Research Article |
Corresponding author: Benoit Guénard ( zeroben@gmail.com ) Academic editor: Brian Lee Fisher
© 2019 Kit Lam Tang, Mac P. Pierce, Benoit Guénard.
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:
Tang KL, Pierce MP, Guénard B (2019) Review of the genus Strumigenys (Hymenoptera, Formicidae, Myrmicinae) in Hong Kong with the description of three new species and the addition of five native and four introduced species records. ZooKeys 831: 1-48. https://doi.org/10.3897/zookeys.831.31515
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The species of the ant genus Strumigenys Smith, 1860 found in Hong Kong are reviewed based on new sampling efforts performed over the past five years (2014–2018). Prior to this, 12 Strumigenys species had been recorded from Hong Kong, all confirmed here. Moreover, we add to this list three newly described species: S. hirsuta sp. n., S. lantaui sp. n., and S. nathistorisoc sp. n., and describe for the first time the worker caste of S. formosa Terayama, Lin & Wu, 1995. We report new records for nine additional species, bringing the total number of species to 24, including four newly recorded species (S. hexamera Brown, 1958, S. membranifera Emery, 1869, S. nepalensis Baroni Urbani and De Andrade, 1994, and S. rogeri Emery, 1890) which are considered to be introduced to Hong Kong. A global review of the introduced Strumigenys species is presented. The taxonomic validity of S. feae and S. formosensis is discussed in light of new specimen measurements. New ecological information on the swarming periods of 11 species is presented on the basis of year-long sampling of aerial insects. Finally, the importance of our results within Southeast Asia and the need for future sampling efforts in the region is discussed.
Ant diversity, biogeography, China, exotic ants, Hong Kong, Strumigenys
With 836 described extant species (
Strumigenys is typically collected from leaf-litter samples from forests floors, though several species are associated with the accumulated leaf litter in trees (
Strumigenys is easily distinguishable from other ant genera by the combination of the following characters: small size (TL: ca 2–5 mm), elongate or triangular mandibles, and for many species the presence of spongiform tissues on the propodeal declivity, petiole and postpetiole, and first abdominal segment. In the field, these species can also be identified by their slow-motion, the occasional presence of thanatotic behaviour (
Despite its small size (1100 km2), Hong Kong has a relatively high level of biodiversity, due to its geographic position within continental Asia and subtropical climate. Prior to this study, 11 native and one introduced species of Strumigenys had been recorded. Here, we review the species of Strumigenys in Hong Kong based on new material collected between 2014 and 2018, describe three new species, and report new records for nine additional species, including four species considered as introduced for the region. We also provide new information on the sociometry of several species collected including reproductive phenology and colony composition.
The specimens examined were collected by members of the Insect Biodiversity and Biogeography Laboratory (IBBL) at the University of Hong Kong throughout Hong Kong between 2014 and 2018. A wide range of sampling methods were used, including Winkler extractors, pitfall traps, Malaise traps, and hand collection. Information on altitude, when not recorded in the field with the help of a GPS, was extracted from Google Earth Pro v. 7.1.8.3036 based on the recorded coordinates. Images were taken with a Leica DFC450 camera mounted on a Leica M205 C dissecting microscope. Image montages of the specimens were taken, stacked, enhanced and measured using the Leica Application Suite v. 4.5.
Female alate specimens of Strumigenys were collected from two projects using Malaise traps. The first project, led by Mr. Christophe Barthélémy, focuses on wasps and has been run since September 2014 at three main locations (Mai Po Nature Reserve, Pak Sha O, and Ping Chan Shai), with a single Malaise trap set at each location. The majority of traps (75%) are collected every two weeks, with occasional 3- or 4-week periods. While the overall period coverage includes the whole year, traps have been run discontinuously at some sites or during specific years (e.g. interruption from 22 November 2014 to 12 April 2015 in Pak Sha O). The second project focuses on mangrove insect diversity with sampling effort spread across 26 sites and seasonally clustered in two seasons from October to January and May to August. At each site one or two Malaise traps were operating for a period of 2 weeks in both seasons. Due to the peculiar habitat sampled in this study, specimens of Strumigenys collected most likely represent transient and not resident species.
Morphological measurements (Fig.
– Total Length (TL). The total length from the mandibular apex to the posterior margin of abdominal tergite IV. Sum of MandL + HL + ML + PL + PPL + GL.
– Head Length (HL). The length of the head capsule excluding the mandibles, measured in full-face view in a straight line from the midpoint of the anterior clypeal margin to the midpoint of the occipital margin. In species where one or both of these margins is concave, the measurement is taken from the midpoint of a transverse line that spans the apices of the projecting portions.
– Head Width (HW). The maximum width of the head in full-face view, excluding the eyes.
– Mandible Length (MandL). The straight-line length of the mandible at full closure, measured in the same plane for which the HL measurement is taken (i.e. full-face view), from the mandibular apex to the anterior clypeal margin, or to the transverse line connecting the anteriormost points when the margin is concave medially.
– Scape Length (SL). The maximum straight-line length of the scape, excluding the basal constriction or neck that occurs just distal of the condylar bulb. (In species with a hypertrophied subbasal lobe on the scape, SL is measured from the tip of the subbasal lobe to the scape apex.)
– Eye Length (EL). The maximum diameter of the eye.
– Pronotal Width (PW). The maximum width of the pronotum in dorsal view. Projecting tubercles or other cuticular prominences at the pronotal humeral angles, if present, are ignored.
– Mesosoma Length (ML) (= Weber’s Length). The diagonal length of the mesosoma in profile from the point at which the pronotum meets the cervical shield to the posterior basal angle of the metapleuron.
– Petiolar Length (PL). The maximum length of the petiole from the posterior petiolar margin to the point it is obscured by the posteroventral lobes of the propodeum in profile. Spongiform tissues, if present, are ignored.
– Petiolar Height (PH). The maximum distance measured between two parallel lines, one tangent with the node apex and the other tangent with the ventral-most point of the petiole in profile. When the ventral margin is concave upward, then the lower line tangent to the uppermost portion of the curve. Spongiform tissues, if present, are ignored.
– Dorsal Petiolar Width (DPW). The maximum width of the petiolar node in dorsal view.
– Postpetiole Length (PPL). The maximum length of the postpetiole, measured in the same plane for which the PL measurement is taken (i.e. profile view), from the anterior margin to the posterior margin. Spongiform tissues, if present, are ignored.
– Gaster Length (GL). The maximum length of the gaster, measured in the same plane for which the PL measurement is taken (i.e. profile view), from the anterior margin to the posterior margin. Spongiform tissues and sting, if present, are ignored.
– Cephalic Index (CI). HW / HL × 100
– Mandibular Index (MI). MandL / HL × 100
– Scape Index (SI). SL / HW × 100
– Ocular Index (OI). EL / HW × 100
– Lateral Petiolar Index (LPI). PH / PL × 100
– Dorsal Petiolar Index (DPI). DPW / PL × 100
Pentastruma canina Brown and Boisvert 1979: 203, figs 2–4 (w.q.m.) JAPAN. Palearctic.
Pyramica canina (Brown & Boisvert, 1979). Combination in Pyramica: Bolton 1999: 1673.
Strumigenys canina (Brown & Boisvert, 1979). Combination in Strumigenys: Baroni Urbani and De Andrade 2007: 116.
HONG KONG: Central & Western District, LFS Plot 3D, 22.278318N, 114.137804E, 04.01.2016, G. Yong, Winkler, IBBL; Central & Western District, Lung Fu Shan, 22.2783N, 114.138017E, 24.04.2015, R.H. Lee, pitfall trap, IBBL; Central & Western District, Lung Fu Shan, 22.278986N, 114.13717E, 18.11.2014, 211 m, M. Wong, Winkler, 4 Corners, IBBL; Central & Western District, Lung Fu Shan, 22.2790333N, 114.1366202E, 30.12.2015, G. Yong, Winkler, IBBL; Central & Western District, Lung Fu Shan, 22.279201N, 114.137209E, 12.09.2018, B. Guénard, hand collection, IBBL; Central & Western District, Lung Fu Shan, 22.28039N, 114.137830E, 25.11.2014, 295 m, M. Wong, Winkler, 12 Random, IBBL; Central & Western District, The Peak, 22.276038N, 114.141995E, 17.08.2015, R.H. Lee, Winkler, IBBL; Central & Western District, The Peak, 22.2767N, 114.1423E, 17.08.2015, R.H. Lee, Winkler, IBBL; North District, A Ma Wat, 22.5191N, 114.2441E, 19.12.2016, R.H. Lee, Winkler, IBBL; North District, H.W. Hang, 22.52819N, 114.2006E, 14.06.2015, 29 m, T. Tsang, Winkler, IBBL; North District, Lai Chi Wo, 22.527N, 114.258E, 08.05.2015, R.H. Lee, Winkler, IBBL; North District, Sheung Wo Hang, 22.522305N, 114.197237E, 16.06.2015, R.H. Lee, Winkler, IBBL; Sha Tin District, Kam Shan Country Park, 22.3562N, 114.15167E, 18.10.2017, R. Cheung, Winkler, IBBL; Sha Tin District, Kam Shan Country Park, 22.37089N, 114.14839E, 18.10.2017, R. Cheung, Winkler, IBBL; Sha Tin District, Lion Rock, 22.357002N, 114.175047E, 13.07.2015, R.H. Lee, Winkler, IBBL; Sha Tin District, Lion Rock, 22.357002N, 114.175047E, 15.08.2017, R.H. Lee, Winkler, IBBL; Sha Tin District, Lion Rock, 22.35805N, 114.176995E, 13.07.2015, R.H. Lee, Winkler, IBBL; Sha Tin District, Lion Rock, 22.360915N, 114.180028E, 13.07.2015, R.H. Lee, Winkler, IBBL; Sha Tin District, Mau Ping Wood, 22.3844N, 114.241E, 20.10.2015, R.H. Lee, Winkler, IBBL; Sha Tin District, Tai Po Kau Nature Reserve, 22.4281N, 114.1808E, 24.02.2016, B. Guénard, Winkler, IBBL; Sha Tin District, Tai Po Kau Nature Reserve, 22.4285N, 114.1808E, 22.02.2017, B. Guénard, Winkler, IBBL; Sha Tin District, Tai Po Kau, 22.41678N, 114.1878E, 03.07.2015, 317 m, T. Tsang, Winkler, IBBL; Sha Tin District, Tai Po Kau, 22.41841N, 114.1779E, 12.07.2015, 295 m, T. Tsang, Winkler, IBBL; Sha Tin District, Tai Po Kau, 22.422858N, 114.180827E, 14.07.2015, R.H. Lee, Winkler, IBBL; Sha Tin District, Tai Po Kau, 22.42706N, 114.179996E, 14.07.2015, R.H. Lee, Winkler, IBBL; Tai Po District, Kadoorie Centre, 22.4291N, 114.11491E, 08.09.2015, R.H. Lee, Winkler, IBBL; Tai Po District, Kadoorie Centre, 22.4297N, 114.1143E, 08.09.2015, R.H. Lee, Winkler, IBBL; Tai Po District, Kadoorie Farm and Botanic Garden, 22.43076N, 114.1215E, 04.07.2011, 335 m, P. Ward, sifted litter, IBBL; Tai Po District, KFBG, 22.4302N, 114.1192E, 14.09.2015, R.H. Lee, Winkler, IBBL; Tai Po District, Pak Sha O, 22.44743N, 114.3082E, 17.10.2017, R. Cheung / M. Pierce, Winkler, IBBL; Tai Po District, Sha Lo Tong, 22.47708333N, 114.18195E, 28.05.2015, R.H. Lee, Winkler, IBBL; Tai Po District, Sha Lo Tong, 22.4817666N, 114.182833E, 28.05.2015, R.H. Lee, Winkler, IBBL; Tai Po District, Sha Shan, 22.449N, 114.145E, 03.11.2015, R.H. Lee, Winkler, IBBL; Tai Po District, Tai Om, 22.44171N, 114.13518E, 28.02.2018, B. Guénard, Winkler, IBBL; Tai Po District, Tai Om, 22.44184N, 114.134571E, 28.02.2018, B. Guénard, Winkler, IBBL; Tai Po District, Tai Om, 22.4419N, 114.133533E, 05.10.2016, R.H. Lee, Winkler, IBBL; Tai Po District, Tai Om, 22.44214N, 114.13533E, 28.02.2018, B. Guénard, Winkler, IBBL; Tai Po District, Tai To Yan, 22.4538N, 114.11937E, 07.08.2015, R.H. Lee, Winkler, IBBL; Tsuen Wan District, Lin Fa Shan, 22.3956N, 114.0885E, 15.07.2016, R.H. Lee, Winkler, IBBL; 41; Tsuen Wan District, Shing Mun, 22.397083N, 114.1539166E, 14.05.2015, R.H. Lee, Winkler, IBBL; Tsuen Wan District, Shing Mun, 22.39755N, 114.15385E, 14.05.2015, R.H. Lee, Winkler, IBBL; Tsuen Wan District, Shing Mun, 22.39845N, 114.1628E, 24.08.2015, 367 m, T. Tsang, Winkler, IBBL; Tuen Mun District, Castle Peak, 22.390117N, 113.955767E, 30.06.2015, R.H. Lee, pitfall trap, IBBL; Yuen Long District, Ng Tung Chai, 22.429589N, 114.131276405085E, 01.11.2016, R.H. Lee, pitfall trap, IBBL; Yuen Long District, Ng Tung Chai, 22.429589N, 114.131276405085E, 01.11.2016, R.H. Lee, Winkler, IBBL.
One of the most common species of Strumigenys in Hong Kong (Fig.
Distribution of Strumigenys species in Hong Kong A S. canina, S. elegantula, and S. emmae B S. exilirhina, S. feae, and S. formosa C S. heteropha, S. hexamera, and S. hirsuta sp. n. D S. kichijo, S. lantaui sp. n., and S. mazu. Circles represent species previously recorded from Hong Kong, diamonds represent newly recorded species, and stars represent new species. Newly recorded introduced species are shown with red squares, and previously recorded introduced species are shown with red circles. Green shaded portions of the map correspond with higher levels of tree cover, and grey with lower levels of tree cover.
Smithistruma elegantula
Pyramica elegantula (Terayama & Kubota, 1989). Combination in Pyramica: Bolton 1999: 1673.
Strumigenys elegantula (Terayama & Kubota, 1989). Combination in Strumigenys: Baroni Urbani and De Andrade 2007: 119.
HONG KONG: Islands District, Shek Pik, 22.2309N, 113.8861E, 18.08.2015, R.H. Lee, Winkler, IBBL; Islands District, Shek Pik, 22.233N, 113.888E, 18.08.2015, R.H. Lee, pitfall trap, IBBL; North District, Lai Chi Wo, 22.527N, 114.258E, 08.05.2015, R.H. Lee, Winkler, IBBL; Tai Po District, Sha Lo Tong, 22.47708N, 114.18195E, 28.05.2015, R.H. Lee, pitfall trap, IBBL; Tai Po District, Tung Ping Chau, 22.5382N, 114.4365E, 02.10.2017, R. Cheung / B. Morgan, Winkler, IBBL; Tai Po District, Wu Kau Tang, 22.49645N, 114.2441E, 25.10.2015, 29 m, T. Tsang, Winkler, IBBL; Tsuen Wan District, Tai Lam Country Park, 22.38091N, 114.05324E, 08.11.2017, R. Cheung / M. Pierce, Winkler, IBBL; Tsuen Wan District, Tai Lam Country Park, 22.38109N, 114.05511E, 08.11.2017, R. Cheung / M. Pierce, Winkler, IBBL; Yuen Long District, Lok Ma Chau, 22.51192N, 114.06064E, 29.05.2018, 1 m, M. Wong, pitfall trap, IBBL; Yuen Long District, Lok Ma Chau, 22.51378N, 114.06301E, 29.05.2018, 1 m, M. Wong, pitfall trap, IBBL.
While this species is seldom collected in Hong Kong (Fig.
Epitritus emmae Emery 1890: 70, pl. 8, fig. 6 (w.) ANTILLES. Neotropic.
Quadristruma emmae
(Emery, 1890). Combination in Quadristruma:
Strumigenys emmae (Emery, 1890). Combination in Strumigenys: Bolton 1999: 1674.
HONG KONG: Central & Western District, HKU campus, near Chemistry building, 22.28275N, 114.13981E, 29.05.2015, C. Wang, Winkler, IBBL; Central & Western District, HKU CYT, 22.28245N, 114.14042E, 07.01.2016, G. Yong, Winkler, IBBL; Central & Western District, The Peak, 22.27604N, 114.14199E, 17.08.2015, R.H. Lee, Winkler, IBBL; Islands District, Disneyland, 22.30812N, 114.04318E, 27.07.2016, B. Guénard, Gut content Water Dragon, IBBL; Yuen Long District, Lok Ma Chau, 22.50942N, 114.06076E, 19.06.2018, 0 m, M. Wong, pitfall trap, IBBL; Yuen Long District, Lok Ma Chau, 22.50963N, 114.06053E, 19.06.2018, 1 m, M. Wong, pitfall trap, IBBL; Yuen Long District, Mai Po, 22.48023N, 114.03576E, 30.07.2018, 10 m, M. Wong, pitfall trap, IBBL; Yuen Long District, Mai Po, 22.48048N, 114.03514E, 30.07.2018, 10 m, M. Wong, pitfall trap, IBBL; Yuen Long District, Mai Po, 22.48153N, 114.03289E, 30.07.2018, 10 m, M. Wong, pitfall trap, IBBL; Yuen Long District, Mai Po, 22.48482N, 114.03335E, 07.08.2018, 1 m, M. Wong, pitfall trap, IBBL; Yuen Long District, Mai Po, 22.4858N, 114.0391E, 26.10.2016, R.H. Lee, pitfall trap, IBBL; Yuen Long District, Mai Po, 22.4868N, 114.0409E, 26.10.2016, R.H. Lee, pitfall trap, IBBL.
An introduced species, likely originating from the Australian realm (
Strumigenys exilirhina
HONG KONG: Central & Western District, HKU Campus, 22.28216N, 114.13829E, 19.11.2014, 113 m, M. Wong, Winkler, 12 Random, IBBL; Central & Western District, HKU campus, near Robert Black, 22.282129N, 114.138105E, 01.05.2015, C. Wang, Winkler, IBBL; Central & Western District, HKU CYT, 22.2824528N, 114.140429E, 07.01.2016, G. Yong, Winkler, IBBL; Central & Western District, LFS Plot 1 B–C, 22.277134N, 114.134792E, 28.12.2015, G. Yong, Winkler, IBBL; Central & Western District, LFS Plot 1 C, 22.277134N, 114.134806E, 28.12.2015, G. Yong, Winkler, IBBL; Central & Western District, Lung Fu Shan Park, N, E, 03.05.2015, C. Wang, Winkler, IBBL; Central & Western District, Lung Fu Shan, 22.276729N, 114.136693E, 24.11.2014, 295 m, M. Wong, Winkler, 12 Random, IBBL; Central & Western District, Lung Fu Shan, 22.28039N, 114.137830E, 25.11.2014, 156 m, M. Wong, Winkler, 4 Corners, IBBL; Central & Western District, Lung Fu Shan, 22.28221N, 114.133476E, 13.11.2014, 115 m, M. Wong, Winkler, 12 Random, IBBL; Central & Western District, Plot 1 B–C, 22.27713N, 114.13479E, 08.01.2016, G. Yong, Winkler, IBBL; Central & Western District, The Peak, 22.276038N, 114.141995E, 17.08.2015, R.H. Lee, Winkler, IBBL; Eastern District, Tai Tam, 22.259933N, 114.22009E, 27.07.2015, R.H. Lee, Winkler, IBBL; Islands District, Lamma Island, 22.20363N, 114.13599E, 14.09.2017, R.H. Lee, Winkler, IBBL; Islands District, Luk Tei Tong, 22.26233N, 113.99066E, 25.10.2016, R.H. Lee, pitfall trap, IBBL; Islands District, Pak Ngan Heung, 22.27099N, 113.98911E, 25.10.2016, R.H. Lee, pitfall trap, IBBL; Islands District, Shek Pik, 22.230898N, 113.88606E, 18.08.2015, R.H. Lee, Winkler, IBBL; Islands District, Shek Pik, 22.240075N, 113.89041E, 18.08.2015, R.H. Lee, Winkler, IBBL; North District, A Ma Wat, 22.5191N, 114.2441E, 19.12.2016, R.H. Lee, Winkler, IBBL; North District, Kuk Po Sam To, 22.523977N, 114.2355E, 15.11.2016, R.H. Lee, Winkler, IBBL; North District, Kuk Po San Uk, 22.529123N, 114.234675E, 15.11.2016, R.H. Lee, Winkler, IBBL; North District, Sheung Wo Hang, 22.52203N, 114.1962E, 12.06.2015, 71 m, T. Tsang, Winkler, IBBL; North District, Sheung Wo Hang, 22.52232N, 114.1972E, 16.06.2015, 99 m, T. Tsang, Winkler, IBBL; Sai Kung District, Pak Tam Chung, 22.400962N, 114.327163E, 05.06.2015, R.H. Lee, Winkler, IBBL; Sha Tin District, Lion Rock, 22.35805N, 114.176995E, 13.07.2015, R.H. Lee, Winkler, IBBL; Sha Tin District, Lion Rock, 22.360915N, 114.180028E, 13.07.2015, R.H. Lee, Winkler, IBBL; Sha Tin District, Lion Rock, 22.36121N, 114.181997E, 13.07.2015, R.H. Lee, Winkler, IBBL; Sha Tin District, Mui Tsz Lam wood, 22.389185N, 114.234462E, 04.10.2016, R.H. Lee, pitfall trap, IBBL; Sha Tin District, Tai Po Kau Nature Reserve, 22.4285N, 114.1808E, 22.02.2017, B. Guénard, Winkler, IBBL; Sha Tin District, Tai Po Kau, 22.41678N, 114.1878E, 03.07.2015, 317 m, T. Tsang, Winkler, IBBL; Sha Tin District, Tai Po Kau, 22.422858N, 114.180827E, 14.07.2015, R.H. Lee, Winkler, IBBL; Sha Tin District, Tai Po Kau, 22.42402N, 114.18029E, 14.07.2015, R.H. Lee, Winkler, IBBL; Sha Tin District, Tai Po Kau, 22.426138N, 114.181783E, 14.07.2015, R.H. Lee, Winkler, IBBL; Sha Tin District, Tai Po Kau, 22.427285N, 114.181298E, 16.09.2015, B. Guénard, hand collection, IBBL; Southern District, Lam Long Shan, 22.23887N, 114.16864E, 20.09.2017, R.H. Lee, Winkler, IBBL; Southern District, Nam Fung Road, 22.2546N, 114.1833E, 20.08.2016, R.H. Lee, pitfall trap, IBBL; Southern District, Nam Fung Road, 22.25519N, 114.1818E, 28.09.2015, 120 m, T. Tsang, Winkler, IBBL; Southern District, Nam Fung Road, 22.25554N, 114.1802E, 01.10.2015, 110 m, T. Tsang, Winkler, IBBL; Tai Po District, Kadoorie Farm and Botanic Garden, 22.43076N, 114.1215E, 04.07.2011, 335 m, P. Ward, sifted litter, IBBL; Tai Po District, KFBG, 22.4302N, 114.1192E, 14.09.2015, R.H. Lee, Winkler, IBBL; Tai Po District, Sha Lo Tong, 22.477083N, 114.18195E, 28.05.2015, R.H. Lee, Winkler, IBBL; Tai Po District, Sha Lo Tong, 22.477N, 114.1797E, 28.05.2015, R.H. Lee, Winkler, IBBL; Tai Po District, Sha Lo Tong, 22.481767N, 114.18283E, 28.05.2015, R.H. Lee, Winkler, IBBL; Tai Po District, Sha Shan, 22.449N, 114.145E, 03.11.2015, R.H. Lee, Winkler, IBBL; Tai Po District, Tai Om, 22.4419N, 114.133533E, 05.10.2016, R.H. Lee, Winkler, IBBL; Tai Po District, To Kwa Peng, 22.42901N, 114.3336E, 25.05.2018, 1 m, R. Cheung / C. Taylor, Malaise trap, IBBL; Tsuen Wan District, Ha Lin Fa Shan, 22.39664N, 114.1019E, 31.07.2015, 355 m, T. Tsang, Winkler, IBBL; Tsuen Wan District, Shing Mun, 22.396783N, 114.1531E, 14.05.2015, R.H. Lee, pitfall trap, IBBL; Tsuen Wan District, Shing Mun, 22.39678N, 114.1531E, 23.08.2015, 238 m, T. Tsang, Winkler, IBBL; Tsuen Wan District, Shing Mun, 22.39693N, 114.153E, 17.05.2016, R.H. Lee, Winkler, IBBL; Tsuen Wan District, Shing Mun, 22.397083N, 114.1539166E, 14.05.2015, R.H. Lee, Winkler, IBBL; Yuen Long District, Kap Lung, 22.41596N, 114.1038E, 11.09.2015, 288 m, T. Tsang, Winkler, IBBL; Yuen Long District, Ng Tung Chai, 22.42959N, 114.13128E, 01.11.2016, R.H. Lee, Winkler, IBBL; Yuen Long District, Sheung Pak Nai, 22.45151N, 113.96213E, 28.05.2018, 1 m, R. Cheung / C. Taylor, Malaise trap, IBBL; Yuen Long District, Sheung Tin Liu Ha, 22.44348N, 114.114E, 03.08.2015, 106 m, T. Tsang, Winkler, IBBL.
This is one of the most common species of Strumigenys in Hong Kong (Fig.
Strumigenys feae Emery 1895: 473 (w.q.) MYANMAR. Indomalaya.
HONG KONG: Tai Po District, Tai Om, 22.43681N, 114.1373E, 07.08.2015, 138 m, T. Tsang, Winkler, IBBL; Tsuen Wan District, Shing Mun, 22.40027N, 114.161E, 04.09.2015, 366 m, T. Tsang, Winkler, IBBL; Tuen Mun District, Castle Peak, 22.389935N, 113.954937E, 30.06.2015, R.H. Lee, pitfall trap, IBBL; Yuen Long District, Kap Lung, 22.41596N, 114.1038E, 11.09.2015, 288 m, T. Tsang, Winkler, IBBL; Sha Tin District, Tai Po Kau Nature Reserve, 22.4285N, 114.1808E, 22.02.2017, B. Guénard, Winkler, IBBL; Tai Po District, Kadoorie Farm and Botanic Garden, 22.43076N, 114.1215E, 04.07.2011, 335 m, P. Ward, sifted litter, IBBL.
Workers (n = 2): TL 3.1–3.3, HL 0.81–0.87, HW 0.52–0.55, MandL 0.39–0.41, SL 0.52–0.53, EL 0.061–0.062, PW 0.26–0.28, ML 0.82, PL 0.30, PH 0.15–0.16, DPW 0.11–0.12, PPL 0.19–0.20, GL 0.58–0.71, CI 63–64, MI 47–48, SI 96–100, OI 11–12, LPI 51–52, DPI 37–40.
In Hong Kong, S. feae was collected within tree plantations of Lophostemon confertus Wilson & Waterh. and in secondary forests, with elevation ranging from 138 to 457 m.
While S. formosensis (Forel, 1912) has been recorded from Hong Kong (
The revised descriptions of S. feae and S. formosensis by
Specimens collected in Hong Kong could not be assigned to either S. feae or S. formosensis without ambiguity under the current descriptions. Preapical teeth are neither fully directed medially as in S. feae, nor with a single continuous proximal margin as in S. formosensis (Fig.
Morphological measurements of S. feae and S. formosensis comparing information on specimens presented in
Species/Specimens | HL | HW | SL | MandL | PW | ML | CI | SI | MI |
---|---|---|---|---|---|---|---|---|---|
Measurements (in mm) from |
|||||||||
S. feae | 0.75–0.80 | 0.47–0.52 | 0.48–0.50 | 0.33–0.36 | 0.27–0.28 | 0.72–0.80 | 61–68 | 94–102 | 41–46 |
S. formosensis | 0.84–0.87 | 0.54–0.56 | 0.52–0.54 | 0.39–0.40 | 0.25–0.28 | 0.75–0.78 | 63–65 | 93–98 | 46–47 |
Measurements (in mm) from two Hong Kong specimens | |||||||||
ANTWEB1017082 | 0.87 | 0.55 | 0.53 | 0.41 | 0.28 | 0.82 | 63 | 96 | 47 |
RHL01266 | 0.81 | 0.52 | 0.52 | 0.39 | 0.26 | 0.82 | 64 | 100 | 48 |
Epitritus formosus Terayama et al., 1995: 85, figs 1–4 (q.) TAIWAN. Indomalaya.
Pyramica formosus (Terayama et al., 1995). Combination in Pyramica: Bolton 1999: 1672.
Strumigenys formosa (Terayama et al., 1995). Combination in Strumigenys: Baroni Urbani and De Andrade 2007: 120.
HONG KONG, Sha Tin District, Tai Po Kau Nature Reserve, 22.426138N 114.181783E, 162 m, 6.VII.2017, R.H. Lee, RHL03476, pitfall trap, IBBL.
Worker (n = 1): TL 1.6, HL 0.35, HW 0.38, MandL 0.13, SL 0.18, EL 0.024, PW 0.24, ML 0.41, PL 0.18, PH 0.10, DPW 0.12, PPL 0.11, GL 0.41, CI 109, MI 37, SI 47, OI 6, LPI 57, DPI 68.
This species has been described from two queens collected in 1988 in Nantou County, Taiwan. To the best of our knowledge, no additional records have been reported in the following 30 years. A single worker was collected in Hong Kong which fits the morphological characteristics and size of S. formosa. In the absence of nest series, assigning this worker to this species might be uncertain, however, the extreme rarity of this species in Hong Kong and Taiwan limits the likelihood of collecting nest series. As a result, in the presence of several convergent characters, we assign the worker collected to S. formosa. Complete description and diagnosis are provided below.
(Fig.
Mesosoma. In profile view, dorsum of mesosoma continuous and slightly concave on its mesonotum portion. Pronotomesopleural suture visible and extending on about one-third on the height of the pronotum. Fine lamellae of spongiform tissues present on propodeal declivity, with its upper posterior portion slightly acute as in female holotype. Metapleural gland bulla well developed. In dorsal view, thorax trapezoidal with pronotum much wider than mesonotum and propodeum. Anterior margin of pronotum convex and forming rounded angles with lateral margins.
Waist segments. Petiolar peduncle long, its lateral margins slightly concave in shape when seen in dorsal view. In profile view, petiolar node low and rounded. In profile view, postpetiole lower than petiole. In dorsal view, postpetiole distinctly larger than petiole, bean shaped, and fully surrounded by spongiform tissues.
Pilosity. On posterior half of head, pilosity limited to a few short J-shaped hairs present on lateral margin of head and oriented apically when head observed in full-face view. More short J-shaped hairs visible in profile view, slightly denser on particular on the posterior margin of head. In full head view, as for the female reproductive caste, frontal lobes covered by about 15 appressed large orbicular hairs arranged longitudinally. Clypeus with sparse presence of small to medium-sized spoon-shaped hairs. Anterior clypeal margin with four spoon-shaped hairs pointing forward and directed towards the mid-point of the clypeus, with central hairs significantly larger than those present on lateral margins. Spoon-shaped hairs completely lacking on mandibles but with finer pubescence present. On scapes, spoon-shaped hairs present on lateral margins and arranged in a crescendo fashion from smaller hairs present from about two-third of the scape on its apical to larger hairs present on the subbasal lobes; all pointing anterodorsally towards the apex of subbasal antennal lobe. In profile view, a few short, acute and erected hairs visible on mesonotum and anterodorsal part of the propodeum. Legs with numerous suberected fine and long hairs present on femurs, with apical portion of femurs bearing a few spoon-shaped hairs. Petiolar node with a continuous collar of four large spoon-shaped hairs oriented backwards and extending from the lateral margin of the petiole at about its midpoint to its dorsal portion, with their size increasing posteriorly. Other thick hairs present on dorsal portion of the petiole and oriented backwards. Sparse erected spoon-shaped hairs present on gaster significantly longer with their basal portion elongated and thin. Fine elongated simple hairs present on sternites and arranged transversely.
Sculpture. Head finely aerolated in all visible portions, including scapes, but not on mandibles. Aerolate sculptures particularly well defined around the eyes, when specimen observed in profile view. In profile view, pronotum mostly reticulated at the exception of its most ventral region which is smooth. Mesopleuron and metapleuron almost entirely smooth and shiny. Posterodorsal part of the propodeum reticulated. In dorsal view, thorax with coarse reticulated sculpture. Coxa, femur and tibia aerolated. In profile view, petiole mainly reticulated at the exception of the anterior part of the petiolar peduncle smooth. In dorsal view, petiole clearly reticulated. Visible part of postpetiolar node smooth and shiny. Gaster entirely smooth and shiny, with only short longitudinal striae present on anterior portion of the dorsal part of the tergite of the fourth metasomal segment.
Colouration. Bright yellow for most of the body at the exception of the gaster which is slightly darker.
The specimen clearly shares all characters of the S. murphyi-group (
Hong Kong, Taiwan. This record of S. formosa represents the second record for this species and the first outside of Taiwan. Therefore, this species should not be considered as endemic to Taiwan.
The only worker known from Hong Kong (Fig.
Strumigenys heteropha
HONG KONG: Islands District, Tei Tong Tsai, 22.25707N, 113.92628E, 29.11.2016, R.H. Lee, Winkler, IBBL; Sha Tin District, Tai Po Kau, 22.41698N, 114.1789E, 03.07.2015, 337 m, T. Tsang, Winkler, IBBL; Sha Tin District, Tai Po Kau, 22.42007N, 114.1829E, 02.07.2015, 291 m, T. Tsang, Winkler, IBBL; Tai Po District, KFBG, 22.4302N, 114.1192E, 14.09.2015, R.H. Lee, Winkler, IBBL; Tsuen Wan District, Shing Mun, 22.39845N, 114.1628E, 24.08.2015, 367 m, T. Tsang, Winkler, IBBL; Tsuen Wan District, Shing Mun, 22.39962N, 114.162E, 12.08.2015, 355 m, T. Tsang, Winkler, IBBL; Yuen Long District, Kap Lung, 22.41596N, 114.1038E, 11.09.2015, 288 m, T. Tsang, Winkler, IBBL; Yuen Long District, Kap Lung, 22.41931N, 114.1018E, 24.09.2015, 190 m, T. Tsang, Winkler, IBBL; Yuen Long District, Sheung Tin Liu Ha, 22.44348N, 114.114E, 03.08.2015, 106 m, T. Tsang, Winkler, IBBL.
This species was collected in several closed-canopy habitats including tree plantations of Lophostemon confertus Wilson & Waterh., secondary forests and Feng Shui woods (Fig.
Epitritus hexamerus Brown 1958: 70, figs 1–3 (w.q.) JAPAN. Palearctic.
Pyramica hexamerus (Brown, 1958). Combination in Pyramica: Bolton 1999: 1672.
Strumigenys hexamera (Brown, 1958). Combination in Strumigenys: Baroni Urbani and De Andrade 2007: 122.
HONG KONG: Sha Tin District, Tai Po Kau, 22.42841N, 114.18197E, 22.02.2017, 160 m, R.H. Lee, Winkler, IBBL; Tai Po District, Ping Shan Chai, 22.486N, 114.187E, 25.03.2017, 142 m, C. Barthélémy, Malaise trap, IBBL.
Worker (n = 1): HL 0.47, HW 0.50, MandL 0.18, SL 0.22, EL 0.036, PW 0.27, ML 0.53, PL 0.23, PH 0.12, DPW 0.15, PPL 0.16, CI 106, MI 38, SI 44, OI 7, LPI 51, DPI 63. Queen (n = 1): TL 2.7, HL 0.54, HW 0.60, MandL 0.20, SL 0.25, EL 0.10, PW 0.37, ML 0.71, PL 0.34, PH 0.17, DPW 0.22, PPL 0.18, GL 0.78, CI 111, MI 37, SI 42, OI 17, LPI 48, DPI 65.
Native : Japan (mainland and Ryukyu Islands), South Korea, Taiwan.
Introduced : Hong Kong, Ogasawara Islands (Japan), United States.
This is a rare species in Hong Kong with only two records, both from secondary forests at elevations of 142 and 160 m (Fig.
The record of S. hexamera in Hong Kong represents the first record of this species for continental China. This species is known as an introduced species in Southeast USA (Alabama, Florida, Louisiana, and Mississippi), and was reported as introduced within the Ogasawara Islands (
Dorsolateral margin of head in full-face view with at most 4 freely laterally projecting flagellate hairs: 1 on the upper scrobe margin posterior to the level of eye, 1 at apicoscrobal position, 0–2 posterior to this on the lateral margin of occipital lobe. Cephalic dorsum, dorsal mesosoma and side of pronotum densely and strongly reticulate-punctate; metapleuron and side of propodeum reticulate-punctate but weaker and fainter than on the dorsum; katepisternum mostly smooth and shining. Dorsal and ventral surfaces of femur with numerous fine erect to suberect hairs. SI 61–63.
Holotype worker: Hong Kong, Hong Kong Island, Lung Fu Shan, 22.27899N, 114.13717E, 211 m, 18 November 2014 (M. Wong) (collection code F2W-m2) [IBBL, ANTWEB1009855]. Paratype workers (n = 5): same data as holotype worker. Holotype queen: same data as holotype worker.
1 queen and 17 workers. HONG KONG: Central & Western District, Lung Fu Shan, 22.279201N, 114.137209E, 12.09.2018, B. Guénard, hand collection, IBBL; Central & Western District, Lung Fu Shan, 22.28039N, 114.13783E, 25.11.2014, 156 m, M. Wong, Winkler, 12 Random, IBBL; Central & Western District, Lung Fu Shan, 22.28221N, 114.133476E, 13.11.2014, 115 m, M. Wong, Winkler, IBBL; Central & Western District, Lung Fu Shan, R.H. Lee, pitfall trap, IBBL; Islands District, Tung Chung, 22.2907N, 113.9371E, 1 m, B.M. Worthington, Winkler, 12 Random, IBBL; Islands District, Tung Chung, 22.2907N, 113.9371E, B.M. Worthington, Winkler, 4 Corners, IBBL; Sai Kung District, Clear Water Bay Country Park, 22.29618N, 114.29239E, 24.10.2017, 113 m, R. Cheung / M. Pierce, Winkler, 12 Random, IBBL; Sai Kung District, Pak Sha O, 22.44743N, 114.3082E, 17.11.2017, 135 m, R. Cheung / M. Pierce, Winkler, 4 Corners, IBBL; Sha Tin District, Tai Po Kau, 22.41678N, 114.1878E, 03.07.2015, 317 m, T. Tsang, Winkler, IBBL; Tai Po District, Ping Shan Chai, 22.486N, 114.187E, 04.06.2016, C. Barthélémy, Malaise trap, IBBL; Tai Po District, Tai To Yan, 22.4538N, 114.11937E, 07.08.2015, 459 m, R.H. Lee, Winkler, IBBL; Tuen Mun District, Castle Peak, 22.389935N, 113.954937E, 30.06.2015, 457 m, R.H. Lee, pitfall trap, IBBL; Tuen Mun District, Castle Peak, 22.39012N, 113.958983E, 30.06.2015, 204 m, R.H. Lee, Winkler, IBBL
Holotype worker: TL 3.1, HL 0.74, HW 0.55, MandL 0.30, SL 0.35, EL 0.054, PW 0.31, ML 0.79, PL 0.35, PH 0.15, DPW 0.14, PPL 0.22, GL 0.69, CI 75, MI 41, SI 63, OI 10, LPI 42, DPI 40. Paratype workers (n = 5): TL 2.9–3.1, HL 0.71–0.74, HW 0.53–0.55, MandL 0.29–0.30, SL 0.34–0.35, EL 0.050–0.057, PW 0.29–0.31, ML 0.74–0.78, PL 0.32–0.34, PH 0.13–0.15, DPW 0.14, PPL 0.20–0.21, GL 0.63–0.70, CI 73–75, MI 40–42, SI 63–65, OI 9–11, LPI 41–44, DPI 43–45. Holotype queen: TL 3.6, HL 0.78, HW 0.59, MandL 0.31, SL 0.37, EL 0.12, PW 0.38, ML 0.89, PL 0.44, PH 0.19, DPW 0.19, PPL 0.23, GL 0.90, CI 76, MI 40, SI 62, OI 21, LPI 43, DPI 44.
(Fig.
Mesosoma. In profile pronotal dorsum broadly convex, with the rest of the dorsum of the mesosoma more or less flat transversely; pronotum marginate dorsolaterally. In dorsal view, lateral margins of the pronotum evenly convex. Propodeal teeth short, triangular and acute, and not subtended by lamella.
Waist segments. Petiole in profile claviform, the node long and low; the peduncle grade evenly into the node without a marked change of slope; node in dorsal view longer than broad. Disc of the postpetiole in dorsal view very slightly broader than long, and slightly shorter than petiolar node. Spongiform tissues present on both petiole and postpetiole; ventral lobes of petiole and postpetiole extensive. In profile view, spongiform tissues present ventrally on the peduncle of the petiole notably larger than that under the petiolar node portion, and markedly thicker than the height of the peduncle. Lateral lobe of petiole restricted to posterior half of the node in profile; in dorsal view present along the posterior margin of the petiolar node and surrounding the disc of postpetiole.
Pilosity. Dorsolateral margin of head in full-face view with at most 4 pairs of freely laterally projecting flagellate hairs: 1 on the upper scrobe margin posterior to the level of eye, 1 at apicoscrobal position, 0–2 posterior to this on the lateral margin of occipital lobe. Cephalic dorsum, against ground pilosity of short, suberect to decumbent, simple hairs, with several erect flagellate hairs close to the occipital margin but without erect hairs anterior to this. Leading edge of scape with apically directed, decumbent simple hairs. Pronotal humeral hair long, flagellate or looped apically. Dorsum and side of mesosoma covered with ground pilosity of short, suberect hairs arising and curving in various directions. Dorsal and ventral surfaces of femur with numerous fine erect to suberect hairs against ground pilosity of appressed hairs; dorsal surface of tibia and basitarsus with 1–4 long filiform erect hairs on each segment. Petiolar node and postpetiole with numerous erect to suberect, flagellate hairs against ground pilosity of posteriorly directed, shorter decumbent hairs; first gastral tergite with numerous curved to subflagellate erect hairs.
Sculpture. Cephalic dorsum densely and strongly reticulate-punctate. Dorsal mesosoma and side of pronotum densely and strongly reticulate-punctate, occasionally with very weak and faint rugulose; metapleuron and side of propodeum also reticulate-punctate to punctate, with reticulation limited to the dorsal half of the propodeum, and weaker and fainter than on the dorsum or side of pronotum, sometimes even partially smooth and shining; katepisternum mostly smooth and shining, with some light punctation and vestiges of sculpture around the margins. Anterior coxae with weak transverse rugulae. Petiole and disc of postpetiole densely and strongly reticulate-punctate. Basigastral costulae arise across the entire width of tergite, short and limited to the basal third or fourth of tergite.
(Fig.
Strumigenys hirsuta is a member of the caniophanes-complex in the S. caniophanes-group and shares all the characters (
Strumigenys hirsuta (HL 0.71–0.74, HW 0.53–0.55, ML 0.74–0.78) is a smaller species than S. dipsas (HL 0.80–0.86, ML 0.87–0.90) and S. pliocera (HL 0.89, ML 0.90); and a larger species than S. benulia (HL 0.56, HW 0.39, ML 0.56). Strumigenys hirsuta (SI 63–65) also has a markedly relatively shorter scape than those 6 species from the caniophanes-complex: S. benulia (SI 72), S. dipsas (SI 73–76), S. paraposta (SI 73–78), S. lacunosa (SI 75), S. daithma (SI 85), and S. pliocera (SI 84).
The species is named for the multiple standing and convoluted hairs present on most of the body.
Hong Kong.
Strumigenys hirsuta appears to be widespread in Hong Kong and has been collected from multiple locations in Hong Kong Island, the New Territories, and Lantau Island (Fig.
Smithistruma kichijo Terayama Lin and Wu 1996: 335, figs 23–25, 28, 29 (w.) TAIWAN. Indomalaya.
Pyramica kichijo (Terayama, Lin & Wu, 1996). Combination in Pyramica: Bolton 1999: 1673.
Strumigenys kichijo (Terayama, Lin & Wu, 1996). Combination in Strumigenys: Baroni Urbani and De Andrade 2007: 122.
HONG KONG: Islands District, Sunset Peak, 22.26112N, 113.956332E, 572 m, 28.03.2016, R.H. Lee, Winkler, IBBL.
Workers (n = 3): TL 2.5–2.6, HL 0.59, HW 0.46–0.47, MandL 0.14–0.16, SL 0.32–0.33, EL 0.045–0.049, PW 0.30, ML 0.61–0.66, PL 0.31–0.33, PH 0.14–0.15, DPW 0.17–0.18, PPL 0.23–0.24, GL 0.60–0.62, CI 78–80, MI 24–27, SI 70, OI 10, LPI 45–48, DPI 53–58.
Bhutan, China (Fujian, Hunan, Yunnan, Hong Kong), Japan, Taiwan, Thailand, Vietnam.
This is a rare species for Hong Kong with a single worker collected (Fig. 2) in secondary forest at a relatively high elevation (572 m).
This is a widespread species in Asia, though rarely collected. The new record from Hong Kong fits within the known range of this species, which ranges in Asia from Hunan (north) to Thailand (south), and from Bhutan (west) to Okinawa (east).
Anterior clypeal margin medially shallowly convex with 6 anteriorly projecting strap-like hairs; lateral margin each with 3 anteriorly directed spatulate hairs that are smaller than those on the clypeal margin. Mandibles without preapical tooth. Antenna 4-segmented. Orbicular hairs present on dorsal surface of scapes, head, pronotum and mesonotum. Mesonotum in profile not forming a differentiated surface between pronotum and propodeum.
Holotype worker: Hong Kong, Lantau Island, Penny’s Bay, 22.3271N, 114.0335E, 9 m, 25 October 2017 (M. Pierce) (collection code WC-PB-NON-06), Winkler [IBBL, ANTWEB1009620]. Paratype workers (n = 2): same data as holotype.
Holotype worker: TL 1.6, HL 0.36, HW 0.31, MandL 0.10, SL 0.18, EL 0.026, PW 0.20, ML 0.39, PL 0.19, PH 0.09, DPW 0.11, PPL 0.13, GL 0.40, CI 86, MI 28, SI 58, OI 8, LPI 51, DPI 57. Paratype workers (n = 2): TL 1.6–1.7, HL 0.37, HW 0.32–0.33, MandL 0.10–0.11, SL 0.19, EL 0.019–0.022, PW 0.21, ML 0.41, PL 0.19, PH 0.10, DPW 0.11, PPL 0.13–0.14, GL 0.43–0.45, CI 86–89, MI 27–30, SI 58–59, OI 6–7, LPI 53, DPI 55–57.
Head. In full-face view occipital margin broadly concave; occipital corner evenly rounded; lateral margin broadly convex and slightly diverging from one another, then forming blunt angle with the strongly converging upper scrobe margin; anterior clypeal margin broadly concave across its width. In profile vertex at or near its highest point evenly curved and convex, without a raised transverse crest. Antenna 4-segmented; scape dorsoventrally flattened and board; subbasal angle expanded anteriorly into a large subbasal lobe. Mandible in full-face view narrow, elongate, curvilinear and without preapical tooth. Proximal to apices with a prominent diastema between the mandibles, through which the labral lobes are visible. Apex of mandible with a nearly vertical series of minute teeth or denticles; apicoventral teeth markedly enlarged.
Mesosoma. In profile view the dorsum of mesosoma broadly, shallowly convex; pronotum bluntly marginate laterally; mesonotum not forming a differentiated surface between pronotum and propodeum; in dorsal view lateral margin with a bluntly rounded angle on each side and meet anteriorly into a broadly convex anterior margin. Propodeum unarmed, declivity with a lamella running down each side.
Waist segments. Petiole in profile elongate and subclavate; peduncle does not grade evenly into the node; node in dorsal view long about the same as broad. Disc of postpetiole in dorsal view broader than long and slightly shorter or about the same as petiolar node. Spongiform tissues present on both petiole and postpetiole; ventral lobes of postpetiole in particular extensive; lateral lobe of petiole restricted to posterior portion of the node in profile; in dorsal view present along the posterior margin of the petiolar node, and surrounding disc of postpetiole.
Pilosity. Anterior clypeal margin with 6 anteriorly projecting strap-like hairs; lateral margin each with 3 anteriorly directed spatulate hairs that are smaller than those on clypeal margin. Leading edge of scape with row of basally directed spatulate hairs. Orbicular hairs present on dorsal surface of scapes and all over the cephalic dorsum, including clypeal dorsum, and promesonotal dorsum; dorsal surface of mandibles with short appressed simple or spatulate hairs. Dorsal surfaces of tibiae with short appressed spatulate hairs. Petiolar node and disc of postpetiole with posteriorly directed spatulate hairs, and at most a few decumbent to suberect short simple hairs on the disc of postpetiole; first gastral tergite with numerous short, simple standing hairs.
Sculpture. Cephalic dorsum, including surface of antennal scrobe and antenna, areolate. Dorsum of mesosoma and side of pronotum areolate to densely reticulate-punctate, and with fine reticulopunctate; mesopleuron and side of propodeum mostly smooth and shining, while in some specimens those can appear opaquer but with undefined sculpture. Dorsum of petiolar node and disc of postpetiole generally smooth and shining; basigastral costulae short and arise across entire width of tergite.
Strumigenys lantaui is a member of the argiola-complex in the S. argiola-group and shares all the characters (
Strumigenys lantaui (HL 0.36–0.37, HW 0.31–0.33, ML 0.39–0.41) is also a smaller species than all other Oriental species in the species group: S. hirashimai (HL 0.40–0.46, HW 0.36–0.40, ML 0.42–0.48), S. lachesis (HL 0.39, HW 0.39, ML 0.42), S. hexamera (HL 0.50–0.53, HW 0.53–0.55, ML 0.57–0.60), S. tisiphone (HL 0.50, HW 0.48, ML 0.53), and S. sinensis (HL 0.52, HW 0.46, ML 0.50).
This species is named after Lantau Island, the type locality and currently only known location for the species.
Hong Kong.
Strumigenys lantaui is currently only known from a single location (Fig. 2) where it was collected by leaf-litter extraction at the inner edge of a secondary forest.
Smithistruma mazu Terayama Lin and Wu 1996: 337, figs 26, 27, 30, 31 (w.) TAIWAN. Indomalaya.
Pyramica mazu (Terayama, Lin & Wu, 1996). Combination in Pyramica: Bolton 1999: 1673.
Strumigenys mazu (Terayama, Lin & Wu, 1996). Combination in Strumigenys: Baroni Urbani and De Andrade 2007: 123.
HONG KONG: Sha Tin District, Tai Po Kau, 22.42007N, 114.1829E, 02.07.2015, 291 m, T. Tsang, Winkler, IBBL; Tsuen Wan District, Tai Lam Country Park, 22.38109N, 114.05511E, 8.XI.2017, 254 m, R. Cheung / M. Pierce, ANTWEB1016463, Winkler, IBBL.
China (Guangxi), Hong Kong, Japan, Taiwan.
This is an uncommon species in Hong Kong where it is known only from a few locations (Fig.
Distribution of Strumigenys species in Hong Kong A S. membranifera, S. minutula, and S. mitis B S. cf. mutica, S. nanzanensis, and S. nathistorisoc sp. n. C S. nepalensis, S. rallarhina, and S. rogeri* D S. sauteri, S. sydorata, and S. tisiphone. Circles represent species previously recorded from Hong Kong, diamonds represent newly recorded species, and stars represent new species. Newly recorded introduced species are shown with red squares. Green shaded portions of the map correspond with higher levels of tree cover, and grey with lower levels of tree cover. *To avoid confusion, S. rogeri (a newly recorded introduced species) is represented by a yellow square instead of a red square.
Strumigenys (Trichoscapa) membranifera Emery 1869: 24, fig. 11 (w.) ITALY. Palearctic.
Strumigenys (Cephaloxys) membranifera (Emery, 1869). Combination in Strumigenys (Cephaloxys): Emery 1916: 205.
Trichoscapa membranifera (Emery, 1869). Combination in Trichoscapa: Brown 1948: 113.
Pyramica membranifera (Emery, 1869). Combination in Pyramica: Bolton 1999: 1673.
Strumigenys membranifera (Emery, 1869). Combination in Strumigenys: Baroni Urbani and De Andrade 2007: 123.
Senior synonym of S. foochowensis, S. membranifera marioni, S. membranifera santschii, S. silvestriana, S. membranifera simillima, S. vitiensis, S. membranifera williamsi: Brown 1948: 114.
HONG KONG: Islands District, Chek Lap Kok, 22.2947N, 113.9336E, 21 m, B.M. Worthington, Winkler, 4 Corners, IBBL; Islands District, Chek Lap Kok, 22.2953N, 113.9354E, 28 m, B.M. Worthington, Winkler, 12 Random, IBBL; Islands District, Chek Lap Kok, 22.2953N, 113.9354E, B.M. Worthington, Winkler, 12 Random, IBBL; Islands District, Chek Lap Kok, 22.2957N, 113.9338E, 15 m, B.M. Worthington, Winkler, 12 Random, IBBL; Islands District, Chek Lap Kok, 22.2957N, 113.9338E, 15 m, B.M. Worthington, Winkler, 4 Corners, IBBL; Islands District, Chek Lap Kok, 22.2957N, 113.9338E, B.M. Worthington, Winkler, 12 Random, IBBL; Islands District, Chek Lap Kok, 22.3139N, 113.9398E, 2 m, B.M. Worthington, Winkler, 4 Corners, IBBL; Islands District, Chek Lap Kok, 22.3139N, 113.9398E, B.M. Worthington, Winkler, 12 Random, IBBL; Islands District, Chek Lap Kok, 22.3153N, 113.9407E, B.M. Worthington, Winkler, 12 Random, IBBL; Islands District, Chek Lap Kok, 22.3153N, 113.9407E, B.M. Worthington, Winkler, 4 Corners, IBBL; Islands District, Disneyland, 22.309433N, 114.04575E, 19.07.2016, B. Guénard, Gut content Water Dragon, IBBL; Tai Po District, Ping Shan Chai, 22.486N, 114.187E, 13.06.2015, C. Barthélémy, Malaise trap, IBBL; Tai Po District, To Kwa Peng, 22.42901N, 114.3336E, 25.05.2018, 1 m, R. Cheung / C. Taylor, Malaise trap, IBBL; Yuen Long District, Lok Ma Chau, 22.51031N, 114.06376E, 16.05.2018, 1 m, M. Wong, pitfall trap, IBBL; Yuen Long District, Lok Ma Chau, 22.51287N, 114.06463E, 17.07.2018, 1 m, M. Wong, pitfall trap, IBBL.
Workers (n = 5): TL 1.9–2.1, HL 0.45–0.47, HW 0.40–0.41, MandL 0.08–0.09, SL 0.20–0.23, EL 0.029–0.037, PW 0.22–0.24, ML 0.49–0.53, PL 0.22–0.26, PH 0.13–0.15, DPW 0.14–0.15, PPL 0.15–0.18, GL 0.47–0.53, CI 87–91, MI 17–20, SI 49–56, OI 7–9, LPI 55–58, DPI 54–61.
Native: Ghana, Sierra Leone, South Africa
Introduced: a widespread species in multiple biogeographic realms. For a full global account, please refer to records presented under antmaps.org (
This is a species restricted to habitats with frequent disturbance, particularly within lowland areas (Hong Kong Airport, Disneyland, and Mai Po Nature Reserve) covered with grasslands or remnants of forests within urbanized matrices (Fig.
The record of this tramp species in Hong Kong is not surprising considering its widespread range in the region and previous records in the nearby provinces of Guangdong and Fujian as well as from Macau for 90 years (
Strumigenys minutula
HONG KONG: Central & Western District, Lung Fu Shan, 22.28221N, 114.133476E, 115 m, 13.11.2014, M. Wong, Winkler, 12 Random, IBBL; North District, H.W. Hang, 22.52819N, 114.2006E, 29 m, 14.06.2015, T. Tsang, Winkler, IBBL; North District, Lai Chi Wo, 22.527N, 114.258E, 08.05.2015, R.H. Lee, Winkler, IBBL; Sai Kung District, Pak Tam Chung, 22.454795N, 114.118215E, 05.06.2015, R.H. Lee, Winkler, IBBL; Sha Tin District, Tai Po Kau, 22.4198N, 114.1839E, 18.05.2016, B. Guénard, hand collection, IBBL; Southern District, Nam Fung Road, 22.25291N, 114.1877E, 70 m, 10.10.2015, T. Tsang, Winkler, IBBL; Southern District, Nam Fung Road, 22.25554N, 114.1802E, 01.10.2015, 110 m, T. Tsang, Winkler, IBBL; Tsuen Wan District, Lin Fa Shan, 22.3956N, 114.0885E, 15.07.2016, R.H. Lee, pitfall trap, IBBL.
This is a rather uncommon species collected from tree plantation, secondary forest, and Feng Shui woods (Fig.
Pyramica mitis Brown 2000: 442, figs 267, 290 (w.q.) PHILIPPINES. Indomalaya.
Strumigenys mitis (Brown, 2000). Combination in Strumigenys: Baroni Urbani and De Andrade 2007: 124.
HONG KONG: Central & Western District, Lung Fu Shan, 22.27896N, 114.13601E, 244 m, 20.11.2014, M. Wong, Winkler, 4 Corners, IBBL; Islands District, Sunset Peak, 22.26084N, 113.95753E, 03.06.2015, R.H. Lee, Winkler, IBBL; Islands District, Sunset Peak, 22.26392N, 113.95376E, 03.06.2015, R.H. Lee, Winkler, IBBL; Sha Tin District, Tai Po Kau, 22.42706N, 114.179996E, 06.06.2017, R.H. Lee, pitfall trap, IBBL; Southern District, Aberdeen Reservoir, 22.25964N, 114.16251E, 29.06.2015, R.H. Lee, Winkler, IBBL; Southern District, Aberdeen Reservoir, 22.26N, 114.162E, 26.06.2015, R.H. Lee, Winkler, IBBL; Southern District, Nam Fung Road, 22.25291N, 114.1877E, 10.10.2015, 70 m, T. Tsang, Winkler, IBBL; Tai Po District, Kadoorie Centre, 22.4291N, 114.11491E, 08.09.2015, R.H. Lee, Winkler, IBBL; Tsuen Wan District, Ha Lin Fa Shan, 22.39664N, 114.1019E, 30.07.2015, 355 m, T. Tsang, Winkler, IBBL; Tsuen Wan District, Ha Lin Fa Shan, 22.39854N, 114.0966E, 410 m, 18.07.2015, T. Tsang, Winkler, IBBL; Tsuen Wan District, Lin Fa Shan, 22.3956N, 114.0885E, 15.07.2016, R.H. Lee, Winkler, IBBL; Tsuen Wan District, Tai Mo Shan, 22.416073N, 114.125158E, 09.06.2015, R.H. Lee, pitfall trap, IBBL; Tsuen Wan District, Tai Mo Shan, 22.416073N, 114.125158E, 21.06.2016, R.H. Lee, pitfall trap, IBBL.
Although this species is not among the most commonly collected, it was found in a wide range of habitats and elevation, including grasslands, shrublands, tree plantations (e.g. L. confertus), and secondary forest at elevation ranging from 70 to 809 m (Fig.
HONG KONG: Tai Po District, Ping Shan Chai, 22.486N, 114.187E, 142 m, 3.VI.2017 to 30.VI.2017, C. Barthélémy, ANTWEB1016246, Malaise trap, IBBL.
Alate females (n = 2): TL 2.2–2.5, HL 0.51–0.57, HW 0.39–0.41, MandL 0.13–0.14, SL 0.33–0.38, EL 0.14–0.16, PW 0.28–0.35, ML 0.58–0.68, PL 0.22–0.24, PH 0.19–0.20, DPW 0.13, PPL 0.11–0.13, GL 0.61–0.73, CI 72–76, MI 25, SI 85–92, OI 36–39, LPI 84–86, DPI 55–59.
This species is known in Hong Kong from two alate females. The shape of the mandibles, including the conspicuous diastema and dentition suggests that this species belongs to the S. mutica-group as defined by
Very little is known about the ecology of S. mutica, as only two alate individuals collected in a secondary forest by Malaise traps are known (Fig.
Two species within the S. mutica-group have been recorded in nearby regions, S. mutica in mainland China (Guangxi, Hunan), Japan, South Korea, and Taiwan, and S. takasago, endemic to Taiwan. The latter species also differs from our specimens by its larger size (HL 0.70, HW 0.63), the conspicuous presence of erect spoon-shaped hairs on the body, and the acute propodeal declivity (
Strumigenys nanzanensis Lin and Wu 1996: 148, figs 13, 30–34 (w.q.) TAIWAN. Indomalaya.
HONG KONG: Tai Po District, Ping Shan Chai, 22.486N, 114.187E, 02.05.2015, C. Barthélémy, Malaise trap, IBBL; Tai Po District, Ping Shan Chai, 22.486N, 114.187E, 09.04.2016, C. Barthélémy, Malaise trap, IBBL; Tsuen Wan District, Shing Mun Reservoir, 22.39718N, 114.15273E, 230 m, 06.07.2011, P. Ward, sifted litter, IBBL.
This is a relatively rare species in Hong Kong known only from secondary forests at elevations between 143 and 230 m (Fig.
Dorsum of head, scape, and mandibles covered with appressed spatulate hairs, but no standing hairs. Side of mesosoma generally smooth and shining. Elongated propodeal spines subtended by narrow concave lamellae. Masticatory margin of mandibles engaging only at the apical half (or slightly less than half) of their lengths, with a prominent diastema proximal to this and first 3 preapical teeth not reaching their counterpart from the opposing mandible. Dentition consisting of a small conical tooth, a series of alternating long conical teeth and low round teeth, a crowded series of minute denticles at the down curvature of the apex of mandible, and a small conical apical tooth.
Holotype worker: HONG KONG: Islands District, Lantau Island, Sunset Peak, 22.263923N, 113.953762E, 467 m, 3 June 2015 (R.H. Lee) (collection code RHL-HK-LSP-T3WM) [IBBL, ANTWEB1016948]. Paratype workers (n = 26): same data as holotype.
Islands District, Sunset Peak, 22.26112N, 113.956332E, 572 m, 03.06.2015, R.H. Lee, Winkler, IBBL; North District, Lai Chi Wo, 22.527N, 114.258E, 08.05.2015, R.H. Lee, Winkler, IBBL; Tai Po District, Wu Kau Tang, 22.49645N, 114.2441E, 29 m, 25.10.2015, T. Tsang, Winkler, IBBL; Tai Po District, Wu Kau Tang, 22.5046N, 114.2422E, 115 m, 21.10.2015, T. Tsang, Winkler, IBBL.
Holotype worker: TL 3.2, HL 0.72, HW 0.57, MandL 0.24, SL 0.33, EL 0.068, PW 0.27, ML 0.79, PL 0.37, PH 0.15, DPW 0.15, PPL 0.26, GL 0.81, CI 79, MI 33, SI 58, OI 12, LPI 41, DPI 40. Paratype workers (n = 26): TL 2.9–3.3, HL 0.67–0.75, HW 0.51–0.60, MandL 0.22–0.25, SL 0.30–0.35, EL 0.064–0.080, PW 0.25–0.30, ML 0.75–0.86, PL 0.34–0.40, PH,0.15–0.18 DPW 0.14–0.17, PPL 0.22–0.26, GL 0.72–0.87, CI 76–81, MI 30–34, SI 56–62, OI 11–15, LPI 42–45, DPI 39–44.
(Fig.
Dentition. Basal most preapical tooth small and conical, sometimes followed by a small denticle; the following tooth also conical, larger and longer; the third tooth low and rounded; in full-face view all first three teeth located on the basal half of the mandible and not reaching their counterpart from the opposing mandible when the mandibles are fully closed. Distal to these, the fourth tooth conical and slightly curved, being the longest of the preapical teeth; the fifth tooth low and rounded, sometimes almost squircle in shape, wider and longer than the third tooth; the sixth tooth conical, similar in length to second tooth; all these three teeth fully engaging with their counterparts from the opposing mandible and are visible in full-face view. Apex of mandible at the down curvature, in anterior view, with a crowded series of around 11 minute denticles, terminating with a small conical apical tooth.
Mesosoma. In profile view the dorsum of mesosoma more or less flat transversely, except for a slight depression at the mesonotum immediately posterior to the pronotum; pronotum marginate dorsolaterally. In dorsal view, lateral margins of the pronotum evenly convex. Propodeum spines elongate acute triangular, subtended on each side by a very narrow concave lamella that broadens slightly basally into a small rounded convex propodeal lobe.
Waist segments. Petiole in profile elongate and subclavate; peduncle does not grade evenly into the node, and about as long as (or slightly shorter than) the node; node in dorsal view longer than broad. Disc of the postpetiole in dorsal view broader than long, and slightly shorter than petiolar node. Spongiform tissues present on both petiole and postpetiole; ventral lobes of petiole and postpetiole extensive; lateral lobe of petiole merely a small flap at the posterolateral angle of the node in profile; in dorsal view present along the posterior margin of the petiolar node, and surrounding the disc of postpetiole, thicker along the posterior margin than that on the anterior margin.
Pilosity. Cephalic dorsum in profile without standing hairs. In full-face view cephalic dorsum covered in rows of anteriorly directed appressed spatulate hairs that are slightly inclined toward the midline; no laterally projecting standing hair; cephalic dorsolateral margin, from the anterolateral margin of the occipital lobe to the frontal carina, with anteriorly directed appressed hairs; leading edge of scape with apically directed, appressed spatulate hairs, and an additional 2 or 3 rows of similar hairs on the surface of the scape. In full-face view, dorsal masticatory margin of mandibles with a row of anteriorly directed spatulate hairs that slightly inclined toward the midline; rest of dorsal surface of mandibles also densely covered in rows of similar hairs. Pronotal dorsum covered sparsely with appressed spatulate hairs directed toward the midline; row of similar appressed hairs on the dorsolateral margins of the pronotum. Propodeal dorsum with a few posteriorly directed, suberect to decumbent short simple hairs; a few similar hairs on the dorsolateral margin of the petiolar node and postpetiole. First gastral tergite with sparse, very short suberect simple hairs; in dorsal view with 1 or 2 pairs of simple apical erect hairs positioned laterally.
Sculpture. Cephalic dorsum, excluding clypeal dorsum, sparsely reticulate-rugulose, with spaces between rugulae densely areolate-rugulose; clypeal dorsum densely reticulate-rugulose; surface of antennal scrobe, antenna and mandibles densely reticulate-punctate. Pronotal dorsum faintly reticulate-rugulose; mesonotal and propodeal dorsum densely reticulate-punctate; side of mesosoma generally smooth and shining, with vestiges of sculpture around margins. Dorsum of petiolar node faintly reticulate-punctate; dorsum of postpetiole smooth and shining. Basigastral costulae short and inconspicuous, rest of gaster smooth and shiny.
Strumigenys nathistorisoc is well distinguished from other Strumigenys species by a combination of the characteristics listed in the diagnosis. It does not fit the description of any existing Strumigenys species group, in particular due to its highly distinctive mandibles and dentition.
Comparing S. nathistorisoc with the most similar appearing Strumigenys species, such as S. kichijo and species from the S. leptothrix-group, these species, in contrast, are often either hairless or have simple or flagellate hairs on the cephalic and pronotal dorsum, or have sculpture on the sides of the mesosoma, or have propodeal spines subtended by medium to broad lamellae. S. nathistorisoc also lacks the laterally projecting hairs in full-face view or the distinct transverse striations on the pronotal dorsum and dorsum of the petiolar node that characterise S. nankunshana.
Focusing on the mandibles and dentition, in contrast to the description of S. nathistorisoc, S. kichijo has only conical teeth. S. nankunshana and species from the S. leptothrix-group have masticatory margins that engage throughout the entire length. S. wilsoniana has a much wider gap between the mandibles, the masticatory margins engage at the apical third (instead of around half as in S. nathistorisoc) of their length, with the basal 2 teeth (instead of 3) situated at around the mid-length of the mandible (instead of sparsely across the basal half of the mandible) and not reaching their counterparts from the opposing mandible when the mandibles are fully closed.
This species is named after the Hong Kong Natural History Society whose members graciously supported our work on the ants of Hong Kong.
Hong Kong
Strumigenys nathistorisoc was only recorded in secondary forests and Feng Shui woods, along a relatively large gradient of elevation ranging from 29 to 572 m (Fig.
Strumigenys nepalensis Baroni Urbani and De Andrade 1994: 57, figs 33, 34 (w.q.) NEPAL. Indomalaya.
Smithistruma nepalensis (Baroni Urbani & De Andrade, 1994). Combination in Smithistruma: Bolton 1995: 385.
Pyramica nepalensis (Baroni Urbani & De Andrade, 1994). Combination in Pyramica: Bolton 1999: 1673.
Strumigenys nepalensis Baroni Urbani & De Andrade, 1994. Combination in Strumigenys: Baroni Urbani and De Andrade 2007: 124.
HONG KONG: Central & Western District, HKU Campus, 22.282164N, 114.138296E, 113 m, 19.11.2014, M. Wong, Winkler, 12 Random, IBBL; Central & Western District, HKU CYT, 22.2824528N, 114.14043E, 07.01.2016, G. Yong, Winkler, IBBL; Islands District, Chek Lap Kok, 22.2939N, 113.9331E, B.M. Worthington, Winkler, 12 Random, IBBL; Islands District, Chek Lap Kok, 22.2947N, 113.9336E, 21 m, B.M. Worthington, Winkler, 4 Corners, IBBL; Islands District, Chek Lap Kok, 22.2957N, 113.9338E, B.M. Worthington, Winkler, 4 Corners, IBBL; Islands District, Chek Lap Kok, 22.2964N, 113.9352E, 10 m, B.M. Worthington, Winkler, 4 Corners, IBBL; Islands District, Chek Lap Kok, 22.298N, 113.9359E, 5 m, B.M. Worthington, Winkler, 4 Corners, IBBL; Islands District, Chek Lap Kok, 22.298N, 113.9359E, B.M. Worthington, Winkler, 4 Corners, IBBL; Islands District, Chek Lap Kok, 22.3139N, 113.9398E, 2 m, B.M. Worthington, Winkler, 4 Corners, IBBL; Islands District, Chek Lap Kok, 22.3153N, 113.9407E, B.M. Worthington, Winkler, 12 Random, IBBL; Islands District, Chek Lap Kok, 22.3204N, 113.9376E, 6 m, B.M. Worthington, Winkler, 12 Random, IBBL; Islands District, Chek Lap Kok, 22.3193N, 113.9377E, B.M. Worthington, Winkler, 12 Random, IBBL; Islands District, Sha Lo Wan, 22.2898N, 113.9069E, 43 m, B.M. Worthington, Winkler, 4 Corners, IBBL; Islands District, Tung Chung, 22.2907N, 113.9371E, 1 m, B.M. Worthington, Winkler, 4 Corners, IBBL; North District, Lai Chi Wo, 22.527N, 114.258E, 08.05.2015, R.H. Lee, Winkler, IBBL; Sha Tin District, Lion Rock, 22.360915N, 114.180028E, 13.07.2015, R.H. Lee, Winkler, IBBL; Yuen Long District, Mai Po, 22.48121N, 114.03332E, 30.07.2018, 1 m, M. Wong, pitfall trap, IBBL; Yuen Long District, Mai Po, 22.48625N, 114.04097E, 03.08.2018, 1 m, M. Wong, pitfall trap, IBBL. MACAU: Hac Sa Reservoir, Coloane Island, 22.1344N, 113.5725E, 20.08.2016, 93 m, C.M. Leong, Winkler, IBBL.
Workers (n = 8): TL 1.3–1.8, HL 0.42–0.46, HW 0.31–0.33, MandL 0.08–0.09, SL 0.18–0.20, EL 0.033–0.043, PW 0.19–0.21, ML 0.44–0.48, PL 0.20–0.22, PH 0.11–0.13, DPW 0.10–0.11, PPL 0.13–0.15, GL 0.43–0.47, CI 70–76, MI 17–21, SI 56–63, OI 11–13, LPI 52–58, DPI 48–54.
China (Yunnan), India, Malaysia, Nepal, Singapore, Thailand, Vietnam.
Introduced : Mauritius, Hong Kong.
This is a common species in urban forest patches or disturbed grassland (e.g. Mai Po Nature Reserve), with only a few records collected within secondary forests and one record within Feng Shui woods (Fig.
New records of Strumigenys nepalensis in Hong Kong expand the current known native range of this species by 800 km eastward from Vietnam. A record from Mauritius (Casent0799280, Ile Aux Aigrettes, −20.419017, 57.730183, 5 m a.s.l., A. Suarez 2.VI.2005; Doug Booher pers. comm.) confirms the tramp character of this species. Specimens collected from Hong Kong, Macau and Mauritius are considered introduced.
Strumigenys rallarhina
HONG KONG: Central & Western District, Lung Fu Shan Park, 22.280693N, 114.137027E, 3 Oct. 2018, B. Guénard, hand collection, IBBL; Central & Western District, Lung Fu Shan, 22.2751778N, 114.138576E, 07.01.2016, G. Yong, Winkler, IBBL; Central & Western District, The Peak, 22.276038N, 114.141995E, 17.08.2015, R.H. Lee, Winkler, IBBL; Islands District, Lamma Island, 22.20575N, 114.13808E, 14.09.2017, R.H. Lee, Winkler, IBBL; Islands District, Lantau Peak, 22.249N, 113.921E, 15.09.2015, R.H. Lee, pitfall trap, IBBL; Islands District, Sunset Peak, 22.260842N, 113.957533E, 03.06.2015, R.H. Lee, Winkler, IBBL; Islands District, Sunset Peak, 22.263923N, 113.953762E, 03.06.2015, R.H. Lee, pitfall trap, IBBL; Islands District, Sunset Peak, 22.263923N, 113.953762E, 03.06.2015, R.H. Lee, Winkler, IBBL; Sha Tin District, Lion Rock, 22.357002N, 114.175047E, 13.07.2015, R.H. Lee, Winkler, IBBL; Sha Tin District, Lion Rock, 22.36121N, 114.181997E, 15.08.2017, R.H. Lee, Winkler, IBBL; Sha Tin District, Mau Ping Wood, 22.3844N, 114.241E, 20.10.2015, R.H. Lee, Winkler, IBBL; Sha Tin District, Tai Po Kau Nature Reserve, 22.4281N, 114.1808E, 24.02.2016, B. Guénard, Winkler, IBBL; Sha Tin District, Tai Po Kau, 22.42402N, 114.18029E, 14.07.2015, R.H. Lee, Winkler, IBBL; Southern District, Nam Fung Road, 22.2546N, 114.1833E, 20.08.2016, R.H. Lee, pitfall trap, IBBL; Tai Po District, Sha Lo Tong, 22.47708N, 114.18195E, 28.05.2015, R.H. Lee, Winkler, IBBL; Tai Po District, Sha Lo Tong, 22.47808N, 114.18193E, 28.05.2015, R.H. Lee, Winkler, IBBL; Tai Po District, Sha Shan, 22.449N, 114.145E, 03.11.2015, R.H. Lee, Winkler, IBBL; Tsuen Wan District, Shing Mun Reservoir, 22.39718N, 114.15273E, 230 m, 06.07.2011, P. Ward, sifted litter, IBBL; Tai Po District, Tai Om, 22.442321N, 114.134738E, 28.02.2018, B. Guénard, Winkler, IBBL; Tsuen Wan District, Shing Mun, 22.39678N, 114.1531E, 238 m, 23.08.2015, T. Tsang, Winkler, IBBL; Tsuen Wan District, Shing Mun, 22.39693N, 114.153E, 14.05.2015, R.H. Lee, Winkler, IBBL; Tsuen Wan District, Tai Lam, 22.3956N, 114.0928E, 26.10.2015, R.H. Lee, Winkler, IBBL; Tuen Mun District, Castle Peak, 22.389935N, 113.954937E, 30.06.2015, R.H. Lee, Winkler, IBBL.
This is a relatively widespread species collected in a wide range of habitats and elevation, including grassland, roadside trees, shrubland, bamboo forest, secondary forest and Feng Shui woods at elevation ranging from 56 to 589 m (Fig.
Strumigenys rogeri Emery 1890: 68, pl. 7, fig. 6. SAINT THOMAS, U.S. VIRGIN ISLANDS. Neotropical.
HONG KONG: Tai Po District, Sai Keng, 22.41998N 114.26824E, 1 m, 26.VI.2018–10.VII.2018, R. Cheung / C. Taylor, Malaise trap, IBBL. VIETNAM: Cat Tien National Park, 11.26.237N, 107.25.431E, 145 m, 3.VI.2018, B. Guénard, IBBL, hand collection.
Alate (n = 1) TL 2.5, HL 0.58, HW 0.46., MandL 0.32, SL 0.35, EL 0.10, PW 0.32, ML 0.60, PL 0.28, PH 0.15, DPW 0.13, PPL 0.10, GL 0.62, CI 78, MI 54, SI 77, OI 21, LPI 54, DPI 48.
Native : Afrotropical region, known from Ivory Coast to Zanzibar Archipelago (Tanzania) and south to Angola.
Introduced
: A widespread species in multiple biogeographic realms. For a full global account, see antmaps.org (
The record of this tramp species in Hong Kong is not surprising considering its widespread range in nearby countries (Philippines, Taiwan, and Vietnam), which have relatively similar climatic conditions. However, a single alate has been collected from a mangrove habitat, an unlikely habitat for this species, and no workers have been collected in Hong Kong. Nonetheless, the record from Hong Kong is the first observation of this species for mainland China.
Pentastruma sauteri Forel 1912: 51 (w.) TAIWAN. Indomalaya.
Pyramica sauteri (Forel, 1912). Combination in Pyramica: Bolton 1999: 1673.
Strumigenys sauteri (Forel, 1912). Combination in Strumigenys: Baroni Urbani and De Andrade 2007: 127.
HONG KONG: Central & Western District, HKU CYT, 22.2824528N, 114.140431E, 07.01.2016, G. Yong, Winkler, IBBL; Central & Western District, LFS Plot 1 B–C, 22.277134N, 114.134793E, 28.12.2015, G. Yong, Winkler, IBBL; Central & Western District, LFS Plot 1 C, 22.277134N, 114.134808E, 28.12.2015, G. Yong, Winkler, IBBL; Central & Western District, Lung Fu Shan, 22.276729N, 114.136693E, 295 m, 24.11.2014, M. Wong, Winkler, 4 Corners, IBBL; Central & Western District, Lung Fu Shan, 22.27896N, 114.13601E, 244 m,20.11.2014, M. Wong, Winkler, 12 Random, IBBL; Central & Western District, Lung Fu Shan, 22.28221N, 114.133476E, 115 m, 13.11.2014, M. Wong, Winkler, 12 Random, IBBL; Central & Western District, Plot 1 B–C, 22.277134N, 114.134794E, 08.01.2016, G. Yong, Winkler, IBBL; Islands District, Sunset Peak, 22.26112N, 113.956332E, 03.06.2015, R.H. Lee, Winkler, IBBL; Islands District, Tei Tong Tsai, 22.257066N, 113.926281747627E, 29.11.2016, R.H. Lee, Winkler, IBBL; North District, A Ma Wat, 22.5191N, 114.2441E, 19.12.2016, R.H. Lee, Winkler, IBBL; Sai Kung District, Pak Tam Chung, 22.400033N, 114.330997E, 05.06.2015, R.H. Lee, pitfall trap, IBBL; Sha Tin District, Lion Rock, 22.36121N, 114.181997E, 13.07.2015, R.H. Lee, pitfall trap, IBBL; Sha Tin District, Tai Po Kau Nature Reserve, 22.4288N, 114.1813E, 22.02.2017, B. Guénard, Winkler, IBBL; Sha Tin District, Tai Po Kau, 22.41841N, 114.1779E, 295 m, 12.07.2015, T. Tsang, Winkler, IBBL; Sha Tin District, Tai Po Kau, 22.427285N, 114.181298E, 16.09.2015, B. Guénard, hand collection, IBBL; Sha Tin District, Tai Po Kau, 22.42781N, 114.181462E, 08.10.2018, B. Guénard, hand collection, IBBL; Southern District, Aberdeen Reservoir, 22.259638N, 114.162508E, 29.06.2015, R.H. Lee, Winkler, IBBL; Southern District, Aberdeen Reservoir, 22.26N, 114.162E, 26.06.2015, R.H. Lee, Winkler, IBBL; Tai Po District, Hunch Backs, 22.4139N, 114.2489E, 13.11.2015, R.H. Lee, pitfall trap, IBBL; Tai Po District, Ping Shan Chai, 22.486N, 114.187E, 19.03.2016, C. Barthélémy, Malaise trap, IBBL; Tai Po District, Tai Om, 22.44157N, 114.13513E, 28.02.2018, B. Guénard, Winkler, IBBL; Tai Po District, Tap Mun, 22.47N, 114.363E, 28.07.2015, R.H. Lee, pitfall trap, IBBL; Tsuen Wan District, Ha Lin Fa Shan, 22.39608N, 114.1014E, 28.07.2015, 344 m, T. Tsang, Winkler, IBBL; Tsuen Wan District, Lin Fa Shan, 22.3956N, 114.0885E, 15.07.2016, R.H. Lee, pitfall trap, IBBL; Tsuen Wan District, Lin Fa Shan, 22.3956N, 114.0885E, 15.07.2016, R.H. Lee, Winkler, IBBL; Tsuen Wan District, Shing Mun, 22.39845N, 114.1628E, 367 m, 24.08.2015, T. Tsang, Winkler, IBBL; Tsuen Wan District, Shing Mun, 22.39962N, 114.162E, 355 m, 12.08.2015, T. Tsang, Winkler, IBBL; Yuen Long District, Kap Lung, 22.41596N, 114.1038E, 288 m, 11.09.2015, T. Tsang, Winkler, IBBL; Yuen Long District, Ng Tung Chai 22.43492N, 114.12927E, 01.11.2016, R.H. Lee, Winkler, IBBL.
This is a widespread species found in diverse habitats including grasslands, shrublands, plantations (e.g. L. confertus), urban forest remnants, secondary forest, and Feng Shui woods. Specimens were collected at elevation ranging from 19 to 630 m (Fig.
Strumigenys sydorata
HONG KONG: North District, Kuk Po San Uk, 22.52912N, 114.23468E, 15.11.2016, R.H. Lee, Winkler, IBBL; Sha Tin District, Tai Po Kau, 22.42614N, 114.18178E, 162 m, 06.07.2017, R.H. Lee, pitfall trap, IBBL; Tai Po District, Sha Lo Tong, 22.481767N, 114.18283E, 28.05.2015, R.H. Lee, Winkler, IBBL; Tai Po District, Tai Om, 22.4419N, 114.1335E, 76 m, 05.10.2016, Winkler, IBBL; Tai Po District, Tai Om, 22.4423N, 114.1343E, 81 m, 07.08.2015, T. Tsang, Winkler, IBBL.
Worker (n = 1): TL 2.5, HL 0.69, HW 0.53, MandL 0.19, SL 0.28, EL 0.059, PW 0.30, ML 0.66, PL 0.24, PH 0.17, DPW 0.15, PPL 0.16, GL 0.52, CI 77, MI 28, SI 53, OI 11, LPI 70, DPI 62.
China (Hong Kong), Indonesia (Java), Thailand, Vietnam.
This is a rare species in Hong Kong collected only within secondary forests and Feng Shui woods (Fig.
This new record from Hong Kong represents another important geographic extension of 900 km north-eastward in Mainland Asia, with the closest record known from Cúc Phương in Vietnam (
Pyramica tisiphone
Strumigenys tisiphone (Bolton, 2000). Combination in Strumigenys: Baroni Urbani and De Andrade 2007: 129.
HONG KONG: Central & Western District, Lung Fu Shan, 22.27518N, 114.13858E, 07.01.2016, G. Wong, Winkler, IBBL; Sha Tin District, Tai Po Kau Nature Reserve, 22.4288N, 114.1813E, 22.02.2017, B. Guénard, Winkler, IBBL; Tsuen Wan District, Tai Mo Shan, 22.41496N, 114.12608E, 816 m, 24.06.2016, R.H. Lee, Winkler, IBBL.
Worker (n = 1): TL 2.4, HL 0.54, HW 0.50, MandL 0.20, SL 0.24, EL 0.036, PW 0.29, ML 0.59, PL 0.29, PH 0.16, DPW 0.16, PPL 0.19, GL 0.55, CI 93, MI 37, SI 48, OI 7, LPI 56, DPI 56.
Hong Kong, Guangdong, Hubei, Hunan (China).
This is a rare species in Hong Kong, collected only within secondary forest but through a wide elevational range extending from 141 to 816 m (Fig.
The Hong Kong record confirms the distribution of S. tisiphone within China and represents the south-easternmost record for the species. The previous record in China is from Gutian, central Guangdong (24.2N, 116.6E) (
The genus Strumigenys currently includes 839 valid species and ranks as the third most diverse ant genus, after Camponotus (1031 valid species + 457 subspecies) and Pheidole (1004 valid species + 134 subspecies) (
List of the twenty-four Strumigenys species recorded in Hong Kong, with reference of their first record, collection within recent years (IBBL = Insect Biodiversity and Biogeography Laboratory at HKU) and type of habitat collected presented.
Strumigenys species | First published record in HK | Specimen at IBBL | Type of habitat |
---|---|---|---|
S. canina Brown & Boisvert, 1979 |
|
Yes | Secondary forest; tree plantation; Feng Shui woods |
S. elegantula Terayama & Kubota, 1989 |
|
Yes | Reclaimed land; mixed woodland; semi-open forest |
S. emmae Emery, 1890 |
|
Yes | Reclaimed land; secondary forest |
S. exilirhina Bolton, 2000 |
|
Yes | Semi-open forest; secondary forest; reclaimed land |
S. feae Forel, 1912 |
|
Yes | Disturbed secondary forest |
S. formosa Terayama. Ling & Wu, 1995 | New record | Yes | Secondary forest |
S. heteropha Bolton, 2000 |
|
Yes | Semi-open forest |
S. hexamera Brown, 1958 | New record | Yes | Secondary forest |
S. hirsuta sp. n. | New species | Yes | Disturbed secondary forest; semi-open forest |
S. kichijo Terayama, Lin & Wu, 1996 | New record | Yes | Secondary forest |
S. lantaui sp. n. | New species | Yes | Reclaimed land |
S. mazu Terayama, Lin & Wu, 1996 |
|
Yes | Reclaimed land |
S. membranifera Emery, 1869 | New record | Yes | Secondary forest |
S. minutula Terayama & Kubota, 1989 |
|
Yes | Semi-open forest; reclaimed land |
S. mitis Brown, 2000 |
|
Yes | Disturbed secondary forest; semi-open forest |
S. cf. mutica (Brown, 1949) | New record | Yes | Mangrove (alates in Malaise trap) |
S. nanzanensis Lin & Wu, 1996 |
|
Yes | Secondary forest |
S. nathistorisoc sp. n. | New species | Yes | Secondary forest |
S. nepalensis Baroni Urbani & De Andrade, 1994 | New record | Yes | Secondary forest |
S. rallarhina Bolton, 2000 |
|
Yes | Secondary forest; semi-open forest; Feng Shui woods |
S. rogeri Emery, 1890 | New record | Yes | Mangrove (alate in Malaise trap) |
S. sauteri Forel, 1912 |
|
Yes | Semi-open forest; secondary forest |
S. sydorata Bolton, 2000 | New record | Yes | Feng Shui woods |
S. tisiphone Bolton, 2000 | New record | Yes | Secondary forest |
The number of native Strumigenys species now recorded from continental China is 49 (Guénard et al. 2012,
In addition, the use of Malaise traps resulted in the discovery of new species records on the basis of alate gynes (S. cf. mutica and S. rogeri). This resulted in new information on the phenology of several Strumigenys species within Hong Kong. While many tropical ant species exhibit multiple swarming periods (
Phenology of 11 Strumigenys species collected in Hong Kong on the basis of alate female specimens collected within Malaise traps, with the exception of S. canina with females and males collected in leaf litter. Dark grey areas represent periods during which a given species was collected (in front of a species name) or the period in which sampling was conducted (Period sampled). Numbers in the last row of the table represent the number of species collected within a given period.
By its central position in Asia and its leading role in regional and global trade, Hong Kong presents numerous opportunities for the introduction, establishment, and spread of introduced species (
Globally, 24 Strumigenys species have been recorded outside of their putative native range (Table
List of the 24 Strumigenys species with records outside their native range with a presentation by biogeographic realms of their putative native and introduced ranges (data from antmaps.org,
Strumigenys species | Native range | Introduced range |
---|---|---|
S. eggersi Emery, 1890 | Neotropical, Panamanian | Nearctic, Oriental, Panamanian (Galapagos Islands) |
S. emmae (Emery, 1890) | Australian | Afrotropical, Madagascan, Nearctic, Neotropical, Oceanian, Oriental, Panamanian, Saharo-Arabian |
S. epinotalis Weber, 1934 | Neotropical, Panamanian | Nearctic |
S. godeffroyi Mayr, 1866 | Australian, Oceanian (West part), Oriental | Madagascan, Oceanian (East part), |
S. gundlachi (Roger, 1862) | Neotropical, Panamanian | Nearctic |
S. hexamera (Brown, 1958) | Oriental, Sino-Japanese | Nearctic, Oceanian |
S. lanuginosa Wheeler, 1905 | Neotropical, Panamanian | Nearctic |
S. lewisi Cameron, 1886 | Oriental, Sino-Japanese | Oceanian, Palearctic (West) |
S. louisianae Roger, 1863 | Nearctic, Neotropical, Panamanian | Panamanian (Cocos Island, Galapagos Islands) |
S. ludovici Forel, 1904 | Afrotropical | Madagascan |
S. lujae Forel, 1902 | Afrotropical | Oceanian (not established) |
S. mandibularis Smith, 1860 | Neotropical | Afrotropical, Madagascan |
S. margaritae Forel, 1893 | Nearctic (south), Neotropical, Panamanian | Nearctic (north) |
S. maxillaris Baroni Urbani, 2007 | Afrotropical | Madagascan |
S. membranifera Emery, 1869 | Afrotropical | Australian, Madagascan, Nearctic, Neotropical, Oceanian, Oriental, Palearctic, Panamanian, Saharo-Arabian, Sino-Japanese |
S. minutula Terayama & Kubota, 1989 | Oriental, Sino-Japanese | Palearctic (not established) |
S. nepalensis Baroni Urbani & De Andrade, 1994 | Oriental | Madagascan (Mauritius), Sino-Japanese (Hong Kong, Macau) |
S. nigrescens Wheeler, 1911 | Panamanian | Panamanian (Cocos Island) |
S. perplexa (Smith, 1876) | Australian | Australian (New Zealand) |
S. rogeri Emery, 1890 | Afrotropical | Madagascan, Nearctic, Neotropical, Oceanian, Oriental, Palearctic (not established), Panamanian |
S. silvestrii Emery, 1906 | Neotropical | Nearctic, Oriental?, Palearctic, Panamanian |
S. simoni Emery, 1895 | Afrotropical | Madagascan |
S. solifontis Brown, 1949 | Oriental, Sino-Japanese | Nearctic (not established) |
S. xenos Brown, 1955 | Australian | Australian (Lord Howe Island, New Zealand) |
We thank the following persons for providing specimens used within this study: Christophe Barthélémy, Roy Cheung, Patrick Grootaert, Lim Luk, Brett Morgan, Roger Lee, Christopher Taylor, Toby Tsang, Chase Wang, Mark Wong, Brian Worthington, Gordon Yong. We also thank Doug Booher and an anonymous reviewer for their valuable comments on a previous version of the manuscript. Finally, we also thank several funding bodies who supported this research including The Hong Kong Natural History Society, the Environmental Protection Department of Hong Kong (ECF Projects 32-2015 and 69-2016), the Airport Authority Hong Kong, Ocean Park Conservation Foundation Hong Kong (OT01_1617).