020, L Clennell (https://www.inaturalist.org/observations/61293565); Our Lady of Carmel’s Parish [Taipa], 17 Aug 2020 14:14, L Clennell (https://www.inaturalist.org/observations/56723739); ibidem 14 Sep 2020 16:07, Kit Chang (https://www.inaturalist.org/observations/59561942); Circuito da Barragem de Hac-Sá, Coloane, 4 Jul 2020 15:26, Annie Lao (https://www.inaturalist.org/observations/51892005).
This taxon has recently been elevated to species rank by Jákl (in
Larvae, cocoons, and freshly emerged adults have been observed inside decomposing tree trunks and branches (pers. obs.), thereby confirming the saproxylic habit of its immature stages. In Hong Kong (then referred to as Glycyphana nicobarica), larvae were successfully reared to adulthood on fermented sawdust, and several adult specimens were found inside a compost heap composed of pig waste and sawdust (
Cetonia mandarina Weber, 1801 (= Cetonia fusca Herbst, 1790).
Cetonia submarmorea Burmeister, 1842.
Cetonia orientalis Gory & Percheron, 1833: 193
Within the Palearctic Region, this species is known from the Chinese provinces of Chongqing, Fujian, Guangxi, Guizhou, Hubei, Hunan, Jiangxi, Sichuan, Shandong, Zhenjiang, the Hong Kong SAR, North and South Korea as well as the Russian Far East (
1♂, 1♀: Coloane, Ká-Hó, 16 Jun 2018, dead on roadside, L Clennell (MACT); 1♂: Coloane, A-Mà Cultural Village, 13–15 Jun 2019, aggregation on sap of Albizia lebbeck, R Perissinotto & L Clennell (MACT); 1♂: Macau, University of East Asia Library, 4 May 1990, ER Easton leg (UMEC); 1♀: ibidem, on building, 1 Aug 1989, ER Easton leg (UMEC); 1♂: ibidem 30 Jul 1989, ER Easton leg (UMEC); 1♂: ibidem, on building, 12 Jul 1989, ER Easton leg (UMEC); 1♀: ibidem no data, ER Easton leg (UMEC).
Taipa, University of East Asia Campus, near library, 28 May 1991 (
This is the only species currently seen in reasonable numbers in the Macau SAR, but only from late spring and throughout the summer. Specimens are generally of a bright green colour with golden sheen and white markings, but the background colour can turn olive-green or even darker in some specimens. Adult size varies within the approximate range of 20–25 mm in TL and 10–13 mm in MW. Its diet appears to be the most variable exhibited by any of the cetoniines encountered in Macau, with adults recorded in aggregations on sap flows of Albizia lebbeck (Fig.
Cetonia marmorata Fabricius, 1792
Cetonia speculifera Swartz, 1817: 53.
In the Palearctic Region this species is only known from the Chinese provinces of Hainan, Henan, Hunan and Jiangxi (
1♂: Coloane, A-Mà Cultural Village, 19 Jun 2019, dead under tree, R Perissinotto & L Clennell (MACT).
Alto de Coloane, 14 Jun 2019, on sap flow of Albizia lebbeck, R Perissinotto & L Clennell; ibidem 5 Jul 2020, on sap flow of Sapium discolor, R Perissinotto & L Clennell; Coloane Village, 8 Jul 2020, landing on tree trunk, R Perissinotto & L Clennell.
This species has a rather sporadic occurrence in Macau, having been observed only twice in 2019 and always on sap flows of Albizia lebbeck, and then again on another two occasions in 2020, on sap flows of Sapium discolor and in hovering flight respectively (pers. obs.). Adult size varies in the approximate range of 20–23 mm TL and 11–13 mm MW. Although it has not been recorded formally from nearby Hong Kong, a few observations reported on the citizen science platform iNaturalist from that area (e.g., https://www.inaturalist.org/observations/25994523; https://www.inaturalist.org/observations/24358351; https://www.inaturalist.org/observations/1126433) indicate that this species [or the closely related P. (L.) brevitarsis (Lewis, 1879)] may occur there too. It has probably been overlooked in the past, as superficially it resembles quite well P. (C.) orientalis orientalis both in size and general appearance. Even an alerted observer needs to be within close distance in order to be able to appreciate the stockier body shape, the reduction of white maculation on the dorsal surface and the gold-red sheen that allow the diagnosis of this species against P. (C.) orientalis orientalis. Adult activity of P. (L.) speculifera in Macau seems to be restricted to the summer months.
Cetonia floricola Herbst, 1790 (= Cetonia metallica Herbst, 1782)
Protaetia intricata WW Saunders, 1852: 31
This species appears to be rather restricted geographically, having so far been recorded only in the Chinese provinces of Fujian and Zhejiang (
1♂: Coloane, Ká-Hó, 2 Jun 2019, on flowers of Syzigium buxifolium, R Perissinotto & L Clennell (SJCP).
Coloane, Ká-Hó, 29 May 2020, on flowers of Syzigium buxifolium, R Perissinotto [identification uncertain].
This is certainly the rarest cetoniine recorded so far in Macau, having been observed with certainty only once in June 2019, feeding on flowers of Syzigium buxifolium. A second potential specimen was observed in a nearby locality on the same flowers in May 2020, but its identification could not be conclusively verified as it was too far above the ground. According to S. Jákl (pers. comm.), this species is extremely rare throughout its limited distribution range and to our knowledge has not been reported from Hong Kong yet. The approximate size of the 2019 male specimen was 15 mm TL and 9 mm MW.
Cetonia mandarina Weber, 1801 (= Cetonia fusca Herbst, 1790)
Cetonia fusca Herbst, 1790: 257
Occurring widely in the Palearctic Region, especially the Chinese provinces and municipalities of Fujian, Guangdong, Guangxi, Hainan, Hubei, Jiangxi, Zhenjang, Shanghai, the Hong Kong SAR and the island of Taiwan as well as Japan and India’s Sikkim Province (
1♂: Macau, University of East Asia, Jun 1990, ER Easton leg (UMEC); 1♂: Coloane, Cheoc Van, 29 Jun 2019, crushed on sidewalk, R Perissinotto & L Clennell (MACT).
Coloane, Hác-Sá, 4 Apr 2019, on flowers of Ligustrum sinense, R Perissinotto; Coloane Village, 17 Jul 2020, on building wall, L Clennell; Coloane, Oscar Farm, on rice stem, 24 Oct 2020, Kit Chang (pers. comm.).
Despite being one of the most worldwide spread cetoniine, this species is extremely scarce in Macau. Adults are active mainly in spring and summer and range in size from approximately 13 to 15 mm TL and from 8 to 9 mm MW. In Macau, they have been observed feeding only on flowers of Ligustrum sinense, but the widely used common name of Asian mango flower beetle for the species indicates a diet with this staple component in its natural habitat. Globally, it has actually shown a very variable diet, including a multitude of flowers, fruits and even bee honey. In Hawaii, where it was first recorded in 1949 (
Agestrata luconica Eschscholtz, 1829
Scarabaeus orichalcus Linnaeus, 1769: 504.
North-eastern India (Sikkim and Arunachal Pradesh), the Chinese provinces of Guangdong, Guangxi and Hainan, the Hong Kong SAR and Taiwan. Also widespread in the Oriental Region (
1♂: Macau, University of East Asia, 28 May 1989, ER Easton leg (UMEC); 1♂: Coloane, Cheoc Van, 15 Jun 2019, crushed on road under street light, R Perissinotto & L Clennell (MACT); unknown sex: Alto de Coloane, 18 Oct 2020, elytron found under spot-light, R Perissinotto & L Clennell (MACT).
Taipa, University of East Asia Campus, 3 Sep 1991, near library (in
This is by far the largest cetoniine beetle in Macau, reaching a total length of 40–45 mm and a maximum width of 18–20 mm. Although it is regularly recorded in nearby Hong Kong (see e.g., https://www.inaturalist.org/observations?place_id=7613&subview=grid&taxon_id=127588), it is a rare occurrence in Macau. During this study only two males were recorded, one crushed on a road under a street light and a second, which also died after flying into an incandescent spot-light at the Coloane A-Mà statue. The remnants of a third specimen were also retrieved in October 2020 under the same spot-light. According to
Lomaptera mohnikii J. Thomson, 1877
Thaumastopeus shangaicus Neervoort van de Poll, 1886: 181.
Known in the Palearctic Region from the Chinese provinces of Hainan and Yunnan, the Shanghai Municipality and the Hong Kong SAR (
1♀: Coloane Village, 31 Mar 2019, extracted prematurely from broken cocoon, R Perissinotto & L Clennell (MACT); 1♀: Coloane Village, 22 May 2020, on flowers of Psychotria serpens, R Perissinotto (MACT); 1♂: ibidem 28 May 2020, dead on roadside, R Perissinotto (MACT).
No locality and date, 23 mm [in
This is the second largest cetoniine species found in Macau, attaining a size in the range of 22–30 mm TL and 9–13 mm MW. Specimens are very stable in their colour, which is generally shiny and black with a dark blue sheen. It has been confused in the past with the closely related T. nigritus (Frölich, 1792) (e.g.,
Euselates magna J Thomson, 1880
Euselates magna J Thomson, 1880
Euselates magna J. Thomson, 1880: 277
Known in the Palearctic Region from the Chinese provinces of Hainan, Hubei and the Hong Kong SAR (
1♀: Coloane, Hác-Sá, 14 May 2019, on flowers of Psychotria serpens, R Perissinotto (MACT); 1♂, 1♀: Coloane Village, 2 Jul 2019, dead on roadside, R Perissinotto & L Clennell (MACT).
Coloane, Hác-Sá, 28 Apr 2019, on flowers of Lonicera japonica, R Perissinotto & L Clennell; ibidem 3 May 2019, on flowers of Psychotria serpens, R Perissinotto & L Clennell; ibidem 15 May 2020, R Perissinotto; St. Francis Xavier’s Parish [Coloane], 16 May 2020 10:35, L Clennell (https://www.inaturalist.org/observations/56121519); ibidem 11 Jul 2020 9:45, Kisu Wong (https://www.inaturalist.org/observations/57338916); ibidem 11 Jul 2020 10:45, Kit Chang (https://www.inaturalist.org/observations/52662946).
This species has been previously reported from nearby Hong Kong with its synonymic name of E. schoenfeldti Kraatz, 1893 (
Results of this census show a significant increase in the number of cetoniine species occurring in the Macau SAR to eleven, compared to only four reported in previous publications (
Of special interest are the two Protaetia species [P. (L.) speculifera and P. (P.) intricata] that were previously unreported from the region, including Hong Kong, possibly due to their low frequency of occurrence in this area or to their superficial resemblance with other sympatric species. Both factors appear to be involved, as the two species were observed only on two occasions and only once, respectively, in each year of the census. Protaetia (P.) intricata is known for its remarkable scarcity across its entire and relatively small distribution range (S. Jákl, pers. comm.). Because of its small size and dark brown to olive-green background colour, it can potentially be confused with poorly ornamented varieties of the more common P. (P.) fusca by an untrained eye, or when not inspected at close range. Protaetia (L.) speculifera, on the other hand, is regarded as relatively common and much more widely distributed than P. (P.) intricata. However, it can be easily confused with the numerically dominant P. (C.) o. orientalis, and ever more so with the closely related P. (L.) brevitarsis, when not analysed in detail. The latter species has apparently been recorded in the mainland province of Guangdong, but not in either Macau or Hong Kong (
While the cetoniine diversity of Macau is larger than expected, what is of concern is the relatively poor abundance of most species recorded. Indeed, the frequency of occurrence of the various species reveals that only P. (C.) o. orientalis and Glycyphana (G.) laotica can be regarded as widespread and seasonally relatively common in Macau. All the others were recorded only on a few occasions and generally as single individuals, which is an indication that most local populations are under extreme stress and on the verge of becoming unsustainable. Some of the records may actually represent migrants from neighbouring regions on a dispersal flight and, thus, may not even have viable populations established within the Macau SAR.
Unfortunately, the few remaining areas of natural vegetation in the territory, mainly hills, are being systematically manipulated with undergrowth vegetation and dead or moribund trees removed, shredded and turned to compost. This process was escalated in the wake of the destructive impact of Typhoon Hato in August 2017, when trees were uprooted and damaged on a large-scale. The prompt intervention of the authorities ensured that all the damaged trees were cut and removed and, in their place, new young trees were planted within an ongoing rehabilitation programme. The problem is that these new trees are planted in an plantation-type manner, with ample space between each other and removal of any undergrowth inadvertently regarded as weeds. Trees are also regularly pruned of their lower branches. While all this is presumably done with the purpose of improving the aesthetic appearance of these green areas, it deprives the soil of its natural buffer against desiccation and extreme temperatures, thereby annihilating the habitat of soil invertebrates, including cetoniine larvae. The removal and destruction of the older, dead, or moribund trees also deprives the larval stages of all saproxylic species of their natural habitat. This seems to be impacting negatively in particular the two Schizorhinini species, which are also the largest cetoniines occurring in Macau, namely Agestrata orichalca and Thaumastopeus shangaicus. Both were regularly recorded in the past (
We thank the Macau Anglican College (Taipa, Macau) for supporting this project and providing funding towards its completion. We are particularly grateful to Stanislav Jákl (Prague, Czech Republic) for his invaluable assistance with the taxonomic revision of the more complex species. We wish to extend our thanks to a number of members of the Macau Entomological Society and general public for contributing with photos and observations to the compilation of the species record. These include Kit Chang, Kisu Wong, Hannah Leung, Erik Kwan, Annie Lao, Peggi Chao, Ben Wong, Chi-Man Leong and Angus Chan. Philip Kuok is also thanked for his invaluable help with flower and host-plant identifications. Finally, we are grateful to Wilson Hoi and Suki Chong (University of Macau Library) for facilitating access to the Easton Collection and providing photographs and data of relevant specimens.