Research Article |
Corresponding author: Hans R. Feijen ( hans.feijen@naturalis.nl ) Academic editor: Rudolf Meier
© 2020 Hans R. Feijen, Cobi Feijen.
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:
Feijen HR, Feijen C (2020) A revision of the genus Teleopsis Rondani (Diptera, Diopsidae) in Sri Lanka with descriptions of two new species and a review of the other stalk-eyed flies from the island. ZooKeys 946: 113-151. https://doi.org/10.3897/zookeys.946.53108
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The literature on Sri Lankan Diopsidae is reviewed. Eight Diopsidae are now known to occur in Sri Lanka, five species in the genus Teleopsis and one species each in the genera Sphyracephala, Diopsis, and Cyrtodiopsis. The presence of Cyrtodiopsis requires confirmation to exclude the possibility of mislabelling. All five Teleopsis species are endemic, as are the Diopsis species and probably the Cyrtodiopsis species. Only Sphyracephala bipunctipennis Senior-White has a larger distribution as it also occurs in India. A key is presented for the Diopsidae of Sri Lanka. Three Teleopsis species were already known to occur in Sri Lanka: T. ferruginea Röder, T. krombeini Feijen and T. maculata Feijen. These species form the T. ferruginea species group. Two new species are now described for this group: Teleopsis neglecta sp. nov. and Teleopsis sorora sp. nov. Teleopsis ferruginea is redescribed, as an earlier redescription turned out to be based on a series of specimens of its sister species T. sorora sp. nov. The other three Diopsidae of Sri Lanka are listed and illustrated. Allometric aspects of the five Teleopsis species are discussed. Three Teleopsis species are sexually dimorphic with regard to eye span, while two species are monomorphic. It is assumed that sexual dimorphism developed independently in the T. ferruginea species group. This brings the number of known cases of independent development of sexual dimorphism in the Diopsidae to ten.
Cyrtodiopsis, Diopsis, Sphyracephala, sexual dimorphism, stalk-eyed flies, Teleopsis
Five species and three genera of Diopsidae were known to occur in Sri Lanka (
In the collection of ZMUO, three specimens of Cyrtodiopsis Frey with Ceylon (Sri Lanka) labels were found. These belong to the Cyrtodiopsis dalmanni species group and would form a remarkable extension of the range of genus and species group. A key will be presented to the eight species now known to occur in Sri Lanka. The three species of the genera Sphyracephala, Cyrtodiopsis and Diopsis will be listed and illustrated. Allometric aspects with regard to the sexual dimorphism of the eye stalks in the Teleopsis ferruginea species group will be discussed. Allometric data will also be presented for the monomorphic Diopsis species.
The description of T. sorora sp. nov. is based on a large series of pinned specimens. For the description of T. neglecta sp. nov. only two pinned specimens in rather poor condition were available, one specimen lacking the abdomen, while a male specimen lacked the head. Fortunately, five photographs of live specimens became available via www.iNaturalist.org. From the same source also photographs for T. krombeini and T. sorora sp. nov. were obtained. The redescription of T. ferruginea (Röder, 1893) is based on the rather teneral female holotype and two pinned male specimens. For the rate of dimorphism D, the difference between males and females in allometric slope for eye span on body length is used in the Diopsidae (
RMNH Naturalis Biodiversity Center (formerly Rijksmuseum van Natuurlijke Historie), Leiden, The Netherlands,
USNM National Museum of Natural History (formerly United States National Museum), Washington D.C., United States of America,
D Rate of Dimorphism,
SE Standard Error.
The literature on Diopsidae from Sri Lanka is rather limited. The first paper is by Röder (1893) and describes Diopsis ferruginea from southern Sri Lanka (Ceylon meridionalis). Wulp (1896) listed Diopsis ferruginea in his catalogue of Diptera from South Asia. Likewise,
Family Diopsidae Billberg, 1820
Diopsidae:
Teleopsis
Rondani, 1875: 442;
Not Cyrtodiopsis Frey, 1928: 70;
Not Megalabops Frey, 1928: 70;
Diopsis ferruginea
Röder, 1893: 235; Wulp 1896: 171;
? Megalabops ferruginea (Röder):
Megalabops ferruginea
(Röder):
Teleopsis ferruginea
(Röder):
Not Teleopsis ferruginea: Curran, 1936: 2 (= Cyrtodiopsis currani Shillito, 1940).
Not Teleopsis ferruginea:
Holotype
, ♀, [Sri Lanka], Ceylon meridionalis [South Sri Lanka], v.1889, H. Fruhstorfer (
Holotype ♀; 2 ♂, Uva, Lunugala, [7°2'26"N, 81°12'06"E, ~760 m], 25.ix.[19]53, F. Keiser (
Teleopsis ferruginea can be recognised by its size, slender habitus, bareness, wing pattern (apical infuscation, three crossbands, broad preapical crossband, irregular central crossband with darker patches along veins, irregular narrow basal crossband, two small pale spots between basal and central crossbands, two distinct clear spots between central and preapical crossbands), wing mostly covered by microtrichia except for bare spots on basal third, small, setula-like inner vertical seta 0.5× the stalk diameter, outer vertical seta 1.4× stalk diameter, tiny base of inner vertical seta, no facial teeth, pollinose collar, reddish brown, thinly pollinose scutum and scutellum, ratio scutellar spine/scutellum ~ 2.8, moderately incrassate front femora with around 44–60 (♂) tubercles, large glossy spot laterally on terga 1 and 2, abdomen brown with dark parts of terga 3–5 forming a black circle, pair of pollinose spots on tergum 3, left male spiracle 7 in lateral slit of synsternum, right spiracle 7 in synsternum, articulate surstyli very small, apically rounded (as long as wide in lateral view), surstyli without microtrichia, large male cerci apically pointed (ratio length/width 1.6), anterior arm of phallapodeme quite straight, only slightly curving downward anteriorly, ratio eye span/body length 0.81 in ♀, 0.85 and 1.01 in ♂, and assumed sexual dimorphism with regard to eye span of ~ 0.8. Teleopsis ferruginea can be considered the sister species of T. sorora sp. nov. and gives its name to the T. ferruginea species group.
Measurements. Body length holotype ♀ 6.3 mm (estimate, specimen is teneral, see Fig.
Head. Central part glossy dark brown, almost black (Figs
Thorax. Collar brown pollinose, but anteriorly and laterally more blackish brown; scutum, scutellum and scutellar spines reddish brown (ferruginous), thinly pollinose (Figs
Wing. Irrorated with three crossbands (Figs
Legs
. Front leg with brown coxa, trochanter and femur, coxa glossy on outer side and pollinose on inner side, femur pollinose with vague darker spot on outer side, tibia and basal half of metatarsus blackish brown, remainder of tarsus very pale brown; mid leg and hind leg brown, hind femur and hind tibia dark brown; femur 1 (Figs
Preabdomen. Terga 1 and 2 and base of tergum 3 brown, remainder of tergum 3, terga 4, 5 and 6 blackish, the dark parts of terga 3–5 forming a black circle (Figs
Teleopsis ferruginea ♂, Lunugala 12 six basal abdominal segments, ventral view (note absence of sternum 6) 13 epandrium with surstyli and cerci, posterior view 14 phallapodeme and aedeagus, lateral view 15 ejaculatory apodeme and sac 16 synsternum 7+8, natural, curved state in dorso-anterior view and stretched state in ventral view. Scale bars: 0.5 mm (12); 0.1 mm (13–16).
Female postabdomen. Given the teneral and damaged state (Fig.
Male postabdomen. Strongly deflexed, sternum 5 represented by two very small, strongly sclerotised sclerites (Fig.
Teleopsis ferruginea occurs in the Uva Province in south-eastern Sri Lanka. The holotype originates from southern Sri Lanka.
Teleopsis krombeini Feijen, 1998: 57.
Holotype
, ♂, Sri Lanka, Kan[dy] Dist[rict], Thawalamtenne, 2200 ft, 4.ix.1980, K.V. Krombein et al. (USNM). Paratypes: 4 ♀, 6 ♂ and 2 ?sex, same data as holotype (USNM, RMNH); 1 ♀, Kitulgala, Bandarakele Jungle, Keg[alle] Dist., 17–18.iii.1979, K. V. Krombein et al. (USNM); 3 ♀ Kandy, 28.v.1892, Lt Col. Yerbury (
Photographs (www.inaturalist.org/observations/29425824) by Amila Prasanna Sumanapala taken at Central Province, Matale District, Rattota, 7°31'05"N, 80°43'52"E, 1155 m, 27.ii.2019. Although these pictures were sufficient for identification, they were not sharp enough to be reproduced here.
Holotype and paratypes from USNM and RMNH were re-examined. Holotype ♂ and a paratype ♀ were photographed (Figs
Measurements . Body length ♀ 5.9 mm ± SE 0.2 (range 5.4–6.5, N = 5), ♂ 5.9 mm ± 0.2 (range 5.0–6.4, N = 7); eye span ♀ 4.6 mm ± 0.1 (range 4.2–5.0, N = 5), ♂ 5.7 mm ± 0.4 (range 4.2–6.8, N = 7); wing length ♀ 4.3 mm ± 0.1 (range 4.0–4.7, N = 5), ♂ 4.4 mm ± 0.1 (range 3.8–4.7, N = 7); length of scutellar spine ♀ 1.14 ± 0.05 (range 1.04–1.30, N = 5), ♂ 1.11 mm ± 0.05 (range 0.89–1.25, N = 7).
Head
. Eye span (Figs
Thorax. Ratio scutellar spine/scutellum in ♀ 3.16 ± 0.06 (N = 5) and in ♂ 3.13 ± 0.05 (N = 7), ratio scutellar spine/body length in ♀ and ♂ 0.19 ± 0.00 (N = 5, resp. 7); apical seta small, one-fifth of length of scutellar spine (lacking in most specimens).
Wing
. See Fig.
Male postabdomen
. Sternum 6 indiscernible; synsternum 7+8 a short transverse sclerite with parallel anterior and posterior edges (Fig.
Teleopsis krombeini is now known from Kandy District and Matale District, Central Province and Kegalle District, Sabaragamuwa Province.
Teleopsis maculata Feijen, 1998: 61.
Holotype
, ♂, Sri Lanka, Nuwara Eliya, 14.vii.1892, Lt Col. Yerbury (
The USNM paratype was re-examined and photographed (Figs
Teleopsis maculata forms part of the T. ferruginea species group. For the position of this monomorphic species within this group can be referred to the remarks made under T. neglecta sp. nov.
Head
. Eye span (Figs
Thorax. Ratio scutellar spine/scutellum in paratype ♂ 3.00, ratio scutellar spine/body length in holotype 0.20 and in paratype ♂ 0.19; ratio apical seta/scutellar spine in holotype 0.27 and in paratype ♂ 0.29.
Wing
. See Fig.
Male postabdomen
. Sternum 6 indiscernible; synsternum 7+8 (Fig.
Teleopsis maculata is known from the Central Province (Nuwara Eliya district). As the Hakgala Reserve is partly located in Uva Province, it probably also occurs there.
Holotype
, ♂, Ceylon [Sri Lanka, Central Province], Pundaluoya, [7°0'47"N, 80°39'48"E, ~1060 m], 90–115 [undated, but 90–115 probably indicates1890], E. E. Green (
Photographs: 1 ♂?, Sabaragamuwa province, Ratnapura, Kalawana, 6°25'12"N, 80°25'05"E, 510 m, 6.xi.2018 by Amila Prasanna Sumanapala (Fig.
Teleopsis neglecta sp. nov., live photographs 34 by Amila Prasanna Sumanapala, Kalawana (www.inaturalist.org/observations/29425825) 35 by “Baeru”, Sinharaja Rainforest (www.inaturalist.org/observations/45907083).
Teleopsis neglecta sp. nov. can be recognised by its slender habitus, bareness, wing pattern (apical 10% vaguely infuscated, three distinct crossbands strongly interconnected giving four distinct pale spots, basal anterior spot not extending into cell bm+dm), wing mostly covered by microtrichia except for most of basal quarter and anterior spots, inner vertical seta and outer vertical seta spinous, tiny base of inner vertical seta, no facial teeth, dorsally glossy collar, reddish brown, thinly pollinose scutum and scutellum, ratio scutellar spine/scutellum ~ 3.1, incrassate front femora with around 54 (♂) tubercles, abdomen dark, large glossy spot laterally on terga 1 and 2, pair of pollinose spots on tergum 3, tergum 4 glossy, tergum 5 densely pollinose, male spiracles 7 symmetrically in synsternum, surstyli articulate, slender, apically rounded, ratio length/width in lateral view 2.5, surstyli without microtrichia, broad male cerci, ratio eye span/body length ~0.60–0.70 in ♂, and assumed sexual monomorphism with regard to eye span.
Teleopsis neglecta sp. nov. forms part of the T. ferruginea species group. Like T. maculata, it is more distant from the dimorphic species in this group (T. ferruginea, T. krombeini and T. sorora sp. nov.), also given the differences in the male synsternum. However, for an understanding of the phylogenetic relationship between T. neglecta sp. nov. and T. maculata more information has to become available (morphology of female genitalia, molecular analyses and wing geometric morphometrics analyses).
Measurements . Body length holotype ♂ 6.9 mm (estimate: collar - abdominal apex 6.3 mm, head length assumed 0.6 mm); eye span paratype 4.8 mm; wing length holotype 4.1 mm and paratype 4.8 mm; length of scutellar spine holotype 1.08 mm and paratype 1.18 mm.
Head. Central part yellowish brown (Figs
Thorax
. Collar dorsally glossy brown, but posteriorly and laterally pollinose; scutum reddish brown pollinose (darker in live photographs, Figs
Wing
. Irrorated with three distinct crossbands (Figs
Legs
. Front leg yellowish brown pollinose (darker in live flies), femur with very vague brown stripe on inner side, tibia darker brown; mid leg brown, femur with dark brown stripes on distal half; hind leg brown, femur with dark brown stripe on whole length, hind tibia darker brown; femur 1 (Fig.
Preabdomen
. Terga 1, 2 and 3 reddish brown to black, other terga slightly darker; basal terga thinly pollinose, a glossy lateral spot on tergum 1 and basal half of tergum 2, laterally on tergum 3 a pair of more densely pollinose spots, tergum 4 glossy dorsally, tergum 5 densely pollinose, appearing pale grey on live photograph; seam between terga 2 and 3 not very distinct; sternum 1 and intersclerite blackish brown, other sterna brown, sternum 1 and most of sternum 2 glossy (Figs
Teleopsis neglecta sp. nov. 36–39 unknown sex, paratype, Pundaluoya 40 ♂, holotype, Pundaluoya 36 head and thorax, dorsal view 37 central head, anterior view 38 thorax, lateral view 39 front femur, lateral view 40 abdomen, ventral (left) and dorsolateral (right) view. Scale bars: 0.5 mm.
Male postabdomen. Sternum 5 represented by two sclerites with only the central sections strongly sclerotised; sternum 6 indiscernible, only the two characteristic anterior tiny setulae could be found (Fig.
Teleopsis neglecta sp. nov., ♂, holotype, Pundaluoya 41 basal section of abdomen, ventral view 42 phallapodeme and aedeagus, lateral view 43 ejaculatory apodeme and sac 44 epandrium with surstyli and cerci, posterior view 45 sterna 4 and 5, ventral view (arrow indicating the anterior setulae of the otherwise absent sternum 6) 46 synsternum 7+8, ventral view 47 same, details of lateral sections. Scale bars: 0.2 mm (41); 0.1 mm (42–47).
Teleopsis neglecta sp. nov. is known from Sabaragamuwa Province, Southern Province and Central Province.
The specific epithet neglecta reflects the fact that, after collecting, it took 130 years for this species to be finally described (neglecta, ignored).
Teleopsis ferruginea:
Holotype
, ♂ Sri Lanka, Kan. Dist. [Central Province, Kandy District], Udawattakele Sanct., [7°17'55"N, 80°38'32"E, ~ 600 m], 1–3.ix.1980, K.V. Krombein, P.B. Karunaratne, T. Wijesinhe, L. Jayawickrema, V. Gunawardane (USNM). Paratypes: 3 ♀, 5 ♂, 1 ?sex, same data as holotype; 4 ♀, 6 ♂, Kandy, Udawattakele Sanct., Kan. Dist., 6–8.vi.1978, K. V. Krombein, P. B. Karunaratne, T. Wijesinhe, V. Kulasekare, L. Jayawickrema; 2 ♀, 3♂, Udawattakele Sanct., Kan. Dist., 8–11.ii.1979, K. V. Krombein, P. B. Karunaratne, T. Wijesinhe, S. Siriwardane, T. Gunawardane; 1 ♀, 3 ♂, Kandy Reservoir Jungle, Kan. Dist., [probably Darwin reservoir, 7°17'01"N, 80°38'18"E, 600 m], 10.ii.1979, K. V. Krombein, P. B. Karunaratne, T. Wijesinhe, S. Siriwardane, T. Gunawardane (all Krombein material in USNM with some specimens in RMNH); 1 ♂, C.P. [Central Province], Kandy, Roseneath [tea plantation?], [7°16'44"N, 80°38'19"E, ~ 655 m], 12.vii.1953, F. Keiser (
First set of photographs by Pieter D. H. Prins taken at Kandy, K. F. G. & G. Korale, Udawattakele Sanctuary, 7°18'11"N, 80°38'32"E, 22.xi.2010, 580 m, 23.xi.2010 and 12.xii.2010 (www.inaturalist.org/observations/35209123). Second set of photographs (www.inaturalist.org/observations/36624976) from same location and by the same photographer, 5.xii.2014 (Figs
Teleopsis sorora sp. nov. is the most colourful of all diopsids with its glossy black head, reddish legs, reddish thorax, reddish basal abdomen and black apical abdomen. Furthermore it can be recognized by its slender habitus, bareness, wing pattern (broad and curved dark preapical crossband and two very indistinct crossbands), small glabrous area of wing, setula-like inner vertical seta 0.6× the stalk diameter (usually broken off), medium-sized outer vertical seta 1.8× stalk diameter, small base of inner vertical seta, no facial teeth, blackish collar covered with dense white pollinosity, reddish brown, thinly pollinose scutum and scutellum, moderately curved scutellar spines, ratio scutellar spine/scutellum close to 3.0, moderately incrassate front femora (ratio length/width ~ 4.5) with around 48 (♀) to 50 (♂) tubercles, blackish terga 3–5 forming a circle, pair of pollinose spots on tergum 3, rectangular♀ sternum 6, almost completely divided ♀ sternum 7, ♀ spiracle 7 in membrane, rounded pentagonal subanal plate, rather elongate ♀ cerci, round spermathecae with 8–10 rounded protuberances, right ♂ spiracle 7 in synsternum 7+8, left spiracle 7 in lateral slit of synsternum, articulate and very small surstyli wider than long (ratio length/width 0.5) without microtrichia and with 10 setulae, large and rectangular ♂ cerci (ratio length/width 1.9), phallapodeme with broad anterior arm, strongly curving downward anteriorly, small eye span in female (79% of body length), medium-sized eye span in male (99% of body length), and low rate of sexual dimorphism with regard to eye span D = 0.82. Teleopsis sorora sp. nov. can be considered the sister species of T. ferruginea and forms part of the T. ferruginea species group.
The following description is partly based on the redescription of Teleopsis ferruginea by
Measurements. Body length ♀ 5.8 mm ± SE 0.2 (range 4.8–6.5, N = 9), ♂ 5.9 mm ± 0.1 (range 4.7–6.5, N = 20); eye span ♀ 4.6 mm ± 0.2 (range 3.8–5.3, N = 10), ♂ 5.9 mm ± 0.2 (range 4.1–7.3, N = 20); wing length ♀ 4.4 mm ± 0.2 (range 3.7–4.8, N = 8), ♂ 4.5 mm ± 0.1 (range 3.8–4.8, N = 17); length of scutellar spine ♀ 1.18 ± 0.03 (range 1.01–1.33, N = 9), ♂ 1.17 mm ± 0.02 (range 0.99–1.30, N = 19).
Teleopsis sorora sp. nov. 48–49 live photographs by Pieter D.H. Prins, Udawattakele (www.inaturalist.org/observations/36624976) 50 ♂, holotype, Udawattakele, photograph Cobi Feijen. Scale bar: 1 mm.
Head. Central part glossy black (Figs
Thorax. Collar blackish brown, covered with dense white pollinosity, dorsoposterior edge brown and laterally a brown band; scutum, scutellum and scutellar spines brown, almost reddish brown, thinly pollinose (Figs
Wing. Irrorated with a dominant, dark, curved preapical band (Figs
Teleopsis sorora sp. nov., ♂, paratype, Udawattakele 56 epandrium with surstyli and cerci, posterior view 57 phallapodeme and aedeagus, lateral view 58 ejaculatory apodeme and sac 59 sternum 5, ventral view 60 synsternum 7+8, ventral view 61 same, details of lateral sections. Scale bars: 0.1 mm.
Legs
. Front leg with coxa glossy brown on outer side and dark brown pollinose on inner side, pale brown on anterior side, trochanter and femur pale brown, pollinose, femur with small dark spot basally on inner side and large black spot on distal two-thirds of outer side (Figs
Preabdomen
. Terga 1 and 2 and base of tergum 3 brown, remainder of tergum 3 and terga 4, 5 and 6 blackish brown, forming a black circle (Figs
Female postabdomen
. Deflexed; terga 6 and 7 single rectangular sclerites (Fig.
Male postabdomen
. Sternum 4 a single rectangular sclerite; sternum 5 consisting of two small strongly sclerotised sclerites with anteriorly vaguely sclerotised sections (Fig.
The specimens of the type series are from three neighbouring locations in Kandy: Udawattakele Sanctuary, Darwin Reservoir and Roseneath. If the
For the phylogenetic position of Teleopsis within the Diopsidae can be referred to
Within the species group, T. ferruginea, T. sorora sp. nov., and T. krombeini form a subgroup based on similarities in shape and setulae of the surstylus, the lateral slit in the male synsternum accommodating left spiracle 7, the sexual dimorphism with regard to eye span and the similar allometric slope for male eye span on body length. Teleopsis ferruginea and T. sorora sp. nov. are obvious sister species based on shape and colouration of central head, colour pattern of scutum and dorsal abdomen and male genitalia. The sexually monomorphic T. neglecta sp. nov. and T. maculata stand separate from the three dimorphic species, given also that in both species the left male spiracle 7 is located in sclerite. However, as indicated above, more information is required to determine the relationships between T. neglecta sp. nov. and T. maculata and with the group of dimorphic species.
1 | Arista tripartite, alula present, vein CuA+CuP extending past cell cua (Fig. |
Sphyracephala bipunctipennis (Senior-White, 1922) |
– | Arista bipartite, alula absent, vein CuA+CuP not extending past cell cua (Figs |
Diopsinae 2 |
2 | Scutellar spine almost straight, apical bristle absent, wing with dark and round apical wing spot and vague central infuscation especially around crossvein r-m (Fig. |
Diopsis near indica |
– | Scutellar spine strongly curved, apical bristle present (often broken off), irrorated wings with dark crossbands and pale spots (Figs |
3 |
3 | No supra-alar spines, covered with long setulae, especially head and legs (Fig. |
Cyrtodiopsis near dalmanni |
– | Supra-alar spines present, almost bare (only some tiny setulae) (Figs |
4 |
4 | Ratio eye span/body length in males < 0.7 (Fig. |
5 |
– | Ratio eye span/body length in males > 0.85, on average ~1.0 (Fig. |
6 |
5 | Central head and collar glossy black (Fig. |
Teleopsis maculata Feijen, 1998 |
– | Central head yellowish brown and thinly pollinose (Figs |
Teleopsis neglecta sp. nov. |
6 | Central head brown, concolorous with stalks (Fig. |
Teleopsis krombeini Feijen, 1998 |
– | Central head black, stalks brown, face smooth and rounded (Fig. |
7 |
7 | Wing with three distinct crossbands, preapical crossband straight (Fig. |
Teleopsis ferruginea (Röder, 1893) |
– | Wing with one dominant, dark, curved preapical crossband and two indistinct crossbands (Fig. |
Teleopsis sorora sp. nov. |
Notes. The three other Diopsidae known from Sri Lanka are Sphyracephala bipunctipennis, Cyrtodiopsis sp. and Diopsis sp. For descriptions of the latter two species, large scale revisions will be required for, respectively, the Cyrtodiopsis dalmanni species group and the Diopsis indica species group. Here, the collecting data are given for the three species concerned. For all three species illustrations are provided for the habitus (Figs
Teleopsis bipunctipennis
Senior-White, 1922: 165, pl. 13, fig. 1;
Pseudodiopsis bipunctipennis
(Senior-White):
Sphyracephala bipunctipennis
(Senior-White):
Holotype
, ♂ Sri Lanka, [Central Province] Suduganga [Sudu Ganga] river, Indiganga, on leaves of Liliacrans (sic!) plant, 10.viii.1919 (
India (Tamil Nadu), Sri Lanka (Central Province). Except for the 1919 type series, no other specimens are known from Sri Lanka.
2 ♀, 1 ♂, Ceylon [Sri Lanka], Morin, 1914 (ZMUO). The label information is very limited. It is not clear whether “Morin” is a locality name or the name of the collector. The only reference to Morin for Sri Lanka is a “Morin Inn” in Negombo.
This species forms part of the Cyrtodiopsis dalmanni species group. The presence of Cyrtodiopsis in Sri Lanka would be rather surprising, given that the nearest relatives in the C. dalmanni group occur in Malaya and Indonesia. The geographically closest Cyrtodiopsis is C. whitei Curran from north-eastern India. However, that species belongs to a different species group. The Sri Lankan record certainly requires confirmation to exclude the possibility of mislabelling.
Although many non-taxonomic papers have been written about “Cyrtodiopsis dalmanni”, the taxonomy of this species and the C. dalmanni species group still requires a full-scale taxonomic revision. This species group can be characterized by the many, long setulae covering the body, the wing pattern with three pale spots in between the central and preapical crossbands and the peculiar peg and hollow modification on the male front leg, the peg located basally on the tibia and the hollow distally on the femur. This leg modification is also referred to as “nutcracker” and can be found in all males, except for small ones. For illustrations of this modification can be referred to
We are grateful to various museums and Diptera curators for access to their collections and/or loan of Sri Lankan Diopsidae: Daniel Whitmore and Erica McAlister (