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Robber flies from mangroves in Hong Kong (Diptera: Asilidae)

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A survey of mangrove sites all around Hong Kong during Autumn 2017 and Spring 2018 revealed the presence of 12 species of robber flies. Only 38 specimens were found in a total of 103 Malaise trap samples operational during at least one month. The robber flies belong to five subfamilies. Two species are new to science and are described and illustrated: Promachus hongkongensis sp. nov. and Ommatius guenardi sp. nov. Based on the species accumulation curve, the total number of species is estimated to be around 16.
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Belgian Journal of Entomology 91: 122 ISSN: 2295-0214
www.srbe-kbve.be
urn:lsid:zoobank.org:pub:AEFC3518-9C03-41DB-B386-B20B302A5683
Belgian Journal of Entomology
Robber flies from mangroves in Hong Kong (Diptera: Asilidae)
Guy TOMASOVIC, Jérôme CONSTANT & Patrick GROOTAERT
Faculté universitaire des Sciences agronomiques, Unité d’Entomologie fonctionnelle et évolutive, Passage des
Déportés, 2, B-5030 Gembloux, Belgium. E-mail: guytomasovic@yahoo.fr (corresponding author)
Published: Brussels, April 14, 2020
TOMASOVIC G. et al. Asilidae from mangroves in Hong Kong
2
Citation: TOMASOVIC G., CONSTANT J. & GROOTAERT P., 2020. - Robber flies from mangroves in Hong Kong
(Diptera: Asilidae). Belgian Journal of Entomology, 91: 122.
ISSN: 1374-5514 (Print Edition)
ISSN: 2295-0214 (Online Edition)
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Front cover: The holotype of Promachus hongkongensis sp. nov. © Jérôme Constant (RBINS).
Belgian Journal of Entomology 91: 122 (2020)
3
Robber flies from mangroves in Hong Kong (Diptera: Asilidae)
Guy TOMASOVIC1, Jérôme CONSTANT2 & Patrick GROOTAERT3
1 Research associate, Faculté universitaire des Sciences agronomiques, Unité d’Entomologie fonctionnelle et
évolutive, Passage des Déportés, 2, B-5030 Gembloux, Belgium
(e-mail: guytomasovic@yahoo.fr corresponding author).
2 Royal Belgian Institute of Natural Sciences, O.D. Taxonomy and Phylogeny, Entomology, Vautierstreet 29, B-
1000 Brussels, Belgium (e-mail: jerome.constant@naturalsciences.be).
3 Royal Belgian Institute of Natural Sciences, O.D. Taxonomy and Phylogeny, Entomology, Vautierstreet 29, B-
1000 Brussels, Belgium; Lee Kong Chian Natural History Museum, National University, Singapore (e-mail:
pgrootaert@yahoo.co.uk).
Abstract
A survey of mangrove sites all around Hong Kong during Autumn 2017 and Spring 2018
revealed the presence of 12 species of robber flies. Only 38 specimens were found in a total of
103 Malaise trap samples operational during at least one month. The robber flies belong to five
subfamilies. Two species are new to science and are described and illustrated: Promachus
hongkongensis sp. nov. and Ommatius guenardi sp. nov. Based on the species accumulation
curve, the total number of species is estimated to be around 16.
Keywords: robber flies, Hong Kong, mangrove, new species
Introduction
In the present paper we report on a survey of the Asilidae or robber flies in the mangroves
around Hong Kong during 2017 and 2018. The survey was done with Malaise traps that were
placed for at least one moth in 24 sites all around Hong Kong in different periods of the year.
Although only 38 specimens were recorded, they represented twelve species.
In general, robber flies do not thrive in humid habitats. They usually prefer dry sandy soils in
which the larvae live. In addition, mangroves with their high salinity represent a harsh
environment for most insects and thus it would not be a surprise that the diversity of robber
flies is low. In an earlier short study in Singapore we found only four robber fly species in
mangroves (TOMASOVIC & GROOTAERT, 2010) although further long term surveys indicated
that many more species are present as can be seen on the website of BOS (Biodversity of
Singapore).
Hong Kong is situated at latitude 22° North. It has a seasonal subtropical climate and the
seasons are more marked with a ‘winter and a summer period’. Climate and weather
information are monitored by the Hong Kong Observatory (2017). Mangroves reach their
northern distribution limit in Hong Kong and they are composed of only eight mangrove tree
species which is much poorer than around the equator. Among them Bruguiera gymnorhiza or
Large-Leafed Orange Mangrove is fairly common. The fauna of Hong Kong belongs to the
Oriental Realm although there are Palaearctic species present that are probably relics from the
glaciations (Grootaert, unpublished).
In the present paper we give the records of the twelve species of robber flies and illustrate male
and female of each species with stacked images. Among them two new species for science are
described.
TOMASOVIC G. et al. Asilidae from mangroves in Hong Kong
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Material and methods
A survey was made from Autumn 2017 until Spring 2018 with Malaise traps in 24 mangrove
sites all around Hong Kong (collected by C.Taylor, U. Chang, Cheung Shun Chi and B.
Guénard). The traps were operational during at least 4 weeks per site. Two weeks in Autumn
and early winter and two weeks in Spring. In total 103 samples were available, but robber flies
were only found in 11 of the 24 sites (stations). Most of the sites were back mangroves (the
traps were placed in the area covered with trees) and only a few were front mangroves (the traps
were placed on the mud flats or sandy beaches in front of the mangrove forest). A code is
attributed to each station e.g. 5BM1 in which 5B refers to the station and M1 to the period that
the trap was operated at that station.
All specimens were conserved in 70% ethanol. Holotypes and paratypes are deposited in the
collections of the Royal Belgian Institute of Natural Sciences in Brussels (RBINS) and some
Voucher specimens in the Natural History Museum of the University of Hong Kong (HKU).
The habitus images were made with a Canon EOS 700 D camera with Sigma DG Macro lens,
stacked with CombineZ software and optimized with Adobe Photoshop CS3.
Fig. 1. Distribution of the Malaise traps in mangrove around Hong Kong. © C. Taylor & U. Chang.
Taxonomy
Twelve species from 5 subfamilies have been collected in the mangroves around Hong Kong.
Family Asilidae Latreille, 1802
Subfamily Apocleinae Papavero, 1973
Genus Irianjaya Koçak & Kemal, 2009
The genus is Oriental and Australasian in distribution with 7 species (TOMASOVIC & VAN
ACHTERBERG, 2011; TOMASOVIC, 2013a; TOMASOVIC & CONSTANT J., 2015). The genus name
Belgian Journal of Entomology 91: 122 (2020)
5
Irianjaya was proposed by KAK & KEMAL (2009) in replacement of Amphiscolops Hull,
1962.
Irianjaya aquila Tomasovic, 2013
(Figs 2, 3)
Irianjaya aquila Tomasovic, 2013a: p. 7879, Figs male p.79 n°810.
MATERIAL EXAMINED. Hong Kong: 1, Sha Tau Kok (Hoi Pui Leng, 1BM2), 10-24.V.2018,
22°31'46.52"N 114°12'28.19"E (C. Taylor, Cheung Shun Chi leg.; RBINS); 1, Sha Tau Kok
(1AM2),10-24.V.2018, 22°32'5.14"N 114°12'39.47"E (C. Taylor, Cheung Shun Chi leg.;
HKU); 1, Hong Kong (label of station missing, HKU01) 2018.
Fig. 2. Irianjaya aquila Tomasovic, 2013, male habitus. A, lateral view. B, dorsal view. Hong Kong, leg. C. Taylor
& Cheung Shun Chi; RBINS. © Jérôme Constant.
DISTRIBUTION. The species was previously only known from Vietnam (TOMASOVIC, 2013a)
and is now also recorded from Hong Kong.
Genus Philodicus Loew, 1847
Type species: Asilus javanus Wiedemann, 1819.
This distinctive genus of the Old Word tropics has a javanese type (Asilus javanus) OLDROYD
(1972: 290). The genus is Afrotropical, Oriental & Palaearctic in distribution (TOMASOVIC,
2012). A key to the species from Southeast Asia and illustrations of the phallus can be found in
TOMASOVIC & CONSTANT (2017: 7)
Philodicus javanus (Wiedemann, 1919)
(Figs 4, 5)
An illustration of the phallus can be found in TOMASOVIC & CONSTANT (2017 p. 7, fig. 5C).
MATERIAL EXAMINED. Hong Kong: 2, 1, Shui Hau (19M2), 15-29.V.2018, 22°13'14.63"N
113°55'8.22"E (C. Taylor, Cheung Shun Chi, leg.; RBINS); 1, Sheung Pak Nai (10M5), 28.V-
11.VI.2018, 22°27'5.44"N 113°57'43.67"E (C. Taylor, Cheung Shun Chi, leg.; RBINS).
TOMASOVIC G. et al. Asilidae from mangroves in Hong Kong
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DISTRIBUTION. Bangladesh, Borneo, India, Indonesia, Java, Pakistan (TOMASOVIC &
CONSTANT, 2017).
Fig. 3. Distribution map of Irianjaya aquila Tomasovic, 2013, I. areolaris (Walker, 1860), I. complens (Walker,
1861), I. halmeheraensis Tomasovic & van Achterberg, 2010 and I. impiger (van der Wulp, 1872).
Genus Promachus Loew, 1848
The species of this genus fall into two main groups, the fasciatus-group with distinctive tufts of
pale hairs on the first three abdominal segments and on the last tergite covering the male
terminalia and the second group without these distinctive features (OLDROYD, 1972). For the
Oriental species we refer to TOMASOVIC (2013b).
Promachus anicius (Walker, 1849)
(Fig. 6)
The phallus and epandrium have been illustrated by TOMASOVIC (2013b p. 20, figs. 10a,10b).
It is the only species of Promachus known at present from continental China and Taiwan. This
species belongs to the fasciatus-group.
Belgian Journal of Entomology 91: 122 (2020)
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The phallus and epandrium have been illustrated by TOMASOVIC (2013b p. 20, figs. 10a,10b).
It is the only species of Promachus known at present from continental China and Taiwan. This
species belongs to the fasciatus-group.
Fig. 4. Philodicus javanus (Wiedemann, 1919), male habitus. A, lateral view. B, dorsal view. To Kwa Peng, leg.
C. Taylor & Cheung Shun Chi; RBINS. © Jérôme Constant.
Fig. 5. Philodicus javanus (Wiedemann, 1919), female habitus. A, lateral view. B, dorsal view. Shui Hau, leg.
C. Taylor & Cheung Shun Chi; RBINS. © Jérôme Constant.
TOMASOVIC G. et al. Asilidae from mangroves in Hong Kong
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MATERIAL EXAMINED. Hong Kong: 2, Shui Hau (19M2), 15-29.V.2018, 22°13'14.63"N
113°55'8.22"E (C. Taylor, Cheung Shun Chi leg.; RBINS).
DISTRIBUTION. China, Taiwan, Korea (GELLER-GRIMM, 2012b; TOMASOVIC, 2013b; YOUNG,
2008).
Fig. 6. Promachus anicius (Walker, 1849), male habitus A, lateral view. B, dorsal view. Shui Hau, leg. C. Taylor
& Cheung Shun Chi; RBINS. © Jérôme Constant.
Belgian Journal of Entomology 91: 122 (2020)
9
Promachus hongkongensis sp. nov.
urn:lsid:zoobank.org:act:B97EE663-AF46-4439-A8B5-B37F2D3B8102
(Figs 79)
This species belongs to the second group of Promachus.
DIAGNOSIS. A medium-sized black species with white hairs. Face whitish, mystax formed by
white and black setae. Wings brown. Legs wholly black with white hairs. Hind femur with
strong black bristles on the ventral part.
Fig. 7. Promachus hongkongensis sp. nov., male habitus. A, lateral view. B, dorsal view. Nam Chung, leg. C.
Taylor & Cheung Shun Chi; RBINS. © Jérôme Constant.
TOMASOVIC G. et al. Asilidae from mangroves in Hong Kong
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ETYMOLOGY. The species epithet refers to the type locality Hong Kong.
TYPE MATERIAL. Holotype male: Hong Kong, Nam Chung (2M2), 27.VI-11.VII.2018,
22°31'32.64"N 114°12'29.28"E (C. Taylor, Cheung Shun Chi leg.; RBINS).
Paratypes: Hong Kong: 1,3, same provenance as holotype; 1, Sha Tau Kok (1AM3), 10-
24.V.2018, 22°32'6.45"N 114°12'39.47"E (C. Taylor, Cheung Shun Chi leg.; RBINS); 1, So
Lo Pun (4BM3), 29.VI-16.VII.2018, 22°32'17.20"N 114°15'21.49"E (C. Taylor, Cheung Shun
Chi leg.; RBINS).
Fig. 8. Promachus hongkongensis sp. nov., female habitus. A, lateral view. B, dorsal view. So Lo Pun, leg. C.
Taylor & Cheung Shun Chi; RBINS. © Jérôme Constant.
DESCRIPTION. Male (Fig. 7). Body length: 20 mm.
Head: Face, frons, vertex and occiput covered with grey-white tomentum. Facial tubercle
marked, mystax dense, with black and white setae. Frons with relatively long white hairs.
Antenna black, scape with few short white and black setae, scape three times longer than
pedicel, pedicel with some black setae, postpedicel as long as scape, style as long as the three
basal segments combined. Ocellar bristles black, occipital hairs white. Palpus black with
numerous black and yellow setae. Proboscis black with long fine setae as far as the middle
ventral part they are white except the last who are black.
Thorax: Black with greyish tomentum. Anterior antepronotum with black setae and white
hairs, posterior antepronotum laterally with long and fine white hairs. Postpronotal lobe and
scutum with sparse, short black setae longer on the posterior part. Bristles black, long and stout:
2 notopleural, 2 supra-alar, 3 post-alar, 8-10 very fine dorsocentral bristles. Scutellum with
white hairs on disc, 6-8 discal and 12 scutellar bristles. Pleura with sparse, fine black and white
hairs. Katatergal setae numerous, long, fine, black and white. Metepisternal hairs white, long
and fine.
Legs: Entirely black. Coxae with greyish tomentum and white hairs, mid coxa with 1 long,
stout and black seta, hind coxa with black setae on tip. All femora swollen with long white and
short black hairs; mid femur on sides with 4 black bristles, hind femur dorsally with 3 black
Belgian Journal of Entomology 91: 122 (2020)
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bristles at the tip and 3 ventral black bristles. Tibiae with white and black setae. Tarsi with black
bristles. Hind tibia and tarsus with short brown brush.
Wing: Light brown with brownish marking in the 1st radial and 2nd+3rd radial cell. Haltere
brown.
Abdomen: Tergites black with a posterior white stripe and sparse white hairs. Tergite I
laterally with tuft of white hairs with 2 black setae. Sternites black with long and fine white
hairs.
Male terminalia: (Fig. 9) Black with black setae and hairs. Epandrium long with rounded
apex. Gonocoxite with 2 long black setae on the ventral and distal part. Dististylus wide, with
narrow apical part with rounded apex (Fig. 9C). Phallus (Fig. 9 A) with long apodeme, sheath
tubular and distiphallus indiscernible.
Female (Fig. 8). Body length: 1921 mm. Similar to male, ovipositor telescopic.
REMARKS. Only two species of the Oriental region have the legs all black (OLDROYD, 1972:
299): P. fulviventris (BECKER, 1925: 72) and P. indigenus (BECKER, 1925: 7475). The new
species is distinct from these two species by the postpedicel that is shorter than the scape and
pedicel together, by the coloration of the chaetotaxy and by the male terminalia.
The male terminalia of the new species resembles those of P. nigribarbatus (BECKER, 1925:
73) known from Korea, Taiwan and Vietnam that are as illustrated by TOMASOVIC (2013b: 5,
phallus fig. 4a p. 18) and YOUNG (2008: 5963 male terminalia figs 1925 p.61) but they differ
strongly by the shape of the phallus.
Fig. 9. Promachus hongkongensis sp. nov., male terminalia. A, phallus. B, epandrium and gonocoxite. C,
dististylus. Shui Hau, leg. C. Taylor & Cheung Shun Chi; RBINS.
TOMASOVIC G. et al. Asilidae from mangroves in Hong Kong
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Subfamily Asilinae Latreille, 1802
Genus Hoplopheromerus Becker, 1925
The genus is Afrotropical, Oriental and Palearctic in distribution (GELLER-GRIMM 2003).
TOMASOVIC (2006) described Hoplopheromerus guangdongi from China and provided a key
for the Oriental species of Hoplopheromerus.
Hoplopheromerus armatipes (Macquart, 1855)
(Figs 1012)
MATERIAL EXAMINED. Hong Kong: 1, Sha Tau Kok (Hoi Pui Leng, 1BM3), 1024.V.2018,
22°31'46.52"N 114°12'28.19"E (C. Taylor, Cheung Shun Chi leg.; RBINS); 1, Sam A Chung
(5BM3), 1730.V.2018, 22°30'31.90"N 114°16'23.09"E (C. Taylor, Cheung Shun Chi leg.;
RBINS); 1, Nam Chung (2M2), 27.VI11.VII.2018, 22°31'32.64"N 114°12'29.28"E (C.
Taylor, Cheung Shun Chi leg.; RBINS); 1, So Lo Pun (4BM1), 1023.V.2017, 22°32'15.76"N
114°15'22.00"E (C. Taylor, Cheung Shun Chi leg.; RBINS).
DISTRIBUTION. China, Taiwan, Japan.
Fig. 10. Hoplopheromerus armatipes Macquart, 1855, male habitus, dorsal view, Hoi Pui Leng, leg. C. Taylor &
Cheung Shun Chi; RBINS. © Jérôme Constant.
Fig. 11. Hoplopheromerus armatipes Macquart, 1855, male habitus, lateral view. Hoi Pui Leng, leg. C. Taylor &
Cheung Shun Chi; RBINS. © Jérôme Constant.
Subfamily Laphriinae Macquart, 1838
Genus Pogonosoma Rondani, 1856
The genus is Australasian, Nearctic, Neotropical, Oriental and Palaearctic in distribution
(GELLER-GRIMM, 2003). Pogonosoma is easily recognised, not only by the three submarginal
cells, but also by the head structure: the vertex is well excavated, the frons broad, with sharply
marked tubercle, and the proboscis and palpi of the same type as in Andrenosoma Rondani,
1856 (OLDROYD, 1972). To date, 6 species are known from the Oriental Region.
Belgian Journal of Entomology 91: 122 (2020)
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Fig. 12. Hoplopheromerus armatipes Macquart, 1855, female habitus. A, lateral view. B, dorsal view. So Lo Pun,
leg. C. Taylor & Cheung Shun Chi; RBINS. © Jérôme Constant.
TOMASOVIC G. et al. Asilidae from mangroves in Hong Kong
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Pogonosoma sp.
(Fig. 13)
MATERIAL EXAMINED. Hong Kong: 1, To Kwa Peng (29M1), 29.XI-5.XII.2017,
22°25'43.07"N 114°19'59.30"E (C. Taylor, Cheung Shun Chi leg.; RBINS).
The female is wholly shiny black and resembles to Pogonosoma funebris Hermann, 1914.
Unfortunately, no male specimens were available to us for comparison.
Fig. 13. Pogonosoma sp., female habitus, lateral view. To Kwa Peng, leg. C. Taylor & Cheung Shun Chi; RBINS.
© Jérôme Constant.
Fig. 14. Leptogaster flaviventris Hsia, 1948, male habitus, dorsal view. To Kwa Peng, leg. C. Taylor & Cheung
Shun Chi; RBINS. © Jérôme Constant.
Subfamily Leptogastrinae Schiner, 1862
The members of this subfamily are slender, bare, medium to large sized. The last recorded
Leptogastrinae from China were by HSIA (1949) who recorded 37 species from China. To
identify the genera of Chinese Leptogastrinae the key of HUA (1989) can be used.
Genus Leptogaster Meigen, 1803
The genus is common in all the zoogeographical regions of the world. In the Oriental region 46
species are known (OLDROYD, 1975). We refer to the keys of HSIA (1949 p. 29-30) and JOSEPH
& PARUI (1983).
Leptogaster flaviventris Hsia, 1949
(Fig. 14)
MATERIAL EXAMINED. Hong Kong: 2, To Kwa Peng (29M1), 29.XI-5.XII.2017,
22°25'43.07"N 114°19'59.30"E (C. Taylor, Cheung Shun Chi leg.; RBINS).
DISTRIBUTION. Japan
REMARKS. The description of HSIA (1949: 36) is based on just one female. It seems to
correspond to our male specimens.
Belgian Journal of Entomology 91: 122 (2020)
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Leptogaster moluccana (Doleshall, 1857)
(Fig. 15)
MATERIAL EXAMINED. Hong Kong: 1, So Lo Pun (4BM2), 29.VI-16.VII.2018, 22°32'15.76"N
114°15'22.00"E (C. Taylor, Cheung Shun Chi leg.; RBINS).
DISTRIBUTION. The species is known from India (West Bengal), Japan, Java, Sumatra, Taiwan
and The Philippines (JOSEPH & PARUI, 1998).
REMARKS. Dr Torsten Dikow brought to our attention that the name Leptogaster moluccana
(Doleshall, 1857) has priority on L. basilaris Coquillet, 1899. Unfortunately, we don’t have an
illustration of the male genitalia of the types for these species.
Fig. 15. Leptogaster moluccana, (Doleshall, 1857), male habitus. A, dorsal view. B, lateral view. So Lo Pun, leg.
C. Taylor & Cheung Shun Chi; RBINS. © Jérôme Constant.
TOMASOVIC G. et al. Asilidae from mangroves in Hong Kong
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Genus Mesoleptogaster Frey, 1937
For the genus we refer to the keys of HSIA (1949: 24) and of HUA (1989: 28). There are four
species in the Oriental region with one species in Taiwan OLDROYD (1975).
Mesoleptogaster gracilipes Hsia, 1949
(Figs 1617)
It is the only species known from Taiwan. We refer to the key provided by HSIA (1949).
MATERIAL EXAMINED. Hong Kong: 1, Sha Tau Kok (Hoi Pui Leng, 1BM2), 10-24.V.2018,
2°31'46.52"N 114°12'28.19"E (C. Taylor, Cheung Shun Chi leg.; RBINS); 2, To Kwa Peng
(29M1), 29.XI-5.XII.2017, 22°25'43.07"N 114°19'59.30"E (C. Taylor, Cheung Shun Chi leg.;
RBINS); 1, Sheung Pak Nai (10M5), 28.V-11.VI.2018, 22°27'5.44"N 113°57'43.67"E (C.
Taylor, Cheung Shun Chi leg.; RBINS).
Fig. 16. Mesoleptogaster gracilipes Hsia, 1948, male habitus, lateral view. Sha Tau Kok, leg. C. Taylor & Cheung
Shun Chi; RBINS. © Jérôme Constant.
Fig. 17. Mesoleptogaster gracilipes Hsia, 1948, male. habitus lateral view. Sheung Pak Nai, leg.C. Taylor &
Cheung Shun Chi; RBINS. © Jérôme Constant.
Subfamily Ommatiinae HardY, 1927
This subfamily is characterized by a plumose style of the antenna and have been recorded from
all zoogeographical regions.
Genus Emphysomera Schiner, 1866
A key to the 16 species of Emphysomera from the Oriental and Australian regions is given by
SCARBROUGH & MARASCIA (1999 p. 205-206). Among them, E. jonesi (Joseph & Parui, 1984)
is known from China, while the following three species, E. aequalis Becker, 1925, E.
conopsoides (Wiedemann, 1828) and E. nigra Schiner, 1868 are known from Taiwan
SCARBROUGH & MARASCIA (1999).
Emphysomera conopsoides (Wiedemann, 1828)
(Figs 1820)
The male genitalia have been illustrated by SCARBROUGH & MARASIA (1999: 213, fig. 4548
& 4952).
Belgian Journal of Entomology 91: 122 (2020)
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Fig. 18. Emphysomera conopsoides (Wiedemann, 1828), male habitus, lateral view. To Kwa Peng, leg. C. Taylor
& Cheung Shun Chi; RBINS. © Jérôme Constant.
MATERIAL EXAMINED. Hong Kong: 2, Yim Tin Tsai (45AM5), 1-15.VI.2018, 22°22'31.66"N
114°18'3.71"E (C. Taylor, Cheung Shun Chi leg.; RBINS); 1, To Kwa Peng (29M2), 8-
25.V.2018, 22°25'43.07"N 114°19'59.30"E (C. Taylor, Cheung Shun Chi leg.; RBINS).
DISTRIBUTION. The species is known from China, Indonesia, Malaysia, Laos and Taiwan.
Genus Ommatius Wiedemann, 1821
The genus is worldwide in distribution and more than hundred species of Ommatius are known
from the Oriental region. The species can be identified with OLDROYD (1972), JOSEPH & PARUI
(1998) and SCARBROUGH & COSTANTINO (2005).
Ommatius tamenensis Joseph & Parui 1998
(Fig. 21)
A small black species with black and yellowish-brown legs and light brownish subcostal cell.
It was described from Nord East India. The male genitalia are illustrated by JOSEPH & PARUI
(1998a p. 241-242 fig. 140).
TOMASOVIC G. et al. Asilidae from mangroves in Hong Kong
18
MATERIAL EXAMINED. Hong Kong: 3, 1, Yim Tin Tsai (45AM5), 1-15.VI.2018,
22°22'31.66"N 114°18'3.71"E (C. Taylor, Cheung Shun Chi leg.; RBINS); 1, To Kwa Peng
(29M1), 29.XI-5.XII.2017, 22°25'43.07"N 114°19'59.30"E (C. Taylor, Cheung Shun Chi leg.;
HKU); 1, To Kwa Peng (29M2), 8-25.V.2018, 22°25'43.07"N 114°19'59.30"E (C. Taylor,
Cheung Shun Chi leg.; RBINS).
REMARKS. The male genitalia readily distinguishe Ommatius tamenensis Joseph & Parui, 1983
(JOSEPH & PARUI 1998) from all the other known species.
Fig. 19. Emphysomera conopsoides (Wiedemann, 1828), female habitus. A, lateral view. B, dorsal view. So Lo
Pun, leg. C. Taylor & Cheung Shun Chi; RBINS. © Jérôme Constant.
Belgian Journal of Entomology 91: 122 (2020)
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Fig. 20. Emphysomera conopsoides (Wiedemann, 1828) distribution map.
Ommatius guenardi sp. nov.
urn:lsid:zoobank.org:act:FA96DDFC-3E55-40D5-ADF2-EF5E84717696
(Fig. 22)
DIAGNOSIS. Small and slender black species with hyaline wings and yellow legs, hind femur
dorsally brown on apical 1/3. Mystax with two long, strong and yellow setae with white setae
below and above black setae. Thorax black with light brown-greyish tomentum.
ETYMOLOGY. The new species is dedicated to Prof. Benoit Guénard who kindly allowed us to
study the robber flies from the insect survey of the mangroves in Hong Kong.
TYPE MATERIAL. Holotype male: Hong Kong: Tung Chung (14M5), 29.V-12.VI.2018,
22°16'55.34"N 113°55'43.39"E (C. Taylor, Cheung Shun Chi leg.; RBINS).
DESCRIPTION. Male: Body length: 10 mm
Head: (Fig. 22 A) Face with yellowish tomentum. Mystax with two long, strong and yellow
setae and with white short setae below and long, fine and black setae above. Antenna black,
scape, pedicel and postpedicel very short and of almost the same length; style very long with a
line of long, fine and black hair (Fig. 22 A). Frons with fine and white orbital hairs. Ocellar
tubercle with 2 fine, black setae. Postocular setae proclinate, black. Occiput with greyish
tomentum, lower occipital hairs white. Palpus black with long, fine and white setae. Proboscis
black.
Thorax: Black. Antepronotum with light brown tomentum and laterally short white hairs,
Scutum and scutellum with brownish tomentum. Setae black and stout, 2 notopleural, 2 postalar
bristles. Pleura with greyish tomentum. Katatergal setae white, long and fine.
Legs: Coxa with white tomentum; fore coxa with fine pale hairs. Fore femur yellow with a
ventral row of yellow setae. Mid femur yellow with a ventral row of minute yellow setae and 1
to 2 black or yellow setae lateral. Hind femur yellow with one large brown patch on the distal
ventral part, 1 long, black seta on the central ventral part and laterally 2 shorter black setae.
Tibia yellow with pale chaetotaxy, hind tibia brown at the tip. Tarsi brownish with black setae
TOMASOVIC G. et al. Asilidae from mangroves in Hong Kong
20
Fig. 21. Ommatius tamenensis Joseph & Parui 1998, male habitus. A, lateral view. B, dorsal view. Yim Tin Tsai,
leg. C. Taylor, Cheung Shun Chi; RBINS. © Jérôme Constant.
Wing: Hyaline with tip smoky brown infuscated. Haltere white
Abdomen: Black. Tergite I laterally with clear, short setae. Sternites III-IV with 2-3 yellowish,
fine setae.
Male terminalia: (Fig. 22 B, C).
REMARKS. This species can be easily differentiated from all the other known species of
Ommatinae by the two long and strong setae on the lower fascial margin.
Discussion
To our knowledge few papers deal with robber flies in mangroves. TOMASOVIC & GROOTAERT
(2010) recorded only four species in a survey of eleven mangrove sites all around the island of
Singapore that were sampled during one month (5 May to 12 June 2009): Promachus amorges
(Walker, 1849), Maira aenea (Fabricius, 1805), Orthogonis scapularis (Wiedemann, 1828) and
Leptogaster moluccana (Doleshall, 1857). The latter species was the most common with 84
specimens recorded in the mangroves, but this species also occurs in swamp forest and thus it
is not exclusive for mangroves. It is also the only species in common between Singapore and
Hong Kong. In hybotid flies (Diptera: Hybotidae) as was shown by GROOTAERT (2019), none
of the Singaporean hybotid fly species were found in Hong Kong.
During the survey of Hong Kong’s mangroves, we found robber flies in only 11 of the 24
sampled sites. That is only 46% of the sites. This is a first indication that robber flies do not
thrive in mangroves. Most of the traps were placed in back mangrove, but no relation was found
between the soil type at the place of the traps that was either muddy or sandy. Robber flies can
fly over long distances and indeed distance is not immediately a limiting factor as we could see
in a mangrove on Coney Island (Pulau Serangoon) in Singapore where large numbers of robber
flies were observed in true mangrove. However, there was a huge dry sandy area adjacent to
Belgian Journal of Entomology 91: 122 (2020)
21
Fig. 22. Ommatius guenardi sp. nov. male holotype. A, head. B, habitus lateral view. C, dorsal view. Tung Chung,
leg. C. Taylor & Cheung Shun Chi; RBINS. © Jérôme Constant.
this mangrove. The robber flies are supposed to breed there and the adults hunt in the insect
rich mangrove (Grootaert & Lim, unpublished).
Moreover, robber flies were found in only 15% of the samples taken in the Hong Kong
mangroves. In fact, only 38 specimens were recorded. Confirming the fact that robber flies are
rare in mangrove. Nevertheless, the diversity is surprisingly high with 12 species. Many more
species could be expected since the collection per site was only two weeks in Autumn and two
weeks at the same site in Spring and in only a few cases the sampling was extended a few
weeks.
Acknowledgements
The Hong Kong Mangroves project is supported by the Environment and Conservation Fund (ECF Project
69/2016). We heartily thank Dr Stefano Cannicci and Dr Benoit Guénard from Hong Kong University for leading
the survey of the mangroves in Hong Kong and allowing us to study the Diptera of these samples. Samples were
taken by Mr Christopher Taylor, Mr Cheung Shun Chi and Ms Ukyoung Chang.
TOMASOVIC G. et al. Asilidae from mangroves in Hong Kong
22
References
BOS (Biodiversity of Singapore) - A Digital Reference Collection for Singapore's Biodiversity.
https://singapore.biodiversity.online [accessed on 25 July 2019].
BECKER T., 1925. - H. Sauter’s Formosa-Ausbeute: Asilinae III. (Dipt.). Entomologische Mitteilungen, 14: 6282.
GELLER-GRIMM F., 2003. - A world catalogue of the genera of the family Asilidae (Diptera). Studia dipterological,
10: 473526.
GELLER-GRIMM F., 2012. - Asilidae Homepage. www.geller-grimm.de/asilidae.htm [accessed on 25 July 2019].
GROOTAERT P., 2019. - Species turnover between the northern and southern part of the South-China Sea in the
Elaphropeza Macquart mangrove fly communities of Hong Kong and Singapore (Insecta, Diptera, Hybotidae)
European Journal of Taxonomy, 554: 127. https://doi.org/10.5852/ejt.2019.554.
HONG KONG OBSERVATORY, 2017. - Daily Extract for 2017. https://www.hko.gov.hk/cis/dailyExtract_e.htm?y=
2017&m=11 [accessed on 6 March 2020].
HSIA K.L., 1949. - Studies on Chinese Asilidae 1. Leptogastrinae. Sinensia, 19(1-6) : 2356.
HUA L., 1989. - Key to genera of Chinese Asilidae (II). Jiangxi Plant Protection, 1: 1040.
JOSEPH A.N.T. & PARUI P., 1983a. - New and little-known Indian Asilidae (Diptera) VI. Key to Indian Ommatius
Wiedemann with descriptions of fourteen new species. Entomologica Scandinavica, 14: 8597.
JOSEPH A.N.T. & PARUI P., 1983b. - A review of the Asilidae (Diptera) from the Oriental region. Oriental Insects,
17: 269393.
JOSEPH A.N.T. & PARUI P., 1998. - The Fauna of India and the adjacent countries Diptera (Asilidae) (Part-1)
General Introduction and Tribes Leptogasterini, Laphriini, Atomosini, Stichopogonini and Ommatini.
Zoological Survey of India, 1278.
OLDROYD, H., 1972. - Robber flies (Diptera: Asilidae) of the Philippine Islands. Pacific Insects, 14: 201337.
OLDROYD H., 1975. - Family Asilidae. In: Delfinado, M.D.& Hardy, E. - A catalog of the Diptera of Oriental
region. Vol. II. University Press of Hawaii, Honolulu, 99156.
SCARBROUGH A.G., & COSTANTINO J.E., 2005. - The genus Ommatius Wiedemann, dilatipennis species group
(Diptera: Asilidae). Proceedings of the Entomologigal Society of Washington, 107: 789807.
SCARBROUGH A.G., & MARASCIA C., 1999. - Synopsis of the Oriental and Australian Species of Emphysomera
Schiner (Diptera, Asilidae). Mitteilungen aus dem Museum für Naturkunde in Berlin, 46(2): 203229.
TOMASOVIC G., 2006. - Une nouvelle espèce d’Hoplopheromerus Becker, 1925 de Chine est décrite. La présence
d’espèces d’Emphysomera Schiner, 1866 est citée pour la première fois au Cambodge (Diptera Asilidae).
Bulletin S.R.B.E./K.B.V.E., 142: 6871.
TOMASOVIC G., 2012. - Etude sur l’édéage d’espèces africaines du genre Philodicus Loew 1848 (Diptera:
Asilidae), conservées dans des institutions de Belgique. Entomologie faunistique - Faunistic Entomology,
2012(2011) 64(1): 2327.
TOMASOVIC G., 2013a. - Etude sur des Asilidae collectés au Viêtnam dans le Parc National de Cat Tien (Diptera:
Asilidae). Bulletin S.R.B.E./K.B.V.E., 149: 7488.
TOMASOVIC G., 2013b. - Etude sur l’édéage des mâles appartenant au genre Promachus Loew, 1848 (Diptera:
Asilidae) 2. Des régions néartique, néotropicale, orientale et paléarctique. Entomologie faunistique Faunistic
Entomology, 66: 325.
TOMASOVIC G. & CONSTANT J., 2015. - Notes on the genus Irianjaya Koçak & Kemal with a new species from
the Philippines (Diptera: Asilidae: Asilinae). Belgian Journal of Entomology, 30: 19.
TOMASOVIC G. & CONSTANT J., 2017. - Notes on Oriental Asilidae with six new species from Viet Nam (Diptera:
Brachycera). Belgian Journal of Entomology, 47: 123.
TOMASOVIC G. & GROOTAERT P., 2010. - Asilidae (Diptera) from mangrove, an unusual habitat for robber flies
(Southeast Asia, Singapore). Bulletin S.R.B.E./K.B.V.E.,146: 151156.
TOMASOVIC G. & VAN ACHTERBERG C., 2011. - Three new species of the genus Irianjaya Koçak & Kemal from
Indonesia (Diptera: Asilidae: Asilinae). Zoologische Mededelingen, 85: 161168.
YOUNG C.L., 2008. - Robber flies of South Korea-V. South Korean species of the Subfamily Apocleinae Papavero,
1973 (Diptera: Asilidae). Zootaxa, 1713: 5368.
_____________________________________________________________
... De récents travaux ont démontré qu'une grande diversité se retrouvait également dans des biotopes qui ne sont a priori pas leurs milieux préférés. C'est ainsi qu'ils ont récemment été retrouvés dans des milieux humides des forêts tropicales de la République du Congo (Tomasovic & Bakker, 2010), de la Guyane française (Vieira, Camargo, Pollet & Dikow, 2019) ainsi que dans les mangroves entourant Singapour (Tomasovic & Grootaert, 2010) ou Hong Kong (Tomasovic, Constant & Grootaert, 2020). ...
... We examined the type of villiersi in Paris). Londt 1989 Cette liste de vingt espèces est à mettre en relation avec la diversité observée dans les 5 autres relevés réalisés précédemment en milieu tropical humide : 15 espèces observées dans une forêt néotropicale humide du Panama (Barro Colorado Island) (Shelly, 1985) ; 9 espèces dans une savane tropicale chaude et humide, subéquatoriale du Congo Brazzaville (Réserve des Gorilles de Lésio-Louna) (Tomasovic, 2009) ; 5 espèces dans une forêt dense ombrophile en République démocratique du Congo (Réserve de la Biosphère de Luki) (Tomasovic & De Bakker, 2010) ; 16 espèces dans une forêt pluviale de plaine en Guyane française (Mitaraka) (Vieira, Camargo, Pollet & Dikow, 2019) ; 12 espèces dans les mangroves de Hong Kong (Tomasovic, Constant & Grootaert, 2020). ...
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Biodiversity of Singapore) -A Digital Reference Collection for Singapore's Biodiversity
BOS (Biodiversity of Singapore) -A Digital Reference Collection for Singapore's Biodiversity. https://singapore.biodiversity.online [accessed on 25 July 2019].
Key to genera of Chinese Asilidae (II)
  • Hua L
HUA L., 1989. -Key to genera of Chinese Asilidae (II). Jiangxi Plant Protection, 1: 10-40.
Robber flies (Diptera: Asilidae) of the Philippine Islands
  • H Oldroyd
OLDROYD, H., 1972. -Robber flies (Diptera: Asilidae) of the Philippine Islands. Pacific Insects, 14: 201-337.
Une nouvelle espèce d'Hoplopheromerus Becker, 1925 de Chine est décrite. La présence d'espèces d'Emphysomera Schiner, 1866 est citée pour la première fois au Cambodge (Diptera Asilidae)
  • Tomasovic G
TOMASOVIC G., 2006. -Une nouvelle espèce d'Hoplopheromerus Becker, 1925 de Chine est décrite. La présence d'espèces d'Emphysomera Schiner, 1866 est citée pour la première fois au Cambodge (Diptera Asilidae). Bulletin S.R.B.E./K.B.V.E., 142: 68-71.
Etude sur l'édéage des mâles appartenant au genre Promachus Loew, 1848 (Diptera: Asilidae) 2. Des régions néartique, néotropicale, orientale et paléarctique. Entomologie faunistique -Faunistic Entomology
  • Tomasovic G
TOMASOVIC G., 2013b. -Etude sur l'édéage des mâles appartenant au genre Promachus Loew, 1848 (Diptera: Asilidae) 2. Des régions néartique, néotropicale, orientale et paléarctique. Entomologie faunistique -Faunistic Entomology, 66: 3-25.